--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:11:45 PM CET
+From: Tyler Hicks <tyhicks@canonical.com>
+Date: Mon, 4 Nov 2019 12:22:02 +0100
+Subject: cpu/speculation: Uninline and export CPU mitigations helpers
+
+From: Tyler Hicks <tyhicks@canonical.com>
+
+commit 731dc9df975a5da21237a18c3384f811a7a41cc6 upstream.
+
+A kernel module may need to check the value of the "mitigations=" kernel
+command line parameter as part of its setup when the module needs
+to perform software mitigations for a CPU flaw.
+
+Uninline and export the helper functions surrounding the cpu_mitigations
+enum to allow for their usage from a module.
+
+Lastly, privatize the enum and cpu_mitigations variable since the value of
+cpu_mitigations can be checked with the exported helper functions.
+
+Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
+Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ include/linux/cpu.h | 25 ++-----------------------
+ kernel/cpu.c | 27 ++++++++++++++++++++++++++-
+ 2 files changed, 28 insertions(+), 24 deletions(-)
+
+--- a/include/linux/cpu.h
++++ b/include/linux/cpu.h
+@@ -216,28 +216,7 @@ static inline int cpuhp_smt_enable(void)
+ static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; }
+ #endif
+
+-/*
+- * These are used for a global "mitigations=" cmdline option for toggling
+- * optional CPU mitigations.
+- */
+-enum cpu_mitigations {
+- CPU_MITIGATIONS_OFF,
+- CPU_MITIGATIONS_AUTO,
+- CPU_MITIGATIONS_AUTO_NOSMT,
+-};
+-
+-extern enum cpu_mitigations cpu_mitigations;
+-
+-/* mitigations=off */
+-static inline bool cpu_mitigations_off(void)
+-{
+- return cpu_mitigations == CPU_MITIGATIONS_OFF;
+-}
+-
+-/* mitigations=auto,nosmt */
+-static inline bool cpu_mitigations_auto_nosmt(void)
+-{
+- return cpu_mitigations == CPU_MITIGATIONS_AUTO_NOSMT;
+-}
++extern bool cpu_mitigations_off(void);
++extern bool cpu_mitigations_auto_nosmt(void);
+
+ #endif /* _LINUX_CPU_H_ */
+--- a/kernel/cpu.c
++++ b/kernel/cpu.c
+@@ -2339,7 +2339,18 @@ void __init boot_cpu_hotplug_init(void)
+ this_cpu_write(cpuhp_state.state, CPUHP_ONLINE);
+ }
+
+-enum cpu_mitigations cpu_mitigations __ro_after_init = CPU_MITIGATIONS_AUTO;
++/*
++ * These are used for a global "mitigations=" cmdline option for toggling
++ * optional CPU mitigations.
++ */
++enum cpu_mitigations {
++ CPU_MITIGATIONS_OFF,
++ CPU_MITIGATIONS_AUTO,
++ CPU_MITIGATIONS_AUTO_NOSMT,
++};
++
++static enum cpu_mitigations cpu_mitigations __ro_after_init =
++ CPU_MITIGATIONS_AUTO;
+
+ static int __init mitigations_parse_cmdline(char *arg)
+ {
+@@ -2356,3 +2367,17 @@ static int __init mitigations_parse_cmdl
+ return 0;
+ }
+ early_param("mitigations", mitigations_parse_cmdline);
++
++/* mitigations=off */
++bool cpu_mitigations_off(void)
++{
++ return cpu_mitigations == CPU_MITIGATIONS_OFF;
++}
++EXPORT_SYMBOL_GPL(cpu_mitigations_off);
++
++/* mitigations=auto,nosmt */
++bool cpu_mitigations_auto_nosmt(void)
++{
++ return cpu_mitigations == CPU_MITIGATIONS_AUTO_NOSMT;
++}
++EXPORT_SYMBOL_GPL(cpu_mitigations_auto_nosmt);
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:11:45 PM CET
+From: "Gomez Iglesias, Antonio" <antonio.gomez.iglesias@intel.com>
+Date: Mon, 4 Nov 2019 12:22:03 +0100
+Subject: Documentation: Add ITLB_MULTIHIT documentation
+
+From: "Gomez Iglesias, Antonio" <antonio.gomez.iglesias@intel.com>
+
+commit 7f00cc8d4a51074eb0ad4c3f16c15757b1ddfb7d upstream.
+
+Add the initial ITLB_MULTIHIT documentation.
+
+[ tglx: Add it to the index so it gets actually built. ]
+
+Signed-off-by: Antonio Gomez Iglesias <antonio.gomez.iglesias@intel.com>
+Signed-off-by: Nelson D'Souza <nelson.dsouza@linux.intel.com>
+Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ Documentation/admin-guide/hw-vuln/index.rst | 1
+ Documentation/admin-guide/hw-vuln/multihit.rst | 163 +++++++++++++++++++++++++
+ 2 files changed, 164 insertions(+)
+ create mode 100644 Documentation/admin-guide/hw-vuln/multihit.rst
+
+--- a/Documentation/admin-guide/hw-vuln/index.rst
++++ b/Documentation/admin-guide/hw-vuln/index.rst
+@@ -13,3 +13,4 @@ are configurable at compile, boot or run
+ l1tf
+ mds
+ tsx_async_abort
++ multihit.rst
+--- /dev/null
++++ b/Documentation/admin-guide/hw-vuln/multihit.rst
+@@ -0,0 +1,163 @@
++iTLB multihit
++=============
++
++iTLB multihit is an erratum where some processors may incur a machine check
++error, possibly resulting in an unrecoverable CPU lockup, when an
++instruction fetch hits multiple entries in the instruction TLB. This can
++occur when the page size is changed along with either the physical address
++or cache type. A malicious guest running on a virtualized system can
++exploit this erratum to perform a denial of service attack.
++
++
++Affected processors
++-------------------
++
++Variations of this erratum are present on most Intel Core and Xeon processor
++models. The erratum is not present on:
++
++ - non-Intel processors
++
++ - Some Atoms (Airmont, Bonnell, Goldmont, GoldmontPlus, Saltwell, Silvermont)
++
++ - Intel processors that have the PSCHANGE_MC_NO bit set in the
++ IA32_ARCH_CAPABILITIES MSR.
++
++
++Related CVEs
++------------
++
++The following CVE entry is related to this issue:
++
++ ============== =================================================
++ CVE-2018-12207 Machine Check Error Avoidance on Page Size Change
++ ============== =================================================
++
++
++Problem
++-------
++
++Privileged software, including OS and virtual machine managers (VMM), are in
++charge of memory management. A key component in memory management is the control
++of the page tables. Modern processors use virtual memory, a technique that creates
++the illusion of a very large memory for processors. This virtual space is split
++into pages of a given size. Page tables translate virtual addresses to physical
++addresses.
++
++To reduce latency when performing a virtual to physical address translation,
++processors include a structure, called TLB, that caches recent translations.
++There are separate TLBs for instruction (iTLB) and data (dTLB).
++
++Under this errata, instructions are fetched from a linear address translated
++using a 4 KB translation cached in the iTLB. Privileged software modifies the
++paging structure so that the same linear address using large page size (2 MB, 4
++MB, 1 GB) with a different physical address or memory type. After the page
++structure modification but before the software invalidates any iTLB entries for
++the linear address, a code fetch that happens on the same linear address may
++cause a machine-check error which can result in a system hang or shutdown.
++
++
++Attack scenarios
++----------------
++
++Attacks against the iTLB multihit erratum can be mounted from malicious
++guests in a virtualized system.
++
++
++iTLB multihit system information
++--------------------------------
++
++The Linux kernel provides a sysfs interface to enumerate the current iTLB
++multihit status of the system:whether the system is vulnerable and which
++mitigations are active. The relevant sysfs file is:
++
++/sys/devices/system/cpu/vulnerabilities/itlb_multihit
++
++The possible values in this file are:
++
++.. list-table::
++
++ * - Not affected
++ - The processor is not vulnerable.
++ * - KVM: Mitigation: Split huge pages
++ - Software changes mitigate this issue.
++ * - KVM: Vulnerable
++ - The processor is vulnerable, but no mitigation enabled
++
++
++Enumeration of the erratum
++--------------------------------
++
++A new bit has been allocated in the IA32_ARCH_CAPABILITIES (PSCHANGE_MC_NO) msr
++and will be set on CPU's which are mitigated against this issue.
++
++ ======================================= =========== ===============================
++ IA32_ARCH_CAPABILITIES MSR Not present Possibly vulnerable,check model
++ IA32_ARCH_CAPABILITIES[PSCHANGE_MC_NO] '0' Likely vulnerable,check model
++ IA32_ARCH_CAPABILITIES[PSCHANGE_MC_NO] '1' Not vulnerable
++ ======================================= =========== ===============================
++
++
++Mitigation mechanism
++-------------------------
++
++This erratum can be mitigated by restricting the use of large page sizes to
++non-executable pages. This forces all iTLB entries to be 4K, and removes
++the possibility of multiple hits.
++
++In order to mitigate the vulnerability, KVM initially marks all huge pages
++as non-executable. If the guest attempts to execute in one of those pages,
++the page is broken down into 4K pages, which are then marked executable.
++
++If EPT is disabled or not available on the host, KVM is in control of TLB
++flushes and the problematic situation cannot happen. However, the shadow
++EPT paging mechanism used by nested virtualization is vulnerable, because
++the nested guest can trigger multiple iTLB hits by modifying its own
++(non-nested) page tables. For simplicity, KVM will make large pages
++non-executable in all shadow paging modes.
++
++Mitigation control on the kernel command line and KVM - module parameter
++------------------------------------------------------------------------
++
++The KVM hypervisor mitigation mechanism for marking huge pages as
++non-executable can be controlled with a module parameter "nx_huge_pages=".
++The kernel command line allows to control the iTLB multihit mitigations at
++boot time with the option "kvm.nx_huge_pages=".
++
++The valid arguments for these options are:
++
++ ========== ================================================================
++ force Mitigation is enabled. In this case, the mitigation implements
++ non-executable huge pages in Linux kernel KVM module. All huge
++ pages in the EPT are marked as non-executable.
++ If a guest attempts to execute in one of those pages, the page is
++ broken down into 4K pages, which are then marked executable.
++
++ off Mitigation is disabled.
++
++ auto Enable mitigation only if the platform is affected and the kernel
++ was not booted with the "mitigations=off" command line parameter.
++ This is the default option.
++ ========== ================================================================
++
++
++Mitigation selection guide
++--------------------------
++
++1. No virtualization in use
++^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++ The system is protected by the kernel unconditionally and no further
++ action is required.
++
++2. Virtualization with trusted guests
++^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++ If the guest comes from a trusted source, you may assume that the guest will
++ not attempt to maliciously exploit these errata and no further action is
++ required.
++
++3. Virtualization with untrusted guests
++^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++ If the guest comes from an untrusted source, the guest host kernel will need
++ to apply iTLB multihit mitigation via the kernel command line or kvm
++ module parameter.
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:10:49 PM CET
+From: Jon Bloomfield <jon.bloomfield@intel.com>
+Date: Mon, 23 Apr 2018 11:12:15 -0700
+Subject: drm/i915: Add gen9 BCS cmdparsing
+
+From: Jon Bloomfield <jon.bloomfield@intel.com>
+
+commit 0f2f39758341df70202ae1c42d5a1e4ee392b6d3 upstream.
+
+For gen9 we enable cmdparsing on the BCS ring, specifically
+to catch inadvertent accesses to sensitive registers
+
+Unlike gen7/hsw, we use the parser only to block certain
+registers. We can rely on h/w to block restricted commands,
+so the command tables only provide enough info to allow the
+parser to delineate each command, and identify commands that
+access registers.
+
+Note: This patch deliberately ignores checkpatch issues in
+favour of matching the style of the surrounding code. We'll
+correct the entire file in one go in a later patch.
+
+v3: rebase (Mika)
+v4: Add RING_TIMESTAMP registers to whitelist (Jon)
+
+Signed-off-by: Jon Bloomfield <jon.bloomfield@intel.com>
+Cc: Tony Luck <tony.luck@intel.com>
+Cc: Dave Airlie <airlied@redhat.com>
+Cc: Takashi Iwai <tiwai@suse.de>
+Cc: Tyler Hicks <tyhicks@canonical.com>
+Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
+Reviewed-by: Chris Wilson <chris.p.wilson@intel.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/gpu/drm/i915/i915_cmd_parser.c | 116 ++++++++++++++++++++++++++++++---
+ drivers/gpu/drm/i915/i915_reg.h | 4 +
+ 2 files changed, 110 insertions(+), 10 deletions(-)
+
+--- a/drivers/gpu/drm/i915/i915_cmd_parser.c
++++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
+@@ -443,6 +443,47 @@ static const struct drm_i915_cmd_descrip
+ CMD( MI_LOAD_SCAN_LINES_EXCL, SMI, !F, 0x3F, R ),
+ };
+
++/*
++ * For Gen9 we can still rely on the h/w to enforce cmd security, and only
++ * need to re-enforce the register access checks. We therefore only need to
++ * teach the cmdparser how to find the end of each command, and identify
++ * register accesses. The table doesn't need to reject any commands, and so
++ * the only commands listed here are:
++ * 1) Those that touch registers
++ * 2) Those that do not have the default 8-bit length
++ *
++ * Note that the default MI length mask chosen for this table is 0xFF, not
++ * the 0x3F used on older devices. This is because the vast majority of MI
++ * cmds on Gen9 use a standard 8-bit Length field.
++ * All the Gen9 blitter instructions are standard 0xFF length mask, and
++ * none allow access to non-general registers, so in fact no BLT cmds are
++ * included in the table at all.
++ *
++ */
++static const struct drm_i915_cmd_descriptor gen9_blt_cmds[] = {
++ CMD( MI_NOOP, SMI, F, 1, S ),
++ CMD( MI_USER_INTERRUPT, SMI, F, 1, S ),
++ CMD( MI_WAIT_FOR_EVENT, SMI, F, 1, S ),
++ CMD( MI_FLUSH, SMI, F, 1, S ),
++ CMD( MI_ARB_CHECK, SMI, F, 1, S ),
++ CMD( MI_REPORT_HEAD, SMI, F, 1, S ),
++ CMD( MI_ARB_ON_OFF, SMI, F, 1, S ),
++ CMD( MI_SUSPEND_FLUSH, SMI, F, 1, S ),
++ CMD( MI_LOAD_SCAN_LINES_INCL, SMI, !F, 0x3F, S ),
++ CMD( MI_LOAD_SCAN_LINES_EXCL, SMI, !F, 0x3F, S ),
++ CMD( MI_STORE_DWORD_IMM, SMI, !F, 0x3FF, S ),
++ CMD( MI_LOAD_REGISTER_IMM(1), SMI, !F, 0xFF, W,
++ .reg = { .offset = 1, .mask = 0x007FFFFC, .step = 2 } ),
++ CMD( MI_UPDATE_GTT, SMI, !F, 0x3FF, S ),
++ CMD( MI_STORE_REGISTER_MEM_GEN8, SMI, F, 4, W,
++ .reg = { .offset = 1, .mask = 0x007FFFFC } ),
++ CMD( MI_FLUSH_DW, SMI, !F, 0x3F, S ),
++ CMD( MI_LOAD_REGISTER_MEM_GEN8, SMI, F, 4, W,
++ .reg = { .offset = 1, .mask = 0x007FFFFC } ),
++ CMD( MI_LOAD_REGISTER_REG, SMI, !F, 0xFF, W,
++ .reg = { .offset = 1, .mask = 0x007FFFFC, .step = 1 } ),
++};
++
+ static const struct drm_i915_cmd_descriptor noop_desc =
+ CMD(MI_NOOP, SMI, F, 1, S);
+
+@@ -489,6 +530,11 @@ static const struct drm_i915_cmd_table h
+ { hsw_blt_cmds, ARRAY_SIZE(hsw_blt_cmds) },
+ };
+
++static const struct drm_i915_cmd_table gen9_blt_cmd_table[] = {
++ { gen9_blt_cmds, ARRAY_SIZE(gen9_blt_cmds) },
++};
++
++
+ /*
+ * Register whitelists, sorted by increasing register offset.
+ */
+@@ -604,6 +650,29 @@ static const struct drm_i915_reg_descrip
+ REG64_IDX(RING_TIMESTAMP, BLT_RING_BASE),
+ };
+
++static const struct drm_i915_reg_descriptor gen9_blt_regs[] = {
++ REG64_IDX(RING_TIMESTAMP, RENDER_RING_BASE),
++ REG64_IDX(RING_TIMESTAMP, BSD_RING_BASE),
++ REG32(BCS_SWCTRL),
++ REG64_IDX(RING_TIMESTAMP, BLT_RING_BASE),
++ REG64_IDX(BCS_GPR, 0),
++ REG64_IDX(BCS_GPR, 1),
++ REG64_IDX(BCS_GPR, 2),
++ REG64_IDX(BCS_GPR, 3),
++ REG64_IDX(BCS_GPR, 4),
++ REG64_IDX(BCS_GPR, 5),
++ REG64_IDX(BCS_GPR, 6),
++ REG64_IDX(BCS_GPR, 7),
++ REG64_IDX(BCS_GPR, 8),
++ REG64_IDX(BCS_GPR, 9),
++ REG64_IDX(BCS_GPR, 10),
++ REG64_IDX(BCS_GPR, 11),
++ REG64_IDX(BCS_GPR, 12),
++ REG64_IDX(BCS_GPR, 13),
++ REG64_IDX(BCS_GPR, 14),
++ REG64_IDX(BCS_GPR, 15),
++};
++
+ #undef REG64
+ #undef REG32
+
+@@ -629,6 +698,10 @@ static const struct drm_i915_reg_table h
+ { gen7_blt_regs, ARRAY_SIZE(gen7_blt_regs) },
+ };
+
++static const struct drm_i915_reg_table gen9_blt_reg_tables[] = {
++ { gen9_blt_regs, ARRAY_SIZE(gen9_blt_regs) },
++};
++
+ static u32 gen7_render_get_cmd_length_mask(u32 cmd_header)
+ {
+ u32 client = cmd_header >> INSTR_CLIENT_SHIFT;
+@@ -684,6 +757,17 @@ static u32 gen7_blt_get_cmd_length_mask(
+ return 0;
+ }
+
++static u32 gen9_blt_get_cmd_length_mask(u32 cmd_header)
++{
++ u32 client = cmd_header >> INSTR_CLIENT_SHIFT;
++
++ if (client == INSTR_MI_CLIENT || client == INSTR_BC_CLIENT)
++ return 0xFF;
++
++ DRM_DEBUG_DRIVER("CMD: Abnormal blt cmd length! 0x%08X\n", cmd_header);
++ return 0;
++}
++
+ static bool validate_cmds_sorted(const struct intel_engine_cs *engine,
+ const struct drm_i915_cmd_table *cmd_tables,
+ int cmd_table_count)
+@@ -841,7 +925,8 @@ void intel_engine_init_cmd_parser(struct
+ int cmd_table_count;
+ int ret;
+
+- if (!IS_GEN(engine->i915, 7))
++ if (!IS_GEN(engine->i915, 7) && !(IS_GEN(engine->i915, 9) &&
++ engine->class == COPY_ENGINE_CLASS))
+ return;
+
+ switch (engine->class) {
+@@ -862,7 +947,6 @@ void intel_engine_init_cmd_parser(struct
+ engine->reg_tables = ivb_render_reg_tables;
+ engine->reg_table_count = ARRAY_SIZE(ivb_render_reg_tables);
+ }
+-
+ engine->get_cmd_length_mask = gen7_render_get_cmd_length_mask;
+ break;
+ case VIDEO_DECODE_CLASS:
+@@ -871,7 +955,16 @@ void intel_engine_init_cmd_parser(struct
+ engine->get_cmd_length_mask = gen7_bsd_get_cmd_length_mask;
+ break;
+ case COPY_ENGINE_CLASS:
+- if (IS_HASWELL(engine->i915)) {
++ engine->get_cmd_length_mask = gen7_blt_get_cmd_length_mask;
++ if (IS_GEN(engine->i915, 9)) {
++ cmd_tables = gen9_blt_cmd_table;
++ cmd_table_count = ARRAY_SIZE(gen9_blt_cmd_table);
++ engine->get_cmd_length_mask =
++ gen9_blt_get_cmd_length_mask;
++
++ /* BCS Engine unsafe without parser */
++ engine->flags |= I915_ENGINE_REQUIRES_CMD_PARSER;
++ } else if (IS_HASWELL(engine->i915)) {
+ cmd_tables = hsw_blt_ring_cmd_table;
+ cmd_table_count = ARRAY_SIZE(hsw_blt_ring_cmd_table);
+ } else {
+@@ -879,15 +972,17 @@ void intel_engine_init_cmd_parser(struct
+ cmd_table_count = ARRAY_SIZE(gen7_blt_cmd_table);
+ }
+
+- if (IS_HASWELL(engine->i915)) {
++ if (IS_GEN(engine->i915, 9)) {
++ engine->reg_tables = gen9_blt_reg_tables;
++ engine->reg_table_count =
++ ARRAY_SIZE(gen9_blt_reg_tables);
++ } else if (IS_HASWELL(engine->i915)) {
+ engine->reg_tables = hsw_blt_reg_tables;
+ engine->reg_table_count = ARRAY_SIZE(hsw_blt_reg_tables);
+ } else {
+ engine->reg_tables = ivb_blt_reg_tables;
+ engine->reg_table_count = ARRAY_SIZE(ivb_blt_reg_tables);
+ }
+-
+- engine->get_cmd_length_mask = gen7_blt_get_cmd_length_mask;
+ break;
+ case VIDEO_ENHANCEMENT_CLASS:
+ cmd_tables = hsw_vebox_cmd_table;
+@@ -1260,9 +1355,9 @@ int intel_engine_cmd_parser(struct intel
+ }
+
+ /*
+- * If the batch buffer contains a chained batch, return an
+- * error that tells the caller to abort and dispatch the
+- * workload as a non-secure batch.
++ * We don't try to handle BATCH_BUFFER_START because it adds
++ * non-trivial complexity. Instead we abort the scan and return
++ * and error to indicate that the batch is unsafe.
+ */
+ if (desc->cmd.value == MI_BATCH_BUFFER_START) {
+ ret = -EACCES;
+@@ -1342,6 +1437,7 @@ int i915_cmd_parser_get_version(struct d
+ * the parser enabled.
+ * 9. Don't whitelist or handle oacontrol specially, as ownership
+ * for oacontrol state is moving to i915-perf.
++ * 10. Support for Gen9 BCS Parsing
+ */
+- return 9;
++ return 10;
+ }
+--- a/drivers/gpu/drm/i915/i915_reg.h
++++ b/drivers/gpu/drm/i915/i915_reg.h
+@@ -577,6 +577,10 @@ static inline bool i915_mmio_reg_valid(i
+ */
+ #define BCS_SWCTRL _MMIO(0x22200)
+
++/* There are 16 GPR registers */
++#define BCS_GPR(n) _MMIO(0x22600 + (n) * 8)
++#define BCS_GPR_UDW(n) _MMIO(0x22600 + (n) * 8 + 4)
++
+ #define GPGPU_THREADS_DISPATCHED _MMIO(0x2290)
+ #define GPGPU_THREADS_DISPATCHED_UDW _MMIO(0x2290 + 4)
+ #define HS_INVOCATION_COUNT _MMIO(0x2300)
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:10:49 PM CET
+From: Jon Bloomfield <jon.bloomfield@intel.com>
+Date: Wed, 1 Aug 2018 09:33:59 -0700
+Subject: drm/i915: Add support for mandatory cmdparsing
+
+From: Jon Bloomfield <jon.bloomfield@intel.com>
+
+commit 311a50e76a33d1e029563c24b2ff6db0c02b5afe upstream.
+
+The existing cmdparser for gen7 can be bypassed by specifying
+batch_len=0 in the execbuf call. This is safe because bypassing
+simply reduces the cmd-set available.
+
+In a later patch we will introduce cmdparsing for gen9, as a
+security measure, which must be strictly enforced since without
+it we are vulnerable to DoS attacks.
+
+Introduce the concept of 'required' cmd parsing that cannot be
+bypassed by submitting zero-length bb's.
+
+v2: rebase (Mika)
+v2: rebase (Mika)
+v3: fix conflict on engine flags (Mika)
+
+Signed-off-by: Jon Bloomfield <jon.bloomfield@intel.com>
+Cc: Tony Luck <tony.luck@intel.com>
+Cc: Dave Airlie <airlied@redhat.com>
+Cc: Takashi Iwai <tiwai@suse.de>
+Cc: Tyler Hicks <tyhicks@canonical.com>
+Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
+Reviewed-by: Chris Wilson <chris.p.wilson@intel.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 3 ++-
+ drivers/gpu/drm/i915/gt/intel_engine_types.h | 13 ++++++++++---
+ drivers/gpu/drm/i915/i915_cmd_parser.c | 6 +++---
+ 3 files changed, 15 insertions(+), 7 deletions(-)
+
+--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
++++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+@@ -295,7 +295,8 @@ static inline u64 gen8_noncanonical_addr
+
+ static inline bool eb_use_cmdparser(const struct i915_execbuffer *eb)
+ {
+- return intel_engine_needs_cmd_parser(eb->engine) && eb->batch_len;
++ return intel_engine_requires_cmd_parser(eb->engine) ||
++ (intel_engine_using_cmd_parser(eb->engine) && eb->batch_len);
+ }
+
+ static int eb_create(struct i915_execbuffer *eb)
+--- a/drivers/gpu/drm/i915/gt/intel_engine_types.h
++++ b/drivers/gpu/drm/i915/gt/intel_engine_types.h
+@@ -460,12 +460,13 @@ struct intel_engine_cs {
+
+ struct intel_engine_hangcheck hangcheck;
+
+-#define I915_ENGINE_NEEDS_CMD_PARSER BIT(0)
++#define I915_ENGINE_USING_CMD_PARSER BIT(0)
+ #define I915_ENGINE_SUPPORTS_STATS BIT(1)
+ #define I915_ENGINE_HAS_PREEMPTION BIT(2)
+ #define I915_ENGINE_HAS_SEMAPHORES BIT(3)
+ #define I915_ENGINE_NEEDS_BREADCRUMB_TASKLET BIT(4)
+ #define I915_ENGINE_IS_VIRTUAL BIT(5)
++#define I915_ENGINE_REQUIRES_CMD_PARSER BIT(7)
+ unsigned int flags;
+
+ /*
+@@ -526,9 +527,15 @@ struct intel_engine_cs {
+ };
+
+ static inline bool
+-intel_engine_needs_cmd_parser(const struct intel_engine_cs *engine)
++intel_engine_using_cmd_parser(const struct intel_engine_cs *engine)
+ {
+- return engine->flags & I915_ENGINE_NEEDS_CMD_PARSER;
++ return engine->flags & I915_ENGINE_USING_CMD_PARSER;
++}
++
++static inline bool
++intel_engine_requires_cmd_parser(const struct intel_engine_cs *engine)
++{
++ return engine->flags & I915_ENGINE_REQUIRES_CMD_PARSER;
+ }
+
+ static inline bool
+--- a/drivers/gpu/drm/i915/i915_cmd_parser.c
++++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
+@@ -917,7 +917,7 @@ void intel_engine_init_cmd_parser(struct
+ return;
+ }
+
+- engine->flags |= I915_ENGINE_NEEDS_CMD_PARSER;
++ engine->flags |= I915_ENGINE_USING_CMD_PARSER;
+ }
+
+ /**
+@@ -929,7 +929,7 @@ void intel_engine_init_cmd_parser(struct
+ */
+ void intel_engine_cleanup_cmd_parser(struct intel_engine_cs *engine)
+ {
+- if (!intel_engine_needs_cmd_parser(engine))
++ if (!intel_engine_using_cmd_parser(engine))
+ return;
+
+ fini_hash_table(engine);
+@@ -1317,7 +1317,7 @@ int i915_cmd_parser_get_version(struct d
+
+ /* If the command parser is not enabled, report 0 - unsupported */
+ for_each_engine(engine, dev_priv, id) {
+- if (intel_engine_needs_cmd_parser(engine)) {
++ if (intel_engine_using_cmd_parser(engine)) {
+ active = true;
+ break;
+ }
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:10:49 PM CET
+From: Jon Bloomfield <jon.bloomfield@intel.com>
+Date: Wed, 1 Aug 2018 09:45:50 -0700
+Subject: drm/i915: Allow parsing of unsized batches
+
+From: Jon Bloomfield <jon.bloomfield@intel.com>
+
+commit 435e8fc059dbe0eec823a75c22da2972390ba9e0 upstream.
+
+In "drm/i915: Add support for mandatory cmdparsing" we introduced the
+concept of mandatory parsing. This allows the cmdparser to be invoked
+even when user passes batch_len=0 to the execbuf ioctl's.
+
+However, the cmdparser needs to know the extents of the buffer being
+scanned. Refactor the code to ensure the cmdparser uses the actual
+object size, instead of the incoming length, if user passes 0.
+
+Signed-off-by: Jon Bloomfield <jon.bloomfield@intel.com>
+Cc: Tony Luck <tony.luck@intel.com>
+Cc: Dave Airlie <airlied@redhat.com>
+Cc: Takashi Iwai <tiwai@suse.de>
+Cc: Tyler Hicks <tyhicks@canonical.com>
+Reviewed-by: Chris Wilson <chris.p.wilson@intel.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 9 +++++----
+ 1 file changed, 5 insertions(+), 4 deletions(-)
+
+--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
++++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+@@ -296,7 +296,8 @@ static inline u64 gen8_noncanonical_addr
+ static inline bool eb_use_cmdparser(const struct i915_execbuffer *eb)
+ {
+ return intel_engine_requires_cmd_parser(eb->engine) ||
+- (intel_engine_using_cmd_parser(eb->engine) && eb->batch_len);
++ (intel_engine_using_cmd_parser(eb->engine) &&
++ eb->args->batch_len);
+ }
+
+ static int eb_create(struct i915_execbuffer *eb)
+@@ -2518,6 +2519,9 @@ i915_gem_do_execbuffer(struct drm_device
+ goto err_vma;
+ }
+
++ if (eb.batch_len == 0)
++ eb.batch_len = eb.batch->size - eb.batch_start_offset;
++
+ if (eb_use_cmdparser(&eb)) {
+ struct i915_vma *vma;
+
+@@ -2528,9 +2532,6 @@ i915_gem_do_execbuffer(struct drm_device
+ }
+ }
+
+- if (eb.batch_len == 0)
+- eb.batch_len = eb.batch->size - eb.batch_start_offset;
+-
+ /*
+ * snb/ivb/vlv conflate the "batch in ppgtt" bit with the "non-secure
+ * batch" bit. Hence we need to pin secure batches into the global gtt.
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:10:50 PM CET
+From: Jon Bloomfield <jon.bloomfield@intel.com>
+Date: Thu, 20 Sep 2018 09:58:36 -0700
+Subject: drm/i915/cmdparser: Add support for backward jumps
+
+From: Jon Bloomfield <jon.bloomfield@intel.com>
+
+commit f8c08d8faee5567803c8c533865296ca30286bbf upstream.
+
+To keep things manageable, the pre-gen9 cmdparser does not
+attempt to track any form of nested BB_START's. This did not
+prevent usermode from using nested starts, or even chained
+batches because the cmdparser is not strictly enforced pre gen9.
+
+Instead, the existence of a nested BB_START would cause the batch
+to be emitted in insecure mode, and any privileged capabilities
+would not be available.
+
+For Gen9, the cmdparser becomes mandatory (for BCS at least), and
+so not providing any form of nested BB_START support becomes
+overly restrictive. Any such batch will simply not run.
+
+We make heavy use of backward jumps in igt, and it is much easier
+to add support for this restricted subset of nested jumps, than to
+rewrite the whole of our test suite to avoid them.
+
+Add the required logic to support limited backward jumps, to
+instructions that have already been validated by the parser.
+
+Note that it's not sufficient to simply approve any BB_START
+that jumps backwards in the buffer because this would allow an
+attacker to embed a rogue instruction sequence within the
+operand words of a harmless instruction (say LRI) and jump to
+that.
+
+We introduce a bit array to track every instr offset successfully
+validated, and test the target of BB_START against this. If the
+target offset hits, it is re-written to the same offset in the
+shadow buffer and the BB_START cmd is allowed.
+
+Note: This patch deliberately ignores checkpatch issues in the
+cmdtables, in order to match the style of the surrounding code.
+We'll correct the entire file in one go in a later patch.
+
+v2: set dispatch secure late (Mika)
+v3: rebase (Mika)
+v4: Clear whitelist on each parse
+Minor review updates (Chris)
+v5: Correct backward jump batching
+v6: fix compilation error due to struct eb shuffle (Mika)
+
+Cc: Tony Luck <tony.luck@intel.com>
+Cc: Dave Airlie <airlied@redhat.com>
+Cc: Takashi Iwai <tiwai@suse.de>
+Cc: Tyler Hicks <tyhicks@canonical.com>
+Signed-off-by: Jon Bloomfield <jon.bloomfield@intel.com>
+Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
+Reviewed-by: Chris Wilson <chris.p.wilson@intel.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/gpu/drm/i915/gem/i915_gem_context.c | 5
+ drivers/gpu/drm/i915/gem/i915_gem_context_types.h | 5
+ drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 32 +++-
+ drivers/gpu/drm/i915/i915_cmd_parser.c | 151 +++++++++++++++++++---
+ drivers/gpu/drm/i915/i915_drv.h | 9 -
+ 5 files changed, 176 insertions(+), 26 deletions(-)
+
+--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
++++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
+@@ -315,6 +315,8 @@ static void i915_gem_context_free(struct
+ free_engines(rcu_access_pointer(ctx->engines));
+ mutex_destroy(&ctx->engines_mutex);
+
++ kfree(ctx->jump_whitelist);
++
+ if (ctx->timeline)
+ i915_timeline_put(ctx->timeline);
+
+@@ -465,6 +467,9 @@ __create_context(struct drm_i915_private
+ for (i = 0; i < ARRAY_SIZE(ctx->hang_timestamp); i++)
+ ctx->hang_timestamp[i] = jiffies - CONTEXT_FAST_HANG_JIFFIES;
+
++ ctx->jump_whitelist = NULL;
++ ctx->jump_whitelist_cmds = 0;
++
+ return ctx;
+
+ err_free:
+--- a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
++++ b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
+@@ -197,6 +197,11 @@ struct i915_gem_context {
+ * per vm, which may be one per context or shared with the global GTT)
+ */
+ struct radix_tree_root handles_vma;
++
++ /** jump_whitelist: Bit array for tracking cmds during cmdparsing */
++ unsigned long *jump_whitelist;
++ /** jump_whitelist_cmds: No of cmd slots available */
++ u32 jump_whitelist_cmds;
+ };
+
+ #endif /* __I915_GEM_CONTEXT_TYPES_H__ */
+--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
++++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+@@ -2026,7 +2026,6 @@ shadow_batch_pin(struct i915_execbuffer
+ if (CMDPARSER_USES_GGTT(dev_priv)) {
+ flags = PIN_GLOBAL;
+ vm = &dev_priv->ggtt.vm;
+- eb->batch_flags |= I915_DISPATCH_SECURE;
+ } else if (vma->vm->has_read_only) {
+ flags = PIN_USER;
+ vm = vma->vm;
+@@ -2043,6 +2042,8 @@ static struct i915_vma *eb_parse(struct
+ {
+ struct drm_i915_gem_object *shadow_batch_obj;
+ struct i915_vma *vma;
++ u64 batch_start;
++ u64 shadow_batch_start;
+ int err;
+
+ shadow_batch_obj = i915_gem_batch_pool_get(&eb->engine->batch_pool,
+@@ -2050,12 +2051,27 @@ static struct i915_vma *eb_parse(struct
+ if (IS_ERR(shadow_batch_obj))
+ return ERR_CAST(shadow_batch_obj);
+
+- err = intel_engine_cmd_parser(eb->engine,
++ vma = shadow_batch_pin(eb, shadow_batch_obj);
++ if (IS_ERR(vma))
++ goto out;
++
++ batch_start = gen8_canonical_addr(eb->batch->node.start) +
++ eb->batch_start_offset;
++
++ shadow_batch_start = gen8_canonical_addr(vma->node.start);
++
++ err = intel_engine_cmd_parser(eb->gem_context,
++ eb->engine,
+ eb->batch->obj,
+- shadow_batch_obj,
++ batch_start,
+ eb->batch_start_offset,
+- eb->batch_len);
++ eb->batch_len,
++ shadow_batch_obj,
++ shadow_batch_start);
++
+ if (err) {
++ i915_vma_unpin(vma);
++
+ /*
+ * Unsafe GGTT-backed buffers can still be submitted safely
+ * as non-secure.
+@@ -2070,10 +2086,6 @@ static struct i915_vma *eb_parse(struct
+ goto out;
+ }
+
+- vma = shadow_batch_pin(eb, shadow_batch_obj);
+- if (IS_ERR(vma))
+- goto out;
+-
+ eb->vma[eb->buffer_count] = i915_vma_get(vma);
+ eb->flags[eb->buffer_count] =
+ __EXEC_OBJECT_HAS_PIN | __EXEC_OBJECT_HAS_REF;
+@@ -2081,6 +2093,10 @@ static struct i915_vma *eb_parse(struct
+ eb->buffer_count++;
+ eb->batch_start_offset = 0;
+ eb->batch = vma;
++
++ if (CMDPARSER_USES_GGTT(eb->i915))
++ eb->batch_flags |= I915_DISPATCH_SECURE;
++
+ /* eb->batch_len unchanged */
+ out:
+ i915_gem_object_unpin_pages(shadow_batch_obj);
+--- a/drivers/gpu/drm/i915/i915_cmd_parser.c
++++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
+@@ -482,6 +482,19 @@ static const struct drm_i915_cmd_descrip
+ .reg = { .offset = 1, .mask = 0x007FFFFC } ),
+ CMD( MI_LOAD_REGISTER_REG, SMI, !F, 0xFF, W,
+ .reg = { .offset = 1, .mask = 0x007FFFFC, .step = 1 } ),
++
++ /*
++ * We allow BB_START but apply further checks. We just sanitize the
++ * basic fields here.
++ */
++#define MI_BB_START_OPERAND_MASK GENMASK(SMI-1, 0)
++#define MI_BB_START_OPERAND_EXPECT (MI_BATCH_PPGTT_HSW | 1)
++ CMD( MI_BATCH_BUFFER_START_GEN8, SMI, !F, 0xFF, B,
++ .bits = {{
++ .offset = 0,
++ .mask = MI_BB_START_OPERAND_MASK,
++ .expected = MI_BB_START_OPERAND_EXPECT,
++ }}, ),
+ };
+
+ static const struct drm_i915_cmd_descriptor noop_desc =
+@@ -1292,15 +1305,113 @@ static bool check_cmd(const struct intel
+ return true;
+ }
+
++static int check_bbstart(const struct i915_gem_context *ctx,
++ u32 *cmd, u32 offset, u32 length,
++ u32 batch_len,
++ u64 batch_start,
++ u64 shadow_batch_start)
++{
++ u64 jump_offset, jump_target;
++ u32 target_cmd_offset, target_cmd_index;
++
++ /* For igt compatibility on older platforms */
++ if (CMDPARSER_USES_GGTT(ctx->i915)) {
++ DRM_DEBUG("CMD: Rejecting BB_START for ggtt based submission\n");
++ return -EACCES;
++ }
++
++ if (length != 3) {
++ DRM_DEBUG("CMD: Recursive BB_START with bad length(%u)\n",
++ length);
++ return -EINVAL;
++ }
++
++ jump_target = *(u64*)(cmd+1);
++ jump_offset = jump_target - batch_start;
++
++ /*
++ * Any underflow of jump_target is guaranteed to be outside the range
++ * of a u32, so >= test catches both too large and too small
++ */
++ if (jump_offset >= batch_len) {
++ DRM_DEBUG("CMD: BB_START to 0x%llx jumps out of BB\n",
++ jump_target);
++ return -EINVAL;
++ }
++
++ /*
++ * This cannot overflow a u32 because we already checked jump_offset
++ * is within the BB, and the batch_len is a u32
++ */
++ target_cmd_offset = lower_32_bits(jump_offset);
++ target_cmd_index = target_cmd_offset / sizeof(u32);
++
++ *(u64*)(cmd + 1) = shadow_batch_start + target_cmd_offset;
++
++ if (target_cmd_index == offset)
++ return 0;
++
++ if (ctx->jump_whitelist_cmds <= target_cmd_index) {
++ DRM_DEBUG("CMD: Rejecting BB_START - truncated whitelist array\n");
++ return -EINVAL;
++ } else if (!test_bit(target_cmd_index, ctx->jump_whitelist)) {
++ DRM_DEBUG("CMD: BB_START to 0x%llx not a previously executed cmd\n",
++ jump_target);
++ return -EINVAL;
++ }
++
++ return 0;
++}
++
++static void init_whitelist(struct i915_gem_context *ctx, u32 batch_len)
++{
++ const u32 batch_cmds = DIV_ROUND_UP(batch_len, sizeof(u32));
++ const u32 exact_size = BITS_TO_LONGS(batch_cmds);
++ u32 next_size = BITS_TO_LONGS(roundup_pow_of_two(batch_cmds));
++ unsigned long *next_whitelist;
++
++ if (CMDPARSER_USES_GGTT(ctx->i915))
++ return;
++
++ if (batch_cmds <= ctx->jump_whitelist_cmds) {
++ memset(ctx->jump_whitelist, 0, exact_size * sizeof(u32));
++ return;
++ }
++
++again:
++ next_whitelist = kcalloc(next_size, sizeof(long), GFP_KERNEL);
++ if (next_whitelist) {
++ kfree(ctx->jump_whitelist);
++ ctx->jump_whitelist = next_whitelist;
++ ctx->jump_whitelist_cmds =
++ next_size * BITS_PER_BYTE * sizeof(long);
++ return;
++ }
++
++ if (next_size > exact_size) {
++ next_size = exact_size;
++ goto again;
++ }
++
++ DRM_DEBUG("CMD: Failed to extend whitelist. BB_START may be disallowed\n");
++ memset(ctx->jump_whitelist, 0,
++ BITS_TO_LONGS(ctx->jump_whitelist_cmds) * sizeof(u32));
++
++ return;
++}
++
+ #define LENGTH_BIAS 2
+
+ /**
+ * i915_parse_cmds() - parse a submitted batch buffer for privilege violations
++ * @ctx: the context in which the batch is to execute
+ * @engine: the engine on which the batch is to execute
+ * @batch_obj: the batch buffer in question
+- * @shadow_batch_obj: copy of the batch buffer in question
++ * @batch_start: Canonical base address of batch
+ * @batch_start_offset: byte offset in the batch at which execution starts
+ * @batch_len: length of the commands in batch_obj
++ * @shadow_batch_obj: copy of the batch buffer in question
++ * @shadow_batch_start: Canonical base address of shadow_batch_obj
+ *
+ * Parses the specified batch buffer looking for privilege violations as
+ * described in the overview.
+@@ -1308,13 +1419,17 @@ static bool check_cmd(const struct intel
+ * Return: non-zero if the parser finds violations or otherwise fails; -EACCES
+ * if the batch appears legal but should use hardware parsing
+ */
+-int intel_engine_cmd_parser(struct intel_engine_cs *engine,
++
++int intel_engine_cmd_parser(struct i915_gem_context *ctx,
++ struct intel_engine_cs *engine,
+ struct drm_i915_gem_object *batch_obj,
+- struct drm_i915_gem_object *shadow_batch_obj,
++ u64 batch_start,
+ u32 batch_start_offset,
+- u32 batch_len)
++ u32 batch_len,
++ struct drm_i915_gem_object *shadow_batch_obj,
++ u64 shadow_batch_start)
+ {
+- u32 *cmd, *batch_end;
++ u32 *cmd, *batch_end, offset = 0;
+ struct drm_i915_cmd_descriptor default_desc = noop_desc;
+ const struct drm_i915_cmd_descriptor *desc = &default_desc;
+ bool needs_clflush_after = false;
+@@ -1328,6 +1443,8 @@ int intel_engine_cmd_parser(struct intel
+ return PTR_ERR(cmd);
+ }
+
++ init_whitelist(ctx, batch_len);
++
+ /*
+ * We use the batch length as size because the shadow object is as
+ * large or larger and copy_batch() will write MI_NOPs to the extra
+@@ -1348,16 +1465,6 @@ int intel_engine_cmd_parser(struct intel
+ goto err;
+ }
+
+- /*
+- * We don't try to handle BATCH_BUFFER_START because it adds
+- * non-trivial complexity. Instead we abort the scan and return
+- * and error to indicate that the batch is unsafe.
+- */
+- if (desc->cmd.value == MI_BATCH_BUFFER_START) {
+- ret = -EACCES;
+- goto err;
+- }
+-
+ if (desc->flags & CMD_DESC_FIXED)
+ length = desc->length.fixed;
+ else
+@@ -1377,7 +1484,21 @@ int intel_engine_cmd_parser(struct intel
+ goto err;
+ }
+
++ if (desc->cmd.value == MI_BATCH_BUFFER_START) {
++ ret = check_bbstart(ctx, cmd, offset, length,
++ batch_len, batch_start,
++ shadow_batch_start);
++
++ if (ret)
++ goto err;
++ break;
++ }
++
++ if (ctx->jump_whitelist_cmds > offset)
++ set_bit(offset, ctx->jump_whitelist);
++
+ cmd += length;
++ offset += length;
+ if (cmd >= batch_end) {
+ DRM_DEBUG_DRIVER("CMD: Got to the end of the buffer w/o a BBE cmd!\n");
+ ret = -EINVAL;
+--- a/drivers/gpu/drm/i915/i915_drv.h
++++ b/drivers/gpu/drm/i915/i915_drv.h
+@@ -2727,11 +2727,14 @@ const char *i915_cache_level_str(struct
+ int i915_cmd_parser_get_version(struct drm_i915_private *dev_priv);
+ void intel_engine_init_cmd_parser(struct intel_engine_cs *engine);
+ void intel_engine_cleanup_cmd_parser(struct intel_engine_cs *engine);
+-int intel_engine_cmd_parser(struct intel_engine_cs *engine,
++int intel_engine_cmd_parser(struct i915_gem_context *cxt,
++ struct intel_engine_cs *engine,
+ struct drm_i915_gem_object *batch_obj,
+- struct drm_i915_gem_object *shadow_batch_obj,
++ u64 user_batch_start,
+ u32 batch_start_offset,
+- u32 batch_len);
++ u32 batch_len,
++ struct drm_i915_gem_object *shadow_batch_obj,
++ u64 shadow_batch_start);
+
+ /* i915_perf.c */
+ extern void i915_perf_init(struct drm_i915_private *dev_priv);
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:10:50 PM CET
+From: Ben Hutchings <ben@decadent.org.uk>
+Date: Mon, 11 Nov 2019 08:13:24 -0800
+Subject: drm/i915/cmdparser: Fix jump whitelist clearing
+
+From: Ben Hutchings <ben@decadent.org.uk>
+
+commit ea0b163b13ffc52818c079adb00d55e227a6da6f upstream.
+
+When a jump_whitelist bitmap is reused, it needs to be cleared.
+Currently this is done with memset() and the size calculation assumes
+bitmaps are made of 32-bit words, not longs. So on 64-bit
+architectures, only the first half of the bitmap is cleared.
+
+If some whitelist bits are carried over between successive batches
+submitted on the same context, this will presumably allow embedding
+the rogue instructions that we're trying to reject.
+
+Use bitmap_zero() instead, which gets the calculation right.
+
+Fixes: f8c08d8faee5 ("drm/i915/cmdparser: Add support for backward jumps")
+Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
+Signed-off-by: Jon Bloomfield <jon.bloomfield@intel.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/gpu/drm/i915/i915_cmd_parser.c | 5 ++---
+ 1 file changed, 2 insertions(+), 3 deletions(-)
+
+--- a/drivers/gpu/drm/i915/i915_cmd_parser.c
++++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
+@@ -1374,7 +1374,7 @@ static void init_whitelist(struct i915_g
+ return;
+
+ if (batch_cmds <= ctx->jump_whitelist_cmds) {
+- memset(ctx->jump_whitelist, 0, exact_size * sizeof(u32));
++ bitmap_zero(ctx->jump_whitelist, batch_cmds);
+ return;
+ }
+
+@@ -1394,8 +1394,7 @@ again:
+ }
+
+ DRM_DEBUG("CMD: Failed to extend whitelist. BB_START may be disallowed\n");
+- memset(ctx->jump_whitelist, 0,
+- BITS_TO_LONGS(ctx->jump_whitelist_cmds) * sizeof(u32));
++ bitmap_zero(ctx->jump_whitelist, ctx->jump_whitelist_cmds);
+
+ return;
+ }
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:10:50 PM CET
+From: Jon Bloomfield <jon.bloomfield@intel.com>
+Date: Thu, 20 Sep 2018 09:45:10 -0700
+Subject: drm/i915/cmdparser: Ignore Length operands during command matching
+
+From: Jon Bloomfield <jon.bloomfield@intel.com>
+
+commit 926abff21a8f29ef159a3ac893b05c6e50e043c3 upstream.
+
+Some of the gen instruction macros (e.g. MI_DISPLAY_FLIP) have the
+length directly encoded in them. Since these are used directly in
+the tables, the Length becomes part of the comparison used for
+matching during parsing. Thus, if the cmd being parsed has a
+different length to that in the table, it is not matched and the
+cmd is accepted via the default variable length path.
+
+Fix by masking out everything except the Opcode in the cmd tables
+
+Cc: Tony Luck <tony.luck@intel.com>
+Cc: Dave Airlie <airlied@redhat.com>
+Cc: Takashi Iwai <tiwai@suse.de>
+Cc: Tyler Hicks <tyhicks@canonical.com>
+Signed-off-by: Jon Bloomfield <jon.bloomfield@intel.com>
+Reviewed-by: Chris Wilson <chris.p.wilson@intel.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/gpu/drm/i915/i915_cmd_parser.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/gpu/drm/i915/i915_cmd_parser.c
++++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
+@@ -188,7 +188,7 @@ struct drm_i915_cmd_table {
+ #define CMD(op, opm, f, lm, fl, ...) \
+ { \
+ .flags = (fl) | ((f) ? CMD_DESC_FIXED : 0), \
+- .cmd = { (op), ~0u << (opm) }, \
++ .cmd = { (op & ~0u << (opm)), ~0u << (opm) }, \
+ .length = { (lm) }, \
+ __VA_ARGS__ \
+ }
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:10:49 PM CET
+From: Jon Bloomfield <jon.bloomfield@intel.com>
+Date: Thu, 27 Sep 2018 10:23:17 -0700
+Subject: drm/i915/cmdparser: Use explicit goto for error paths
+
+From: Jon Bloomfield <jon.bloomfield@intel.com>
+
+commit 0546a29cd884fb8184731c79ab008927ca8859d0 upstream.
+
+In the next patch we will be adding a second valid
+termination condition which will require a small
+amount of refactoring to share logic with the BB_END
+case.
+
+Refactor all error conditions to jump to a dedicated
+exit path, with 'break' reserved only for a successful
+parse.
+
+Cc: Tony Luck <tony.luck@intel.com>
+Cc: Dave Airlie <airlied@redhat.com>
+Cc: Takashi Iwai <tiwai@suse.de>
+Cc: Tyler Hicks <tyhicks@canonical.com>
+Signed-off-by: Jon Bloomfield <jon.bloomfield@intel.com>
+Reviewed-by: Chris Wilson <chris.p.wilson@intel.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/gpu/drm/i915/i915_cmd_parser.c | 25 +++++++++++++------------
+ 1 file changed, 13 insertions(+), 12 deletions(-)
+
+--- a/drivers/gpu/drm/i915/i915_cmd_parser.c
++++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
+@@ -1337,21 +1337,15 @@ int intel_engine_cmd_parser(struct intel
+ do {
+ u32 length;
+
+- if (*cmd == MI_BATCH_BUFFER_END) {
+- if (needs_clflush_after) {
+- void *ptr = page_mask_bits(shadow_batch_obj->mm.mapping);
+- drm_clflush_virt_range(ptr,
+- (void *)(cmd + 1) - ptr);
+- }
++ if (*cmd == MI_BATCH_BUFFER_END)
+ break;
+- }
+
+ desc = find_cmd(engine, *cmd, desc, &default_desc);
+ if (!desc) {
+ DRM_DEBUG_DRIVER("CMD: Unrecognized command: 0x%08X\n",
+ *cmd);
+ ret = -EINVAL;
+- break;
++ goto err;
+ }
+
+ /*
+@@ -1361,7 +1355,7 @@ int intel_engine_cmd_parser(struct intel
+ */
+ if (desc->cmd.value == MI_BATCH_BUFFER_START) {
+ ret = -EACCES;
+- break;
++ goto err;
+ }
+
+ if (desc->flags & CMD_DESC_FIXED)
+@@ -1375,22 +1369,29 @@ int intel_engine_cmd_parser(struct intel
+ length,
+ batch_end - cmd);
+ ret = -EINVAL;
+- break;
++ goto err;
+ }
+
+ if (!check_cmd(engine, desc, cmd, length)) {
+ ret = -EACCES;
+- break;
++ goto err;
+ }
+
+ cmd += length;
+ if (cmd >= batch_end) {
+ DRM_DEBUG_DRIVER("CMD: Got to the end of the buffer w/o a BBE cmd!\n");
+ ret = -EINVAL;
+- break;
++ goto err;
+ }
+ } while (1);
+
++ if (needs_clflush_after) {
++ void *ptr = page_mask_bits(shadow_batch_obj->mm.mapping);
++
++ drm_clflush_virt_range(ptr, (void *)(cmd + 1) - ptr);
++ }
++
++err:
+ i915_gem_object_unpin_map(shadow_batch_obj);
+ return ret;
+ }
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:10:49 PM CET
+From: Jon Bloomfield <jon.bloomfield@intel.com>
+Date: Fri, 8 Jun 2018 08:53:46 -0700
+Subject: drm/i915: Disable Secure Batches for gen6+
+
+From: Jon Bloomfield <jon.bloomfield@intel.com>
+
+commit 44157641d448cbc0c4b73c5231d2b911f0cb0427 upstream.
+
+Retroactively stop reporting support for secure batches
+through the api for gen6+ so that older binaries trigger
+the fallback path instead.
+
+Older binaries use secure batches pre gen6 to access resources
+that are not available to normal usermode processes. However,
+all known userspace explicitly checks for HAS_SECURE_BATCHES
+before relying on the secure batch feature.
+
+Since there are no known binaries relying on this for newer gens
+we can kill secure batches from gen6, via I915_PARAM_HAS_SECURE_BATCHES.
+
+v2: rebase (Mika)
+v3: rebase (Mika)
+
+Signed-off-by: Jon Bloomfield <jon.bloomfield@intel.com>
+Cc: Tony Luck <tony.luck@intel.com>
+Cc: Dave Airlie <airlied@redhat.com>
+Cc: Takashi Iwai <tiwai@suse.de>
+Cc: Tyler Hicks <tyhicks@canonical.com>
+Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
+Reviewed-by: Chris Wilson <chris.p.wilson@intel.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 12 ++++++++++--
+ drivers/gpu/drm/i915/i915_drv.c | 2 +-
+ drivers/gpu/drm/i915/i915_drv.h | 1 +
+ 3 files changed, 12 insertions(+), 3 deletions(-)
+
+--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
++++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+@@ -2351,6 +2351,7 @@ i915_gem_do_execbuffer(struct drm_device
+ struct drm_i915_gem_exec_object2 *exec,
+ struct drm_syncobj **fences)
+ {
++ struct drm_i915_private *i915 = to_i915(dev);
+ struct i915_execbuffer eb;
+ struct dma_fence *in_fence = NULL;
+ struct dma_fence *exec_fence = NULL;
+@@ -2362,7 +2363,7 @@ i915_gem_do_execbuffer(struct drm_device
+ BUILD_BUG_ON(__EXEC_OBJECT_INTERNAL_FLAGS &
+ ~__EXEC_OBJECT_UNKNOWN_FLAGS);
+
+- eb.i915 = to_i915(dev);
++ eb.i915 = i915;
+ eb.file = file;
+ eb.args = args;
+ if (DBG_FORCE_RELOC || !(args->flags & I915_EXEC_NO_RELOC))
+@@ -2382,8 +2383,15 @@ i915_gem_do_execbuffer(struct drm_device
+
+ eb.batch_flags = 0;
+ if (args->flags & I915_EXEC_SECURE) {
++ if (INTEL_GEN(i915) >= 11)
++ return -ENODEV;
++
++ /* Return -EPERM to trigger fallback code on old binaries. */
++ if (!HAS_SECURE_BATCHES(i915))
++ return -EPERM;
++
+ if (!drm_is_current_master(file) || !capable(CAP_SYS_ADMIN))
+- return -EPERM;
++ return -EPERM;
+
+ eb.batch_flags |= I915_DISPATCH_SECURE;
+ }
+--- a/drivers/gpu/drm/i915/i915_drv.c
++++ b/drivers/gpu/drm/i915/i915_drv.c
+@@ -387,7 +387,7 @@ static int i915_getparam_ioctl(struct dr
+ value = !!(dev_priv->caps.scheduler & I915_SCHEDULER_CAP_SEMAPHORES);
+ break;
+ case I915_PARAM_HAS_SECURE_BATCHES:
+- value = capable(CAP_SYS_ADMIN);
++ value = HAS_SECURE_BATCHES(dev_priv) && capable(CAP_SYS_ADMIN);
+ break;
+ case I915_PARAM_CMD_PARSER_VERSION:
+ value = i915_cmd_parser_get_version(dev_priv);
+--- a/drivers/gpu/drm/i915/i915_drv.h
++++ b/drivers/gpu/drm/i915/i915_drv.h
+@@ -2249,6 +2249,7 @@ IS_SUBPLATFORM(const struct drm_i915_pri
+ #define HAS_LLC(dev_priv) (INTEL_INFO(dev_priv)->has_llc)
+ #define HAS_SNOOP(dev_priv) (INTEL_INFO(dev_priv)->has_snoop)
+ #define HAS_EDRAM(dev_priv) ((dev_priv)->edram_size_mb)
++#define HAS_SECURE_BATCHES(dev_priv) (INTEL_GEN(dev_priv) < 6)
+ #define HAS_WT(dev_priv) ((IS_HASWELL(dev_priv) || \
+ IS_BROADWELL(dev_priv)) && HAS_EDRAM(dev_priv))
+
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:10:50 PM CET
+From: Imre Deak <imre.deak@intel.com>
+Date: Mon, 9 Jul 2018 18:24:27 +0300
+Subject: drm/i915/gen8+: Add RC6 CTX corruption WA
+
+From: Imre Deak <imre.deak@intel.com>
+
+commit 7e34f4e4aad3fd34c02b294a3cf2321adf5b4438 upstream.
+
+In some circumstances the RC6 context can get corrupted. We can detect
+this and take the required action, that is disable RC6 and runtime PM.
+The HW recovers from the corrupted state after a system suspend/resume
+cycle, so detect the recovery and re-enable RC6 and runtime PM.
+
+v2: rebase (Mika)
+v3:
+- Move intel_suspend_gt_powersave() to the end of the GEM suspend
+ sequence.
+- Add commit message.
+v4:
+- Rebased on intel_uncore_forcewake_put(i915->uncore, ...) API
+ change.
+v5: rebased on gem/gt split (Mika)
+
+Signed-off-by: Imre Deak <imre.deak@intel.com>
+Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/gpu/drm/i915/gt/intel_gt_pm.c | 8 ++
+ drivers/gpu/drm/i915/i915_drv.c | 4 +
+ drivers/gpu/drm/i915/i915_drv.h | 8 +-
+ drivers/gpu/drm/i915/i915_reg.h | 2
+ drivers/gpu/drm/i915/intel_pm.c | 107 +++++++++++++++++++++++++++++++++-
+ drivers/gpu/drm/i915/intel_pm.h | 3
+ 6 files changed, 128 insertions(+), 4 deletions(-)
+
+--- a/drivers/gpu/drm/i915/gt/intel_gt_pm.c
++++ b/drivers/gpu/drm/i915/gt/intel_gt_pm.c
+@@ -36,6 +36,9 @@ static int intel_gt_unpark(struct intel_
+ i915->gt.awake = intel_display_power_get(i915, POWER_DOMAIN_GT_IRQ);
+ GEM_BUG_ON(!i915->gt.awake);
+
++ if (NEEDS_RC6_CTX_CORRUPTION_WA(i915))
++ intel_uncore_forcewake_get(&i915->uncore, FORCEWAKE_ALL);
++
+ intel_enable_gt_powersave(i915);
+
+ i915_update_gfx_val(i915);
+@@ -70,6 +73,11 @@ static int intel_gt_park(struct intel_wa
+ if (INTEL_GEN(i915) >= 6)
+ gen6_rps_idle(i915);
+
++ if (NEEDS_RC6_CTX_CORRUPTION_WA(i915)) {
++ intel_rc6_ctx_wa_check(i915);
++ intel_uncore_forcewake_put(&i915->uncore, FORCEWAKE_ALL);
++ }
++
+ GEM_BUG_ON(!wakeref);
+ intel_display_power_put(i915, POWER_DOMAIN_GT_IRQ, wakeref);
+
+--- a/drivers/gpu/drm/i915/i915_drv.c
++++ b/drivers/gpu/drm/i915/i915_drv.c
+@@ -2156,6 +2156,8 @@ static int i915_drm_suspend_late(struct
+
+ i915_gem_suspend_late(dev_priv);
+
++ intel_rc6_ctx_wa_suspend(dev_priv);
++
+ intel_uncore_suspend(&dev_priv->uncore);
+
+ intel_power_domains_suspend(dev_priv,
+@@ -2372,6 +2374,8 @@ static int i915_drm_resume_early(struct
+
+ intel_power_domains_resume(dev_priv);
+
++ intel_rc6_ctx_wa_resume(dev_priv);
++
+ intel_gt_sanitize(dev_priv, true);
+
+ enable_rpm_wakeref_asserts(&dev_priv->runtime_pm);
+--- a/drivers/gpu/drm/i915/i915_drv.h
++++ b/drivers/gpu/drm/i915/i915_drv.h
+@@ -696,6 +696,8 @@ struct intel_rps {
+
+ struct intel_rc6 {
+ bool enabled;
++ bool ctx_corrupted;
++ intel_wakeref_t ctx_corrupted_wakeref;
+ u64 prev_hw_residency[4];
+ u64 cur_residency[4];
+ };
+@@ -2288,10 +2290,12 @@ IS_SUBPLATFORM(const struct drm_i915_pri
+ /* Early gen2 have a totally busted CS tlb and require pinned batches. */
+ #define HAS_BROKEN_CS_TLB(dev_priv) (IS_I830(dev_priv) || IS_I845G(dev_priv))
+
++#define NEEDS_RC6_CTX_CORRUPTION_WA(dev_priv) \
++ (IS_BROADWELL(dev_priv) || IS_GEN(dev_priv, 9))
++
+ /* WaRsDisableCoarsePowerGating:skl,cnl */
+ #define NEEDS_WaRsDisableCoarsePowerGating(dev_priv) \
+- (IS_CANNONLAKE(dev_priv) || \
+- IS_SKL_GT3(dev_priv) || IS_SKL_GT4(dev_priv))
++ (IS_CANNONLAKE(dev_priv) || IS_GEN(dev_priv, 9))
+
+ #define HAS_GMBUS_IRQ(dev_priv) (INTEL_GEN(dev_priv) >= 4)
+ #define HAS_GMBUS_BURST_READ(dev_priv) (INTEL_GEN(dev_priv) >= 10 || \
+--- a/drivers/gpu/drm/i915/i915_reg.h
++++ b/drivers/gpu/drm/i915/i915_reg.h
+@@ -493,6 +493,8 @@ static inline bool i915_mmio_reg_valid(i
+ #define ECOCHK_PPGTT_WT_HSW (0x2 << 3)
+ #define ECOCHK_PPGTT_WB_HSW (0x3 << 3)
+
++#define GEN8_RC6_CTX_INFO _MMIO(0x8504)
++
+ #define GAC_ECO_BITS _MMIO(0x14090)
+ #define ECOBITS_SNB_BIT (1 << 13)
+ #define ECOBITS_PPGTT_CACHE64B (3 << 8)
+--- a/drivers/gpu/drm/i915/intel_pm.c
++++ b/drivers/gpu/drm/i915/intel_pm.c
+@@ -8564,6 +8564,95 @@ static void intel_init_emon(struct drm_i
+ dev_priv->ips.corr = (lcfuse & LCFUSE_HIV_MASK);
+ }
+
++static bool intel_rc6_ctx_corrupted(struct drm_i915_private *dev_priv)
++{
++ return !I915_READ(GEN8_RC6_CTX_INFO);
++}
++
++static void intel_rc6_ctx_wa_init(struct drm_i915_private *i915)
++{
++ if (!NEEDS_RC6_CTX_CORRUPTION_WA(i915))
++ return;
++
++ if (intel_rc6_ctx_corrupted(i915)) {
++ DRM_INFO("RC6 context corrupted, disabling runtime power management\n");
++ i915->gt_pm.rc6.ctx_corrupted = true;
++ i915->gt_pm.rc6.ctx_corrupted_wakeref =
++ intel_runtime_pm_get(&i915->runtime_pm);
++ }
++}
++
++static void intel_rc6_ctx_wa_cleanup(struct drm_i915_private *i915)
++{
++ if (i915->gt_pm.rc6.ctx_corrupted) {
++ intel_runtime_pm_put(&i915->runtime_pm,
++ i915->gt_pm.rc6.ctx_corrupted_wakeref);
++ i915->gt_pm.rc6.ctx_corrupted = false;
++ }
++}
++
++/**
++ * intel_rc6_ctx_wa_suspend - system suspend sequence for the RC6 CTX WA
++ * @i915: i915 device
++ *
++ * Perform any steps needed to clean up the RC6 CTX WA before system suspend.
++ */
++void intel_rc6_ctx_wa_suspend(struct drm_i915_private *i915)
++{
++ if (i915->gt_pm.rc6.ctx_corrupted)
++ intel_runtime_pm_put(&i915->runtime_pm,
++ i915->gt_pm.rc6.ctx_corrupted_wakeref);
++}
++
++/**
++ * intel_rc6_ctx_wa_resume - system resume sequence for the RC6 CTX WA
++ * @i915: i915 device
++ *
++ * Perform any steps needed to re-init the RC6 CTX WA after system resume.
++ */
++void intel_rc6_ctx_wa_resume(struct drm_i915_private *i915)
++{
++ if (!i915->gt_pm.rc6.ctx_corrupted)
++ return;
++
++ if (intel_rc6_ctx_corrupted(i915)) {
++ i915->gt_pm.rc6.ctx_corrupted_wakeref =
++ intel_runtime_pm_get(&i915->runtime_pm);
++ return;
++ }
++
++ DRM_INFO("RC6 context restored, re-enabling runtime power management\n");
++ i915->gt_pm.rc6.ctx_corrupted = false;
++}
++
++static void intel_disable_rc6(struct drm_i915_private *dev_priv);
++
++/**
++ * intel_rc6_ctx_wa_check - check for a new RC6 CTX corruption
++ * @i915: i915 device
++ *
++ * Check if an RC6 CTX corruption has happened since the last check and if so
++ * disable RC6 and runtime power management.
++*/
++void intel_rc6_ctx_wa_check(struct drm_i915_private *i915)
++{
++ if (!NEEDS_RC6_CTX_CORRUPTION_WA(i915))
++ return;
++
++ if (i915->gt_pm.rc6.ctx_corrupted)
++ return;
++
++ if (!intel_rc6_ctx_corrupted(i915))
++ return;
++
++ DRM_NOTE("RC6 context corruption, disabling runtime power management\n");
++
++ intel_disable_rc6(i915);
++ i915->gt_pm.rc6.ctx_corrupted = true;
++ i915->gt_pm.rc6.ctx_corrupted_wakeref =
++ intel_runtime_pm_get_noresume(&i915->runtime_pm);
++}
++
+ void intel_init_gt_powersave(struct drm_i915_private *dev_priv)
+ {
+ struct intel_rps *rps = &dev_priv->gt_pm.rps;
+@@ -8577,6 +8666,8 @@ void intel_init_gt_powersave(struct drm_
+ pm_runtime_get(&dev_priv->drm.pdev->dev);
+ }
+
++ intel_rc6_ctx_wa_init(dev_priv);
++
+ /* Initialize RPS limits (for userspace) */
+ if (IS_CHERRYVIEW(dev_priv))
+ cherryview_init_gt_powersave(dev_priv);
+@@ -8615,6 +8706,8 @@ void intel_cleanup_gt_powersave(struct d
+ if (IS_VALLEYVIEW(dev_priv))
+ valleyview_cleanup_gt_powersave(dev_priv);
+
++ intel_rc6_ctx_wa_cleanup(dev_priv);
++
+ if (!HAS_RC6(dev_priv))
+ pm_runtime_put(&dev_priv->drm.pdev->dev);
+ }
+@@ -8643,7 +8736,7 @@ static inline void intel_disable_llc_pst
+ i915->gt_pm.llc_pstate.enabled = false;
+ }
+
+-static void intel_disable_rc6(struct drm_i915_private *dev_priv)
++static void __intel_disable_rc6(struct drm_i915_private *dev_priv)
+ {
+ lockdep_assert_held(&dev_priv->gt_pm.rps.lock);
+
+@@ -8662,6 +8755,13 @@ static void intel_disable_rc6(struct drm
+ dev_priv->gt_pm.rc6.enabled = false;
+ }
+
++static void intel_disable_rc6(struct drm_i915_private *dev_priv)
++{
++ mutex_lock(&dev_priv->gt_pm.rps.lock);
++ __intel_disable_rc6(dev_priv);
++ mutex_unlock(&dev_priv->gt_pm.rps.lock);
++}
++
+ static void intel_disable_rps(struct drm_i915_private *dev_priv)
+ {
+ lockdep_assert_held(&dev_priv->gt_pm.rps.lock);
+@@ -8687,7 +8787,7 @@ void intel_disable_gt_powersave(struct d
+ {
+ mutex_lock(&dev_priv->gt_pm.rps.lock);
+
+- intel_disable_rc6(dev_priv);
++ __intel_disable_rc6(dev_priv);
+ intel_disable_rps(dev_priv);
+ if (HAS_LLC(dev_priv))
+ intel_disable_llc_pstate(dev_priv);
+@@ -8714,6 +8814,9 @@ static void intel_enable_rc6(struct drm_
+ if (dev_priv->gt_pm.rc6.enabled)
+ return;
+
++ if (dev_priv->gt_pm.rc6.ctx_corrupted)
++ return;
++
+ if (IS_CHERRYVIEW(dev_priv))
+ cherryview_enable_rc6(dev_priv);
+ else if (IS_VALLEYVIEW(dev_priv))
+--- a/drivers/gpu/drm/i915/intel_pm.h
++++ b/drivers/gpu/drm/i915/intel_pm.h
+@@ -36,6 +36,9 @@ void intel_cleanup_gt_powersave(struct d
+ void intel_sanitize_gt_powersave(struct drm_i915_private *dev_priv);
+ void intel_enable_gt_powersave(struct drm_i915_private *dev_priv);
+ void intel_disable_gt_powersave(struct drm_i915_private *dev_priv);
++void intel_rc6_ctx_wa_check(struct drm_i915_private *i915);
++void intel_rc6_ctx_wa_suspend(struct drm_i915_private *i915);
++void intel_rc6_ctx_wa_resume(struct drm_i915_private *i915);
+ void gen6_rps_busy(struct drm_i915_private *dev_priv);
+ void gen6_rps_idle(struct drm_i915_private *dev_priv);
+ void gen6_rps_boost(struct i915_request *rq);
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:10:50 PM CET
+From: Uma Shankar <uma.shankar@intel.com>
+Date: Tue, 7 Aug 2018 21:15:35 +0530
+Subject: drm/i915: Lower RM timeout to avoid DSI hard hangs
+
+From: Uma Shankar <uma.shankar@intel.com>
+
+commit 1d85a299c4db57c55e0229615132c964d17aa765 upstream.
+
+In BXT/APL, device 2 MMIO reads from MIPI controller requires its PLL
+to be turned ON. When MIPI PLL is turned off (MIPI Display is not
+active or connected), and someone (host or GT engine) tries to read
+MIPI registers, it causes hard hang. This is a hardware restriction
+or limitation.
+
+Driver by itself doesn't read MIPI registers when MIPI display is off.
+But any userspace application can submit unprivileged batch buffer for
+execution. In that batch buffer there can be mmio reads. And these
+reads are allowed even for unprivileged applications. If these
+register reads are for MIPI DSI controller and MIPI display is not
+active during that time, then the MMIO read operation causes system
+hard hang and only way to recover is hard reboot. A genuine
+process/application won't submit batch buffer like this and doesn't
+cause any issue. But on a compromised system, a malign userspace
+process/app can generate such batch buffer and can trigger system
+hard hang (denial of service attack).
+
+The fix is to lower the internal MMIO timeout value to an optimum
+value of 950us as recommended by hardware team. If the timeout is
+beyond 1ms (which will hit for any value we choose if MMIO READ on a
+DSI specific register is performed without PLL ON), it causes the
+system hang. But if the timeout value is lower than it will be below
+the threshold (even if timeout happens) and system will not get into
+a hung state. This will avoid a system hang without losing any
+programming or GT interrupts, taking the worst case of lowest CDCLK
+frequency and early DC5 abort into account.
+
+Signed-off-by: Uma Shankar <uma.shankar@intel.com>
+Reviewed-by: Jon Bloomfield <jon.bloomfield@intel.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/gpu/drm/i915/i915_reg.h | 4 ++++
+ drivers/gpu/drm/i915/intel_pm.c | 8 ++++++++
+ 2 files changed, 12 insertions(+)
+
+--- a/drivers/gpu/drm/i915/i915_reg.h
++++ b/drivers/gpu/drm/i915/i915_reg.h
+@@ -7233,6 +7233,10 @@ enum {
+ #define SKL_CSR_DC5_DC6_COUNT _MMIO(0x8002C)
+ #define BXT_CSR_DC3_DC5_COUNT _MMIO(0x80038)
+
++/* Display Internal Timeout Register */
++#define RM_TIMEOUT _MMIO(0x42060)
++#define MMIO_TIMEOUT_US(us) ((us) << 0)
++
+ /* interrupts */
+ #define DE_MASTER_IRQ_CONTROL (1 << 31)
+ #define DE_SPRITEB_FLIP_DONE (1 << 29)
+--- a/drivers/gpu/drm/i915/intel_pm.c
++++ b/drivers/gpu/drm/i915/intel_pm.c
+@@ -125,6 +125,14 @@ static void bxt_init_clock_gating(struct
+ */
+ I915_WRITE(GEN9_CLKGATE_DIS_0, I915_READ(GEN9_CLKGATE_DIS_0) |
+ PWM1_GATING_DIS | PWM2_GATING_DIS);
++
++ /*
++ * Lower the display internal timeout.
++ * This is needed to avoid any hard hangs when DSI port PLL
++ * is off and a MMIO access is attempted by any privilege
++ * application, using batch buffers or any other means.
++ */
++ I915_WRITE(RM_TIMEOUT, MMIO_TIMEOUT_US(950));
+ }
+
+ static void glk_init_clock_gating(struct drm_i915_private *dev_priv)
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:10:49 PM CET
+From: Jon Bloomfield <jon.bloomfield@intel.com>
+Date: Fri, 8 Jun 2018 10:05:26 -0700
+Subject: drm/i915: Remove Master tables from cmdparser
+
+From: Jon Bloomfield <jon.bloomfield@intel.com>
+
+commit 66d8aba1cd6db34af10de465c0d52af679288cb6 upstream.
+
+The previous patch has killed support for secure batches
+on gen6+, and hence the cmdparsers master tables are
+now dead code. Remove them.
+
+Signed-off-by: Jon Bloomfield <jon.bloomfield@intel.com>
+Cc: Tony Luck <tony.luck@intel.com>
+Cc: Dave Airlie <airlied@redhat.com>
+Cc: Takashi Iwai <tiwai@suse.de>
+Cc: Tyler Hicks <tyhicks@canonical.com>
+Reviewed-by: Chris Wilson <chris.p.wilson@intel.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 7 --
+ drivers/gpu/drm/i915/i915_cmd_parser.c | 84 ++++++-------------------
+ drivers/gpu/drm/i915/i915_drv.h | 3
+ 3 files changed, 26 insertions(+), 68 deletions(-)
+
+--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
++++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+@@ -2009,7 +2009,7 @@ static int i915_reset_gen7_sol_offsets(s
+ return 0;
+ }
+
+-static struct i915_vma *eb_parse(struct i915_execbuffer *eb, bool is_master)
++static struct i915_vma *eb_parse(struct i915_execbuffer *eb)
+ {
+ struct drm_i915_gem_object *shadow_batch_obj;
+ struct i915_vma *vma;
+@@ -2024,8 +2024,7 @@ static struct i915_vma *eb_parse(struct
+ eb->batch->obj,
+ shadow_batch_obj,
+ eb->batch_start_offset,
+- eb->batch_len,
+- is_master);
++ eb->batch_len);
+ if (err) {
+ if (err == -EACCES) /* unhandled chained batch */
+ vma = NULL;
+@@ -2484,7 +2483,7 @@ i915_gem_do_execbuffer(struct drm_device
+ if (eb_use_cmdparser(&eb)) {
+ struct i915_vma *vma;
+
+- vma = eb_parse(&eb, drm_is_current_master(file));
++ vma = eb_parse(&eb);
+ if (IS_ERR(vma)) {
+ err = PTR_ERR(vma);
+ goto err_vma;
+--- a/drivers/gpu/drm/i915/i915_cmd_parser.c
++++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
+@@ -52,13 +52,11 @@
+ * granting userspace undue privileges. There are three categories of privilege.
+ *
+ * First, commands which are explicitly defined as privileged or which should
+- * only be used by the kernel driver. The parser generally rejects such
+- * commands, though it may allow some from the drm master process.
++ * only be used by the kernel driver. The parser rejects such commands
+ *
+ * Second, commands which access registers. To support correct/enhanced
+ * userspace functionality, particularly certain OpenGL extensions, the parser
+- * provides a whitelist of registers which userspace may safely access (for both
+- * normal and drm master processes).
++ * provides a whitelist of registers which userspace may safely access
+ *
+ * Third, commands which access privileged memory (i.e. GGTT, HWS page, etc).
+ * The parser always rejects such commands.
+@@ -83,9 +81,9 @@
+ * in the per-engine command tables.
+ *
+ * Other command table entries map fairly directly to high level categories
+- * mentioned above: rejected, master-only, register whitelist. The parser
+- * implements a number of checks, including the privileged memory checks, via a
+- * general bitmasking mechanism.
++ * mentioned above: rejected, register whitelist. The parser implements a number
++ * of checks, including the privileged memory checks, via a general bitmasking
++ * mechanism.
+ */
+
+ /*
+@@ -103,8 +101,6 @@ struct drm_i915_cmd_descriptor {
+ * CMD_DESC_REJECT: The command is never allowed
+ * CMD_DESC_REGISTER: The command should be checked against the
+ * register whitelist for the appropriate ring
+- * CMD_DESC_MASTER: The command is allowed if the submitting process
+- * is the DRM master
+ */
+ u32 flags;
+ #define CMD_DESC_FIXED (1<<0)
+@@ -112,7 +108,6 @@ struct drm_i915_cmd_descriptor {
+ #define CMD_DESC_REJECT (1<<2)
+ #define CMD_DESC_REGISTER (1<<3)
+ #define CMD_DESC_BITMASK (1<<4)
+-#define CMD_DESC_MASTER (1<<5)
+
+ /*
+ * The command's unique identification bits and the bitmask to get them.
+@@ -208,14 +203,13 @@ struct drm_i915_cmd_table {
+ #define R CMD_DESC_REJECT
+ #define W CMD_DESC_REGISTER
+ #define B CMD_DESC_BITMASK
+-#define M CMD_DESC_MASTER
+
+ /* Command Mask Fixed Len Action
+ ---------------------------------------------------------- */
+ static const struct drm_i915_cmd_descriptor gen7_common_cmds[] = {
+ CMD( MI_NOOP, SMI, F, 1, S ),
+ CMD( MI_USER_INTERRUPT, SMI, F, 1, R ),
+- CMD( MI_WAIT_FOR_EVENT, SMI, F, 1, M ),
++ CMD( MI_WAIT_FOR_EVENT, SMI, F, 1, R ),
+ CMD( MI_ARB_CHECK, SMI, F, 1, S ),
+ CMD( MI_REPORT_HEAD, SMI, F, 1, S ),
+ CMD( MI_SUSPEND_FLUSH, SMI, F, 1, S ),
+@@ -312,7 +306,7 @@ static const struct drm_i915_cmd_descrip
+ CMD( MI_URB_ATOMIC_ALLOC, SMI, F, 1, S ),
+ CMD( MI_SET_APPID, SMI, F, 1, S ),
+ CMD( MI_RS_CONTEXT, SMI, F, 1, S ),
+- CMD( MI_LOAD_SCAN_LINES_INCL, SMI, !F, 0x3F, M ),
++ CMD( MI_LOAD_SCAN_LINES_INCL, SMI, !F, 0x3F, R ),
+ CMD( MI_LOAD_SCAN_LINES_EXCL, SMI, !F, 0x3F, R ),
+ CMD( MI_LOAD_REGISTER_REG, SMI, !F, 0xFF, W,
+ .reg = { .offset = 1, .mask = 0x007FFFFC, .step = 1 } ),
+@@ -445,7 +439,7 @@ static const struct drm_i915_cmd_descrip
+ };
+
+ static const struct drm_i915_cmd_descriptor hsw_blt_cmds[] = {
+- CMD( MI_LOAD_SCAN_LINES_INCL, SMI, !F, 0x3F, M ),
++ CMD( MI_LOAD_SCAN_LINES_INCL, SMI, !F, 0x3F, R ),
+ CMD( MI_LOAD_SCAN_LINES_EXCL, SMI, !F, 0x3F, R ),
+ };
+
+@@ -462,7 +456,6 @@ static const struct drm_i915_cmd_descrip
+ #undef R
+ #undef W
+ #undef B
+-#undef M
+
+ static const struct drm_i915_cmd_table gen7_render_cmd_table[] = {
+ { gen7_common_cmds, ARRAY_SIZE(gen7_common_cmds) },
+@@ -611,47 +604,29 @@ static const struct drm_i915_reg_descrip
+ REG64_IDX(RING_TIMESTAMP, BLT_RING_BASE),
+ };
+
+-static const struct drm_i915_reg_descriptor ivb_master_regs[] = {
+- REG32(FORCEWAKE_MT),
+- REG32(DERRMR),
+- REG32(GEN7_PIPE_DE_LOAD_SL(PIPE_A)),
+- REG32(GEN7_PIPE_DE_LOAD_SL(PIPE_B)),
+- REG32(GEN7_PIPE_DE_LOAD_SL(PIPE_C)),
+-};
+-
+-static const struct drm_i915_reg_descriptor hsw_master_regs[] = {
+- REG32(FORCEWAKE_MT),
+- REG32(DERRMR),
+-};
+-
+ #undef REG64
+ #undef REG32
+
+ struct drm_i915_reg_table {
+ const struct drm_i915_reg_descriptor *regs;
+ int num_regs;
+- bool master;
+ };
+
+ static const struct drm_i915_reg_table ivb_render_reg_tables[] = {
+- { gen7_render_regs, ARRAY_SIZE(gen7_render_regs), false },
+- { ivb_master_regs, ARRAY_SIZE(ivb_master_regs), true },
++ { gen7_render_regs, ARRAY_SIZE(gen7_render_regs) },
+ };
+
+ static const struct drm_i915_reg_table ivb_blt_reg_tables[] = {
+- { gen7_blt_regs, ARRAY_SIZE(gen7_blt_regs), false },
+- { ivb_master_regs, ARRAY_SIZE(ivb_master_regs), true },
++ { gen7_blt_regs, ARRAY_SIZE(gen7_blt_regs) },
+ };
+
+ static const struct drm_i915_reg_table hsw_render_reg_tables[] = {
+- { gen7_render_regs, ARRAY_SIZE(gen7_render_regs), false },
+- { hsw_render_regs, ARRAY_SIZE(hsw_render_regs), false },
+- { hsw_master_regs, ARRAY_SIZE(hsw_master_regs), true },
++ { gen7_render_regs, ARRAY_SIZE(gen7_render_regs) },
++ { hsw_render_regs, ARRAY_SIZE(hsw_render_regs) },
+ };
+
+ static const struct drm_i915_reg_table hsw_blt_reg_tables[] = {
+- { gen7_blt_regs, ARRAY_SIZE(gen7_blt_regs), false },
+- { hsw_master_regs, ARRAY_SIZE(hsw_master_regs), true },
++ { gen7_blt_regs, ARRAY_SIZE(gen7_blt_regs) },
+ };
+
+ static u32 gen7_render_get_cmd_length_mask(u32 cmd_header)
+@@ -1028,22 +1003,16 @@ __find_reg(const struct drm_i915_reg_des
+ }
+
+ static const struct drm_i915_reg_descriptor *
+-find_reg(const struct intel_engine_cs *engine, bool is_master, u32 addr)
++find_reg(const struct intel_engine_cs *engine, u32 addr)
+ {
+ const struct drm_i915_reg_table *table = engine->reg_tables;
++ const struct drm_i915_reg_descriptor *reg = NULL;
+ int count = engine->reg_table_count;
+
+- for (; count > 0; ++table, --count) {
+- if (!table->master || is_master) {
+- const struct drm_i915_reg_descriptor *reg;
+-
+- reg = __find_reg(table->regs, table->num_regs, addr);
+- if (reg != NULL)
+- return reg;
+- }
+- }
++ for (; !reg && (count > 0); ++table, --count)
++ reg = __find_reg(table->regs, table->num_regs, addr);
+
+- return NULL;
++ return reg;
+ }
+
+ /* Returns a vmap'd pointer to dst_obj, which the caller must unmap */
+@@ -1127,8 +1096,7 @@ static u32 *copy_batch(struct drm_i915_g
+
+ static bool check_cmd(const struct intel_engine_cs *engine,
+ const struct drm_i915_cmd_descriptor *desc,
+- const u32 *cmd, u32 length,
+- const bool is_master)
++ const u32 *cmd, u32 length)
+ {
+ if (desc->flags & CMD_DESC_SKIP)
+ return true;
+@@ -1138,12 +1106,6 @@ static bool check_cmd(const struct intel
+ return false;
+ }
+
+- if ((desc->flags & CMD_DESC_MASTER) && !is_master) {
+- DRM_DEBUG_DRIVER("CMD: Rejected master-only command: 0x%08X\n",
+- *cmd);
+- return false;
+- }
+-
+ if (desc->flags & CMD_DESC_REGISTER) {
+ /*
+ * Get the distance between individual register offset
+@@ -1157,7 +1119,7 @@ static bool check_cmd(const struct intel
+ offset += step) {
+ const u32 reg_addr = cmd[offset] & desc->reg.mask;
+ const struct drm_i915_reg_descriptor *reg =
+- find_reg(engine, is_master, reg_addr);
++ find_reg(engine, reg_addr);
+
+ if (!reg) {
+ DRM_DEBUG_DRIVER("CMD: Rejected register 0x%08X in command: 0x%08X (%s)\n",
+@@ -1244,7 +1206,6 @@ static bool check_cmd(const struct intel
+ * @shadow_batch_obj: copy of the batch buffer in question
+ * @batch_start_offset: byte offset in the batch at which execution starts
+ * @batch_len: length of the commands in batch_obj
+- * @is_master: is the submitting process the drm master?
+ *
+ * Parses the specified batch buffer looking for privilege violations as
+ * described in the overview.
+@@ -1256,8 +1217,7 @@ int intel_engine_cmd_parser(struct intel
+ struct drm_i915_gem_object *batch_obj,
+ struct drm_i915_gem_object *shadow_batch_obj,
+ u32 batch_start_offset,
+- u32 batch_len,
+- bool is_master)
++ u32 batch_len)
+ {
+ u32 *cmd, *batch_end;
+ struct drm_i915_cmd_descriptor default_desc = noop_desc;
+@@ -1323,7 +1283,7 @@ int intel_engine_cmd_parser(struct intel
+ break;
+ }
+
+- if (!check_cmd(engine, desc, cmd, length, is_master)) {
++ if (!check_cmd(engine, desc, cmd, length)) {
+ ret = -EACCES;
+ break;
+ }
+--- a/drivers/gpu/drm/i915/i915_drv.h
++++ b/drivers/gpu/drm/i915/i915_drv.h
+@@ -2717,8 +2717,7 @@ int intel_engine_cmd_parser(struct intel
+ struct drm_i915_gem_object *batch_obj,
+ struct drm_i915_gem_object *shadow_batch_obj,
+ u32 batch_start_offset,
+- u32 batch_len,
+- bool is_master);
++ u32 batch_len);
+
+ /* i915_perf.c */
+ extern void i915_perf_init(struct drm_i915_private *dev_priv);
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:10:49 PM CET
+From: Jon Bloomfield <jon.bloomfield@intel.com>
+Date: Fri, 20 Apr 2018 14:26:01 -0700
+Subject: drm/i915: Rename gen7 cmdparser tables
+
+From: Jon Bloomfield <jon.bloomfield@intel.com>
+
+commit 0a2f661b6c21815a7fa60e30babe975fee8e73c6 upstream.
+
+We're about to introduce some new tables for later gens, and the
+current naming for the gen7 tables will no longer make sense.
+
+v2: rebase
+
+Signed-off-by: Jon Bloomfield <jon.bloomfield@intel.com>
+Cc: Tony Luck <tony.luck@intel.com>
+Cc: Dave Airlie <airlied@redhat.com>
+Cc: Takashi Iwai <tiwai@suse.de>
+Cc: Tyler Hicks <tyhicks@canonical.com>
+Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
+Reviewed-by: Chris Wilson <chris.p.wilson@intel.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/gpu/drm/i915/i915_cmd_parser.c | 70 ++++++++++++++++-----------------
+ 1 file changed, 35 insertions(+), 35 deletions(-)
+
+--- a/drivers/gpu/drm/i915/i915_cmd_parser.c
++++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
+@@ -212,7 +212,7 @@ struct drm_i915_cmd_table {
+
+ /* Command Mask Fixed Len Action
+ ---------------------------------------------------------- */
+-static const struct drm_i915_cmd_descriptor common_cmds[] = {
++static const struct drm_i915_cmd_descriptor gen7_common_cmds[] = {
+ CMD( MI_NOOP, SMI, F, 1, S ),
+ CMD( MI_USER_INTERRUPT, SMI, F, 1, R ),
+ CMD( MI_WAIT_FOR_EVENT, SMI, F, 1, M ),
+@@ -245,7 +245,7 @@ static const struct drm_i915_cmd_descrip
+ CMD( MI_BATCH_BUFFER_START, SMI, !F, 0xFF, S ),
+ };
+
+-static const struct drm_i915_cmd_descriptor render_cmds[] = {
++static const struct drm_i915_cmd_descriptor gen7_render_cmds[] = {
+ CMD( MI_FLUSH, SMI, F, 1, S ),
+ CMD( MI_ARB_ON_OFF, SMI, F, 1, R ),
+ CMD( MI_PREDICATE, SMI, F, 1, S ),
+@@ -329,7 +329,7 @@ static const struct drm_i915_cmd_descrip
+ CMD( GFX_OP_3DSTATE_BINDING_TABLE_EDIT_PS, S3D, !F, 0x1FF, S ),
+ };
+
+-static const struct drm_i915_cmd_descriptor video_cmds[] = {
++static const struct drm_i915_cmd_descriptor gen7_video_cmds[] = {
+ CMD( MI_ARB_ON_OFF, SMI, F, 1, R ),
+ CMD( MI_SET_APPID, SMI, F, 1, S ),
+ CMD( MI_STORE_DWORD_IMM, SMI, !F, 0xFF, B,
+@@ -373,7 +373,7 @@ static const struct drm_i915_cmd_descrip
+ CMD( MFX_WAIT, SMFX, F, 1, S ),
+ };
+
+-static const struct drm_i915_cmd_descriptor vecs_cmds[] = {
++static const struct drm_i915_cmd_descriptor gen7_vecs_cmds[] = {
+ CMD( MI_ARB_ON_OFF, SMI, F, 1, R ),
+ CMD( MI_SET_APPID, SMI, F, 1, S ),
+ CMD( MI_STORE_DWORD_IMM, SMI, !F, 0xFF, B,
+@@ -411,7 +411,7 @@ static const struct drm_i915_cmd_descrip
+ }}, ),
+ };
+
+-static const struct drm_i915_cmd_descriptor blt_cmds[] = {
++static const struct drm_i915_cmd_descriptor gen7_blt_cmds[] = {
+ CMD( MI_DISPLAY_FLIP, SMI, !F, 0xFF, R ),
+ CMD( MI_STORE_DWORD_IMM, SMI, !F, 0x3FF, B,
+ .bits = {{
+@@ -464,35 +464,35 @@ static const struct drm_i915_cmd_descrip
+ #undef B
+ #undef M
+
+-static const struct drm_i915_cmd_table gen7_render_cmds[] = {
+- { common_cmds, ARRAY_SIZE(common_cmds) },
+- { render_cmds, ARRAY_SIZE(render_cmds) },
++static const struct drm_i915_cmd_table gen7_render_cmd_table[] = {
++ { gen7_common_cmds, ARRAY_SIZE(gen7_common_cmds) },
++ { gen7_render_cmds, ARRAY_SIZE(gen7_render_cmds) },
+ };
+
+-static const struct drm_i915_cmd_table hsw_render_ring_cmds[] = {
+- { common_cmds, ARRAY_SIZE(common_cmds) },
+- { render_cmds, ARRAY_SIZE(render_cmds) },
++static const struct drm_i915_cmd_table hsw_render_ring_cmd_table[] = {
++ { gen7_common_cmds, ARRAY_SIZE(gen7_common_cmds) },
++ { gen7_render_cmds, ARRAY_SIZE(gen7_render_cmds) },
+ { hsw_render_cmds, ARRAY_SIZE(hsw_render_cmds) },
+ };
+
+-static const struct drm_i915_cmd_table gen7_video_cmds[] = {
+- { common_cmds, ARRAY_SIZE(common_cmds) },
+- { video_cmds, ARRAY_SIZE(video_cmds) },
++static const struct drm_i915_cmd_table gen7_video_cmd_table[] = {
++ { gen7_common_cmds, ARRAY_SIZE(gen7_common_cmds) },
++ { gen7_video_cmds, ARRAY_SIZE(gen7_video_cmds) },
+ };
+
+-static const struct drm_i915_cmd_table hsw_vebox_cmds[] = {
+- { common_cmds, ARRAY_SIZE(common_cmds) },
+- { vecs_cmds, ARRAY_SIZE(vecs_cmds) },
++static const struct drm_i915_cmd_table hsw_vebox_cmd_table[] = {
++ { gen7_common_cmds, ARRAY_SIZE(gen7_common_cmds) },
++ { gen7_vecs_cmds, ARRAY_SIZE(gen7_vecs_cmds) },
+ };
+
+-static const struct drm_i915_cmd_table gen7_blt_cmds[] = {
+- { common_cmds, ARRAY_SIZE(common_cmds) },
+- { blt_cmds, ARRAY_SIZE(blt_cmds) },
++static const struct drm_i915_cmd_table gen7_blt_cmd_table[] = {
++ { gen7_common_cmds, ARRAY_SIZE(gen7_common_cmds) },
++ { gen7_blt_cmds, ARRAY_SIZE(gen7_blt_cmds) },
+ };
+
+-static const struct drm_i915_cmd_table hsw_blt_ring_cmds[] = {
+- { common_cmds, ARRAY_SIZE(common_cmds) },
+- { blt_cmds, ARRAY_SIZE(blt_cmds) },
++static const struct drm_i915_cmd_table hsw_blt_ring_cmd_table[] = {
++ { gen7_common_cmds, ARRAY_SIZE(gen7_common_cmds) },
++ { gen7_blt_cmds, ARRAY_SIZE(gen7_blt_cmds) },
+ { hsw_blt_cmds, ARRAY_SIZE(hsw_blt_cmds) },
+ };
+
+@@ -872,12 +872,12 @@ void intel_engine_init_cmd_parser(struct
+ switch (engine->class) {
+ case RENDER_CLASS:
+ if (IS_HASWELL(engine->i915)) {
+- cmd_tables = hsw_render_ring_cmds;
++ cmd_tables = hsw_render_ring_cmd_table;
+ cmd_table_count =
+- ARRAY_SIZE(hsw_render_ring_cmds);
++ ARRAY_SIZE(hsw_render_ring_cmd_table);
+ } else {
+- cmd_tables = gen7_render_cmds;
+- cmd_table_count = ARRAY_SIZE(gen7_render_cmds);
++ cmd_tables = gen7_render_cmd_table;
++ cmd_table_count = ARRAY_SIZE(gen7_render_cmd_table);
+ }
+
+ if (IS_HASWELL(engine->i915)) {
+@@ -891,17 +891,17 @@ void intel_engine_init_cmd_parser(struct
+ engine->get_cmd_length_mask = gen7_render_get_cmd_length_mask;
+ break;
+ case VIDEO_DECODE_CLASS:
+- cmd_tables = gen7_video_cmds;
+- cmd_table_count = ARRAY_SIZE(gen7_video_cmds);
++ cmd_tables = gen7_video_cmd_table;
++ cmd_table_count = ARRAY_SIZE(gen7_video_cmd_table);
+ engine->get_cmd_length_mask = gen7_bsd_get_cmd_length_mask;
+ break;
+ case COPY_ENGINE_CLASS:
+ if (IS_HASWELL(engine->i915)) {
+- cmd_tables = hsw_blt_ring_cmds;
+- cmd_table_count = ARRAY_SIZE(hsw_blt_ring_cmds);
++ cmd_tables = hsw_blt_ring_cmd_table;
++ cmd_table_count = ARRAY_SIZE(hsw_blt_ring_cmd_table);
+ } else {
+- cmd_tables = gen7_blt_cmds;
+- cmd_table_count = ARRAY_SIZE(gen7_blt_cmds);
++ cmd_tables = gen7_blt_cmd_table;
++ cmd_table_count = ARRAY_SIZE(gen7_blt_cmd_table);
+ }
+
+ if (IS_HASWELL(engine->i915)) {
+@@ -915,8 +915,8 @@ void intel_engine_init_cmd_parser(struct
+ engine->get_cmd_length_mask = gen7_blt_get_cmd_length_mask;
+ break;
+ case VIDEO_ENHANCEMENT_CLASS:
+- cmd_tables = hsw_vebox_cmds;
+- cmd_table_count = ARRAY_SIZE(hsw_vebox_cmds);
++ cmd_tables = hsw_vebox_cmd_table;
++ cmd_table_count = ARRAY_SIZE(hsw_vebox_cmd_table);
+ /* VECS can use the same length_mask function as VCS */
+ engine->get_cmd_length_mask = gen7_bsd_get_cmd_length_mask;
+ break;
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:10:49 PM CET
+From: Jon Bloomfield <jon.bloomfield@intel.com>
+Date: Tue, 22 May 2018 13:59:06 -0700
+Subject: drm/i915: Support ro ppgtt mapped cmdparser shadow buffers
+
+From: Jon Bloomfield <jon.bloomfield@intel.com>
+
+commit 4f7af1948abcb18b4772fe1bcd84d7d27d96258c upstream.
+
+For Gen7, the original cmdparser motive was to permit limited
+use of register read/write instructions in unprivileged BB's.
+This worked by copying the user supplied bb to a kmd owned
+bb, and running it in secure mode, from the ggtt, only if
+the scanner finds no unsafe commands or registers.
+
+For Gen8+ we can't use this same technique because running bb's
+from the ggtt also disables access to ppgtt space. But we also
+do not actually require 'secure' execution since we are only
+trying to reduce the available command/register set. Instead we
+will copy the user buffer to a kmd owned read-only bb in ppgtt,
+and run in the usual non-secure mode.
+
+Note that ro pages are only supported by ppgtt (not ggtt), but
+luckily that's exactly what we need.
+
+Add the required paths to map the shadow buffer to ppgtt ro for Gen8+
+
+v2: IS_GEN7/IS_GEN (Mika)
+v3: rebase
+v4: rebase
+v5: rebase
+
+Signed-off-by: Jon Bloomfield <jon.bloomfield@intel.com>
+Cc: Tony Luck <tony.luck@intel.com>
+Cc: Dave Airlie <airlied@redhat.com>
+Cc: Takashi Iwai <tiwai@suse.de>
+Cc: Tyler Hicks <tyhicks@canonical.com>
+Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
+Reviewed-by: Chris Wilson <chris.p.wilson@intel.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 58 +++++++++++++++++--------
+ drivers/gpu/drm/i915/i915_drv.h | 14 ++++++
+ drivers/gpu/drm/i915/i915_gem.c | 16 ++++++
+ 3 files changed, 69 insertions(+), 19 deletions(-)
+
+--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
++++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+@@ -2010,6 +2010,34 @@ static int i915_reset_gen7_sol_offsets(s
+ return 0;
+ }
+
++static struct i915_vma *
++shadow_batch_pin(struct i915_execbuffer *eb, struct drm_i915_gem_object *obj)
++{
++ struct drm_i915_private *dev_priv = eb->i915;
++ struct i915_vma * const vma = *eb->vma;
++ struct i915_address_space *vm;
++ u64 flags;
++
++ /*
++ * PPGTT backed shadow buffers must be mapped RO, to prevent
++ * post-scan tampering
++ */
++ if (CMDPARSER_USES_GGTT(dev_priv)) {
++ flags = PIN_GLOBAL;
++ vm = &dev_priv->ggtt.vm;
++ eb->batch_flags |= I915_DISPATCH_SECURE;
++ } else if (vma->vm->has_read_only) {
++ flags = PIN_USER;
++ vm = vma->vm;
++ i915_gem_object_set_readonly(obj);
++ } else {
++ DRM_DEBUG("Cannot prevent post-scan tampering without RO capable vm\n");
++ return ERR_PTR(-EINVAL);
++ }
++
++ return i915_gem_object_pin(obj, vm, NULL, 0, 0, flags);
++}
++
+ static struct i915_vma *eb_parse(struct i915_execbuffer *eb)
+ {
+ struct drm_i915_gem_object *shadow_batch_obj;
+@@ -2027,14 +2055,21 @@ static struct i915_vma *eb_parse(struct
+ eb->batch_start_offset,
+ eb->batch_len);
+ if (err) {
+- if (err == -EACCES) /* unhandled chained batch */
++ /*
++ * Unsafe GGTT-backed buffers can still be submitted safely
++ * as non-secure.
++ * For PPGTT backing however, we have no choice but to forcibly
++ * reject unsafe buffers
++ */
++ if (CMDPARSER_USES_GGTT(eb->i915) && (err == -EACCES))
++ /* Execute original buffer non-secure */
+ vma = NULL;
+ else
+ vma = ERR_PTR(err);
+ goto out;
+ }
+
+- vma = i915_gem_object_ggtt_pin(shadow_batch_obj, NULL, 0, 0, 0);
++ vma = shadow_batch_pin(eb, shadow_batch_obj);
+ if (IS_ERR(vma))
+ goto out;
+
+@@ -2043,7 +2078,9 @@ static struct i915_vma *eb_parse(struct
+ __EXEC_OBJECT_HAS_PIN | __EXEC_OBJECT_HAS_REF;
+ vma->exec_flags = &eb->flags[eb->buffer_count];
+ eb->buffer_count++;
+-
++ eb->batch_start_offset = 0;
++ eb->batch = vma;
++ /* eb->batch_len unchanged */
+ out:
+ i915_gem_object_unpin_pages(shadow_batch_obj);
+ return vma;
+@@ -2489,21 +2526,6 @@ i915_gem_do_execbuffer(struct drm_device
+ err = PTR_ERR(vma);
+ goto err_vma;
+ }
+-
+- if (vma) {
+- /*
+- * Batch parsed and accepted:
+- *
+- * Set the DISPATCH_SECURE bit to remove the NON_SECURE
+- * bit from MI_BATCH_BUFFER_START commands issued in
+- * the dispatch_execbuffer implementations. We
+- * specifically don't want that set on batches the
+- * command parser has accepted.
+- */
+- eb.batch_flags |= I915_DISPATCH_SECURE;
+- eb.batch_start_offset = 0;
+- eb.batch = vma;
+- }
+ }
+
+ if (eb.batch_len == 0)
+--- a/drivers/gpu/drm/i915/i915_drv.h
++++ b/drivers/gpu/drm/i915/i915_drv.h
+@@ -2246,6 +2246,12 @@ IS_SUBPLATFORM(const struct drm_i915_pri
+ #define VEBOX_MASK(dev_priv) \
+ ENGINE_INSTANCES_MASK(dev_priv, VECS0, I915_MAX_VECS)
+
++/*
++ * The Gen7 cmdparser copies the scanned buffer to the ggtt for execution
++ * All later gens can run the final buffer from the ppgtt
++ */
++#define CMDPARSER_USES_GGTT(dev_priv) IS_GEN(dev_priv, 7)
++
+ #define HAS_LLC(dev_priv) (INTEL_INFO(dev_priv)->has_llc)
+ #define HAS_SNOOP(dev_priv) (INTEL_INFO(dev_priv)->has_snoop)
+ #define HAS_EDRAM(dev_priv) ((dev_priv)->edram_size_mb)
+@@ -2529,6 +2535,14 @@ i915_gem_object_ggtt_pin(struct drm_i915
+
+ int i915_gem_object_unbind(struct drm_i915_gem_object *obj);
+
++struct i915_vma * __must_check
++i915_gem_object_pin(struct drm_i915_gem_object *obj,
++ struct i915_address_space *vm,
++ const struct i915_ggtt_view *view,
++ u64 size,
++ u64 alignment,
++ u64 flags);
++
+ void i915_gem_runtime_suspend(struct drm_i915_private *dev_priv);
+
+ static inline int __must_check
+--- a/drivers/gpu/drm/i915/i915_gem.c
++++ b/drivers/gpu/drm/i915/i915_gem.c
+@@ -1025,6 +1025,20 @@ i915_gem_object_ggtt_pin(struct drm_i915
+ {
+ struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
+ struct i915_address_space *vm = &dev_priv->ggtt.vm;
++
++ return i915_gem_object_pin(obj, vm, view, size, alignment,
++ flags | PIN_GLOBAL);
++}
++
++struct i915_vma *
++i915_gem_object_pin(struct drm_i915_gem_object *obj,
++ struct i915_address_space *vm,
++ const struct i915_ggtt_view *view,
++ u64 size,
++ u64 alignment,
++ u64 flags)
++{
++ struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
+ struct i915_vma *vma;
+ int ret;
+
+@@ -1091,7 +1105,7 @@ i915_gem_object_ggtt_pin(struct drm_i915
+ return ERR_PTR(ret);
+ }
+
+- ret = i915_vma_pin(vma, size, alignment, flags | PIN_GLOBAL);
++ ret = i915_vma_pin(vma, size, alignment, flags);
+ if (ret)
+ return ERR_PTR(ret);
+
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:11:45 PM CET
+From: Junaid Shahid <junaids@google.com>
+Date: Fri, 1 Nov 2019 00:14:08 +0100
+Subject: kvm: Add helper function for creating VM worker threads
+
+From: Junaid Shahid <junaids@google.com>
+
+commit c57c80467f90e5504c8df9ad3555d2c78800bf94 upstream.
+
+Add a function to create a kernel thread associated with a given VM. In
+particular, it ensures that the worker thread inherits the priority and
+cgroups of the calling thread.
+
+Signed-off-by: Junaid Shahid <junaids@google.com>
+Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ include/linux/kvm_host.h | 6 +++
+ virt/kvm/kvm_main.c | 84 +++++++++++++++++++++++++++++++++++++++++++++++
+ 2 files changed, 90 insertions(+)
+
+--- a/include/linux/kvm_host.h
++++ b/include/linux/kvm_host.h
+@@ -1382,4 +1382,10 @@ static inline int kvm_arch_vcpu_run_pid_
+ }
+ #endif /* CONFIG_HAVE_KVM_VCPU_RUN_PID_CHANGE */
+
++typedef int (*kvm_vm_thread_fn_t)(struct kvm *kvm, uintptr_t data);
++
++int kvm_vm_create_worker_thread(struct kvm *kvm, kvm_vm_thread_fn_t thread_fn,
++ uintptr_t data, const char *name,
++ struct task_struct **thread_ptr);
++
+ #endif
+--- a/virt/kvm/kvm_main.c
++++ b/virt/kvm/kvm_main.c
+@@ -50,6 +50,7 @@
+ #include <linux/bsearch.h>
+ #include <linux/io.h>
+ #include <linux/lockdep.h>
++#include <linux/kthread.h>
+
+ #include <asm/processor.h>
+ #include <asm/ioctl.h>
+@@ -4365,3 +4366,86 @@ void kvm_exit(void)
+ kvm_vfio_ops_exit();
+ }
+ EXPORT_SYMBOL_GPL(kvm_exit);
++
++struct kvm_vm_worker_thread_context {
++ struct kvm *kvm;
++ struct task_struct *parent;
++ struct completion init_done;
++ kvm_vm_thread_fn_t thread_fn;
++ uintptr_t data;
++ int err;
++};
++
++static int kvm_vm_worker_thread(void *context)
++{
++ /*
++ * The init_context is allocated on the stack of the parent thread, so
++ * we have to locally copy anything that is needed beyond initialization
++ */
++ struct kvm_vm_worker_thread_context *init_context = context;
++ struct kvm *kvm = init_context->kvm;
++ kvm_vm_thread_fn_t thread_fn = init_context->thread_fn;
++ uintptr_t data = init_context->data;
++ int err;
++
++ err = kthread_park(current);
++ /* kthread_park(current) is never supposed to return an error */
++ WARN_ON(err != 0);
++ if (err)
++ goto init_complete;
++
++ err = cgroup_attach_task_all(init_context->parent, current);
++ if (err) {
++ kvm_err("%s: cgroup_attach_task_all failed with err %d\n",
++ __func__, err);
++ goto init_complete;
++ }
++
++ set_user_nice(current, task_nice(init_context->parent));
++
++init_complete:
++ init_context->err = err;
++ complete(&init_context->init_done);
++ init_context = NULL;
++
++ if (err)
++ return err;
++
++ /* Wait to be woken up by the spawner before proceeding. */
++ kthread_parkme();
++
++ if (!kthread_should_stop())
++ err = thread_fn(kvm, data);
++
++ return err;
++}
++
++int kvm_vm_create_worker_thread(struct kvm *kvm, kvm_vm_thread_fn_t thread_fn,
++ uintptr_t data, const char *name,
++ struct task_struct **thread_ptr)
++{
++ struct kvm_vm_worker_thread_context init_context = {};
++ struct task_struct *thread;
++
++ *thread_ptr = NULL;
++ init_context.kvm = kvm;
++ init_context.parent = current;
++ init_context.thread_fn = thread_fn;
++ init_context.data = data;
++ init_completion(&init_context.init_done);
++
++ thread = kthread_run(kvm_vm_worker_thread, &init_context,
++ "%s-%d", name, task_pid_nr(current));
++ if (IS_ERR(thread))
++ return PTR_ERR(thread);
++
++ /* kthread_run is never supposed to return NULL */
++ WARN_ON(thread == NULL);
++
++ wait_for_completion(&init_context.init_done);
++
++ if (!init_context.err)
++ *thread_ptr = thread;
++
++ return init_context.err;
++}
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:11:45 PM CET
+From: Paolo Bonzini <pbonzini@redhat.com>
+Date: Mon, 4 Nov 2019 12:22:02 +0100
+Subject: kvm: mmu: ITLB_MULTIHIT mitigation
+
+From: Paolo Bonzini <pbonzini@redhat.com>
+
+commit b8e8c8303ff28c61046a4d0f6ea99aea609a7dc0 upstream.
+
+With some Intel processors, putting the same virtual address in the TLB
+as both a 4 KiB and 2 MiB page can confuse the instruction fetch unit
+and cause the processor to issue a machine check resulting in a CPU lockup.
+
+Unfortunately when EPT page tables use huge pages, it is possible for a
+malicious guest to cause this situation.
+
+Add a knob to mark huge pages as non-executable. When the nx_huge_pages
+parameter is enabled (and we are using EPT), all huge pages are marked as
+NX. If the guest attempts to execute in one of those pages, the page is
+broken down into 4K pages, which are then marked executable.
+
+This is not an issue for shadow paging (except nested EPT), because then
+the host is in control of TLB flushes and the problematic situation cannot
+happen. With nested EPT, again the nested guest can cause problems shadow
+and direct EPT is treated in the same way.
+
+[ tglx: Fixup default to auto and massage wording a bit ]
+
+Originally-by: Junaid Shahid <junaids@google.com>
+Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ Documentation/admin-guide/kernel-parameters.txt | 19 +++
+ arch/x86/include/asm/kvm_host.h | 2
+ arch/x86/kernel/cpu/bugs.c | 13 ++
+ arch/x86/kvm/mmu.c | 141 ++++++++++++++++++++++--
+ arch/x86/kvm/paging_tmpl.h | 29 +++-
+ arch/x86/kvm/x86.c | 9 +
+ 6 files changed, 200 insertions(+), 13 deletions(-)
+
+--- a/Documentation/admin-guide/kernel-parameters.txt
++++ b/Documentation/admin-guide/kernel-parameters.txt
+@@ -2040,6 +2040,19 @@
+ KVM MMU at runtime.
+ Default is 0 (off)
+
++ kvm.nx_huge_pages=
++ [KVM] Controls the software workaround for the
++ X86_BUG_ITLB_MULTIHIT bug.
++ force : Always deploy workaround.
++ off : Never deploy workaround.
++ auto : Deploy workaround based on the presence of
++ X86_BUG_ITLB_MULTIHIT.
++
++ Default is 'auto'.
++
++ If the software workaround is enabled for the host,
++ guests do need not to enable it for nested guests.
++
+ kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM.
+ Default is 1 (enabled)
+
+@@ -2613,6 +2626,12 @@
+ l1tf=off [X86]
+ mds=off [X86]
+ tsx_async_abort=off [X86]
++ kvm.nx_huge_pages=off [X86]
++
++ Exceptions:
++ This does not have any effect on
++ kvm.nx_huge_pages when
++ kvm.nx_huge_pages=force.
+
+ auto (default)
+ Mitigate all CPU vulnerabilities, but leave SMT
+--- a/arch/x86/include/asm/kvm_host.h
++++ b/arch/x86/include/asm/kvm_host.h
+@@ -321,6 +321,7 @@ struct kvm_mmu_page {
+ struct hlist_node hash_link;
+ bool unsync;
+ bool mmio_cached;
++ bool lpage_disallowed; /* Can't be replaced by an equiv large page */
+
+ /*
+ * The following two entries are used to key the shadow page in the
+@@ -950,6 +951,7 @@ struct kvm_vm_stat {
+ ulong mmu_unsync;
+ ulong remote_tlb_flush;
+ ulong lpages;
++ ulong nx_lpage_splits;
+ ulong max_mmu_page_hash_collisions;
+ };
+
+--- a/arch/x86/kernel/cpu/bugs.c
++++ b/arch/x86/kernel/cpu/bugs.c
+@@ -1253,6 +1253,9 @@ void x86_spec_ctrl_setup_ap(void)
+ x86_amd_ssb_disable();
+ }
+
++bool itlb_multihit_kvm_mitigation;
++EXPORT_SYMBOL_GPL(itlb_multihit_kvm_mitigation);
++
+ #undef pr_fmt
+ #define pr_fmt(fmt) "L1TF: " fmt
+
+@@ -1408,17 +1411,25 @@ static ssize_t l1tf_show_state(char *buf
+ l1tf_vmx_states[l1tf_vmx_mitigation],
+ sched_smt_active() ? "vulnerable" : "disabled");
+ }
++
++static ssize_t itlb_multihit_show_state(char *buf)
++{
++ if (itlb_multihit_kvm_mitigation)
++ return sprintf(buf, "KVM: Mitigation: Split huge pages\n");
++ else
++ return sprintf(buf, "KVM: Vulnerable\n");
++}
+ #else
+ static ssize_t l1tf_show_state(char *buf)
+ {
+ return sprintf(buf, "%s\n", L1TF_DEFAULT_MSG);
+ }
+-#endif
+
+ static ssize_t itlb_multihit_show_state(char *buf)
+ {
+ return sprintf(buf, "Processor vulnerable\n");
+ }
++#endif
+
+ static ssize_t mds_show_state(char *buf)
+ {
+--- a/arch/x86/kvm/mmu.c
++++ b/arch/x86/kvm/mmu.c
+@@ -47,6 +47,20 @@
+ #include <asm/kvm_page_track.h>
+ #include "trace.h"
+
++extern bool itlb_multihit_kvm_mitigation;
++
++static int __read_mostly nx_huge_pages = -1;
++
++static int set_nx_huge_pages(const char *val, const struct kernel_param *kp);
++
++static struct kernel_param_ops nx_huge_pages_ops = {
++ .set = set_nx_huge_pages,
++ .get = param_get_bool,
++};
++
++module_param_cb(nx_huge_pages, &nx_huge_pages_ops, &nx_huge_pages, 0644);
++__MODULE_PARM_TYPE(nx_huge_pages, "bool");
++
+ /*
+ * When setting this variable to true it enables Two-Dimensional-Paging
+ * where the hardware walks 2 page tables:
+@@ -318,6 +332,11 @@ static inline bool spte_ad_enabled(u64 s
+ return !(spte & shadow_acc_track_value);
+ }
+
++static bool is_nx_huge_page_enabled(void)
++{
++ return READ_ONCE(nx_huge_pages);
++}
++
+ static inline u64 spte_shadow_accessed_mask(u64 spte)
+ {
+ MMU_WARN_ON((spte & shadow_mmio_mask) == shadow_mmio_value);
+@@ -1162,6 +1181,15 @@ static void account_shadowed(struct kvm
+ kvm_mmu_gfn_disallow_lpage(slot, gfn);
+ }
+
++static void account_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp)
++{
++ if (sp->lpage_disallowed)
++ return;
++
++ ++kvm->stat.nx_lpage_splits;
++ sp->lpage_disallowed = true;
++}
++
+ static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp)
+ {
+ struct kvm_memslots *slots;
+@@ -1179,6 +1207,12 @@ static void unaccount_shadowed(struct kv
+ kvm_mmu_gfn_allow_lpage(slot, gfn);
+ }
+
++static void unaccount_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp)
++{
++ --kvm->stat.nx_lpage_splits;
++ sp->lpage_disallowed = false;
++}
++
+ static bool __mmu_gfn_lpage_is_disallowed(gfn_t gfn, int level,
+ struct kvm_memory_slot *slot)
+ {
+@@ -2753,6 +2787,9 @@ static bool __kvm_mmu_prepare_zap_page(s
+ kvm_reload_remote_mmus(kvm);
+ }
+
++ if (sp->lpage_disallowed)
++ unaccount_huge_nx_page(kvm, sp);
++
+ sp->role.invalid = 1;
+ return list_unstable;
+ }
+@@ -2972,6 +3009,11 @@ static int set_spte(struct kvm_vcpu *vcp
+ if (!speculative)
+ spte |= spte_shadow_accessed_mask(spte);
+
++ if (level > PT_PAGE_TABLE_LEVEL && (pte_access & ACC_EXEC_MASK) &&
++ is_nx_huge_page_enabled()) {
++ pte_access &= ~ACC_EXEC_MASK;
++ }
++
+ if (pte_access & ACC_EXEC_MASK)
+ spte |= shadow_x_mask;
+ else
+@@ -3192,9 +3234,32 @@ static void direct_pte_prefetch(struct k
+ __direct_pte_prefetch(vcpu, sp, sptep);
+ }
+
++static void disallowed_hugepage_adjust(struct kvm_shadow_walk_iterator it,
++ gfn_t gfn, kvm_pfn_t *pfnp, int *levelp)
++{
++ int level = *levelp;
++ u64 spte = *it.sptep;
++
++ if (it.level == level && level > PT_PAGE_TABLE_LEVEL &&
++ is_nx_huge_page_enabled() &&
++ is_shadow_present_pte(spte) &&
++ !is_large_pte(spte)) {
++ /*
++ * A small SPTE exists for this pfn, but FNAME(fetch)
++ * and __direct_map would like to create a large PTE
++ * instead: just force them to go down another level,
++ * patching back for them into pfn the next 9 bits of
++ * the address.
++ */
++ u64 page_mask = KVM_PAGES_PER_HPAGE(level) - KVM_PAGES_PER_HPAGE(level - 1);
++ *pfnp |= gfn & page_mask;
++ (*levelp)--;
++ }
++}
++
+ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t gpa, int write,
+ int map_writable, int level, kvm_pfn_t pfn,
+- bool prefault)
++ bool prefault, bool lpage_disallowed)
+ {
+ struct kvm_shadow_walk_iterator it;
+ struct kvm_mmu_page *sp;
+@@ -3207,6 +3272,12 @@ static int __direct_map(struct kvm_vcpu
+
+ trace_kvm_mmu_spte_requested(gpa, level, pfn);
+ for_each_shadow_entry(vcpu, gpa, it) {
++ /*
++ * We cannot overwrite existing page tables with an NX
++ * large page, as the leaf could be executable.
++ */
++ disallowed_hugepage_adjust(it, gfn, &pfn, &level);
++
+ base_gfn = gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);
+ if (it.level == level)
+ break;
+@@ -3217,6 +3288,8 @@ static int __direct_map(struct kvm_vcpu
+ it.level - 1, true, ACC_ALL);
+
+ link_shadow_page(vcpu, it.sptep, sp);
++ if (lpage_disallowed)
++ account_huge_nx_page(vcpu->kvm, sp);
+ }
+ }
+
+@@ -3508,11 +3581,14 @@ static int nonpaging_map(struct kvm_vcpu
+ {
+ int r;
+ int level;
+- bool force_pt_level = false;
++ bool force_pt_level;
+ kvm_pfn_t pfn;
+ unsigned long mmu_seq;
+ bool map_writable, write = error_code & PFERR_WRITE_MASK;
++ bool lpage_disallowed = (error_code & PFERR_FETCH_MASK) &&
++ is_nx_huge_page_enabled();
+
++ force_pt_level = lpage_disallowed;
+ level = mapping_level(vcpu, gfn, &force_pt_level);
+ if (likely(!force_pt_level)) {
+ /*
+@@ -3546,7 +3622,8 @@ static int nonpaging_map(struct kvm_vcpu
+ goto out_unlock;
+ if (likely(!force_pt_level))
+ transparent_hugepage_adjust(vcpu, gfn, &pfn, &level);
+- r = __direct_map(vcpu, v, write, map_writable, level, pfn, prefault);
++ r = __direct_map(vcpu, v, write, map_writable, level, pfn,
++ prefault, false);
+ out_unlock:
+ spin_unlock(&vcpu->kvm->mmu_lock);
+ kvm_release_pfn_clean(pfn);
+@@ -4132,6 +4209,8 @@ static int tdp_page_fault(struct kvm_vcp
+ unsigned long mmu_seq;
+ int write = error_code & PFERR_WRITE_MASK;
+ bool map_writable;
++ bool lpage_disallowed = (error_code & PFERR_FETCH_MASK) &&
++ is_nx_huge_page_enabled();
+
+ MMU_WARN_ON(!VALID_PAGE(vcpu->arch.mmu->root_hpa));
+
+@@ -4142,8 +4221,9 @@ static int tdp_page_fault(struct kvm_vcp
+ if (r)
+ return r;
+
+- force_pt_level = !check_hugepage_cache_consistency(vcpu, gfn,
+- PT_DIRECTORY_LEVEL);
++ force_pt_level =
++ lpage_disallowed ||
++ !check_hugepage_cache_consistency(vcpu, gfn, PT_DIRECTORY_LEVEL);
+ level = mapping_level(vcpu, gfn, &force_pt_level);
+ if (likely(!force_pt_level)) {
+ if (level > PT_DIRECTORY_LEVEL &&
+@@ -4172,7 +4252,8 @@ static int tdp_page_fault(struct kvm_vcp
+ goto out_unlock;
+ if (likely(!force_pt_level))
+ transparent_hugepage_adjust(vcpu, gfn, &pfn, &level);
+- r = __direct_map(vcpu, gpa, write, map_writable, level, pfn, prefault);
++ r = __direct_map(vcpu, gpa, write, map_writable, level, pfn,
++ prefault, lpage_disallowed);
+ out_unlock:
+ spin_unlock(&vcpu->kvm->mmu_lock);
+ kvm_release_pfn_clean(pfn);
+@@ -6099,10 +6180,58 @@ static void kvm_set_mmio_spte_mask(void)
+ kvm_mmu_set_mmio_spte_mask(mask, mask);
+ }
+
++static bool get_nx_auto_mode(void)
++{
++ /* Return true when CPU has the bug, and mitigations are ON */
++ return boot_cpu_has_bug(X86_BUG_ITLB_MULTIHIT) && !cpu_mitigations_off();
++}
++
++static void __set_nx_huge_pages(bool val)
++{
++ nx_huge_pages = itlb_multihit_kvm_mitigation = val;
++}
++
++static int set_nx_huge_pages(const char *val, const struct kernel_param *kp)
++{
++ bool old_val = nx_huge_pages;
++ bool new_val;
++
++ /* In "auto" mode deploy workaround only if CPU has the bug. */
++ if (sysfs_streq(val, "off"))
++ new_val = 0;
++ else if (sysfs_streq(val, "force"))
++ new_val = 1;
++ else if (sysfs_streq(val, "auto"))
++ new_val = get_nx_auto_mode();
++ else if (strtobool(val, &new_val) < 0)
++ return -EINVAL;
++
++ __set_nx_huge_pages(new_val);
++
++ if (new_val != old_val) {
++ struct kvm *kvm;
++ int idx;
++
++ mutex_lock(&kvm_lock);
++
++ list_for_each_entry(kvm, &vm_list, vm_list) {
++ idx = srcu_read_lock(&kvm->srcu);
++ kvm_mmu_zap_all_fast(kvm);
++ srcu_read_unlock(&kvm->srcu, idx);
++ }
++ mutex_unlock(&kvm_lock);
++ }
++
++ return 0;
++}
++
+ int kvm_mmu_module_init(void)
+ {
+ int ret = -ENOMEM;
+
++ if (nx_huge_pages == -1)
++ __set_nx_huge_pages(get_nx_auto_mode());
++
+ /*
+ * MMU roles use union aliasing which is, generally speaking, an
+ * undefined behavior. However, we supposedly know how compilers behave
+--- a/arch/x86/kvm/paging_tmpl.h
++++ b/arch/x86/kvm/paging_tmpl.h
+@@ -614,13 +614,14 @@ static void FNAME(pte_prefetch)(struct k
+ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
+ struct guest_walker *gw,
+ int write_fault, int hlevel,
+- kvm_pfn_t pfn, bool map_writable, bool prefault)
++ kvm_pfn_t pfn, bool map_writable, bool prefault,
++ bool lpage_disallowed)
+ {
+ struct kvm_mmu_page *sp = NULL;
+ struct kvm_shadow_walk_iterator it;
+ unsigned direct_access, access = gw->pt_access;
+ int top_level, ret;
+- gfn_t base_gfn;
++ gfn_t gfn, base_gfn;
+
+ direct_access = gw->pte_access;
+
+@@ -665,13 +666,25 @@ static int FNAME(fetch)(struct kvm_vcpu
+ link_shadow_page(vcpu, it.sptep, sp);
+ }
+
+- base_gfn = gw->gfn;
++ /*
++ * FNAME(page_fault) might have clobbered the bottom bits of
++ * gw->gfn, restore them from the virtual address.
++ */
++ gfn = gw->gfn | ((addr & PT_LVL_OFFSET_MASK(gw->level)) >> PAGE_SHIFT);
++ base_gfn = gfn;
+
+ trace_kvm_mmu_spte_requested(addr, gw->level, pfn);
+
+ for (; shadow_walk_okay(&it); shadow_walk_next(&it)) {
+ clear_sp_write_flooding_count(it.sptep);
+- base_gfn = gw->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);
++
++ /*
++ * We cannot overwrite existing page tables with an NX
++ * large page, as the leaf could be executable.
++ */
++ disallowed_hugepage_adjust(it, gfn, &pfn, &hlevel);
++
++ base_gfn = gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);
+ if (it.level == hlevel)
+ break;
+
+@@ -683,6 +696,8 @@ static int FNAME(fetch)(struct kvm_vcpu
+ sp = kvm_mmu_get_page(vcpu, base_gfn, addr,
+ it.level - 1, true, direct_access);
+ link_shadow_page(vcpu, it.sptep, sp);
++ if (lpage_disallowed)
++ account_huge_nx_page(vcpu->kvm, sp);
+ }
+ }
+
+@@ -759,9 +774,11 @@ static int FNAME(page_fault)(struct kvm_
+ int r;
+ kvm_pfn_t pfn;
+ int level = PT_PAGE_TABLE_LEVEL;
+- bool force_pt_level = false;
+ unsigned long mmu_seq;
+ bool map_writable, is_self_change_mapping;
++ bool lpage_disallowed = (error_code & PFERR_FETCH_MASK) &&
++ is_nx_huge_page_enabled();
++ bool force_pt_level = lpage_disallowed;
+
+ pgprintk("%s: addr %lx err %x\n", __func__, addr, error_code);
+
+@@ -851,7 +868,7 @@ static int FNAME(page_fault)(struct kvm_
+ if (!force_pt_level)
+ transparent_hugepage_adjust(vcpu, walker.gfn, &pfn, &level);
+ r = FNAME(fetch)(vcpu, addr, &walker, write_fault,
+- level, pfn, map_writable, prefault);
++ level, pfn, map_writable, prefault, lpage_disallowed);
+ kvm_mmu_audit(vcpu, AUDIT_POST_PAGE_FAULT);
+
+ out_unlock:
+--- a/arch/x86/kvm/x86.c
++++ b/arch/x86/kvm/x86.c
+@@ -213,6 +213,7 @@ struct kvm_stats_debugfs_item debugfs_en
+ { "mmu_unsync", VM_STAT(mmu_unsync) },
+ { "remote_tlb_flush", VM_STAT(remote_tlb_flush) },
+ { "largepages", VM_STAT(lpages, .mode = 0444) },
++ { "nx_largepages_splitted", VM_STAT(nx_lpage_splits, .mode = 0444) },
+ { "max_mmu_page_hash_collisions",
+ VM_STAT(max_mmu_page_hash_collisions) },
+ { NULL }
+@@ -1256,6 +1257,14 @@ static u64 kvm_get_arch_capabilities(voi
+ rdmsrl(MSR_IA32_ARCH_CAPABILITIES, data);
+
+ /*
++ * If nx_huge_pages is enabled, KVM's shadow paging will ensure that
++ * the nested hypervisor runs with NX huge pages. If it is not,
++ * L1 is anyway vulnerable to ITLB_MULTIHIT explots from other
++ * L1 guests, so it need not worry about its own (L2) guests.
++ */
++ data |= ARCH_CAP_PSCHANGE_MC_NO;
++
++ /*
+ * If we're doing cache flushes (either "always" or "cond")
+ * we will do one whenever the guest does a vmlaunch/vmresume.
+ * If an outer hypervisor is doing the cache flush for us
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:11:45 PM CET
+From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+Date: Wed, 23 Oct 2019 12:23:33 +0200
+Subject: kvm/x86: Export MDS_NO=0 to guests when TSX is enabled
+
+From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+
+commit e1d38b63acd843cfdd4222bf19a26700fd5c699e upstream.
+
+Export the IA32_ARCH_CAPABILITIES MSR bit MDS_NO=0 to guests on TSX
+Async Abort(TAA) affected hosts that have TSX enabled and updated
+microcode. This is required so that the guests don't complain,
+
+ "Vulnerable: Clear CPU buffers attempted, no microcode"
+
+when the host has the updated microcode to clear CPU buffers.
+
+Microcode update also adds support for MSR_IA32_TSX_CTRL which is
+enumerated by the ARCH_CAP_TSX_CTRL bit in IA32_ARCH_CAPABILITIES MSR.
+Guests can't do this check themselves when the ARCH_CAP_TSX_CTRL bit is
+not exported to the guests.
+
+In this case export MDS_NO=0 to the guests. When guests have
+CPUID.MD_CLEAR=1, they deploy MDS mitigation which also mitigates TAA.
+
+Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+Signed-off-by: Borislav Petkov <bp@suse.de>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Tested-by: Neelima Krishnan <neelima.krishnan@intel.com>
+Reviewed-by: Tony Luck <tony.luck@intel.com>
+Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/x86/kvm/x86.c | 19 +++++++++++++++++++
+ 1 file changed, 19 insertions(+)
+
+--- a/arch/x86/kvm/x86.c
++++ b/arch/x86/kvm/x86.c
+@@ -1267,6 +1267,25 @@ static u64 kvm_get_arch_capabilities(voi
+ if (l1tf_vmx_mitigation != VMENTER_L1D_FLUSH_NEVER)
+ data |= ARCH_CAP_SKIP_VMENTRY_L1DFLUSH;
+
++ /*
++ * On TAA affected systems, export MDS_NO=0 when:
++ * - TSX is enabled on the host, i.e. X86_FEATURE_RTM=1.
++ * - Updated microcode is present. This is detected by
++ * the presence of ARCH_CAP_TSX_CTRL_MSR and ensures
++ * that VERW clears CPU buffers.
++ *
++ * When MDS_NO=0 is exported, guests deploy clear CPU buffer
++ * mitigation and don't complain:
++ *
++ * "Vulnerable: Clear CPU buffers attempted, no microcode"
++ *
++ * If TSX is disabled on the system, guests are also mitigated against
++ * TAA and clear CPU buffer mitigation is not required for guests.
++ */
++ if (boot_cpu_has_bug(X86_BUG_TAA) && boot_cpu_has(X86_FEATURE_RTM) &&
++ (data & ARCH_CAP_TSX_CTRL_MSR))
++ data &= ~ARCH_CAP_MDS_NO;
++
+ return data;
+ }
+
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:11:45 PM CET
+From: Junaid Shahid <junaids@google.com>
+Date: Fri, 1 Nov 2019 00:14:14 +0100
+Subject: kvm: x86: mmu: Recovery of shattered NX large pages
+
+From: Junaid Shahid <junaids@google.com>
+
+commit 1aa9b9572b10529c2e64e2b8f44025d86e124308 upstream.
+
+The page table pages corresponding to broken down large pages are zapped in
+FIFO order, so that the large page can potentially be recovered, if it is
+not longer being used for execution. This removes the performance penalty
+for walking deeper EPT page tables.
+
+By default, one large page will last about one hour once the guest
+reaches a steady state.
+
+Signed-off-by: Junaid Shahid <junaids@google.com>
+Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ Documentation/admin-guide/kernel-parameters.txt | 6 +
+ arch/x86/include/asm/kvm_host.h | 4
+ arch/x86/kvm/mmu.c | 129 ++++++++++++++++++++++++
+ arch/x86/kvm/mmu.h | 4
+ arch/x86/kvm/x86.c | 11 ++
+ virt/kvm/kvm_main.c | 30 +++++
+ 6 files changed, 183 insertions(+), 1 deletion(-)
+
+--- a/Documentation/admin-guide/kernel-parameters.txt
++++ b/Documentation/admin-guide/kernel-parameters.txt
+@@ -2053,6 +2053,12 @@
+ If the software workaround is enabled for the host,
+ guests do need not to enable it for nested guests.
+
++ kvm.nx_huge_pages_recovery_ratio=
++ [KVM] Controls how many 4KiB pages are periodically zapped
++ back to huge pages. 0 disables the recovery, otherwise if
++ the value is N KVM will zap 1/Nth of the 4KiB pages every
++ minute. The default is 60.
++
+ kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM.
+ Default is 1 (enabled)
+
+--- a/arch/x86/include/asm/kvm_host.h
++++ b/arch/x86/include/asm/kvm_host.h
+@@ -319,6 +319,8 @@ struct kvm_rmap_head {
+ struct kvm_mmu_page {
+ struct list_head link;
+ struct hlist_node hash_link;
++ struct list_head lpage_disallowed_link;
++
+ bool unsync;
+ bool mmio_cached;
+ bool lpage_disallowed; /* Can't be replaced by an equiv large page */
+@@ -864,6 +866,7 @@ struct kvm_arch {
+ * Hash table of struct kvm_mmu_page.
+ */
+ struct list_head active_mmu_pages;
++ struct list_head lpage_disallowed_mmu_pages;
+ struct kvm_page_track_notifier_node mmu_sp_tracker;
+ struct kvm_page_track_notifier_head track_notifier_head;
+
+@@ -938,6 +941,7 @@ struct kvm_arch {
+ bool exception_payload_enabled;
+
+ struct kvm_pmu_event_filter *pmu_event_filter;
++ struct task_struct *nx_lpage_recovery_thread;
+ };
+
+ struct kvm_vm_stat {
+--- a/arch/x86/kvm/mmu.c
++++ b/arch/x86/kvm/mmu.c
+@@ -37,6 +37,7 @@
+ #include <linux/uaccess.h>
+ #include <linux/hash.h>
+ #include <linux/kern_levels.h>
++#include <linux/kthread.h>
+
+ #include <asm/page.h>
+ #include <asm/pat.h>
+@@ -50,16 +51,26 @@
+ extern bool itlb_multihit_kvm_mitigation;
+
+ static int __read_mostly nx_huge_pages = -1;
++static uint __read_mostly nx_huge_pages_recovery_ratio = 60;
+
+ static int set_nx_huge_pages(const char *val, const struct kernel_param *kp);
++static int set_nx_huge_pages_recovery_ratio(const char *val, const struct kernel_param *kp);
+
+ static struct kernel_param_ops nx_huge_pages_ops = {
+ .set = set_nx_huge_pages,
+ .get = param_get_bool,
+ };
+
++static struct kernel_param_ops nx_huge_pages_recovery_ratio_ops = {
++ .set = set_nx_huge_pages_recovery_ratio,
++ .get = param_get_uint,
++};
++
+ module_param_cb(nx_huge_pages, &nx_huge_pages_ops, &nx_huge_pages, 0644);
+ __MODULE_PARM_TYPE(nx_huge_pages, "bool");
++module_param_cb(nx_huge_pages_recovery_ratio, &nx_huge_pages_recovery_ratio_ops,
++ &nx_huge_pages_recovery_ratio, 0644);
++__MODULE_PARM_TYPE(nx_huge_pages_recovery_ratio, "uint");
+
+ /*
+ * When setting this variable to true it enables Two-Dimensional-Paging
+@@ -1187,6 +1198,8 @@ static void account_huge_nx_page(struct
+ return;
+
+ ++kvm->stat.nx_lpage_splits;
++ list_add_tail(&sp->lpage_disallowed_link,
++ &kvm->arch.lpage_disallowed_mmu_pages);
+ sp->lpage_disallowed = true;
+ }
+
+@@ -1211,6 +1224,7 @@ static void unaccount_huge_nx_page(struc
+ {
+ --kvm->stat.nx_lpage_splits;
+ sp->lpage_disallowed = false;
++ list_del(&sp->lpage_disallowed_link);
+ }
+
+ static bool __mmu_gfn_lpage_is_disallowed(gfn_t gfn, int level,
+@@ -6218,6 +6232,8 @@ static int set_nx_huge_pages(const char
+ idx = srcu_read_lock(&kvm->srcu);
+ kvm_mmu_zap_all_fast(kvm);
+ srcu_read_unlock(&kvm->srcu, idx);
++
++ wake_up_process(kvm->arch.nx_lpage_recovery_thread);
+ }
+ mutex_unlock(&kvm_lock);
+ }
+@@ -6311,3 +6327,116 @@ void kvm_mmu_module_exit(void)
+ unregister_shrinker(&mmu_shrinker);
+ mmu_audit_disable();
+ }
++
++static int set_nx_huge_pages_recovery_ratio(const char *val, const struct kernel_param *kp)
++{
++ unsigned int old_val;
++ int err;
++
++ old_val = nx_huge_pages_recovery_ratio;
++ err = param_set_uint(val, kp);
++ if (err)
++ return err;
++
++ if (READ_ONCE(nx_huge_pages) &&
++ !old_val && nx_huge_pages_recovery_ratio) {
++ struct kvm *kvm;
++
++ mutex_lock(&kvm_lock);
++
++ list_for_each_entry(kvm, &vm_list, vm_list)
++ wake_up_process(kvm->arch.nx_lpage_recovery_thread);
++
++ mutex_unlock(&kvm_lock);
++ }
++
++ return err;
++}
++
++static void kvm_recover_nx_lpages(struct kvm *kvm)
++{
++ int rcu_idx;
++ struct kvm_mmu_page *sp;
++ unsigned int ratio;
++ LIST_HEAD(invalid_list);
++ ulong to_zap;
++
++ rcu_idx = srcu_read_lock(&kvm->srcu);
++ spin_lock(&kvm->mmu_lock);
++
++ ratio = READ_ONCE(nx_huge_pages_recovery_ratio);
++ to_zap = ratio ? DIV_ROUND_UP(kvm->stat.nx_lpage_splits, ratio) : 0;
++ while (to_zap && !list_empty(&kvm->arch.lpage_disallowed_mmu_pages)) {
++ /*
++ * We use a separate list instead of just using active_mmu_pages
++ * because the number of lpage_disallowed pages is expected to
++ * be relatively small compared to the total.
++ */
++ sp = list_first_entry(&kvm->arch.lpage_disallowed_mmu_pages,
++ struct kvm_mmu_page,
++ lpage_disallowed_link);
++ WARN_ON_ONCE(!sp->lpage_disallowed);
++ kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list);
++ WARN_ON_ONCE(sp->lpage_disallowed);
++
++ if (!--to_zap || need_resched() || spin_needbreak(&kvm->mmu_lock)) {
++ kvm_mmu_commit_zap_page(kvm, &invalid_list);
++ if (to_zap)
++ cond_resched_lock(&kvm->mmu_lock);
++ }
++ }
++
++ spin_unlock(&kvm->mmu_lock);
++ srcu_read_unlock(&kvm->srcu, rcu_idx);
++}
++
++static long get_nx_lpage_recovery_timeout(u64 start_time)
++{
++ return READ_ONCE(nx_huge_pages) && READ_ONCE(nx_huge_pages_recovery_ratio)
++ ? start_time + 60 * HZ - get_jiffies_64()
++ : MAX_SCHEDULE_TIMEOUT;
++}
++
++static int kvm_nx_lpage_recovery_worker(struct kvm *kvm, uintptr_t data)
++{
++ u64 start_time;
++ long remaining_time;
++
++ while (true) {
++ start_time = get_jiffies_64();
++ remaining_time = get_nx_lpage_recovery_timeout(start_time);
++
++ set_current_state(TASK_INTERRUPTIBLE);
++ while (!kthread_should_stop() && remaining_time > 0) {
++ schedule_timeout(remaining_time);
++ remaining_time = get_nx_lpage_recovery_timeout(start_time);
++ set_current_state(TASK_INTERRUPTIBLE);
++ }
++
++ set_current_state(TASK_RUNNING);
++
++ if (kthread_should_stop())
++ return 0;
++
++ kvm_recover_nx_lpages(kvm);
++ }
++}
++
++int kvm_mmu_post_init_vm(struct kvm *kvm)
++{
++ int err;
++
++ err = kvm_vm_create_worker_thread(kvm, kvm_nx_lpage_recovery_worker, 0,
++ "kvm-nx-lpage-recovery",
++ &kvm->arch.nx_lpage_recovery_thread);
++ if (!err)
++ kthread_unpark(kvm->arch.nx_lpage_recovery_thread);
++
++ return err;
++}
++
++void kvm_mmu_pre_destroy_vm(struct kvm *kvm)
++{
++ if (kvm->arch.nx_lpage_recovery_thread)
++ kthread_stop(kvm->arch.nx_lpage_recovery_thread);
++}
+--- a/arch/x86/kvm/mmu.h
++++ b/arch/x86/kvm/mmu.h
+@@ -210,4 +210,8 @@ void kvm_mmu_gfn_allow_lpage(struct kvm_
+ bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm,
+ struct kvm_memory_slot *slot, u64 gfn);
+ int kvm_arch_write_log_dirty(struct kvm_vcpu *vcpu);
++
++int kvm_mmu_post_init_vm(struct kvm *kvm);
++void kvm_mmu_pre_destroy_vm(struct kvm *kvm);
++
+ #endif
+--- a/arch/x86/kvm/x86.c
++++ b/arch/x86/kvm/x86.c
+@@ -9342,6 +9342,7 @@ int kvm_arch_init_vm(struct kvm *kvm, un
+
+ INIT_HLIST_HEAD(&kvm->arch.mask_notifier_list);
+ INIT_LIST_HEAD(&kvm->arch.active_mmu_pages);
++ INIT_LIST_HEAD(&kvm->arch.lpage_disallowed_mmu_pages);
+ INIT_LIST_HEAD(&kvm->arch.assigned_dev_head);
+ atomic_set(&kvm->arch.noncoherent_dma_count, 0);
+
+@@ -9373,6 +9374,11 @@ int kvm_arch_init_vm(struct kvm *kvm, un
+ return 0;
+ }
+
++int kvm_arch_post_init_vm(struct kvm *kvm)
++{
++ return kvm_mmu_post_init_vm(kvm);
++}
++
+ static void kvm_unload_vcpu_mmu(struct kvm_vcpu *vcpu)
+ {
+ vcpu_load(vcpu);
+@@ -9474,6 +9480,11 @@ int x86_set_memory_region(struct kvm *kv
+ }
+ EXPORT_SYMBOL_GPL(x86_set_memory_region);
+
++void kvm_arch_pre_destroy_vm(struct kvm *kvm)
++{
++ kvm_mmu_pre_destroy_vm(kvm);
++}
++
+ void kvm_arch_destroy_vm(struct kvm *kvm)
+ {
+ if (current->mm == kvm->mm) {
+--- a/virt/kvm/kvm_main.c
++++ b/virt/kvm/kvm_main.c
+@@ -626,6 +626,23 @@ static int kvm_create_vm_debugfs(struct
+ return 0;
+ }
+
++/*
++ * Called after the VM is otherwise initialized, but just before adding it to
++ * the vm_list.
++ */
++int __weak kvm_arch_post_init_vm(struct kvm *kvm)
++{
++ return 0;
++}
++
++/*
++ * Called just after removing the VM from the vm_list, but before doing any
++ * other destruction.
++ */
++void __weak kvm_arch_pre_destroy_vm(struct kvm *kvm)
++{
++}
++
+ static struct kvm *kvm_create_vm(unsigned long type)
+ {
+ int r, i;
+@@ -676,11 +693,15 @@ static struct kvm *kvm_create_vm(unsigne
+ rcu_assign_pointer(kvm->buses[i],
+ kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL_ACCOUNT));
+ if (!kvm->buses[i])
+- goto out_err;
++ goto out_err_no_mmu_notifier;
+ }
+
+ r = kvm_init_mmu_notifier(kvm);
+ if (r)
++ goto out_err_no_mmu_notifier;
++
++ r = kvm_arch_post_init_vm(kvm);
++ if (r)
+ goto out_err;
+
+ mutex_lock(&kvm_lock);
+@@ -692,6 +713,11 @@ static struct kvm *kvm_create_vm(unsigne
+ return kvm;
+
+ out_err:
++#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
++ if (kvm->mmu_notifier.ops)
++ mmu_notifier_unregister(&kvm->mmu_notifier, current->mm);
++#endif
++out_err_no_mmu_notifier:
+ cleanup_srcu_struct(&kvm->irq_srcu);
+ out_err_no_irq_srcu:
+ cleanup_srcu_struct(&kvm->srcu);
+@@ -734,6 +760,8 @@ static void kvm_destroy_vm(struct kvm *k
+ mutex_lock(&kvm_lock);
+ list_del(&kvm->vm_list);
+ mutex_unlock(&kvm_lock);
++ kvm_arch_pre_destroy_vm(kvm);
++
+ kvm_free_irq_routing(kvm);
+ for (i = 0; i < KVM_NR_BUSES; i++) {
+ struct kvm_io_bus *bus = kvm_get_bus(kvm, i);
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:11:45 PM CET
+From: Paolo Bonzini <pbonzini@redhat.com>
+Date: Fri, 11 Oct 2019 11:59:48 +0200
+Subject: kvm: x86, powerpc: do not allow clearing largepages debugfs entry
+
+From: Paolo Bonzini <pbonzini@redhat.com>
+
+commit 833b45de69a6016c4b0cebe6765d526a31a81580 upstream.
+
+The largepages debugfs entry is incremented/decremented as shadow
+pages are created or destroyed. Clearing it will result in an
+underflow, which is harmless to KVM but ugly (and could be
+misinterpreted by tools that use debugfs information), so make
+this particular statistic read-only.
+
+Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Cc: kvm-ppc@vger.kernel.org
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/powerpc/kvm/book3s.c | 8 ++++----
+ arch/x86/kvm/x86.c | 6 +++---
+ include/linux/kvm_host.h | 2 ++
+ virt/kvm/kvm_main.c | 10 +++++++---
+ 4 files changed, 16 insertions(+), 10 deletions(-)
+
+--- a/arch/powerpc/kvm/book3s.c
++++ b/arch/powerpc/kvm/book3s.c
+@@ -36,8 +36,8 @@
+ #include "book3s.h"
+ #include "trace.h"
+
+-#define VM_STAT(x) offsetof(struct kvm, stat.x), KVM_STAT_VM
+-#define VCPU_STAT(x) offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU
++#define VM_STAT(x, ...) offsetof(struct kvm, stat.x), KVM_STAT_VM, ## __VA_ARGS__
++#define VCPU_STAT(x, ...) offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU, ## __VA_ARGS__
+
+ /* #define EXIT_DEBUG */
+
+@@ -69,8 +69,8 @@ struct kvm_stats_debugfs_item debugfs_en
+ { "pthru_all", VCPU_STAT(pthru_all) },
+ { "pthru_host", VCPU_STAT(pthru_host) },
+ { "pthru_bad_aff", VCPU_STAT(pthru_bad_aff) },
+- { "largepages_2M", VM_STAT(num_2M_pages) },
+- { "largepages_1G", VM_STAT(num_1G_pages) },
++ { "largepages_2M", VM_STAT(num_2M_pages, .mode = 0444) },
++ { "largepages_1G", VM_STAT(num_1G_pages, .mode = 0444) },
+ { NULL }
+ };
+
+--- a/arch/x86/kvm/x86.c
++++ b/arch/x86/kvm/x86.c
+@@ -92,8 +92,8 @@ u64 __read_mostly efer_reserved_bits = ~
+ static u64 __read_mostly efer_reserved_bits = ~((u64)EFER_SCE);
+ #endif
+
+-#define VM_STAT(x) offsetof(struct kvm, stat.x), KVM_STAT_VM
+-#define VCPU_STAT(x) offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU
++#define VM_STAT(x, ...) offsetof(struct kvm, stat.x), KVM_STAT_VM, ## __VA_ARGS__
++#define VCPU_STAT(x, ...) offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU, ## __VA_ARGS__
+
+ #define KVM_X2APIC_API_VALID_FLAGS (KVM_X2APIC_API_USE_32BIT_IDS | \
+ KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK)
+@@ -212,7 +212,7 @@ struct kvm_stats_debugfs_item debugfs_en
+ { "mmu_cache_miss", VM_STAT(mmu_cache_miss) },
+ { "mmu_unsync", VM_STAT(mmu_unsync) },
+ { "remote_tlb_flush", VM_STAT(remote_tlb_flush) },
+- { "largepages", VM_STAT(lpages) },
++ { "largepages", VM_STAT(lpages, .mode = 0444) },
+ { "max_mmu_page_hash_collisions",
+ VM_STAT(max_mmu_page_hash_collisions) },
+ { NULL }
+--- a/include/linux/kvm_host.h
++++ b/include/linux/kvm_host.h
+@@ -1090,6 +1090,7 @@ enum kvm_stat_kind {
+
+ struct kvm_stat_data {
+ int offset;
++ int mode;
+ struct kvm *kvm;
+ };
+
+@@ -1097,6 +1098,7 @@ struct kvm_stats_debugfs_item {
+ const char *name;
+ int offset;
+ enum kvm_stat_kind kind;
++ int mode;
+ };
+ extern struct kvm_stats_debugfs_item debugfs_entries[];
+ extern struct dentry *kvm_debugfs_dir;
+--- a/virt/kvm/kvm_main.c
++++ b/virt/kvm/kvm_main.c
+@@ -617,8 +617,9 @@ static int kvm_create_vm_debugfs(struct
+
+ stat_data->kvm = kvm;
+ stat_data->offset = p->offset;
++ stat_data->mode = p->mode ? p->mode : 0644;
+ kvm->debugfs_stat_data[p - debugfs_entries] = stat_data;
+- debugfs_create_file(p->name, 0644, kvm->debugfs_dentry,
++ debugfs_create_file(p->name, stat_data->mode, kvm->debugfs_dentry,
+ stat_data, stat_fops_per_vm[p->kind]);
+ }
+ return 0;
+@@ -3930,7 +3931,9 @@ static int kvm_debugfs_open(struct inode
+ if (!refcount_inc_not_zero(&stat_data->kvm->users_count))
+ return -ENOENT;
+
+- if (simple_attr_open(inode, file, get, set, fmt)) {
++ if (simple_attr_open(inode, file, get,
++ stat_data->mode & S_IWUGO ? set : NULL,
++ fmt)) {
+ kvm_put_kvm(stat_data->kvm);
+ return -ENOMEM;
+ }
+@@ -4178,7 +4181,8 @@ static void kvm_init_debug(void)
+
+ kvm_debugfs_num_entries = 0;
+ for (p = debugfs_entries; p->name; ++p, kvm_debugfs_num_entries++) {
+- debugfs_create_file(p->name, 0644, kvm_debugfs_dir,
++ int mode = p->mode ? p->mode : 0644;
++ debugfs_create_file(p->name, mode, kvm_debugfs_dir,
+ (void *)(long)p->offset,
+ stat_fops[p->kind]);
+ }
netfilter-ipset-copy-the-right-mac-address-in-hash-i.patch
arm64-errata-update-stale-comment.patch
net-ibmvnic-unlock-rtnl_lock-in-reset-so-linkwatch_e.patch
+drm-i915-rename-gen7-cmdparser-tables.patch
+drm-i915-disable-secure-batches-for-gen6.patch
+drm-i915-remove-master-tables-from-cmdparser.patch
+drm-i915-add-support-for-mandatory-cmdparsing.patch
+drm-i915-support-ro-ppgtt-mapped-cmdparser-shadow-buffers.patch
+drm-i915-allow-parsing-of-unsized-batches.patch
+drm-i915-add-gen9-bcs-cmdparsing.patch
+drm-i915-cmdparser-use-explicit-goto-for-error-paths.patch
+drm-i915-cmdparser-add-support-for-backward-jumps.patch
+drm-i915-cmdparser-ignore-length-operands-during-command-matching.patch
+drm-i915-lower-rm-timeout-to-avoid-dsi-hard-hangs.patch
+drm-i915-gen8-add-rc6-ctx-corruption-wa.patch
+drm-i915-cmdparser-fix-jump-whitelist-clearing.patch
+x86-msr-add-the-ia32_tsx_ctrl-msr.patch
+x86-cpu-add-a-helper-function-x86_read_arch_cap_msr.patch
+x86-cpu-add-a-tsx-cmdline-option-with-tsx-disabled-by-default.patch
+x86-speculation-taa-add-mitigation-for-tsx-async-abort.patch
+x86-speculation-taa-add-sysfs-reporting-for-tsx-async-abort.patch
+kvm-x86-export-mds_no-0-to-guests-when-tsx-is-enabled.patch
+x86-tsx-add-auto-option-to-the-tsx-cmdline-parameter.patch
+x86-speculation-taa-add-documentation-for-tsx-async-abort.patch
+x86-tsx-add-config-options-to-set-tsx-on-off-auto.patch
+x86-speculation-taa-fix-printing-of-taa_msg_smt-on-ibrs_all-cpus.patch
+x86-bugs-add-itlb_multihit-bug-infrastructure.patch
+x86-cpu-add-tremont-to-the-cpu-vulnerability-whitelist.patch
+cpu-speculation-uninline-and-export-cpu-mitigations-helpers.patch
+documentation-add-itlb_multihit-documentation.patch
+kvm-x86-powerpc-do-not-allow-clearing-largepages-debugfs-entry.patch
+kvm-mmu-itlb_multihit-mitigation.patch
+kvm-add-helper-function-for-creating-vm-worker-threads.patch
+kvm-x86-mmu-recovery-of-shattered-nx-large-pages.patch
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:11:45 PM CET
+From: Vineela Tummalapalli <vineela.tummalapalli@intel.com>
+Date: Mon, 4 Nov 2019 12:22:01 +0100
+Subject: x86/bugs: Add ITLB_MULTIHIT bug infrastructure
+
+From: Vineela Tummalapalli <vineela.tummalapalli@intel.com>
+
+commit db4d30fbb71b47e4ecb11c4efa5d8aad4b03dfae upstream.
+
+Some processors may incur a machine check error possibly resulting in an
+unrecoverable CPU lockup when an instruction fetch encounters a TLB
+multi-hit in the instruction TLB. This can occur when the page size is
+changed along with either the physical address or cache type. The relevant
+erratum can be found here:
+
+ https://bugzilla.kernel.org/show_bug.cgi?id=205195
+
+There are other processors affected for which the erratum does not fully
+disclose the impact.
+
+This issue affects both bare-metal x86 page tables and EPT.
+
+It can be mitigated by either eliminating the use of large pages or by
+using careful TLB invalidations when changing the page size in the page
+tables.
+
+Just like Spectre, Meltdown, L1TF and MDS, a new bit has been allocated in
+MSR_IA32_ARCH_CAPABILITIES (PSCHANGE_MC_NO) and will be set on CPUs which
+are mitigated against this issue.
+
+Signed-off-by: Vineela Tummalapalli <vineela.tummalapalli@intel.com>
+Co-developed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ Documentation/ABI/testing/sysfs-devices-system-cpu | 1
+ arch/x86/include/asm/cpufeatures.h | 1
+ arch/x86/include/asm/msr-index.h | 7 ++
+ arch/x86/kernel/cpu/bugs.c | 13 ++++
+ arch/x86/kernel/cpu/common.c | 63 +++++++++++----------
+ drivers/base/cpu.c | 8 ++
+ include/linux/cpu.h | 2
+ 7 files changed, 66 insertions(+), 29 deletions(-)
+
+--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
++++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
+@@ -487,6 +487,7 @@ What: /sys/devices/system/cpu/vulnerabi
+ /sys/devices/system/cpu/vulnerabilities/l1tf
+ /sys/devices/system/cpu/vulnerabilities/mds
+ /sys/devices/system/cpu/vulnerabilities/tsx_async_abort
++ /sys/devices/system/cpu/vulnerabilities/itlb_multihit
+ Date: January 2018
+ Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
+ Description: Information about CPU vulnerabilities
+--- a/arch/x86/include/asm/cpufeatures.h
++++ b/arch/x86/include/asm/cpufeatures.h
+@@ -398,5 +398,6 @@
+ #define X86_BUG_MSBDS_ONLY X86_BUG(20) /* CPU is only affected by the MSDBS variant of BUG_MDS */
+ #define X86_BUG_SWAPGS X86_BUG(21) /* CPU is affected by speculation through SWAPGS */
+ #define X86_BUG_TAA X86_BUG(22) /* CPU is affected by TSX Async Abort(TAA) */
++#define X86_BUG_ITLB_MULTIHIT X86_BUG(23) /* CPU may incur MCE during certain page attribute changes */
+
+ #endif /* _ASM_X86_CPUFEATURES_H */
+--- a/arch/x86/include/asm/msr-index.h
++++ b/arch/x86/include/asm/msr-index.h
+@@ -93,6 +93,13 @@
+ * Microarchitectural Data
+ * Sampling (MDS) vulnerabilities.
+ */
++#define ARCH_CAP_PSCHANGE_MC_NO BIT(6) /*
++ * The processor is not susceptible to a
++ * machine check error due to modifying the
++ * code page size along with either the
++ * physical address or cache type
++ * without TLB invalidation.
++ */
+ #define ARCH_CAP_TSX_CTRL_MSR BIT(7) /* MSR for TSX control is available. */
+ #define ARCH_CAP_TAA_NO BIT(8) /*
+ * Not susceptible to
+--- a/arch/x86/kernel/cpu/bugs.c
++++ b/arch/x86/kernel/cpu/bugs.c
+@@ -1415,6 +1415,11 @@ static ssize_t l1tf_show_state(char *buf
+ }
+ #endif
+
++static ssize_t itlb_multihit_show_state(char *buf)
++{
++ return sprintf(buf, "Processor vulnerable\n");
++}
++
+ static ssize_t mds_show_state(char *buf)
+ {
+ if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
+@@ -1520,6 +1525,9 @@ static ssize_t cpu_show_common(struct de
+ case X86_BUG_TAA:
+ return tsx_async_abort_show_state(buf);
+
++ case X86_BUG_ITLB_MULTIHIT:
++ return itlb_multihit_show_state(buf);
++
+ default:
+ break;
+ }
+@@ -1561,4 +1569,9 @@ ssize_t cpu_show_tsx_async_abort(struct
+ {
+ return cpu_show_common(dev, attr, buf, X86_BUG_TAA);
+ }
++
++ssize_t cpu_show_itlb_multihit(struct device *dev, struct device_attribute *attr, char *buf)
++{
++ return cpu_show_common(dev, attr, buf, X86_BUG_ITLB_MULTIHIT);
++}
+ #endif
+--- a/arch/x86/kernel/cpu/common.c
++++ b/arch/x86/kernel/cpu/common.c
+@@ -1016,13 +1016,14 @@ static void identify_cpu_without_cpuid(s
+ #endif
+ }
+
+-#define NO_SPECULATION BIT(0)
+-#define NO_MELTDOWN BIT(1)
+-#define NO_SSB BIT(2)
+-#define NO_L1TF BIT(3)
+-#define NO_MDS BIT(4)
+-#define MSBDS_ONLY BIT(5)
+-#define NO_SWAPGS BIT(6)
++#define NO_SPECULATION BIT(0)
++#define NO_MELTDOWN BIT(1)
++#define NO_SSB BIT(2)
++#define NO_L1TF BIT(3)
++#define NO_MDS BIT(4)
++#define MSBDS_ONLY BIT(5)
++#define NO_SWAPGS BIT(6)
++#define NO_ITLB_MULTIHIT BIT(7)
+
+ #define VULNWL(_vendor, _family, _model, _whitelist) \
+ { X86_VENDOR_##_vendor, _family, _model, X86_FEATURE_ANY, _whitelist }
+@@ -1043,26 +1044,26 @@ static const __initconst struct x86_cpu_
+ VULNWL(NSC, 5, X86_MODEL_ANY, NO_SPECULATION),
+
+ /* Intel Family 6 */
+- VULNWL_INTEL(ATOM_SALTWELL, NO_SPECULATION),
+- VULNWL_INTEL(ATOM_SALTWELL_TABLET, NO_SPECULATION),
+- VULNWL_INTEL(ATOM_SALTWELL_MID, NO_SPECULATION),
+- VULNWL_INTEL(ATOM_BONNELL, NO_SPECULATION),
+- VULNWL_INTEL(ATOM_BONNELL_MID, NO_SPECULATION),
+-
+- VULNWL_INTEL(ATOM_SILVERMONT, NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS),
+- VULNWL_INTEL(ATOM_SILVERMONT_X, NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS),
+- VULNWL_INTEL(ATOM_SILVERMONT_MID, NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS),
+- VULNWL_INTEL(ATOM_AIRMONT, NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS),
+- VULNWL_INTEL(XEON_PHI_KNL, NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS),
+- VULNWL_INTEL(XEON_PHI_KNM, NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS),
++ VULNWL_INTEL(ATOM_SALTWELL, NO_SPECULATION | NO_ITLB_MULTIHIT),
++ VULNWL_INTEL(ATOM_SALTWELL_TABLET, NO_SPECULATION | NO_ITLB_MULTIHIT),
++ VULNWL_INTEL(ATOM_SALTWELL_MID, NO_SPECULATION | NO_ITLB_MULTIHIT),
++ VULNWL_INTEL(ATOM_BONNELL, NO_SPECULATION | NO_ITLB_MULTIHIT),
++ VULNWL_INTEL(ATOM_BONNELL_MID, NO_SPECULATION | NO_ITLB_MULTIHIT),
++
++ VULNWL_INTEL(ATOM_SILVERMONT, NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS | NO_ITLB_MULTIHIT),
++ VULNWL_INTEL(ATOM_SILVERMONT_X, NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS | NO_ITLB_MULTIHIT),
++ VULNWL_INTEL(ATOM_SILVERMONT_MID, NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS | NO_ITLB_MULTIHIT),
++ VULNWL_INTEL(ATOM_AIRMONT, NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS | NO_ITLB_MULTIHIT),
++ VULNWL_INTEL(XEON_PHI_KNL, NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS | NO_ITLB_MULTIHIT),
++ VULNWL_INTEL(XEON_PHI_KNM, NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS | NO_ITLB_MULTIHIT),
+
+ VULNWL_INTEL(CORE_YONAH, NO_SSB),
+
+- VULNWL_INTEL(ATOM_AIRMONT_MID, NO_L1TF | MSBDS_ONLY | NO_SWAPGS),
++ VULNWL_INTEL(ATOM_AIRMONT_MID, NO_L1TF | MSBDS_ONLY | NO_SWAPGS | NO_ITLB_MULTIHIT),
+
+- VULNWL_INTEL(ATOM_GOLDMONT, NO_MDS | NO_L1TF | NO_SWAPGS),
+- VULNWL_INTEL(ATOM_GOLDMONT_X, NO_MDS | NO_L1TF | NO_SWAPGS),
+- VULNWL_INTEL(ATOM_GOLDMONT_PLUS, NO_MDS | NO_L1TF | NO_SWAPGS),
++ VULNWL_INTEL(ATOM_GOLDMONT, NO_MDS | NO_L1TF | NO_SWAPGS | NO_ITLB_MULTIHIT),
++ VULNWL_INTEL(ATOM_GOLDMONT_X, NO_MDS | NO_L1TF | NO_SWAPGS | NO_ITLB_MULTIHIT),
++ VULNWL_INTEL(ATOM_GOLDMONT_PLUS, NO_MDS | NO_L1TF | NO_SWAPGS | NO_ITLB_MULTIHIT),
+
+ /*
+ * Technically, swapgs isn't serializing on AMD (despite it previously
+@@ -1073,14 +1074,14 @@ static const __initconst struct x86_cpu_
+ */
+
+ /* AMD Family 0xf - 0x12 */
+- VULNWL_AMD(0x0f, NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS),
+- VULNWL_AMD(0x10, NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS),
+- VULNWL_AMD(0x11, NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS),
+- VULNWL_AMD(0x12, NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS),
++ VULNWL_AMD(0x0f, NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT),
++ VULNWL_AMD(0x10, NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT),
++ VULNWL_AMD(0x11, NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT),
++ VULNWL_AMD(0x12, NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT),
+
+ /* FAMILY_ANY must be last, otherwise 0x0f - 0x12 matches won't work */
+- VULNWL_AMD(X86_FAMILY_ANY, NO_MELTDOWN | NO_L1TF | NO_MDS | NO_SWAPGS),
+- VULNWL_HYGON(X86_FAMILY_ANY, NO_MELTDOWN | NO_L1TF | NO_MDS | NO_SWAPGS),
++ VULNWL_AMD(X86_FAMILY_ANY, NO_MELTDOWN | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT),
++ VULNWL_HYGON(X86_FAMILY_ANY, NO_MELTDOWN | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT),
+ {}
+ };
+
+@@ -1105,6 +1106,10 @@ static void __init cpu_set_bug_bits(stru
+ {
+ u64 ia32_cap = x86_read_arch_cap_msr();
+
++ /* Set ITLB_MULTIHIT bug if cpu is not in the whitelist and not mitigated */
++ if (!cpu_matches(NO_ITLB_MULTIHIT) && !(ia32_cap & ARCH_CAP_PSCHANGE_MC_NO))
++ setup_force_cpu_bug(X86_BUG_ITLB_MULTIHIT);
++
+ if (cpu_matches(NO_SPECULATION))
+ return;
+
+--- a/drivers/base/cpu.c
++++ b/drivers/base/cpu.c
+@@ -561,6 +561,12 @@ ssize_t __weak cpu_show_tsx_async_abort(
+ return sprintf(buf, "Not affected\n");
+ }
+
++ssize_t __weak cpu_show_itlb_multihit(struct device *dev,
++ struct device_attribute *attr, char *buf)
++{
++ return sprintf(buf, "Not affected\n");
++}
++
+ static DEVICE_ATTR(meltdown, 0444, cpu_show_meltdown, NULL);
+ static DEVICE_ATTR(spectre_v1, 0444, cpu_show_spectre_v1, NULL);
+ static DEVICE_ATTR(spectre_v2, 0444, cpu_show_spectre_v2, NULL);
+@@ -568,6 +574,7 @@ static DEVICE_ATTR(spec_store_bypass, 04
+ static DEVICE_ATTR(l1tf, 0444, cpu_show_l1tf, NULL);
+ static DEVICE_ATTR(mds, 0444, cpu_show_mds, NULL);
+ static DEVICE_ATTR(tsx_async_abort, 0444, cpu_show_tsx_async_abort, NULL);
++static DEVICE_ATTR(itlb_multihit, 0444, cpu_show_itlb_multihit, NULL);
+
+ static struct attribute *cpu_root_vulnerabilities_attrs[] = {
+ &dev_attr_meltdown.attr,
+@@ -577,6 +584,7 @@ static struct attribute *cpu_root_vulner
+ &dev_attr_l1tf.attr,
+ &dev_attr_mds.attr,
+ &dev_attr_tsx_async_abort.attr,
++ &dev_attr_itlb_multihit.attr,
+ NULL
+ };
+
+--- a/include/linux/cpu.h
++++ b/include/linux/cpu.h
+@@ -62,6 +62,8 @@ extern ssize_t cpu_show_mds(struct devic
+ extern ssize_t cpu_show_tsx_async_abort(struct device *dev,
+ struct device_attribute *attr,
+ char *buf);
++extern ssize_t cpu_show_itlb_multihit(struct device *dev,
++ struct device_attribute *attr, char *buf);
+
+ extern __printf(4, 5)
+ struct device *cpu_device_create(struct device *parent, void *drvdata,
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:11:45 PM CET
+From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+Date: Wed, 23 Oct 2019 10:52:35 +0200
+Subject: x86/cpu: Add a helper function x86_read_arch_cap_msr()
+
+From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+
+commit 286836a70433fb64131d2590f4bf512097c255e1 upstream.
+
+Add a helper function to read the IA32_ARCH_CAPABILITIES MSR.
+
+Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+Signed-off-by: Borislav Petkov <bp@suse.de>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Tested-by: Neelima Krishnan <neelima.krishnan@intel.com>
+Reviewed-by: Mark Gross <mgross@linux.intel.com>
+Reviewed-by: Tony Luck <tony.luck@intel.com>
+Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/x86/kernel/cpu/common.c | 15 +++++++++++----
+ arch/x86/kernel/cpu/cpu.h | 2 ++
+ 2 files changed, 13 insertions(+), 4 deletions(-)
+
+--- a/arch/x86/kernel/cpu/common.c
++++ b/arch/x86/kernel/cpu/common.c
+@@ -1091,19 +1091,26 @@ static bool __init cpu_matches(unsigned
+ return m && !!(m->driver_data & which);
+ }
+
+-static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
++u64 x86_read_arch_cap_msr(void)
+ {
+ u64 ia32_cap = 0;
+
++ if (boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES))
++ rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap);
++
++ return ia32_cap;
++}
++
++static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
++{
++ u64 ia32_cap = x86_read_arch_cap_msr();
++
+ if (cpu_matches(NO_SPECULATION))
+ return;
+
+ setup_force_cpu_bug(X86_BUG_SPECTRE_V1);
+ setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
+
+- if (cpu_has(c, X86_FEATURE_ARCH_CAPABILITIES))
+- rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap);
+-
+ if (!cpu_matches(NO_SSB) && !(ia32_cap & ARCH_CAP_SSB_NO) &&
+ !cpu_has(c, X86_FEATURE_AMD_SSB_NO))
+ setup_force_cpu_bug(X86_BUG_SPEC_STORE_BYPASS);
+--- a/arch/x86/kernel/cpu/cpu.h
++++ b/arch/x86/kernel/cpu/cpu.h
+@@ -62,4 +62,6 @@ unsigned int aperfmperf_get_khz(int cpu)
+
+ extern void x86_spec_ctrl_setup_ap(void);
+
++extern u64 x86_read_arch_cap_msr(void);
++
+ #endif /* ARCH_X86_CPU_H */
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:11:45 PM CET
+From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+Date: Wed, 23 Oct 2019 11:01:53 +0200
+Subject: x86/cpu: Add a "tsx=" cmdline option with TSX disabled by default
+
+From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+
+commit 95c5824f75f3ba4c9e8e5a4b1a623c95390ac266 upstream.
+
+Add a kernel cmdline parameter "tsx" to control the Transactional
+Synchronization Extensions (TSX) feature. On CPUs that support TSX
+control, use "tsx=on|off" to enable or disable TSX. Not specifying this
+option is equivalent to "tsx=off". This is because on certain processors
+TSX may be used as a part of a speculative side channel attack.
+
+Carve out the TSX controlling functionality into a separate compilation
+unit because TSX is a CPU feature while the TSX async abort control
+machinery will go to cpu/bugs.c.
+
+ [ bp: - Massage, shorten and clear the arg buffer.
+ - Clarifications of the tsx= possible options - Josh.
+ - Expand on TSX_CTRL availability - Pawan. ]
+
+Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+Signed-off-by: Borislav Petkov <bp@suse.de>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ Documentation/admin-guide/kernel-parameters.txt | 26 ++++
+ arch/x86/kernel/cpu/Makefile | 2
+ arch/x86/kernel/cpu/common.c | 2
+ arch/x86/kernel/cpu/cpu.h | 16 +++
+ arch/x86/kernel/cpu/intel.c | 5
+ arch/x86/kernel/cpu/tsx.c | 125 ++++++++++++++++++++++++
+ 6 files changed, 175 insertions(+), 1 deletion(-)
+ create mode 100644 arch/x86/kernel/cpu/tsx.c
+
+--- a/Documentation/admin-guide/kernel-parameters.txt
++++ b/Documentation/admin-guide/kernel-parameters.txt
+@@ -4813,6 +4813,32 @@
+ interruptions from clocksource watchdog are not
+ acceptable).
+
++ tsx= [X86] Control Transactional Synchronization
++ Extensions (TSX) feature in Intel processors that
++ support TSX control.
++
++ This parameter controls the TSX feature. The options are:
++
++ on - Enable TSX on the system. Although there are
++ mitigations for all known security vulnerabilities,
++ TSX has been known to be an accelerator for
++ several previous speculation-related CVEs, and
++ so there may be unknown security risks associated
++ with leaving it enabled.
++
++ off - Disable TSX on the system. (Note that this
++ option takes effect only on newer CPUs which are
++ not vulnerable to MDS, i.e., have
++ MSR_IA32_ARCH_CAPABILITIES.MDS_NO=1 and which get
++ the new IA32_TSX_CTRL MSR through a microcode
++ update. This new MSR allows for the reliable
++ deactivation of the TSX functionality.)
++
++ Not specifying this option is equivalent to tsx=off.
++
++ See Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
++ for more details.
++
+ turbografx.map[2|3]= [HW,JOY]
+ TurboGraFX parallel port interface
+ Format:
+--- a/arch/x86/kernel/cpu/Makefile
++++ b/arch/x86/kernel/cpu/Makefile
+@@ -30,7 +30,7 @@ obj-$(CONFIG_PROC_FS) += proc.o
+ obj-$(CONFIG_X86_FEATURE_NAMES) += capflags.o powerflags.o
+
+ ifdef CONFIG_CPU_SUP_INTEL
+-obj-y += intel.o intel_pconfig.o
++obj-y += intel.o intel_pconfig.o tsx.o
+ obj-$(CONFIG_PM) += intel_epb.o
+ endif
+ obj-$(CONFIG_CPU_SUP_AMD) += amd.o
+--- a/arch/x86/kernel/cpu/common.c
++++ b/arch/x86/kernel/cpu/common.c
+@@ -1560,6 +1560,8 @@ void __init identify_boot_cpu(void)
+ #endif
+ cpu_detect_tlb(&boot_cpu_data);
+ setup_cr_pinning();
++
++ tsx_init();
+ }
+
+ void identify_secondary_cpu(struct cpuinfo_x86 *c)
+--- a/arch/x86/kernel/cpu/cpu.h
++++ b/arch/x86/kernel/cpu/cpu.h
+@@ -44,6 +44,22 @@ struct _tlb_table {
+ extern const struct cpu_dev *const __x86_cpu_dev_start[],
+ *const __x86_cpu_dev_end[];
+
++#ifdef CONFIG_CPU_SUP_INTEL
++enum tsx_ctrl_states {
++ TSX_CTRL_ENABLE,
++ TSX_CTRL_DISABLE,
++ TSX_CTRL_NOT_SUPPORTED,
++};
++
++extern __ro_after_init enum tsx_ctrl_states tsx_ctrl_state;
++
++extern void __init tsx_init(void);
++extern void tsx_enable(void);
++extern void tsx_disable(void);
++#else
++static inline void tsx_init(void) { }
++#endif /* CONFIG_CPU_SUP_INTEL */
++
+ extern void get_cpu_cap(struct cpuinfo_x86 *c);
+ extern void get_cpu_address_sizes(struct cpuinfo_x86 *c);
+ extern void cpu_detect_cache_sizes(struct cpuinfo_x86 *c);
+--- a/arch/x86/kernel/cpu/intel.c
++++ b/arch/x86/kernel/cpu/intel.c
+@@ -761,6 +761,11 @@ static void init_intel(struct cpuinfo_x8
+ detect_tme(c);
+
+ init_intel_misc_features(c);
++
++ if (tsx_ctrl_state == TSX_CTRL_ENABLE)
++ tsx_enable();
++ if (tsx_ctrl_state == TSX_CTRL_DISABLE)
++ tsx_disable();
+ }
+
+ #ifdef CONFIG_X86_32
+--- /dev/null
++++ b/arch/x86/kernel/cpu/tsx.c
+@@ -0,0 +1,125 @@
++// SPDX-License-Identifier: GPL-2.0
++/*
++ * Intel Transactional Synchronization Extensions (TSX) control.
++ *
++ * Copyright (C) 2019 Intel Corporation
++ *
++ * Author:
++ * Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
++ */
++
++#include <linux/cpufeature.h>
++
++#include <asm/cmdline.h>
++
++#include "cpu.h"
++
++enum tsx_ctrl_states tsx_ctrl_state __ro_after_init = TSX_CTRL_NOT_SUPPORTED;
++
++void tsx_disable(void)
++{
++ u64 tsx;
++
++ rdmsrl(MSR_IA32_TSX_CTRL, tsx);
++
++ /* Force all transactions to immediately abort */
++ tsx |= TSX_CTRL_RTM_DISABLE;
++
++ /*
++ * Ensure TSX support is not enumerated in CPUID.
++ * This is visible to userspace and will ensure they
++ * do not waste resources trying TSX transactions that
++ * will always abort.
++ */
++ tsx |= TSX_CTRL_CPUID_CLEAR;
++
++ wrmsrl(MSR_IA32_TSX_CTRL, tsx);
++}
++
++void tsx_enable(void)
++{
++ u64 tsx;
++
++ rdmsrl(MSR_IA32_TSX_CTRL, tsx);
++
++ /* Enable the RTM feature in the cpu */
++ tsx &= ~TSX_CTRL_RTM_DISABLE;
++
++ /*
++ * Ensure TSX support is enumerated in CPUID.
++ * This is visible to userspace and will ensure they
++ * can enumerate and use the TSX feature.
++ */
++ tsx &= ~TSX_CTRL_CPUID_CLEAR;
++
++ wrmsrl(MSR_IA32_TSX_CTRL, tsx);
++}
++
++static bool __init tsx_ctrl_is_supported(void)
++{
++ u64 ia32_cap = x86_read_arch_cap_msr();
++
++ /*
++ * TSX is controlled via MSR_IA32_TSX_CTRL. However, support for this
++ * MSR is enumerated by ARCH_CAP_TSX_MSR bit in MSR_IA32_ARCH_CAPABILITIES.
++ *
++ * TSX control (aka MSR_IA32_TSX_CTRL) is only available after a
++ * microcode update on CPUs that have their MSR_IA32_ARCH_CAPABILITIES
++ * bit MDS_NO=1. CPUs with MDS_NO=0 are not planned to get
++ * MSR_IA32_TSX_CTRL support even after a microcode update. Thus,
++ * tsx= cmdline requests will do nothing on CPUs without
++ * MSR_IA32_TSX_CTRL support.
++ */
++ return !!(ia32_cap & ARCH_CAP_TSX_CTRL_MSR);
++}
++
++void __init tsx_init(void)
++{
++ char arg[4] = {};
++ int ret;
++
++ if (!tsx_ctrl_is_supported())
++ return;
++
++ ret = cmdline_find_option(boot_command_line, "tsx", arg, sizeof(arg));
++ if (ret >= 0) {
++ if (!strcmp(arg, "on")) {
++ tsx_ctrl_state = TSX_CTRL_ENABLE;
++ } else if (!strcmp(arg, "off")) {
++ tsx_ctrl_state = TSX_CTRL_DISABLE;
++ } else {
++ tsx_ctrl_state = TSX_CTRL_DISABLE;
++ pr_err("tsx: invalid option, defaulting to off\n");
++ }
++ } else {
++ /* tsx= not provided, defaulting to off */
++ tsx_ctrl_state = TSX_CTRL_DISABLE;
++ }
++
++ if (tsx_ctrl_state == TSX_CTRL_DISABLE) {
++ tsx_disable();
++
++ /*
++ * tsx_disable() will change the state of the
++ * RTM CPUID bit. Clear it here since it is now
++ * expected to be not set.
++ */
++ setup_clear_cpu_cap(X86_FEATURE_RTM);
++ } else if (tsx_ctrl_state == TSX_CTRL_ENABLE) {
++
++ /*
++ * HW defaults TSX to be enabled at bootup.
++ * We may still need the TSX enable support
++ * during init for special cases like
++ * kexec after TSX is disabled.
++ */
++ tsx_enable();
++
++ /*
++ * tsx_enable() will change the state of the
++ * RTM CPUID bit. Force it here since it is now
++ * expected to be set.
++ */
++ setup_force_cpu_cap(X86_FEATURE_RTM);
++ }
++}
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:11:45 PM CET
+From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+Date: Mon, 4 Nov 2019 12:22:01 +0100
+Subject: x86/cpu: Add Tremont to the cpu vulnerability whitelist
+
+From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+
+commit cad14885a8d32c1c0d8eaa7bf5c0152a22b6080e upstream.
+
+Add the new cpu family ATOM_TREMONT_D to the cpu vunerability
+whitelist. ATOM_TREMONT_D is not affected by X86_BUG_ITLB_MULTIHIT.
+
+ATOM_TREMONT_D might have mitigations against other issues as well, but
+only the ITLB multihit mitigation is confirmed at this point.
+
+Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/x86/kernel/cpu/common.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+--- a/arch/x86/kernel/cpu/common.c
++++ b/arch/x86/kernel/cpu/common.c
+@@ -1073,6 +1073,8 @@ static const __initconst struct x86_cpu_
+ * good enough for our purposes.
+ */
+
++ VULNWL_INTEL(ATOM_TREMONT_X, NO_ITLB_MULTIHIT),
++
+ /* AMD Family 0xf - 0x12 */
+ VULNWL_AMD(0x0f, NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT),
+ VULNWL_AMD(0x10, NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT),
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:11:45 PM CET
+From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+Date: Wed, 23 Oct 2019 10:45:50 +0200
+Subject: x86/msr: Add the IA32_TSX_CTRL MSR
+
+From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+
+commit c2955f270a84762343000f103e0640d29c7a96f3 upstream.
+
+Transactional Synchronization Extensions (TSX) may be used on certain
+processors as part of a speculative side channel attack. A microcode
+update for existing processors that are vulnerable to this attack will
+add a new MSR - IA32_TSX_CTRL to allow the system administrator the
+option to disable TSX as one of the possible mitigations.
+
+The CPUs which get this new MSR after a microcode upgrade are the ones
+which do not set MSR_IA32_ARCH_CAPABILITIES.MDS_NO (bit 5) because those
+CPUs have CPUID.MD_CLEAR, i.e., the VERW implementation which clears all
+CPU buffers takes care of the TAA case as well.
+
+ [ Note that future processors that are not vulnerable will also
+ support the IA32_TSX_CTRL MSR. ]
+
+Add defines for the new IA32_TSX_CTRL MSR and its bits.
+
+TSX has two sub-features:
+
+1. Restricted Transactional Memory (RTM) is an explicitly-used feature
+ where new instructions begin and end TSX transactions.
+2. Hardware Lock Elision (HLE) is implicitly used when certain kinds of
+ "old" style locks are used by software.
+
+Bit 7 of the IA32_ARCH_CAPABILITIES indicates the presence of the
+IA32_TSX_CTRL MSR.
+
+There are two control bits in IA32_TSX_CTRL MSR:
+
+ Bit 0: When set, it disables the Restricted Transactional Memory (RTM)
+ sub-feature of TSX (will force all transactions to abort on the
+ XBEGIN instruction).
+
+ Bit 1: When set, it disables the enumeration of the RTM and HLE feature
+ (i.e. it will make CPUID(EAX=7).EBX{bit4} and
+ CPUID(EAX=7).EBX{bit11} read as 0).
+
+The other TSX sub-feature, Hardware Lock Elision (HLE), is
+unconditionally disabled by the new microcode but still enumerated
+as present by CPUID(EAX=7).EBX{bit4}, unless disabled by
+IA32_TSX_CTRL_MSR[1] - TSX_CTRL_CPUID_CLEAR.
+
+Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+Signed-off-by: Borislav Petkov <bp@suse.de>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Tested-by: Neelima Krishnan <neelima.krishnan@intel.com>
+Reviewed-by: Mark Gross <mgross@linux.intel.com>
+Reviewed-by: Tony Luck <tony.luck@intel.com>
+Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/x86/include/asm/msr-index.h | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+--- a/arch/x86/include/asm/msr-index.h
++++ b/arch/x86/include/asm/msr-index.h
+@@ -93,6 +93,7 @@
+ * Microarchitectural Data
+ * Sampling (MDS) vulnerabilities.
+ */
++#define ARCH_CAP_TSX_CTRL_MSR BIT(7) /* MSR for TSX control is available. */
+
+ #define MSR_IA32_FLUSH_CMD 0x0000010b
+ #define L1D_FLUSH BIT(0) /*
+@@ -103,6 +104,10 @@
+ #define MSR_IA32_BBL_CR_CTL 0x00000119
+ #define MSR_IA32_BBL_CR_CTL3 0x0000011e
+
++#define MSR_IA32_TSX_CTRL 0x00000122
++#define TSX_CTRL_RTM_DISABLE BIT(0) /* Disable RTM feature */
++#define TSX_CTRL_CPUID_CLEAR BIT(1) /* Disable TSX enumeration */
++
+ #define MSR_IA32_SYSENTER_CS 0x00000174
+ #define MSR_IA32_SYSENTER_ESP 0x00000175
+ #define MSR_IA32_SYSENTER_EIP 0x00000176
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:11:45 PM CET
+From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+Date: Wed, 23 Oct 2019 12:32:55 +0200
+Subject: x86/speculation/taa: Add documentation for TSX Async Abort
+
+From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+
+commit a7a248c593e4fd7a67c50b5f5318fe42a0db335e upstream.
+
+Add the documenation for TSX Async Abort. Include the description of
+the issue, how to check the mitigation state, control the mitigation,
+guidance for system administrators.
+
+ [ bp: Add proper SPDX tags, touch ups by Josh and me. ]
+
+Co-developed-by: Antonio Gomez Iglesias <antonio.gomez.iglesias@intel.com>
+
+Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+Signed-off-by: Antonio Gomez Iglesias <antonio.gomez.iglesias@intel.com>
+Signed-off-by: Borislav Petkov <bp@suse.de>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Reviewed-by: Mark Gross <mgross@linux.intel.com>
+Reviewed-by: Tony Luck <tony.luck@intel.com>
+Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ Documentation/ABI/testing/sysfs-devices-system-cpu | 1
+ Documentation/admin-guide/hw-vuln/index.rst | 1
+ Documentation/admin-guide/hw-vuln/tsx_async_abort.rst | 276 ++++++++++++++++++
+ Documentation/admin-guide/kernel-parameters.txt | 38 ++
+ Documentation/x86/index.rst | 1
+ Documentation/x86/tsx_async_abort.rst | 117 +++++++
+ 6 files changed, 434 insertions(+)
+ create mode 100644 Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
+ create mode 100644 Documentation/x86/tsx_async_abort.rst
+
+--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
++++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
+@@ -486,6 +486,7 @@ What: /sys/devices/system/cpu/vulnerabi
+ /sys/devices/system/cpu/vulnerabilities/spec_store_bypass
+ /sys/devices/system/cpu/vulnerabilities/l1tf
+ /sys/devices/system/cpu/vulnerabilities/mds
++ /sys/devices/system/cpu/vulnerabilities/tsx_async_abort
+ Date: January 2018
+ Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
+ Description: Information about CPU vulnerabilities
+--- a/Documentation/admin-guide/hw-vuln/index.rst
++++ b/Documentation/admin-guide/hw-vuln/index.rst
+@@ -12,3 +12,4 @@ are configurable at compile, boot or run
+ spectre
+ l1tf
+ mds
++ tsx_async_abort
+--- /dev/null
++++ b/Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
+@@ -0,0 +1,276 @@
++.. SPDX-License-Identifier: GPL-2.0
++
++TAA - TSX Asynchronous Abort
++======================================
++
++TAA is a hardware vulnerability that allows unprivileged speculative access to
++data which is available in various CPU internal buffers by using asynchronous
++aborts within an Intel TSX transactional region.
++
++Affected processors
++-------------------
++
++This vulnerability only affects Intel processors that support Intel
++Transactional Synchronization Extensions (TSX) when the TAA_NO bit (bit 8)
++is 0 in the IA32_ARCH_CAPABILITIES MSR. On processors where the MDS_NO bit
++(bit 5) is 0 in the IA32_ARCH_CAPABILITIES MSR, the existing MDS mitigations
++also mitigate against TAA.
++
++Whether a processor is affected or not can be read out from the TAA
++vulnerability file in sysfs. See :ref:`tsx_async_abort_sys_info`.
++
++Related CVEs
++------------
++
++The following CVE entry is related to this TAA issue:
++
++ ============== ===== ===================================================
++ CVE-2019-11135 TAA TSX Asynchronous Abort (TAA) condition on some
++ microprocessors utilizing speculative execution may
++ allow an authenticated user to potentially enable
++ information disclosure via a side channel with
++ local access.
++ ============== ===== ===================================================
++
++Problem
++-------
++
++When performing store, load or L1 refill operations, processors write
++data into temporary microarchitectural structures (buffers). The data in
++those buffers can be forwarded to load operations as an optimization.
++
++Intel TSX is an extension to the x86 instruction set architecture that adds
++hardware transactional memory support to improve performance of multi-threaded
++software. TSX lets the processor expose and exploit concurrency hidden in an
++application due to dynamically avoiding unnecessary synchronization.
++
++TSX supports atomic memory transactions that are either committed (success) or
++aborted. During an abort, operations that happened within the transactional region
++are rolled back. An asynchronous abort takes place, among other options, when a
++different thread accesses a cache line that is also used within the transactional
++region when that access might lead to a data race.
++
++Immediately after an uncompleted asynchronous abort, certain speculatively
++executed loads may read data from those internal buffers and pass it to dependent
++operations. This can be then used to infer the value via a cache side channel
++attack.
++
++Because the buffers are potentially shared between Hyper-Threads cross
++Hyper-Thread attacks are possible.
++
++The victim of a malicious actor does not need to make use of TSX. Only the
++attacker needs to begin a TSX transaction and raise an asynchronous abort
++which in turn potenitally leaks data stored in the buffers.
++
++More detailed technical information is available in the TAA specific x86
++architecture section: :ref:`Documentation/x86/tsx_async_abort.rst <tsx_async_abort>`.
++
++
++Attack scenarios
++----------------
++
++Attacks against the TAA vulnerability can be implemented from unprivileged
++applications running on hosts or guests.
++
++As for MDS, the attacker has no control over the memory addresses that can
++be leaked. Only the victim is responsible for bringing data to the CPU. As
++a result, the malicious actor has to sample as much data as possible and
++then postprocess it to try to infer any useful information from it.
++
++A potential attacker only has read access to the data. Also, there is no direct
++privilege escalation by using this technique.
++
++
++.. _tsx_async_abort_sys_info:
++
++TAA system information
++-----------------------
++
++The Linux kernel provides a sysfs interface to enumerate the current TAA status
++of mitigated systems. The relevant sysfs file is:
++
++/sys/devices/system/cpu/vulnerabilities/tsx_async_abort
++
++The possible values in this file are:
++
++.. list-table::
++
++ * - 'Vulnerable'
++ - The CPU is affected by this vulnerability and the microcode and kernel mitigation are not applied.
++ * - 'Vulnerable: Clear CPU buffers attempted, no microcode'
++ - The system tries to clear the buffers but the microcode might not support the operation.
++ * - 'Mitigation: Clear CPU buffers'
++ - The microcode has been updated to clear the buffers. TSX is still enabled.
++ * - 'Mitigation: TSX disabled'
++ - TSX is disabled.
++ * - 'Not affected'
++ - The CPU is not affected by this issue.
++
++.. _ucode_needed:
++
++Best effort mitigation mode
++^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++If the processor is vulnerable, but the availability of the microcode-based
++mitigation mechanism is not advertised via CPUID the kernel selects a best
++effort mitigation mode. This mode invokes the mitigation instructions
++without a guarantee that they clear the CPU buffers.
++
++This is done to address virtualization scenarios where the host has the
++microcode update applied, but the hypervisor is not yet updated to expose the
++CPUID to the guest. If the host has updated microcode the protection takes
++effect; otherwise a few CPU cycles are wasted pointlessly.
++
++The state in the tsx_async_abort sysfs file reflects this situation
++accordingly.
++
++
++Mitigation mechanism
++--------------------
++
++The kernel detects the affected CPUs and the presence of the microcode which is
++required. If a CPU is affected and the microcode is available, then the kernel
++enables the mitigation by default.
++
++
++The mitigation can be controlled at boot time via a kernel command line option.
++See :ref:`taa_mitigation_control_command_line`.
++
++.. _virt_mechanism:
++
++Virtualization mitigation
++^^^^^^^^^^^^^^^^^^^^^^^^^
++
++Affected systems where the host has TAA microcode and TAA is mitigated by
++having disabled TSX previously, are not vulnerable regardless of the status
++of the VMs.
++
++In all other cases, if the host either does not have the TAA microcode or
++the kernel is not mitigated, the system might be vulnerable.
++
++
++.. _taa_mitigation_control_command_line:
++
++Mitigation control on the kernel command line
++---------------------------------------------
++
++The kernel command line allows to control the TAA mitigations at boot time with
++the option "tsx_async_abort=". The valid arguments for this option are:
++
++ ============ =============================================================
++ off This option disables the TAA mitigation on affected platforms.
++ If the system has TSX enabled (see next parameter) and the CPU
++ is affected, the system is vulnerable.
++
++ full TAA mitigation is enabled. If TSX is enabled, on an affected
++ system it will clear CPU buffers on ring transitions. On
++ systems which are MDS-affected and deploy MDS mitigation,
++ TAA is also mitigated. Specifying this option on those
++ systems will have no effect.
++
++ full,nosmt The same as tsx_async_abort=full, with SMT disabled on
++ vulnerable CPUs that have TSX enabled. This is the complete
++ mitigation. When TSX is disabled, SMT is not disabled because
++ CPU is not vulnerable to cross-thread TAA attacks.
++ ============ =============================================================
++
++Not specifying this option is equivalent to "tsx_async_abort=full".
++
++The kernel command line also allows to control the TSX feature using the
++parameter "tsx=" on CPUs which support TSX control. MSR_IA32_TSX_CTRL is used
++to control the TSX feature and the enumeration of the TSX feature bits (RTM
++and HLE) in CPUID.
++
++The valid options are:
++
++ ============ =============================================================
++ off Disables TSX on the system.
++
++ Note that this option takes effect only on newer CPUs which are
++ not vulnerable to MDS, i.e., have MSR_IA32_ARCH_CAPABILITIES.MDS_NO=1
++ and which get the new IA32_TSX_CTRL MSR through a microcode
++ update. This new MSR allows for the reliable deactivation of
++ the TSX functionality.
++
++ on Enables TSX.
++
++ Although there are mitigations for all known security
++ vulnerabilities, TSX has been known to be an accelerator for
++ several previous speculation-related CVEs, and so there may be
++ unknown security risks associated with leaving it enabled.
++
++ auto Disables TSX if X86_BUG_TAA is present, otherwise enables TSX
++ on the system.
++ ============ =============================================================
++
++Not specifying this option is equivalent to "tsx=off".
++
++The following combinations of the "tsx_async_abort" and "tsx" are possible. For
++affected platforms tsx=auto is equivalent to tsx=off and the result will be:
++
++ ========= ========================== =========================================
++ tsx=on tsx_async_abort=full The system will use VERW to clear CPU
++ buffers. Cross-thread attacks are still
++ possible on SMT machines.
++ tsx=on tsx_async_abort=full,nosmt As above, cross-thread attacks on SMT
++ mitigated.
++ tsx=on tsx_async_abort=off The system is vulnerable.
++ tsx=off tsx_async_abort=full TSX might be disabled if microcode
++ provides a TSX control MSR. If so,
++ system is not vulnerable.
++ tsx=off tsx_async_abort=full,nosmt Ditto
++ tsx=off tsx_async_abort=off ditto
++ ========= ========================== =========================================
++
++
++For unaffected platforms "tsx=on" and "tsx_async_abort=full" does not clear CPU
++buffers. For platforms without TSX control (MSR_IA32_ARCH_CAPABILITIES.MDS_NO=0)
++"tsx" command line argument has no effect.
++
++For the affected platforms below table indicates the mitigation status for the
++combinations of CPUID bit MD_CLEAR and IA32_ARCH_CAPABILITIES MSR bits MDS_NO
++and TSX_CTRL_MSR.
++
++ ======= ========= ============= ========================================
++ MDS_NO MD_CLEAR TSX_CTRL_MSR Status
++ ======= ========= ============= ========================================
++ 0 0 0 Vulnerable (needs microcode)
++ 0 1 0 MDS and TAA mitigated via VERW
++ 1 1 0 MDS fixed, TAA vulnerable if TSX enabled
++ because MD_CLEAR has no meaning and
++ VERW is not guaranteed to clear buffers
++ 1 X 1 MDS fixed, TAA can be mitigated by
++ VERW or TSX_CTRL_MSR
++ ======= ========= ============= ========================================
++
++Mitigation selection guide
++--------------------------
++
++1. Trusted userspace and guests
++^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++If all user space applications are from a trusted source and do not execute
++untrusted code which is supplied externally, then the mitigation can be
++disabled. The same applies to virtualized environments with trusted guests.
++
++
++2. Untrusted userspace and guests
++^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
++
++If there are untrusted applications or guests on the system, enabling TSX
++might allow a malicious actor to leak data from the host or from other
++processes running on the same physical core.
++
++If the microcode is available and the TSX is disabled on the host, attacks
++are prevented in a virtualized environment as well, even if the VMs do not
++explicitly enable the mitigation.
++
++
++.. _taa_default_mitigations:
++
++Default mitigations
++-------------------
++
++The kernel's default action for vulnerable processors is:
++
++ - Deploy TSX disable mitigation (tsx_async_abort=full tsx=off).
+--- a/Documentation/admin-guide/kernel-parameters.txt
++++ b/Documentation/admin-guide/kernel-parameters.txt
+@@ -2612,6 +2612,7 @@
+ ssbd=force-off [ARM64]
+ l1tf=off [X86]
+ mds=off [X86]
++ tsx_async_abort=off [X86]
+
+ auto (default)
+ Mitigate all CPU vulnerabilities, but leave SMT
+@@ -2627,6 +2628,7 @@
+ be fully mitigated, even if it means losing SMT.
+ Equivalent to: l1tf=flush,nosmt [X86]
+ mds=full,nosmt [X86]
++ tsx_async_abort=full,nosmt [X86]
+
+ mminit_loglevel=
+ [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this
+@@ -4842,6 +4844,42 @@
+ See Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
+ for more details.
+
++ tsx_async_abort= [X86,INTEL] Control mitigation for the TSX Async
++ Abort (TAA) vulnerability.
++
++ Similar to Micro-architectural Data Sampling (MDS)
++ certain CPUs that support Transactional
++ Synchronization Extensions (TSX) are vulnerable to an
++ exploit against CPU internal buffers which can forward
++ information to a disclosure gadget under certain
++ conditions.
++
++ In vulnerable processors, the speculatively forwarded
++ data can be used in a cache side channel attack, to
++ access data to which the attacker does not have direct
++ access.
++
++ This parameter controls the TAA mitigation. The
++ options are:
++
++ full - Enable TAA mitigation on vulnerable CPUs
++ if TSX is enabled.
++
++ full,nosmt - Enable TAA mitigation and disable SMT on
++ vulnerable CPUs. If TSX is disabled, SMT
++ is not disabled because CPU is not
++ vulnerable to cross-thread TAA attacks.
++ off - Unconditionally disable TAA mitigation
++
++ Not specifying this option is equivalent to
++ tsx_async_abort=full. On CPUs which are MDS affected
++ and deploy MDS mitigation, TAA mitigation is not
++ required and doesn't provide any additional
++ mitigation.
++
++ For details see:
++ Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
++
+ turbografx.map[2|3]= [HW,JOY]
+ TurboGraFX parallel port interface
+ Format:
+--- a/Documentation/x86/index.rst
++++ b/Documentation/x86/index.rst
+@@ -27,6 +27,7 @@ x86-specific Documentation
+ mds
+ microcode
+ resctrl_ui
++ tsx_async_abort
+ usb-legacy-support
+ i386/index
+ x86_64/index
+--- /dev/null
++++ b/Documentation/x86/tsx_async_abort.rst
+@@ -0,0 +1,117 @@
++.. SPDX-License-Identifier: GPL-2.0
++
++TSX Async Abort (TAA) mitigation
++================================
++
++.. _tsx_async_abort:
++
++Overview
++--------
++
++TSX Async Abort (TAA) is a side channel attack on internal buffers in some
++Intel processors similar to Microachitectural Data Sampling (MDS). In this
++case certain loads may speculatively pass invalid data to dependent operations
++when an asynchronous abort condition is pending in a Transactional
++Synchronization Extensions (TSX) transaction. This includes loads with no
++fault or assist condition. Such loads may speculatively expose stale data from
++the same uarch data structures as in MDS, with same scope of exposure i.e.
++same-thread and cross-thread. This issue affects all current processors that
++support TSX.
++
++Mitigation strategy
++-------------------
++
++a) TSX disable - one of the mitigations is to disable TSX. A new MSR
++IA32_TSX_CTRL will be available in future and current processors after
++microcode update which can be used to disable TSX. In addition, it
++controls the enumeration of the TSX feature bits (RTM and HLE) in CPUID.
++
++b) Clear CPU buffers - similar to MDS, clearing the CPU buffers mitigates this
++vulnerability. More details on this approach can be found in
++:ref:`Documentation/admin-guide/hw-vuln/mds.rst <mds>`.
++
++Kernel internal mitigation modes
++--------------------------------
++
++ ============= ============================================================
++ off Mitigation is disabled. Either the CPU is not affected or
++ tsx_async_abort=off is supplied on the kernel command line.
++
++ tsx disabled Mitigation is enabled. TSX feature is disabled by default at
++ bootup on processors that support TSX control.
++
++ verw Mitigation is enabled. CPU is affected and MD_CLEAR is
++ advertised in CPUID.
++
++ ucode needed Mitigation is enabled. CPU is affected and MD_CLEAR is not
++ advertised in CPUID. That is mainly for virtualization
++ scenarios where the host has the updated microcode but the
++ hypervisor does not expose MD_CLEAR in CPUID. It's a best
++ effort approach without guarantee.
++ ============= ============================================================
++
++If the CPU is affected and the "tsx_async_abort" kernel command line parameter is
++not provided then the kernel selects an appropriate mitigation depending on the
++status of RTM and MD_CLEAR CPUID bits.
++
++Below tables indicate the impact of tsx=on|off|auto cmdline options on state of
++TAA mitigation, VERW behavior and TSX feature for various combinations of
++MSR_IA32_ARCH_CAPABILITIES bits.
++
++1. "tsx=off"
++
++========= ========= ============ ============ ============== =================== ======================
++MSR_IA32_ARCH_CAPABILITIES bits Result with cmdline tsx=off
++---------------------------------- -------------------------------------------------------------------------
++TAA_NO MDS_NO TSX_CTRL_MSR TSX state VERW can clear TAA mitigation TAA mitigation
++ after bootup CPU buffers tsx_async_abort=off tsx_async_abort=full
++========= ========= ============ ============ ============== =================== ======================
++ 0 0 0 HW default Yes Same as MDS Same as MDS
++ 0 0 1 Invalid case Invalid case Invalid case Invalid case
++ 0 1 0 HW default No Need ucode update Need ucode update
++ 0 1 1 Disabled Yes TSX disabled TSX disabled
++ 1 X 1 Disabled X None needed None needed
++========= ========= ============ ============ ============== =================== ======================
++
++2. "tsx=on"
++
++========= ========= ============ ============ ============== =================== ======================
++MSR_IA32_ARCH_CAPABILITIES bits Result with cmdline tsx=on
++---------------------------------- -------------------------------------------------------------------------
++TAA_NO MDS_NO TSX_CTRL_MSR TSX state VERW can clear TAA mitigation TAA mitigation
++ after bootup CPU buffers tsx_async_abort=off tsx_async_abort=full
++========= ========= ============ ============ ============== =================== ======================
++ 0 0 0 HW default Yes Same as MDS Same as MDS
++ 0 0 1 Invalid case Invalid case Invalid case Invalid case
++ 0 1 0 HW default No Need ucode update Need ucode update
++ 0 1 1 Enabled Yes None Same as MDS
++ 1 X 1 Enabled X None needed None needed
++========= ========= ============ ============ ============== =================== ======================
++
++3. "tsx=auto"
++
++========= ========= ============ ============ ============== =================== ======================
++MSR_IA32_ARCH_CAPABILITIES bits Result with cmdline tsx=auto
++---------------------------------- -------------------------------------------------------------------------
++TAA_NO MDS_NO TSX_CTRL_MSR TSX state VERW can clear TAA mitigation TAA mitigation
++ after bootup CPU buffers tsx_async_abort=off tsx_async_abort=full
++========= ========= ============ ============ ============== =================== ======================
++ 0 0 0 HW default Yes Same as MDS Same as MDS
++ 0 0 1 Invalid case Invalid case Invalid case Invalid case
++ 0 1 0 HW default No Need ucode update Need ucode update
++ 0 1 1 Disabled Yes TSX disabled TSX disabled
++ 1 X 1 Enabled X None needed None needed
++========= ========= ============ ============ ============== =================== ======================
++
++In the tables, TSX_CTRL_MSR is a new bit in MSR_IA32_ARCH_CAPABILITIES that
++indicates whether MSR_IA32_TSX_CTRL is supported.
++
++There are two control bits in IA32_TSX_CTRL MSR:
++
++ Bit 0: When set it disables the Restricted Transactional Memory (RTM)
++ sub-feature of TSX (will force all transactions to abort on the
++ XBEGIN instruction).
++
++ Bit 1: When set it disables the enumeration of the RTM and HLE feature
++ (i.e. it will make CPUID(EAX=7).EBX{bit4} and
++ CPUID(EAX=7).EBX{bit11} read as 0).
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:11:45 PM CET
+From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+Date: Wed, 23 Oct 2019 11:30:45 +0200
+Subject: x86/speculation/taa: Add mitigation for TSX Async Abort
+
+From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+
+commit 1b42f017415b46c317e71d41c34ec088417a1883 upstream.
+
+TSX Async Abort (TAA) is a side channel vulnerability to the internal
+buffers in some Intel processors similar to Microachitectural Data
+Sampling (MDS). In this case, certain loads may speculatively pass
+invalid data to dependent operations when an asynchronous abort
+condition is pending in a TSX transaction.
+
+This includes loads with no fault or assist condition. Such loads may
+speculatively expose stale data from the uarch data structures as in
+MDS. Scope of exposure is within the same-thread and cross-thread. This
+issue affects all current processors that support TSX, but do not have
+ARCH_CAP_TAA_NO (bit 8) set in MSR_IA32_ARCH_CAPABILITIES.
+
+On CPUs which have their IA32_ARCH_CAPABILITIES MSR bit MDS_NO=0,
+CPUID.MD_CLEAR=1 and the MDS mitigation is clearing the CPU buffers
+using VERW or L1D_FLUSH, there is no additional mitigation needed for
+TAA. On affected CPUs with MDS_NO=1 this issue can be mitigated by
+disabling the Transactional Synchronization Extensions (TSX) feature.
+
+A new MSR IA32_TSX_CTRL in future and current processors after a
+microcode update can be used to control the TSX feature. There are two
+bits in that MSR:
+
+* TSX_CTRL_RTM_DISABLE disables the TSX sub-feature Restricted
+Transactional Memory (RTM).
+
+* TSX_CTRL_CPUID_CLEAR clears the RTM enumeration in CPUID. The other
+TSX sub-feature, Hardware Lock Elision (HLE), is unconditionally
+disabled with updated microcode but still enumerated as present by
+CPUID(EAX=7).EBX{bit4}.
+
+The second mitigation approach is similar to MDS which is clearing the
+affected CPU buffers on return to user space and when entering a guest.
+Relevant microcode update is required for the mitigation to work. More
+details on this approach can be found here:
+
+ https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/mds.html
+
+The TSX feature can be controlled by the "tsx" command line parameter.
+If it is force-enabled then "Clear CPU buffers" (MDS mitigation) is
+deployed. The effective mitigation state can be read from sysfs.
+
+ [ bp:
+ - massage + comments cleanup
+ - s/TAA_MITIGATION_TSX_DISABLE/TAA_MITIGATION_TSX_DISABLED/g - Josh.
+ - remove partial TAA mitigation in update_mds_branch_idle() - Josh.
+ - s/tsx_async_abort_cmdline/tsx_async_abort_parse_cmdline/g
+ ]
+
+Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+Signed-off-by: Borislav Petkov <bp@suse.de>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/x86/include/asm/cpufeatures.h | 1
+ arch/x86/include/asm/msr-index.h | 4 +
+ arch/x86/include/asm/nospec-branch.h | 4 -
+ arch/x86/include/asm/processor.h | 7 ++
+ arch/x86/kernel/cpu/bugs.c | 108 +++++++++++++++++++++++++++++++++++
+ arch/x86/kernel/cpu/common.c | 15 ++++
+ 6 files changed, 137 insertions(+), 2 deletions(-)
+
+--- a/arch/x86/include/asm/cpufeatures.h
++++ b/arch/x86/include/asm/cpufeatures.h
+@@ -397,5 +397,6 @@
+ #define X86_BUG_MDS X86_BUG(19) /* CPU is affected by Microarchitectural data sampling */
+ #define X86_BUG_MSBDS_ONLY X86_BUG(20) /* CPU is only affected by the MSDBS variant of BUG_MDS */
+ #define X86_BUG_SWAPGS X86_BUG(21) /* CPU is affected by speculation through SWAPGS */
++#define X86_BUG_TAA X86_BUG(22) /* CPU is affected by TSX Async Abort(TAA) */
+
+ #endif /* _ASM_X86_CPUFEATURES_H */
+--- a/arch/x86/include/asm/msr-index.h
++++ b/arch/x86/include/asm/msr-index.h
+@@ -94,6 +94,10 @@
+ * Sampling (MDS) vulnerabilities.
+ */
+ #define ARCH_CAP_TSX_CTRL_MSR BIT(7) /* MSR for TSX control is available. */
++#define ARCH_CAP_TAA_NO BIT(8) /*
++ * Not susceptible to
++ * TSX Async Abort (TAA) vulnerabilities.
++ */
+
+ #define MSR_IA32_FLUSH_CMD 0x0000010b
+ #define L1D_FLUSH BIT(0) /*
+--- a/arch/x86/include/asm/nospec-branch.h
++++ b/arch/x86/include/asm/nospec-branch.h
+@@ -314,7 +314,7 @@ DECLARE_STATIC_KEY_FALSE(mds_idle_clear)
+ #include <asm/segment.h>
+
+ /**
+- * mds_clear_cpu_buffers - Mitigation for MDS vulnerability
++ * mds_clear_cpu_buffers - Mitigation for MDS and TAA vulnerability
+ *
+ * This uses the otherwise unused and obsolete VERW instruction in
+ * combination with microcode which triggers a CPU buffer flush when the
+@@ -337,7 +337,7 @@ static inline void mds_clear_cpu_buffers
+ }
+
+ /**
+- * mds_user_clear_cpu_buffers - Mitigation for MDS vulnerability
++ * mds_user_clear_cpu_buffers - Mitigation for MDS and TAA vulnerability
+ *
+ * Clear CPU buffers if the corresponding static key is enabled
+ */
+--- a/arch/x86/include/asm/processor.h
++++ b/arch/x86/include/asm/processor.h
+@@ -988,4 +988,11 @@ enum mds_mitigations {
+ MDS_MITIGATION_VMWERV,
+ };
+
++enum taa_mitigations {
++ TAA_MITIGATION_OFF,
++ TAA_MITIGATION_UCODE_NEEDED,
++ TAA_MITIGATION_VERW,
++ TAA_MITIGATION_TSX_DISABLED,
++};
++
+ #endif /* _ASM_X86_PROCESSOR_H */
+--- a/arch/x86/kernel/cpu/bugs.c
++++ b/arch/x86/kernel/cpu/bugs.c
+@@ -39,6 +39,7 @@ static void __init spectre_v2_select_mit
+ static void __init ssb_select_mitigation(void);
+ static void __init l1tf_select_mitigation(void);
+ static void __init mds_select_mitigation(void);
++static void __init taa_select_mitigation(void);
+
+ /* The base value of the SPEC_CTRL MSR that always has to be preserved. */
+ u64 x86_spec_ctrl_base;
+@@ -105,6 +106,7 @@ void __init check_bugs(void)
+ ssb_select_mitigation();
+ l1tf_select_mitigation();
+ mds_select_mitigation();
++ taa_select_mitigation();
+
+ arch_smt_update();
+
+@@ -269,6 +271,100 @@ static int __init mds_cmdline(char *str)
+ early_param("mds", mds_cmdline);
+
+ #undef pr_fmt
++#define pr_fmt(fmt) "TAA: " fmt
++
++/* Default mitigation for TAA-affected CPUs */
++static enum taa_mitigations taa_mitigation __ro_after_init = TAA_MITIGATION_VERW;
++static bool taa_nosmt __ro_after_init;
++
++static const char * const taa_strings[] = {
++ [TAA_MITIGATION_OFF] = "Vulnerable",
++ [TAA_MITIGATION_UCODE_NEEDED] = "Vulnerable: Clear CPU buffers attempted, no microcode",
++ [TAA_MITIGATION_VERW] = "Mitigation: Clear CPU buffers",
++ [TAA_MITIGATION_TSX_DISABLED] = "Mitigation: TSX disabled",
++};
++
++static void __init taa_select_mitigation(void)
++{
++ u64 ia32_cap;
++
++ if (!boot_cpu_has_bug(X86_BUG_TAA)) {
++ taa_mitigation = TAA_MITIGATION_OFF;
++ return;
++ }
++
++ /* TSX previously disabled by tsx=off */
++ if (!boot_cpu_has(X86_FEATURE_RTM)) {
++ taa_mitigation = TAA_MITIGATION_TSX_DISABLED;
++ goto out;
++ }
++
++ if (cpu_mitigations_off()) {
++ taa_mitigation = TAA_MITIGATION_OFF;
++ return;
++ }
++
++ /* TAA mitigation is turned off on the cmdline (tsx_async_abort=off) */
++ if (taa_mitigation == TAA_MITIGATION_OFF)
++ goto out;
++
++ if (boot_cpu_has(X86_FEATURE_MD_CLEAR))
++ taa_mitigation = TAA_MITIGATION_VERW;
++ else
++ taa_mitigation = TAA_MITIGATION_UCODE_NEEDED;
++
++ /*
++ * VERW doesn't clear the CPU buffers when MD_CLEAR=1 and MDS_NO=1.
++ * A microcode update fixes this behavior to clear CPU buffers. It also
++ * adds support for MSR_IA32_TSX_CTRL which is enumerated by the
++ * ARCH_CAP_TSX_CTRL_MSR bit.
++ *
++ * On MDS_NO=1 CPUs if ARCH_CAP_TSX_CTRL_MSR is not set, microcode
++ * update is required.
++ */
++ ia32_cap = x86_read_arch_cap_msr();
++ if ( (ia32_cap & ARCH_CAP_MDS_NO) &&
++ !(ia32_cap & ARCH_CAP_TSX_CTRL_MSR))
++ taa_mitigation = TAA_MITIGATION_UCODE_NEEDED;
++
++ /*
++ * TSX is enabled, select alternate mitigation for TAA which is
++ * the same as MDS. Enable MDS static branch to clear CPU buffers.
++ *
++ * For guests that can't determine whether the correct microcode is
++ * present on host, enable the mitigation for UCODE_NEEDED as well.
++ */
++ static_branch_enable(&mds_user_clear);
++
++ if (taa_nosmt || cpu_mitigations_auto_nosmt())
++ cpu_smt_disable(false);
++
++out:
++ pr_info("%s\n", taa_strings[taa_mitigation]);
++}
++
++static int __init tsx_async_abort_parse_cmdline(char *str)
++{
++ if (!boot_cpu_has_bug(X86_BUG_TAA))
++ return 0;
++
++ if (!str)
++ return -EINVAL;
++
++ if (!strcmp(str, "off")) {
++ taa_mitigation = TAA_MITIGATION_OFF;
++ } else if (!strcmp(str, "full")) {
++ taa_mitigation = TAA_MITIGATION_VERW;
++ } else if (!strcmp(str, "full,nosmt")) {
++ taa_mitigation = TAA_MITIGATION_VERW;
++ taa_nosmt = true;
++ }
++
++ return 0;
++}
++early_param("tsx_async_abort", tsx_async_abort_parse_cmdline);
++
++#undef pr_fmt
+ #define pr_fmt(fmt) "Spectre V1 : " fmt
+
+ enum spectre_v1_mitigation {
+@@ -786,6 +882,7 @@ static void update_mds_branch_idle(void)
+ }
+
+ #define MDS_MSG_SMT "MDS CPU bug present and SMT on, data leak possible. See https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/mds.html for more details.\n"
++#define TAA_MSG_SMT "TAA CPU bug present and SMT on, data leak possible. See https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/tsx_async_abort.html for more details.\n"
+
+ void arch_smt_update(void)
+ {
+@@ -819,6 +916,17 @@ void arch_smt_update(void)
+ break;
+ }
+
++ switch (taa_mitigation) {
++ case TAA_MITIGATION_VERW:
++ case TAA_MITIGATION_UCODE_NEEDED:
++ if (sched_smt_active())
++ pr_warn_once(TAA_MSG_SMT);
++ break;
++ case TAA_MITIGATION_TSX_DISABLED:
++ case TAA_MITIGATION_OFF:
++ break;
++ }
++
+ mutex_unlock(&spec_ctrl_mutex);
+ }
+
+--- a/arch/x86/kernel/cpu/common.c
++++ b/arch/x86/kernel/cpu/common.c
+@@ -1127,6 +1127,21 @@ static void __init cpu_set_bug_bits(stru
+ if (!cpu_matches(NO_SWAPGS))
+ setup_force_cpu_bug(X86_BUG_SWAPGS);
+
++ /*
++ * When the CPU is not mitigated for TAA (TAA_NO=0) set TAA bug when:
++ * - TSX is supported or
++ * - TSX_CTRL is present
++ *
++ * TSX_CTRL check is needed for cases when TSX could be disabled before
++ * the kernel boot e.g. kexec.
++ * TSX_CTRL check alone is not sufficient for cases when the microcode
++ * update is not present or running as guest that don't get TSX_CTRL.
++ */
++ if (!(ia32_cap & ARCH_CAP_TAA_NO) &&
++ (cpu_has(c, X86_FEATURE_RTM) ||
++ (ia32_cap & ARCH_CAP_TSX_CTRL_MSR)))
++ setup_force_cpu_bug(X86_BUG_TAA);
++
+ if (cpu_matches(NO_MELTDOWN))
+ return;
+
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:11:45 PM CET
+From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+Date: Wed, 23 Oct 2019 12:19:51 +0200
+Subject: x86/speculation/taa: Add sysfs reporting for TSX Async Abort
+
+From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+
+commit 6608b45ac5ecb56f9e171252229c39580cc85f0f upstream.
+
+Add the sysfs reporting file for TSX Async Abort. It exposes the
+vulnerability and the mitigation state similar to the existing files for
+the other hardware vulnerabilities.
+
+Sysfs file path is:
+/sys/devices/system/cpu/vulnerabilities/tsx_async_abort
+
+Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+Signed-off-by: Borislav Petkov <bp@suse.de>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Tested-by: Neelima Krishnan <neelima.krishnan@intel.com>
+Reviewed-by: Mark Gross <mgross@linux.intel.com>
+Reviewed-by: Tony Luck <tony.luck@intel.com>
+Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/x86/kernel/cpu/bugs.c | 23 +++++++++++++++++++++++
+ drivers/base/cpu.c | 9 +++++++++
+ include/linux/cpu.h | 3 +++
+ 3 files changed, 35 insertions(+)
+
+--- a/arch/x86/kernel/cpu/bugs.c
++++ b/arch/x86/kernel/cpu/bugs.c
+@@ -1436,6 +1436,21 @@ static ssize_t mds_show_state(char *buf)
+ sched_smt_active() ? "vulnerable" : "disabled");
+ }
+
++static ssize_t tsx_async_abort_show_state(char *buf)
++{
++ if ((taa_mitigation == TAA_MITIGATION_TSX_DISABLED) ||
++ (taa_mitigation == TAA_MITIGATION_OFF))
++ return sprintf(buf, "%s\n", taa_strings[taa_mitigation]);
++
++ if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
++ return sprintf(buf, "%s; SMT Host state unknown\n",
++ taa_strings[taa_mitigation]);
++ }
++
++ return sprintf(buf, "%s; SMT %s\n", taa_strings[taa_mitigation],
++ sched_smt_active() ? "vulnerable" : "disabled");
++}
++
+ static char *stibp_state(void)
+ {
+ if (spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED)
+@@ -1506,6 +1521,9 @@ static ssize_t cpu_show_common(struct de
+ case X86_BUG_MDS:
+ return mds_show_state(buf);
+
++ case X86_BUG_TAA:
++ return tsx_async_abort_show_state(buf);
++
+ default:
+ break;
+ }
+@@ -1542,4 +1560,9 @@ ssize_t cpu_show_mds(struct device *dev,
+ {
+ return cpu_show_common(dev, attr, buf, X86_BUG_MDS);
+ }
++
++ssize_t cpu_show_tsx_async_abort(struct device *dev, struct device_attribute *attr, char *buf)
++{
++ return cpu_show_common(dev, attr, buf, X86_BUG_TAA);
++}
+ #endif
+--- a/drivers/base/cpu.c
++++ b/drivers/base/cpu.c
+@@ -554,12 +554,20 @@ ssize_t __weak cpu_show_mds(struct devic
+ return sprintf(buf, "Not affected\n");
+ }
+
++ssize_t __weak cpu_show_tsx_async_abort(struct device *dev,
++ struct device_attribute *attr,
++ char *buf)
++{
++ return sprintf(buf, "Not affected\n");
++}
++
+ static DEVICE_ATTR(meltdown, 0444, cpu_show_meltdown, NULL);
+ static DEVICE_ATTR(spectre_v1, 0444, cpu_show_spectre_v1, NULL);
+ static DEVICE_ATTR(spectre_v2, 0444, cpu_show_spectre_v2, NULL);
+ static DEVICE_ATTR(spec_store_bypass, 0444, cpu_show_spec_store_bypass, NULL);
+ static DEVICE_ATTR(l1tf, 0444, cpu_show_l1tf, NULL);
+ static DEVICE_ATTR(mds, 0444, cpu_show_mds, NULL);
++static DEVICE_ATTR(tsx_async_abort, 0444, cpu_show_tsx_async_abort, NULL);
+
+ static struct attribute *cpu_root_vulnerabilities_attrs[] = {
+ &dev_attr_meltdown.attr,
+@@ -568,6 +576,7 @@ static struct attribute *cpu_root_vulner
+ &dev_attr_spec_store_bypass.attr,
+ &dev_attr_l1tf.attr,
+ &dev_attr_mds.attr,
++ &dev_attr_tsx_async_abort.attr,
+ NULL
+ };
+
+--- a/include/linux/cpu.h
++++ b/include/linux/cpu.h
+@@ -59,6 +59,9 @@ extern ssize_t cpu_show_l1tf(struct devi
+ struct device_attribute *attr, char *buf);
+ extern ssize_t cpu_show_mds(struct device *dev,
+ struct device_attribute *attr, char *buf);
++extern ssize_t cpu_show_tsx_async_abort(struct device *dev,
++ struct device_attribute *attr,
++ char *buf);
+
+ extern __printf(4, 5)
+ struct device *cpu_device_create(struct device *parent, void *drvdata,
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:11:45 PM CET
+From: Josh Poimboeuf <jpoimboe@redhat.com>
+Date: Wed, 6 Nov 2019 20:26:46 -0600
+Subject: x86/speculation/taa: Fix printing of TAA_MSG_SMT on IBRS_ALL CPUs
+
+From: Josh Poimboeuf <jpoimboe@redhat.com>
+
+commit 012206a822a8b6ac09125bfaa210a95b9eb8f1c1 upstream.
+
+For new IBRS_ALL CPUs, the Enhanced IBRS check at the beginning of
+cpu_bugs_smt_update() causes the function to return early, unintentionally
+skipping the MDS and TAA logic.
+
+This is not a problem for MDS, because there appears to be no overlap
+between IBRS_ALL and MDS-affected CPUs. So the MDS mitigation would be
+disabled and nothing would need to be done in this function anyway.
+
+But for TAA, the TAA_MSG_SMT string will never get printed on Cascade
+Lake and newer.
+
+The check is superfluous anyway: when 'spectre_v2_enabled' is
+SPECTRE_V2_IBRS_ENHANCED, 'spectre_v2_user' is always
+SPECTRE_V2_USER_NONE, and so the 'spectre_v2_user' switch statement
+handles it appropriately by doing nothing. So just remove the check.
+
+Fixes: 1b42f017415b ("x86/speculation/taa: Add mitigation for TSX Async Abort")
+Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
+Reviewed-by: Borislav Petkov <bp@suse.de>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/x86/kernel/cpu/bugs.c | 4 ----
+ 1 file changed, 4 deletions(-)
+
+--- a/arch/x86/kernel/cpu/bugs.c
++++ b/arch/x86/kernel/cpu/bugs.c
+@@ -886,10 +886,6 @@ static void update_mds_branch_idle(void)
+
+ void arch_smt_update(void)
+ {
+- /* Enhanced IBRS implies STIBP. No update required. */
+- if (spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED)
+- return;
+-
+ mutex_lock(&spec_ctrl_mutex);
+
+ switch (spectre_v2_user) {
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:11:45 PM CET
+From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+Date: Wed, 23 Oct 2019 12:28:57 +0200
+Subject: x86/tsx: Add "auto" option to the tsx= cmdline parameter
+
+From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+
+commit 7531a3596e3272d1f6841e0d601a614555dc6b65 upstream.
+
+Platforms which are not affected by X86_BUG_TAA may want the TSX feature
+enabled. Add "auto" option to the TSX cmdline parameter. When tsx=auto
+disable TSX when X86_BUG_TAA is present, otherwise enable TSX.
+
+More details on X86_BUG_TAA can be found here:
+https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/tsx_async_abort.html
+
+ [ bp: Extend the arg buffer to accommodate "auto\0". ]
+
+Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+Signed-off-by: Borislav Petkov <bp@suse.de>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Reviewed-by: Tony Luck <tony.luck@intel.com>
+Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ Documentation/admin-guide/kernel-parameters.txt | 3 +++
+ arch/x86/kernel/cpu/tsx.c | 7 ++++++-
+ 2 files changed, 9 insertions(+), 1 deletion(-)
+
+--- a/Documentation/admin-guide/kernel-parameters.txt
++++ b/Documentation/admin-guide/kernel-parameters.txt
+@@ -4834,6 +4834,9 @@
+ update. This new MSR allows for the reliable
+ deactivation of the TSX functionality.)
+
++ auto - Disable TSX if X86_BUG_TAA is present,
++ otherwise enable TSX on the system.
++
+ Not specifying this option is equivalent to tsx=off.
+
+ See Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
+--- a/arch/x86/kernel/cpu/tsx.c
++++ b/arch/x86/kernel/cpu/tsx.c
+@@ -75,7 +75,7 @@ static bool __init tsx_ctrl_is_supported
+
+ void __init tsx_init(void)
+ {
+- char arg[4] = {};
++ char arg[5] = {};
+ int ret;
+
+ if (!tsx_ctrl_is_supported())
+@@ -87,6 +87,11 @@ void __init tsx_init(void)
+ tsx_ctrl_state = TSX_CTRL_ENABLE;
+ } else if (!strcmp(arg, "off")) {
+ tsx_ctrl_state = TSX_CTRL_DISABLE;
++ } else if (!strcmp(arg, "auto")) {
++ if (boot_cpu_has_bug(X86_BUG_TAA))
++ tsx_ctrl_state = TSX_CTRL_DISABLE;
++ else
++ tsx_ctrl_state = TSX_CTRL_ENABLE;
+ } else {
+ tsx_ctrl_state = TSX_CTRL_DISABLE;
+ pr_err("tsx: invalid option, defaulting to off\n");
--- /dev/null
+From foo@baz Tue 12 Nov 2019 04:11:45 PM CET
+From: Michal Hocko <mhocko@suse.com>
+Date: Wed, 23 Oct 2019 12:35:50 +0200
+Subject: x86/tsx: Add config options to set tsx=on|off|auto
+
+From: Michal Hocko <mhocko@suse.com>
+
+commit db616173d787395787ecc93eef075fa975227b10 upstream.
+
+There is a general consensus that TSX usage is not largely spread while
+the history shows there is a non trivial space for side channel attacks
+possible. Therefore the tsx is disabled by default even on platforms
+that might have a safe implementation of TSX according to the current
+knowledge. This is a fair trade off to make.
+
+There are, however, workloads that really do benefit from using TSX and
+updating to a newer kernel with TSX disabled might introduce a
+noticeable regressions. This would be especially a problem for Linux
+distributions which will provide TAA mitigations.
+
+Introduce config options X86_INTEL_TSX_MODE_OFF, X86_INTEL_TSX_MODE_ON
+and X86_INTEL_TSX_MODE_AUTO to control the TSX feature. The config
+setting can be overridden by the tsx cmdline options.
+
+ [ bp: Text cleanups from Josh. ]
+
+Suggested-by: Borislav Petkov <bpetkov@suse.de>
+Signed-off-by: Michal Hocko <mhocko@suse.com>
+Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
+Signed-off-by: Borislav Petkov <bp@suse.de>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/x86/Kconfig | 45 +++++++++++++++++++++++++++++++++++++++++++++
+ arch/x86/kernel/cpu/tsx.c | 22 ++++++++++++++++------
+ 2 files changed, 61 insertions(+), 6 deletions(-)
+
+--- a/arch/x86/Kconfig
++++ b/arch/x86/Kconfig
+@@ -1934,6 +1934,51 @@ config X86_INTEL_MEMORY_PROTECTION_KEYS
+
+ If unsure, say y.
+
++choice
++ prompt "TSX enable mode"
++ depends on CPU_SUP_INTEL
++ default X86_INTEL_TSX_MODE_OFF
++ help
++ Intel's TSX (Transactional Synchronization Extensions) feature
++ allows to optimize locking protocols through lock elision which
++ can lead to a noticeable performance boost.
++
++ On the other hand it has been shown that TSX can be exploited
++ to form side channel attacks (e.g. TAA) and chances are there
++ will be more of those attacks discovered in the future.
++
++ Therefore TSX is not enabled by default (aka tsx=off). An admin
++ might override this decision by tsx=on the command line parameter.
++ Even with TSX enabled, the kernel will attempt to enable the best
++ possible TAA mitigation setting depending on the microcode available
++ for the particular machine.
++
++ This option allows to set the default tsx mode between tsx=on, =off
++ and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
++ details.
++
++ Say off if not sure, auto if TSX is in use but it should be used on safe
++ platforms or on if TSX is in use and the security aspect of tsx is not
++ relevant.
++
++config X86_INTEL_TSX_MODE_OFF
++ bool "off"
++ help
++ TSX is disabled if possible - equals to tsx=off command line parameter.
++
++config X86_INTEL_TSX_MODE_ON
++ bool "on"
++ help
++ TSX is always enabled on TSX capable HW - equals the tsx=on command
++ line parameter.
++
++config X86_INTEL_TSX_MODE_AUTO
++ bool "auto"
++ help
++ TSX is enabled on TSX capable HW that is believed to be safe against
++ side channel attacks- equals the tsx=auto command line parameter.
++endchoice
++
+ config EFI
+ bool "EFI runtime service support"
+ depends on ACPI
+--- a/arch/x86/kernel/cpu/tsx.c
++++ b/arch/x86/kernel/cpu/tsx.c
+@@ -73,6 +73,14 @@ static bool __init tsx_ctrl_is_supported
+ return !!(ia32_cap & ARCH_CAP_TSX_CTRL_MSR);
+ }
+
++static enum tsx_ctrl_states x86_get_tsx_auto_mode(void)
++{
++ if (boot_cpu_has_bug(X86_BUG_TAA))
++ return TSX_CTRL_DISABLE;
++
++ return TSX_CTRL_ENABLE;
++}
++
+ void __init tsx_init(void)
+ {
+ char arg[5] = {};
+@@ -88,17 +96,19 @@ void __init tsx_init(void)
+ } else if (!strcmp(arg, "off")) {
+ tsx_ctrl_state = TSX_CTRL_DISABLE;
+ } else if (!strcmp(arg, "auto")) {
+- if (boot_cpu_has_bug(X86_BUG_TAA))
+- tsx_ctrl_state = TSX_CTRL_DISABLE;
+- else
+- tsx_ctrl_state = TSX_CTRL_ENABLE;
++ tsx_ctrl_state = x86_get_tsx_auto_mode();
+ } else {
+ tsx_ctrl_state = TSX_CTRL_DISABLE;
+ pr_err("tsx: invalid option, defaulting to off\n");
+ }
+ } else {
+- /* tsx= not provided, defaulting to off */
+- tsx_ctrl_state = TSX_CTRL_DISABLE;
++ /* tsx= not provided */
++ if (IS_ENABLED(CONFIG_X86_INTEL_TSX_MODE_AUTO))
++ tsx_ctrl_state = x86_get_tsx_auto_mode();
++ else if (IS_ENABLED(CONFIG_X86_INTEL_TSX_MODE_OFF))
++ tsx_ctrl_state = TSX_CTRL_DISABLE;
++ else
++ tsx_ctrl_state = TSX_CTRL_ENABLE;
+ }
+
+ if (tsx_ctrl_state == TSX_CTRL_DISABLE) {
projects / thirdparty / kernel / stable-queue.git / commitdiff
