--- /dev/null
+From 85bd0ba1ff9875798fad94218b627ea9f768f3c3 Mon Sep 17 00:00:00 2001
+From: Marc Zyngier <marc.zyngier@arm.com>
+Date: Sun, 21 Jan 2018 16:42:56 +0000
+Subject: arm/arm64: KVM: Add PSCI version selection API
+
+From: Marc Zyngier <marc.zyngier@arm.com>
+
+commit 85bd0ba1ff9875798fad94218b627ea9f768f3c3 upstream.
+
+Although we've implemented PSCI 0.1, 0.2 and 1.0, we expose either 0.1
+or 1.0 to a guest, defaulting to the latest version of the PSCI
+implementation that is compatible with the requested version. This is
+no different from doing a firmware upgrade on KVM.
+
+But in order to give a chance to hypothetical badly implemented guests
+that would have a fit by discovering something other than PSCI 0.2,
+let's provide a new API that allows userspace to pick one particular
+version of the API.
+
+This is implemented as a new class of "firmware" registers, where
+we expose the PSCI version. This allows the PSCI version to be
+save/restored as part of a guest migration, and also set to
+any supported version if the guest requires it.
+
+Cc: stable@vger.kernel.org #4.16
+Reviewed-by: Christoffer Dall <cdall@kernel.org>
+Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ Documentation/virtual/kvm/api.txt | 9 ++++
+ Documentation/virtual/kvm/arm/psci.txt | 30 ++++++++++++++++
+ arch/arm/include/asm/kvm_host.h | 3 +
+ arch/arm/include/uapi/asm/kvm.h | 6 +++
+ arch/arm/kvm/guest.c | 13 +++++++
+ arch/arm64/include/asm/kvm_host.h | 3 +
+ arch/arm64/include/uapi/asm/kvm.h | 6 +++
+ arch/arm64/kvm/guest.c | 14 +++++++
+ include/kvm/arm_psci.h | 16 +++++++-
+ virt/kvm/arm/psci.c | 60 +++++++++++++++++++++++++++++++++
+ 10 files changed, 156 insertions(+), 4 deletions(-)
+
+--- a/Documentation/virtual/kvm/api.txt
++++ b/Documentation/virtual/kvm/api.txt
+@@ -1940,6 +1940,9 @@ ARM 32-bit VFP control registers have th
+ ARM 64-bit FP registers have the following id bit patterns:
+ 0x4030 0000 0012 0 <regno:12>
+
++ARM firmware pseudo-registers have the following bit pattern:
++ 0x4030 0000 0014 <regno:16>
++
+
+ arm64 registers are mapped using the lower 32 bits. The upper 16 of
+ that is the register group type, or coprocessor number:
+@@ -1956,6 +1959,9 @@ arm64 CCSIDR registers are demultiplexed
+ arm64 system registers have the following id bit patterns:
+ 0x6030 0000 0013 <op0:2> <op1:3> <crn:4> <crm:4> <op2:3>
+
++arm64 firmware pseudo-registers have the following bit pattern:
++ 0x6030 0000 0014 <regno:16>
++
+
+ MIPS registers are mapped using the lower 32 bits. The upper 16 of that is
+ the register group type:
+@@ -2490,7 +2496,8 @@ Possible features:
+ and execute guest code when KVM_RUN is called.
+ - KVM_ARM_VCPU_EL1_32BIT: Starts the CPU in a 32bit mode.
+ Depends on KVM_CAP_ARM_EL1_32BIT (arm64 only).
+- - KVM_ARM_VCPU_PSCI_0_2: Emulate PSCI v0.2 for the CPU.
++ - KVM_ARM_VCPU_PSCI_0_2: Emulate PSCI v0.2 (or a future revision
++ backward compatible with v0.2) for the CPU.
+ Depends on KVM_CAP_ARM_PSCI_0_2.
+ - KVM_ARM_VCPU_PMU_V3: Emulate PMUv3 for the CPU.
+ Depends on KVM_CAP_ARM_PMU_V3.
+--- /dev/null
++++ b/Documentation/virtual/kvm/arm/psci.txt
+@@ -0,0 +1,30 @@
++KVM implements the PSCI (Power State Coordination Interface)
++specification in order to provide services such as CPU on/off, reset
++and power-off to the guest.
++
++The PSCI specification is regularly updated to provide new features,
++and KVM implements these updates if they make sense from a virtualization
++point of view.
++
++This means that a guest booted on two different versions of KVM can
++observe two different "firmware" revisions. This could cause issues if
++a given guest is tied to a particular PSCI revision (unlikely), or if
++a migration causes a different PSCI version to be exposed out of the
++blue to an unsuspecting guest.
++
++In order to remedy this situation, KVM exposes a set of "firmware
++pseudo-registers" that can be manipulated using the GET/SET_ONE_REG
++interface. These registers can be saved/restored by userspace, and set
++to a convenient value if required.
++
++The following register is defined:
++
++* KVM_REG_ARM_PSCI_VERSION:
++
++ - Only valid if the vcpu has the KVM_ARM_VCPU_PSCI_0_2 feature set
++ (and thus has already been initialized)
++ - Returns the current PSCI version on GET_ONE_REG (defaulting to the
++ highest PSCI version implemented by KVM and compatible with v0.2)
++ - Allows any PSCI version implemented by KVM and compatible with
++ v0.2 to be set with SET_ONE_REG
++ - Affects the whole VM (even if the register view is per-vcpu)
+--- a/arch/arm/include/asm/kvm_host.h
++++ b/arch/arm/include/asm/kvm_host.h
+@@ -75,6 +75,9 @@ struct kvm_arch {
+ /* Interrupt controller */
+ struct vgic_dist vgic;
+ int max_vcpus;
++
++ /* Mandated version of PSCI */
++ u32 psci_version;
+ };
+
+ #define KVM_NR_MEM_OBJS 40
+--- a/arch/arm/include/uapi/asm/kvm.h
++++ b/arch/arm/include/uapi/asm/kvm.h
+@@ -180,6 +180,12 @@ struct kvm_arch_memory_slot {
+ #define KVM_REG_ARM_VFP_FPINST 0x1009
+ #define KVM_REG_ARM_VFP_FPINST2 0x100A
+
++/* KVM-as-firmware specific pseudo-registers */
++#define KVM_REG_ARM_FW (0x0014 << KVM_REG_ARM_COPROC_SHIFT)
++#define KVM_REG_ARM_FW_REG(r) (KVM_REG_ARM | KVM_REG_SIZE_U64 | \
++ KVM_REG_ARM_FW | ((r) & 0xffff))
++#define KVM_REG_ARM_PSCI_VERSION KVM_REG_ARM_FW_REG(0)
++
+ /* Device Control API: ARM VGIC */
+ #define KVM_DEV_ARM_VGIC_GRP_ADDR 0
+ #define KVM_DEV_ARM_VGIC_GRP_DIST_REGS 1
+--- a/arch/arm/kvm/guest.c
++++ b/arch/arm/kvm/guest.c
+@@ -22,6 +22,7 @@
+ #include <linux/module.h>
+ #include <linux/vmalloc.h>
+ #include <linux/fs.h>
++#include <kvm/arm_psci.h>
+ #include <asm/cputype.h>
+ #include <linux/uaccess.h>
+ #include <asm/kvm.h>
+@@ -176,6 +177,7 @@ static unsigned long num_core_regs(void)
+ unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu)
+ {
+ return num_core_regs() + kvm_arm_num_coproc_regs(vcpu)
++ + kvm_arm_get_fw_num_regs(vcpu)
+ + NUM_TIMER_REGS;
+ }
+
+@@ -196,6 +198,11 @@ int kvm_arm_copy_reg_indices(struct kvm_
+ uindices++;
+ }
+
++ ret = kvm_arm_copy_fw_reg_indices(vcpu, uindices);
++ if (ret)
++ return ret;
++ uindices += kvm_arm_get_fw_num_regs(vcpu);
++
+ ret = copy_timer_indices(vcpu, uindices);
+ if (ret)
+ return ret;
+@@ -214,6 +221,9 @@ int kvm_arm_get_reg(struct kvm_vcpu *vcp
+ if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE)
+ return get_core_reg(vcpu, reg);
+
++ if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_FW)
++ return kvm_arm_get_fw_reg(vcpu, reg);
++
+ if (is_timer_reg(reg->id))
+ return get_timer_reg(vcpu, reg);
+
+@@ -230,6 +240,9 @@ int kvm_arm_set_reg(struct kvm_vcpu *vcp
+ if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE)
+ return set_core_reg(vcpu, reg);
+
++ if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_FW)
++ return kvm_arm_set_fw_reg(vcpu, reg);
++
+ if (is_timer_reg(reg->id))
+ return set_timer_reg(vcpu, reg);
+
+--- a/arch/arm64/include/asm/kvm_host.h
++++ b/arch/arm64/include/asm/kvm_host.h
+@@ -71,6 +71,9 @@ struct kvm_arch {
+
+ /* Interrupt controller */
+ struct vgic_dist vgic;
++
++ /* Mandated version of PSCI */
++ u32 psci_version;
+ };
+
+ #define KVM_NR_MEM_OBJS 40
+--- a/arch/arm64/include/uapi/asm/kvm.h
++++ b/arch/arm64/include/uapi/asm/kvm.h
+@@ -200,6 +200,12 @@ struct kvm_arch_memory_slot {
+ #define KVM_REG_ARM_TIMER_CNT ARM64_SYS_REG(3, 3, 14, 3, 2)
+ #define KVM_REG_ARM_TIMER_CVAL ARM64_SYS_REG(3, 3, 14, 0, 2)
+
++/* KVM-as-firmware specific pseudo-registers */
++#define KVM_REG_ARM_FW (0x0014 << KVM_REG_ARM_COPROC_SHIFT)
++#define KVM_REG_ARM_FW_REG(r) (KVM_REG_ARM64 | KVM_REG_SIZE_U64 | \
++ KVM_REG_ARM_FW | ((r) & 0xffff))
++#define KVM_REG_ARM_PSCI_VERSION KVM_REG_ARM_FW_REG(0)
++
+ /* Device Control API: ARM VGIC */
+ #define KVM_DEV_ARM_VGIC_GRP_ADDR 0
+ #define KVM_DEV_ARM_VGIC_GRP_DIST_REGS 1
+--- a/arch/arm64/kvm/guest.c
++++ b/arch/arm64/kvm/guest.c
+@@ -25,6 +25,7 @@
+ #include <linux/module.h>
+ #include <linux/vmalloc.h>
+ #include <linux/fs.h>
++#include <kvm/arm_psci.h>
+ #include <asm/cputype.h>
+ #include <linux/uaccess.h>
+ #include <asm/kvm.h>
+@@ -205,7 +206,7 @@ static int get_timer_reg(struct kvm_vcpu
+ unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu)
+ {
+ return num_core_regs() + kvm_arm_num_sys_reg_descs(vcpu)
+- + NUM_TIMER_REGS;
++ + kvm_arm_get_fw_num_regs(vcpu) + NUM_TIMER_REGS;
+ }
+
+ /**
+@@ -225,6 +226,11 @@ int kvm_arm_copy_reg_indices(struct kvm_
+ uindices++;
+ }
+
++ ret = kvm_arm_copy_fw_reg_indices(vcpu, uindices);
++ if (ret)
++ return ret;
++ uindices += kvm_arm_get_fw_num_regs(vcpu);
++
+ ret = copy_timer_indices(vcpu, uindices);
+ if (ret)
+ return ret;
+@@ -243,6 +249,9 @@ int kvm_arm_get_reg(struct kvm_vcpu *vcp
+ if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE)
+ return get_core_reg(vcpu, reg);
+
++ if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_FW)
++ return kvm_arm_get_fw_reg(vcpu, reg);
++
+ if (is_timer_reg(reg->id))
+ return get_timer_reg(vcpu, reg);
+
+@@ -259,6 +268,9 @@ int kvm_arm_set_reg(struct kvm_vcpu *vcp
+ if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE)
+ return set_core_reg(vcpu, reg);
+
++ if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_FW)
++ return kvm_arm_set_fw_reg(vcpu, reg);
++
+ if (is_timer_reg(reg->id))
+ return set_timer_reg(vcpu, reg);
+
+--- a/include/kvm/arm_psci.h
++++ b/include/kvm/arm_psci.h
+@@ -37,10 +37,15 @@ static inline int kvm_psci_version(struc
+ * Our PSCI implementation stays the same across versions from
+ * v0.2 onward, only adding the few mandatory functions (such
+ * as FEATURES with 1.0) that are required by newer
+- * revisions. It is thus safe to return the latest.
++ * revisions. It is thus safe to return the latest, unless
++ * userspace has instructed us otherwise.
+ */
+- if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features))
++ if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features)) {
++ if (vcpu->kvm->arch.psci_version)
++ return vcpu->kvm->arch.psci_version;
++
+ return KVM_ARM_PSCI_LATEST;
++ }
+
+ return KVM_ARM_PSCI_0_1;
+ }
+@@ -48,4 +53,11 @@ static inline int kvm_psci_version(struc
+
+ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu);
+
++struct kvm_one_reg;
++
++int kvm_arm_get_fw_num_regs(struct kvm_vcpu *vcpu);
++int kvm_arm_copy_fw_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices);
++int kvm_arm_get_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg);
++int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg);
++
+ #endif /* __KVM_ARM_PSCI_H__ */
+--- a/virt/kvm/arm/psci.c
++++ b/virt/kvm/arm/psci.c
+@@ -18,6 +18,7 @@
+ #include <linux/arm-smccc.h>
+ #include <linux/preempt.h>
+ #include <linux/kvm_host.h>
++#include <linux/uaccess.h>
+ #include <linux/wait.h>
+
+ #include <asm/cputype.h>
+@@ -427,3 +428,62 @@ int kvm_hvc_call_handler(struct kvm_vcpu
+ smccc_set_retval(vcpu, val, 0, 0, 0);
+ return 1;
+ }
++
++int kvm_arm_get_fw_num_regs(struct kvm_vcpu *vcpu)
++{
++ return 1; /* PSCI version */
++}
++
++int kvm_arm_copy_fw_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
++{
++ if (put_user(KVM_REG_ARM_PSCI_VERSION, uindices))
++ return -EFAULT;
++
++ return 0;
++}
++
++int kvm_arm_get_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
++{
++ if (reg->id == KVM_REG_ARM_PSCI_VERSION) {
++ void __user *uaddr = (void __user *)(long)reg->addr;
++ u64 val;
++
++ val = kvm_psci_version(vcpu, vcpu->kvm);
++ if (copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id)))
++ return -EFAULT;
++
++ return 0;
++ }
++
++ return -EINVAL;
++}
++
++int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
++{
++ if (reg->id == KVM_REG_ARM_PSCI_VERSION) {
++ void __user *uaddr = (void __user *)(long)reg->addr;
++ bool wants_02;
++ u64 val;
++
++ if (copy_from_user(&val, uaddr, KVM_REG_SIZE(reg->id)))
++ return -EFAULT;
++
++ wants_02 = test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features);
++
++ switch (val) {
++ case KVM_ARM_PSCI_0_1:
++ if (wants_02)
++ return -EINVAL;
++ vcpu->kvm->arch.psci_version = val;
++ return 0;
++ case KVM_ARM_PSCI_0_2:
++ case KVM_ARM_PSCI_1_0:
++ if (!wants_02)
++ return -EINVAL;
++ vcpu->kvm->arch.psci_version = val;
++ return 0;
++ }
++ }
++
++ return -EINVAL;
++}
projects / thirdparty / kernel / stable-queue.git / commitdiff
