Tao Su [Tue, 5 Nov 2024 05:48:25 +0000 (13:48 +0800)]
x86: KVM: Advertise CPUIDs for new instructions in Clearwater Forest
Latest Intel platform Clearwater Forest has introduced new instructions
enumerated by CPUIDs of SHA512, SM3, SM4 and AVX-VNNI-INT16. Advertise
these CPUIDs to userspace so that guests can query them directly.
SHA512, SM3 and SM4 are on an expected-dense CPUID leaf and some other
bits on this leaf have kernel usages. Considering they have not truly
kernel usages, hide them in /proc/cpuinfo.
These new instructions only operate in xmm, ymm registers and have no new
VMX controls, so there is no additional host enabling required for guests
to use these instructions, i.e. advertising these CPUIDs to userspace is
safe.
Tested-by: Jiaan Lu <jiaan.lu@intel.com> Tested-by: Xuelian Guo <xuelian.guo@intel.com> Signed-off-by: Tao Su <tao1.su@linux.intel.com>
Message-ID: <20241105054825.870939-1-tao1.su@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Wed, 13 Nov 2024 12:19:23 +0000 (07:19 -0500)]
Documentation: KVM: fix malformed table
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Fixes: 5f6a3badbb74 ("KVM: x86/mmu: Mark page/folio accessed only when zapping leaf SPTEs") Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Wed, 13 Nov 2024 11:33:00 +0000 (06:33 -0500)]
Merge tag 'kvm-x86-misc-6.13' of https://github.com/kvm-x86/linux into HEAD
KVM x86 misc changes for 6.13
- Clean up and optimize KVM's handling of writes to MSR_IA32_APICBASE.
- Quirk KVM's misguided behavior of initialized certain feature MSRs to
their maximum supported feature set, which can result in KVM creating
invalid vCPU state. E.g. initializing PERF_CAPABILITIES to a non-zero
value results in the vCPU having invalid state if userspace hides PDCM
from the guest, which can lead to save/restore failures.
- Fix KVM's handling of non-canonical checks for vCPUs that support LA57
to better follow the "architecture", in quotes because the actual
behavior is poorly documented. E.g. most MSR writes and descriptor
table loads ignore CR4.LA57 and operate purely on whether the CPU
supports LA57.
- Bypass the register cache when querying CPL from kvm_sched_out(), as
filling the cache from IRQ context is generally unsafe, and harden the
cache accessors to try to prevent similar issues from occuring in the
future.
- Advertise AMD_IBPB_RET to userspace, and fix a related bug where KVM
over-advertises SPEC_CTRL when trying to support cross-vendor VMs.
Paolo Bonzini [Wed, 13 Nov 2024 11:32:43 +0000 (06:32 -0500)]
Merge tag 'kvm-x86-vmx-6.13' of https://github.com/kvm-x86/linux into HEAD
KVM VMX change for 6.13
- Remove __invept()'s unused @gpa param, which was left behind when KVM
dropped code for invalidating a specific GPA (Intel never officially
documented support for single-address INVEPT; presumably pre-production
CPUs supported it at some point).
Paolo Bonzini [Wed, 13 Nov 2024 11:31:54 +0000 (06:31 -0500)]
Merge tag 'kvm-x86-mmu-6.13' of https://github.com/kvm-x86/linux into HEAD
KVM x86 MMU changes for 6.13
- Cleanup KVM's handling of Accessed and Dirty bits to dedup code, improve
documentation, harden against unexpected changes, and to simplify
A/D-disabled MMUs by using the hardware-defined A/D bits to track if a
PFN is Accessed and/or Dirty.
- Elide TLB flushes when aging SPTEs, as has been done in x86's primary
MMU for over 10 years.
- Batch TLB flushes when zapping collapsible TDP MMU SPTEs, i.e. when
dirty logging is toggled off, which reduces the time it takes to disable
dirty logging by ~3x.
- Recover huge pages in-place in the TDP MMU instead of zapping the SP
and waiting until the page is re-accessed to create a huge mapping.
Proactively installing huge pages can reduce vCPU jitter in extreme
scenarios.
- Remove support for (poorly) reclaiming page tables in shadow MMUs via
the primary MMU's shrinker interface.
Paolo Bonzini [Wed, 13 Nov 2024 11:24:19 +0000 (06:24 -0500)]
Merge tag 'kvm-x86-generic-6.13' of https://github.com/kvm-x86/linux into HEAD
KVM generic changes for 6.13
- Rework kvm_vcpu_on_spin() to use a single for-loop instead of making two
partial poasses over "all" vCPUs. Opportunistically expand the comment
to better explain the motivation and logic.
- Protect vcpu->pid accesses outside of vcpu->mutex with a rwlock instead
of RCU, so that running a vCPU on a different task doesn't encounter
long stalls due to having to wait for all CPUs become quiescent.
KVM: s390: selftests: Add regression tests for PFCR subfunctions
Check if the PFCR query reported in userspace coincides with the
kernel reported function list. Right now we don't mask the functions
in the kernel so they have to be the same.
Signed-off-by: Hendrik Brueckner <brueckner@linux.ibm.com> Reviewed-by: Hariharan Mari <hari55@linux.ibm.com> Link: https://lore.kernel.org/r/20241107152319.77816-5-brueckner@linux.ibm.com
[frankja@linux.ibm.com: Added commit description] Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Message-ID: <20241107152319.77816-5-brueckner@linux.ibm.com>
Message-security-assist 11 introduces pckmo subfunctions to encrypt
hmac keys.
Signed-off-by: Hendrik Brueckner <brueckner@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20241107152319.77816-3-brueckner@linux.ibm.com Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Message-ID: <20241107152319.77816-3-brueckner@linux.ibm.com>
KVM: s390: selftests: Verify reject memory region operations for ucontrol VMs
Add a test case verifying KVM_SET_USER_MEMORY_REGION and
KVM_SET_USER_MEMORY_REGION2 cannot be executed on ucontrol VMs.
Executing this test case on not patched kernels will cause a null
pointer dereference in the host kernel.
This is fixed with commit:
commit 7816e58967d0 ("kvm: s390: Reject memory region operations for ucontrol VMs")
Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20241107141024.238916-4-schlameuss@linux.ibm.com
[frankja@linux.ibm.com: Fixed patch prefix] Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Message-ID: <20241107141024.238916-4-schlameuss@linux.ibm.com>
Add a test case manipulating s390 storage keys from within the ucontrol
VM.
Storage key instruction (ISKE, SSKE and RRBE) intercepts and
Keyless-subset facility are disabled on first use, where the skeys are
setup by KVM in non ucontrol VMs.
KVM: s390: selftests: Add uc_map_unmap VM test case
Add a test case verifying basic running and interaction of ucontrol VMs.
Fill the segment and page tables for allocated memory and map memory on
first access.
* uc_map_unmap
Store and load data to mapped and unmapped memory and use pic segment
translation handling to map memory on access.
Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Link:
https://lore.kernel.org/r/20241107141024.238916-2-schlameuss@linux.ibm.com
[frankja@linux.ibm.com: Fixed patch prefix] Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Message-ID: <20241107141024.238916-2-schlameuss@linux.ibm.com>
Paolo Bonzini [Wed, 23 Oct 2024 12:45:06 +0000 (14:45 +0200)]
Documentation: kvm: reorganize introduction
Reorganize the text to mention file descriptors as early as possible.
Also mention capabilities early as they are a central part of KVM's
API.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20241023124507.280382-5-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Wed, 23 Oct 2024 12:45:05 +0000 (14:45 +0200)]
Documentation: kvm: replace section numbers with links
In order to simplify further introduction of hyperlinks, replace explicit
section numbers with rST hyperlinks. The section numbers could actually
be removed now, but I'm not going to do a huge change throughout the file
for an RFC...
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20241023124507.280382-4-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Wed, 23 Oct 2024 12:45:04 +0000 (14:45 +0200)]
Documentation: kvm: fix a few mistakes
The only occurrence "Capability: none" actually meant the same as "basic".
Fix that and a few more aesthetic or content issues in the document.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20241023124507.280382-3-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Wed, 23 Oct 2024 12:45:03 +0000 (14:45 +0200)]
KVM: powerpc: remove remaining traces of KVM_CAP_PPC_RMA
This was only needed for PPC970 support, which is long gone: the
implementation was removed in 2014.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20241023124507.280382-2-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Hide KVM's pt_mode module param behind CONFIG_BROKEN, i.e. disable support
for virtualizing Intel PT via guest/host mode unless BROKEN=y. There are
myriad bugs in the implementation, some of which are fatal to the guest,
and others which put the stability and health of the host at risk.
For guest fatalities, the most glaring issue is that KVM fails to ensure
tracing is disabled, and *stays* disabled prior to VM-Enter, which is
necessary as hardware disallows loading (the guest's) RTIT_CTL if tracing
is enabled (enforced via a VMX consistency check). Per the SDM:
If the logical processor is operating with Intel PT enabled (if
IA32_RTIT_CTL.TraceEn = 1) at the time of VM entry, the "load
IA32_RTIT_CTL" VM-entry control must be 0.
On the host side, KVM doesn't validate the guest CPUID configuration
provided by userspace, and even worse, uses the guest configuration to
decide what MSRs to save/load at VM-Enter and VM-Exit. E.g. configuring
guest CPUID to enumerate more address ranges than are supported in hardware
will result in KVM trying to passthrough, save, and load non-existent MSRs,
which generates a variety of WARNs, ToPA ERRORs in the host, a potential
deadlock, etc.
Fixes: f99e3daf94ff ("KVM: x86: Add Intel PT virtualization work mode") Cc: stable@vger.kernel.org Cc: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Tested-by: Adrian Hunter <adrian.hunter@intel.com>
Message-ID: <20241101185031.1799556-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: x86: Unconditionally set irr_pending when updating APICv state
Always set irr_pending (to true) when updating APICv status to fix a bug
where KVM fails to set irr_pending when userspace sets APIC state and
APICv is disabled, which ultimate results in KVM failing to inject the
pending interrupt(s) that userspace stuffed into the vIRR, until another
interrupt happens to be emulated by KVM.
Only the APICv-disabled case is flawed, as KVM forces apic->irr_pending to
be true if APICv is enabled, because not all vIRR updates will be visible
to KVM.
Hit the bug with a big hammer, even though strictly speaking KVM can scan
the vIRR and set/clear irr_pending as appropriate for this specific case.
The bug was introduced by commit 755c2bf87860 ("KVM: x86: lapic: don't
touch irr_pending in kvm_apic_update_apicv when inhibiting it"), which as
the shortlog suggests, deleted code that updated irr_pending.
Before that commit, kvm_apic_update_apicv() did indeed scan the vIRR, with
with the crucial difference that kvm_apic_update_apicv() did the scan even
when APICv was being *disabled*, e.g. due to an AVIC inhibition.
struct kvm_lapic *apic = vcpu->arch.apic;
if (vcpu->arch.apicv_active) {
/* irr_pending is always true when apicv is activated. */
apic->irr_pending = true;
apic->isr_count = 1;
} else {
apic->irr_pending = (apic_search_irr(apic) != -1);
apic->isr_count = count_vectors(apic->regs + APIC_ISR);
}
And _that_ bug (clearing irr_pending) was introduced by commit b26a695a1d78
("kvm: lapic: Introduce APICv update helper function"), prior to which KVM
unconditionally set irr_pending to true in kvm_apic_set_state(), i.e.
assumed that the new virtual APIC state could have a pending IRQ.
Furthermore, in addition to introducing this issue, commit 755c2bf87860
also papered over the underlying bug: KVM doesn't ensure CPUs and devices
see APICv as disabled prior to searching the IRR. Waiting until KVM
emulates an EOI to update irr_pending "works", but only because KVM won't
emulate EOI until after refresh_apicv_exec_ctrl(), and there are plenty of
memory barriers in between. I.e. leaving irr_pending set is basically
hacking around bad ordering.
So, effectively revert to the pre-b26a695a1d78 behavior for state restore,
even though it's sub-optimal if no IRQs are pending, in order to provide a
minimal fix, but leave behind a FIXME to document the ugliness. With luck,
the ordering issue will be fixed and the mess will be cleaned up in the
not-too-distant future.
Fixes: 755c2bf87860 ("KVM: x86: lapic: don't touch irr_pending in kvm_apic_update_apicv when inhibiting it") Cc: stable@vger.kernel.org Cc: Maxim Levitsky <mlevitsk@redhat.com> Reported-by: Yong He <zhuangel570@gmail.com> Closes: https://lkml.kernel.org/r/20241023124527.1092810-1-alexyonghe%40tencent.com Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20241106015135.2462147-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
John Sperbeck [Wed, 6 Nov 2024 03:40:31 +0000 (19:40 -0800)]
KVM: selftests: use X86_MEMTYPE_WB instead of VMX_BASIC_MEM_TYPE_WB
In 08a7d2525511 ("tools arch x86: Sync the msr-index.h copy with the
kernel sources"), VMX_BASIC_MEM_TYPE_WB was removed. Use X86_MEMTYPE_WB
instead.
Fixes: 08a7d2525511 ("tools arch x86: Sync the msr-index.h copy with the
kernel sources") Signed-off-by: John Sperbeck <jsperbeck@google.com>
Message-ID: <20241106034031.503291-1-jsperbeck@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Fri, 8 Nov 2024 09:01:38 +0000 (04:01 -0500)]
Merge tag 'kvm-x86-fixes-6.12-rcN' of https://github.com/kvm-x86/linux into HEAD
KVM x86 and selftests fixes for 6.12:
- Increase the timeout for the memslot performance selftest to avoid false
failures on arm64 and nested x86 platforms.
- Fix a goof in the guest_memfd selftest where a for-loop initialized a
bit mask to zero instead of BIT(0).
- Disable strict aliasing when building KVM selftests to prevent the
compiler from treating things like "u64 *" to "uint64_t *" cases as
undefined behavior, which can lead to nasty, hard to debug failures.
- Force -march=x86-64-v2 for KVM x86 selftests if and only if the uarch
is supported by the compiler.
- When emulating a guest TLB flush for a nested guest, flush vpid01, not
vpid02, if L2 is active but VPID is disabled in vmcs12, i.e. if L2 and
L1 are sharing VPID '0' (from L1's perspective).
- Fix a bug in the SNP initialization flow where KVM would return '0' to
userspace instead of -errno on failure.
Björn Töpel [Mon, 4 Nov 2024 19:15:01 +0000 (20:15 +0100)]
riscv: kvm: Fix out-of-bounds array access
In kvm_riscv_vcpu_sbi_init() the entry->ext_idx can contain an
out-of-bound index. This is used as a special marker for the base
extensions, that cannot be disabled. However, when traversing the
extensions, that special marker is not checked prior indexing the
array.
Add an out-of-bounds check to the function.
Fixes: 56d8a385b605 ("RISC-V: KVM: Allow some SBI extensions to be disabled by default") Signed-off-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Link: https://lore.kernel.org/r/20241104191503.74725-1-bjorn@kernel.org Signed-off-by: Anup Patel <anup@brainfault.org>
Yong-Xuan Wang [Tue, 29 Oct 2024 08:55:39 +0000 (16:55 +0800)]
RISC-V: KVM: Fix APLIC in_clrip and clripnum write emulation
In the section "4.7 Precise effects on interrupt-pending bits"
of the RISC-V AIA specification defines that:
"If the source mode is Level1 or Level0 and the interrupt domain
is configured in MSI delivery mode (domaincfg.DM = 1):
The pending bit is cleared whenever the rectified input value is
low, when the interrupt is forwarded by MSI, or by a relevant
write to an in_clrip register or to clripnum."
Update the aplic_write_pending() to match the spec.
KVM: SVM: Propagate error from snp_guest_req_init() to userspace
If snp_guest_req_init() fails, return the provided error code up the
stack to userspace, e.g. so that userspace can log that KVM_SEV_INIT2
failed, as opposed to some random operation later in VM setup failing
because SNP wasn't actually enabled for the VM.
Note, KVM itself doesn't consult the return value from __sev_guest_init(),
i.e. the fallout is purely that userspace may be confused.
Fixes: 88caf544c930 ("KVM: SEV: Provide support for SNP_GUEST_REQUEST NAE event") Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lore.kernel.org/r/202410192220.MeTyHPxI-lkp@intel.com Link: https://lore.kernel.org/r/20241031203214.1585751-1-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
KVM: nVMX: Treat vpid01 as current if L2 is active, but with VPID disabled
When getting the current VPID, e.g. to emulate a guest TLB flush, return
vpid01 if L2 is running but with VPID disabled, i.e. if VPID is disabled
in vmcs12. Architecturally, if VPID is disabled, then the guest and host
effectively share VPID=0. KVM emulates this behavior by using vpid01 when
running an L2 with VPID disabled (see prepare_vmcs02_early_rare()), and so
KVM must also treat vpid01 as the current VPID while L2 is active.
Unconditionally treating vpid02 as the current VPID when L2 is active
causes KVM to flush TLB entries for vpid02 instead of vpid01, which
results in TLB entries from L1 being incorrectly preserved across nested
VM-Enter to L2 (L2=>L1 isn't problematic, because the TLB flush after
nested VM-Exit flushes vpid01).
The bug manifests as failures in the vmx_apicv_test KVM-Unit-Test, as KVM
incorrectly retains TLB entries for the APIC-access page across a nested
VM-Enter.
Opportunisticaly add comments at various touchpoints to explain the
architectural requirements, and also why KVM uses vpid01 instead of vpid02.
All credit goes to Chao, who root caused the issue and identified the fix.
KVM: selftests: Don't force -march=x86-64-v2 if it's unsupported
Force -march=x86-64-v2 to avoid SSE/AVX instructions if and only if the
uarch definition is supported by the compiler, e.g. gcc 7.5 only supports
x86-64.
Disable strict aliasing, as has been done in the kernel proper for decades
(literally since before git history) to fix issues where gcc will optimize
away loads in code that looks 100% correct, but is _technically_ undefined
behavior, and thus can be thrown away by the compiler.
E.g. arm64's vPMU counter access test casts a uint64_t (unsigned long)
pointer to a u64 (unsigned long long) pointer when setting PMCR.N via
u64p_replace_bits(), which gcc-13 detects and optimizes away, i.e. ignores
the result and uses the original PMCR.
The issue is most easily observed by making set_pmcr_n() noinline and
wrapping the call with printf(), e.g. sans comments, for this code:
with the value stored in [sp + 0x60] ignored by both printf() above and
in the test proper, resulting in a false failure due to vcpu_set_reg()
simply storing the original value, not the intended value.
$ ./vpmu_counter_access
Random seed: 0x6b8b4567
orig = 3040, next = 3040, want = 0
orig = 3040, next = 3040, want = 0
==== Test Assertion Failure ====
aarch64/vpmu_counter_access.c:505: pmcr_n == get_pmcr_n(pmcr)
pid=71578 tid=71578 errno=9 - Bad file descriptor
1 0x400673: run_access_test at vpmu_counter_access.c:522
2 (inlined by) main at vpmu_counter_access.c:643
3 0x4132d7: __libc_start_call_main at libc-start.o:0
4 0x413653: __libc_start_main at ??:0
5 0x40106f: _start at ??:0
Failed to update PMCR.N to 0 (received: 6)
Somewhat bizarrely, gcc-11 also exhibits the same behavior, but only if
set_pmcr_n() is marked noinline, whereas gcc-13 fails even if set_pmcr_n()
is inlined in its sole caller.
Patrick Roy [Thu, 24 Oct 2024 09:59:53 +0000 (10:59 +0100)]
KVM: selftests: fix unintentional noop test in guest_memfd_test.c
The loop in test_create_guest_memfd_invalid() that is supposed to test
that nothing is accepted as a valid flag to KVM_CREATE_GUEST_MEMFD was
initializing `flag` as 0 instead of BIT(0). This caused the loop to
immediately exit instead of iterating over BIT(0), BIT(1), ... .
Fixes: 8a89efd43423 ("KVM: selftests: Add basic selftest for guest_memfd()") Signed-off-by: Patrick Roy <roypat@amazon.co.uk> Reviewed-by: James Gowans <jgowans@amazon.com> Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Link: https://lore.kernel.org/r/20241024095956.3668818-1-roypat@amazon.co.uk Signed-off-by: Sean Christopherson <seanjc@google.com>
When memslot_perf_test is run nested, first iteration of test_memslot_rw_loop
testcase, sometimes takes more than 2 seconds due to build of shadow page tables.
Following iterations are fast.
To be on the safe side, bump the timeout to 10 seconds.
KVM: x86: Short-circuit all of kvm_apic_set_base() if MSR value is unchanged
Do nothing in all of kvm_apic_set_base(), not just __kvm_apic_set_base(),
if the incoming MSR value is the same as the current value. Validating
the mode transitions is obviously unnecessary, and rejecting the write is
pointless if the vCPU already has an invalid value, e.g. if userspace is
doing weird things and modified guest CPUID after setting MSR_IA32_APICBASE.
Bailing early avoids kvm_recalculate_apic_map()'s slow path in the rare
scenario where the map is DIRTY due to some other vCPU dirtying the map,
in which case it's the other vCPU/task's responsibility to recalculate the
map.
Note, kvm_lapic_reset() calls __kvm_apic_set_base() only when emulating
RESET, in which case the old value is guaranteed to be zero, and the new
value is guaranteed to be non-zero. I.e. all callers of
__kvm_apic_set_base() effectively pre-check for the MSR value actually
changing. Don't bother keeping the check in __kvm_apic_set_base(), as no
additional callers are expected, and implying that the MSR might already
be non-zero at the time of kvm_lapic_reset() could confuse readers.
KVM: x86: Unpack msr_data structure prior to calling kvm_apic_set_base()
Pass in the new value and "host initiated" as separate parameters to
kvm_apic_set_base(), as forcing the KVM_SET_SREGS path to declare and fill
an msr_data structure is awkward and kludgy, e.g. __set_sregs_common()
doesn't even bother to set the proper MSR index.
KVM: x86: Rename APIC base setters to better capture their relationship
Rename kvm_set_apic_base() and kvm_lapic_set_base() to kvm_apic_set_base()
and __kvm_apic_set_base() respectively to capture that the underscores
version is a "special" variant (it exists purely to avoid recalculating
the optimized map multiple times when stuffing the RESET value).
Opportunistically add a comment explaining why kvm_lapic_reset() uses the
inner helper. Note, KVM deliberately invokes kvm_arch_vcpu_create() while
kvm->lock is NOT held so that vCPU setup isn't serialized if userspace is
creating multiple/all vCPUs in parallel. I.e. triggering an extra
recalculation is not limited to theoretical/rare edge cases, and so is
worth avoiding.
KVM: x86: Move kvm_set_apic_base() implementation to lapic.c (from x86.c)
Move kvm_set_apic_base() to lapic.c so that the bulk of KVM's local APIC
code resides in lapic.c, regardless of whether or not KVM is emulating the
local APIC in-kernel. This will also allow making various helpers visible
only to lapic.c.
Inline kvm_get_apic_mode() in lapic.h to avoid a CALL+RET as well as an
export. The underlying kvm_apic_mode() helper is public information, i.e.
there is no state/information that needs to be hidden from vendor modules.
KVM: x86: Get vcpu->arch.apic_base directly and drop kvm_get_apic_base()
Access KVM's emulated APIC base MSR value directly instead of bouncing
through a helper, as there is no reason to add a layer of indirection, and
there are other MSRs with a "set" but no "get", e.g. EFER.
KVM: x86: Drop superfluous kvm_lapic_set_base() call when setting APIC state
Now that kvm_lapic_set_base() does nothing if the "new" APIC base MSR is
the same as the current value, drop the kvm_lapic_set_base() call in the
KVM_SET_LAPIC flow that passes in the current value, as it too does
nothing.
Note, the purpose of invoking kvm_lapic_set_base() was purely to set
apic->base_address (see commit 5dbc8f3fed0b ("KVM: use kvm_lapic_set_base()
to change apic_base")). And there is no evidence that explicitly setting
apic->base_address in KVM_SET_LAPIC ever had any functional impact; even
in the original commit 96ad2cc61324 ("KVM: in-kernel LAPIC save and restore
support"), all flows that set apic_base also set apic->base_address to the
same address. E.g. svm_create_vcpu() did open code a write to apic_base,
KVM: x86: Short-circuit all kvm_lapic_set_base() if MSR value isn't changing
Do nothing in kvm_lapic_set_base() if the APIC base MSR value is the same
as the current value. All flows except the handling of the base address
explicitly take effect if and only if relevant bits are changing.
For the base address, invoking kvm_lapic_set_base() before KVM initializes
the base to APIC_DEFAULT_PHYS_BASE during vCPU RESET would be a KVM bug,
i.e. KVM _must_ initialize apic->base_address before exposing the vCPU (to
userspace or KVM at-large).
Note, the inhibit is intended to be set if the base address is _changed_
from the default, i.e. is also covered by the RESET behavior.
Vipin Sharma [Fri, 1 Nov 2024 20:14:37 +0000 (13:14 -0700)]
KVM: x86/mmu: Drop per-VM zapped_obsolete_pages list
Drop the per-VM zapped_obsolete_pages list now that the usage from the
defunct mmu_shrinker is gone, and instead use a local list to track pages
in kvm_zap_obsolete_pages(), the sole remaining user of
zapped_obsolete_pages.
Opportunistically add an assertion to verify and document that slots_lock
must be held, i.e. that there can only be one active instance of
kvm_zap_obsolete_pages() at any given time, and by doing so also prove
that using a local list instead of a per-VM list doesn't change any
functionality (beyond trivialities like list initialization).
Vipin Sharma [Fri, 1 Nov 2024 20:14:37 +0000 (13:14 -0700)]
KVM: x86/mmu: Remove KVM's MMU shrinker
Remove KVM's MMU shrinker and (almost) all of its related code, as the
current implementation is very disruptive to VMs (if it ever runs),
without providing any meaningful benefit[1].
Alternatively, KVM could repurpose its shrinker, e.g. to reclaim pages
from the per-vCPU caches[2], but given that no one has complained about
lack of TDP MMU support for the shrinker in the 3+ years since the TDP MMU
was enabled by default, it's safe to say that there is likely no real use
case for initiating reclaim of KVM's page tables from the shrinker.
And while clever/cute, reclaiming the per-vCPU caches doesn't scale the
same way that reclaiming in-use page table pages does. E.g. the amount of
memory being used by a VM doesn't always directly correlate with the
number vCPUs, and even when it does, reclaiming a few pages from per-vCPU
caches likely won't make much of a dent in the VM's total memory usage,
especially for VMs with huge amounts of memory.
Lastly, if it turns out that there is a strong use case for dropping the
per-vCPU caches, re-introducing the shrinker registration is trivial
compared to the complexity of actually reclaiming pages from the caches.
David Matlack [Fri, 23 Aug 2024 23:56:48 +0000 (16:56 -0700)]
KVM: x86/mmu: WARN if huge page recovery triggered during dirty logging
WARN and bail out of recover_huge_pages_range() if dirty logging is
enabled. KVM shouldn't be recovering huge pages during dirty logging
anyway, since KVM needs to track writes at 4KiB. However it's not out of
the possibility that that changes in the future.
If KVM wants to recover huge pages during dirty logging, make_huge_spte()
must be updated to write-protect the new huge page mapping. Otherwise,
writes through the newly recovered huge page mapping will not be tracked.
Note that this potential risk did not exist back when KVM zapped to
recover huge page mappings, since subsequent accesses would just be
faulted in at PG_LEVEL_4K if dirty logging was enabled.
David Matlack [Fri, 23 Aug 2024 23:56:47 +0000 (16:56 -0700)]
KVM: x86/mmu: Rename make_huge_page_split_spte() to make_small_spte()
Rename make_huge_page_split_spte() to make_small_spte(). This ensures
that the usage of "small_spte" and "huge_spte" are consistent between
make_huge_spte() and make_small_spte().
This should also reduce some confusion as make_huge_page_split_spte()
almost reads like it will create a huge SPTE, when in fact it is
creating a small SPTE to split the huge SPTE.
Recover TDP MMU huge page mappings in-place instead of zapping them when
dirty logging is disabled, and rename functions that recover huge page
mappings when dirty logging is disabled to move away from the "zap
collapsible spte" terminology.
Before KVM flushes TLBs, guest accesses may be translated through either
the (stale) small SPTE or the (new) huge SPTE. This is already possible
when KVM is doing eager page splitting (where TLB flushes are also
batched), and when vCPUs are faulting in huge mappings (where TLBs are
flushed after the new huge SPTE is installed).
Recovering huge pages reduces the number of page faults when dirty
logging is disabled:
vCPU throughput and the latency of disabling dirty-logging are about
equal compared to zapping, but avoiding faults can be beneficial to
remove vCPU jitter in extreme scenarios.
KVM: x86/mmu: Demote the WARN on yielded in xxx_cond_resched() to KVM_MMU_WARN_ON
Convert the WARN in tdp_mmu_iter_cond_resched() that the iterator hasn't
already yielded to a KVM_MMU_WARN_ON() so the code is compiled out for
production kernels (assuming production kernels disable KVM_PROVE_MMU).
Checking for a needed reschedule is a hot path, and KVM sanity checks
iter->yielded in several other less-hot paths, i.e. the odds of KVM not
flagging that something went sideways are quite low. Furthermore, the
odds of KVM not noticing *and* the WARN detecting something worth
investigating are even lower.
KVM: x86/mmu: Check yielded_gfn for forward progress iff resched is needed
Swap the order of the checks in tdp_mmu_iter_cond_resched() so that KVM
checks to see if a resched is needed _before_ checking to see if yielding
must be disallowed to guarantee forward progress. Iterating over TDP MMU
SPTEs is a hot path, e.g. tearing down a root can touch millions of SPTEs,
and not needing to reschedule is by far the common case. On the other
hand, disallowing yielding because forward progress has not been made is a
very rare case.
Returning early for the common case (no resched), effectively reduces the
number of checks from 2 to 1 for the common case, and should make the code
slightly more predictable for the CPU.
To resolve a weird conundrum where the forward progress check currently
returns false, but the need resched check subtly returns iter->yielded,
which _should_ be false (enforced by a WARN), return false unconditionally
(which might also help make the sequence more predictable). If KVM has a
bug where iter->yielded is left danging, continuing to yield is neither
right nor wrong, it was simply an artifact of how the original code was
written.
Unconditionally returning false when yielding is unnecessary or unwanted
will also allow extracting the "should resched" logic to a separate helper
in a future patch.
Linus Torvalds [Sun, 3 Nov 2024 20:25:05 +0000 (10:25 -1000)]
Merge tag 'mm-hotfixes-stable-2024-11-03-10-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"17 hotfixes. 9 are cc:stable. 13 are MM and 4 are non-MM.
The usual collection of singletons - please see the changelogs"
* tag 'mm-hotfixes-stable-2024-11-03-10-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
mm: multi-gen LRU: use {ptep,pmdp}_clear_young_notify()
mm: multi-gen LRU: remove MM_LEAF_OLD and MM_NONLEAF_TOTAL stats
mm, mmap: limit THP alignment of anonymous mappings to PMD-aligned sizes
mm: shrinker: avoid memleak in alloc_shrinker_info
.mailmap: update e-mail address for Eugen Hristev
vmscan,migrate: fix page count imbalance on node stats when demoting pages
mailmap: update Jarkko's email addresses
mm: allow set/clear page_type again
nilfs2: fix potential deadlock with newly created symlinks
Squashfs: fix variable overflow in squashfs_readpage_block
kasan: remove vmalloc_percpu test
tools/mm: -Werror fixes in page-types/slabinfo
mm, swap: avoid over reclaim of full clusters
mm: fix PSWPIN counter for large folios swap-in
mm: avoid VM_BUG_ON when try to map an anon large folio to zero page.
mm/codetag: fix null pointer check logic for ref and tag
mm/gup: stop leaking pinned pages in low memory conditions
Linus Torvalds [Sun, 3 Nov 2024 20:15:50 +0000 (10:15 -1000)]
Merge tag 'dmaengine-fix-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine
Pull dmaengine fixes from Vinod Koul:
- TI driver fix to set EOP for cyclic BCDMA transfers
- sh rz-dmac driver fix for handling config with zero address
* tag 'dmaengine-fix-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine:
dmaengine: ti: k3-udma: Set EOP for all TRs in cyclic BCDMA transfer
dmaengine: sh: rz-dmac: handle configs where one address is zero
Linus Torvalds [Sun, 3 Nov 2024 18:51:53 +0000 (08:51 -1000)]
Merge tag 'driver-core-6.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core revert from Greg KH:
"Here is a single driver core revert for 6.12-rc6. It reverts a change
that came in -rc1 that was supposed to resolve a reported problem, but
caused another one, so revert it for now so that we can get this all
worked out properly in 6.13.
The revert has been in linux-next all week with no reported issues"
* tag 'driver-core-6.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
Revert "driver core: Fix uevent_show() vs driver detach race"
Linus Torvalds [Sun, 3 Nov 2024 18:48:11 +0000 (08:48 -1000)]
Merge tag 'usb-6.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB / Thunderbolt fixes from Greg KH:
"Here are some small USB and Thunderbolt driver fixes for 6.12-rc6 that
have been sitting in my tree this week. Included in here are the
following:
- thunderbolt driver fixes for reported issues
- USB typec driver fixes
- xhci driver fixes for reported problems
- dwc2 driver revert for a broken change
- usb phy driver fix
- usbip tool fix
All of these have been in linux-next this week with no reported
issues"
* tag 'usb-6.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
usb: typec: tcpm: restrict SNK_WAIT_CAPABILITIES_TIMEOUT transitions to non self-powered devices
usb: phy: Fix API devm_usb_put_phy() can not release the phy
usb: typec: use cleanup facility for 'altmodes_node'
usb: typec: fix unreleased fwnode_handle in typec_port_register_altmodes()
usb: typec: qcom-pmic-typec: fix missing fwnode removal in error path
usb: typec: qcom-pmic-typec: use fwnode_handle_put() to release fwnodes
usb: acpi: fix boot hang due to early incorrect 'tunneled' USB3 device links
Revert "usb: dwc2: Skip clock gating on Broadcom SoCs"
xhci: Fix Link TRB DMA in command ring stopped completion event
xhci: Use pm_runtime_get to prevent RPM on unsupported systems
usbip: tools: Fix detach_port() invalid port error path
thunderbolt: Honor TMU requirements in the domain when setting TMU mode
thunderbolt: Fix KASAN reported stack out-of-bounds read in tb_retimer_scan()
Yu Zhao [Sat, 19 Oct 2024 01:29:39 +0000 (01:29 +0000)]
mm: multi-gen LRU: use {ptep,pmdp}_clear_young_notify()
When the MM_WALK capability is enabled, memory that is mostly accessed by
a VM appears younger than it really is, therefore this memory will be less
likely to be evicted. Therefore, the presence of a running VM can
significantly increase swap-outs for non-VM memory, regressing the
performance for the rest of the system.
Fix this regression by always calling {ptep,pmdp}_clear_young_notify()
whenever we clear the young bits on PMDs/PTEs.
[jthoughton@google.com: fix link-time error] Link: https://lkml.kernel.org/r/20241019012940.3656292-3-jthoughton@google.com Fixes: bd74fdaea146 ("mm: multi-gen LRU: support page table walks") Signed-off-by: Yu Zhao <yuzhao@google.com> Signed-off-by: James Houghton <jthoughton@google.com> Reported-by: David Stevens <stevensd@google.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: David Matlack <dmatlack@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Oliver Upton <oliver.upton@linux.dev> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Wei Xu <weixugc@google.com> Cc: <stable@vger.kernel.org> Cc: kernel test robot <lkp@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Yu Zhao [Sat, 19 Oct 2024 01:29:38 +0000 (01:29 +0000)]
mm: multi-gen LRU: remove MM_LEAF_OLD and MM_NONLEAF_TOTAL stats
Patch series "mm: multi-gen LRU: Have secondary MMUs participate in
MM_WALK".
Today, the MM_WALK capability causes MGLRU to clear the young bit from
PMDs and PTEs during the page table walk before eviction, but MGLRU does
not call the clear_young() MMU notifier in this case. By not calling this
notifier, the MM walk takes less time/CPU, but it causes pages that are
accessed mostly through KVM / secondary MMUs to appear younger than they
should be.
We do call the clear_young() notifier today, but only when attempting to
evict the page, so we end up clearing young/accessed information less
frequently for secondary MMUs than for mm PTEs, and therefore they appear
younger and are less likely to be evicted. Therefore, memory that is
*not* being accessed mostly by KVM will be evicted *more* frequently,
worsening performance.
ChromeOS observed a tab-open latency regression when enabling MGLRU with a
setup that involved running a VM:
Tab-open latency histogram (ms)
Version p50 mean p95 p99 max
base 1315 1198 2347 3454 10319
mglru 2559 1311 7399 12060 43758
fix 1119 926 2470 4211 6947
This series replaces the final non-selftest patchs from this series[1],
which introduced a similar change (and a new MMU notifier) with KVM
optimizations. I'll send a separate series (to Sean and Paolo) for the
KVM optimizations.
This series also makes proactive reclaim with MGLRU possible for KVM
memory. I have verified that this functions correctly with the selftest
from [1], but given that that test is a KVM selftest, I'll send it with
the rest of the KVM optimizations later. Andrew, let me know if you'd
like to take the test now anyway.
The removed stats, MM_LEAF_OLD and MM_NONLEAF_TOTAL, are not very helpful
and become more complicated to properly compute when adding
test/clear_young() notifiers in MGLRU's mm walk.
Link: https://lkml.kernel.org/r/20241019012940.3656292-1-jthoughton@google.com Link: https://lkml.kernel.org/r/20241019012940.3656292-2-jthoughton@google.com Fixes: bd74fdaea146 ("mm: multi-gen LRU: support page table walks") Signed-off-by: Yu Zhao <yuzhao@google.com> Signed-off-by: James Houghton <jthoughton@google.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: David Matlack <dmatlack@google.com> Cc: David Rientjes <rientjes@google.com> Cc: David Stevens <stevensd@google.com> Cc: Oliver Upton <oliver.upton@linux.dev> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Wei Xu <weixugc@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Linus Torvalds [Sun, 3 Nov 2024 18:45:03 +0000 (08:45 -1000)]
Merge tag 'char-misc-6.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull misc driver fixes from Greg KH:
"Here are some small char/misc/iio fixes for 6.12-rc6 that resolve
some reported issues. Included in here are the following:
- small IIO driver fixes for many reported issues
- mei driver fix for a suddenly much reported issue for an "old"
issue.
- MAINTAINERS update for a developer who has moved companies and
forgot to update their old entry.
All of these have been in linux-next this week with no reported
issues"
* tag 'char-misc-6.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
mei: use kvmalloc for read buffer
MAINTAINERS: add netup_unidvb maintainer
iio: dac: Kconfig: Fix build error for ltc2664
iio: adc: ad7124: fix division by zero in ad7124_set_channel_odr()
staging: iio: frequency: ad9832: fix division by zero in ad9832_calc_freqreg()
docs: iio: ad7380: fix supply for ad7380-4
iio: adc: ad7380: fix supplies for ad7380-4
iio: adc: ad7380: add missing supplies
iio: adc: ad7380: use devm_regulator_get_enable_read_voltage()
dt-bindings: iio: adc: ad7380: fix ad7380-4 reference supply
iio: light: veml6030: fix microlux value calculation
iio: gts-helper: Fix memory leaks for the error path of iio_gts_build_avail_scale_table()
iio: gts-helper: Fix memory leaks in iio_gts_build_avail_scale_table()
Linus Torvalds [Sun, 3 Nov 2024 18:35:29 +0000 (08:35 -1000)]
Merge tag 'input-for-v6.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
Pull input fixes from Dmitry Torokhov:
- a fix for regression in input core introduced in 6.11 preventing
re-registering input handlers
- a fix for adp5588-keys driver tyring to disable interrupt 0 at
suspend when devices is used without interrupt
- a fix for edt-ft5x06 to stop leaking regmap structure when probing
fails and to make sure it is not released too early on removal.
* tag 'input-for-v6.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: fix regression when re-registering input handlers
Input: adp5588-keys - do not try to disable interrupt 0
Input: edt-ft5x06 - fix regmap leak when probe fails
Linus Torvalds [Sun, 3 Nov 2024 18:29:02 +0000 (08:29 -1000)]
Merge tag 'kbuild-fixes-v6.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild fixes from Masahiro Yamada:
- Fix a memory leak in modpost
- Resolve build issues when cross-compiling RPM and Debian packages
- Fix another regression in Kconfig
- Fix incorrect MODULE_ALIAS() output in modpost
* tag 'kbuild-fixes-v6.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
modpost: fix input MODULE_DEVICE_TABLE() built for 64-bit on 32-bit host
modpost: fix acpi MODULE_DEVICE_TABLE built with mismatched endianness
kconfig: show sub-menu entries even if the prompt is hidden
kbuild: deb-pkg: add pkg.linux-upstream.nokerneldbg build profile
kbuild: deb-pkg: add pkg.linux-upstream.nokernelheaders build profile
kbuild: rpm-pkg: disable kernel-devel package when cross-compiling
sumversion: Fix a memory leak in get_src_version()
Linus Torvalds [Sun, 3 Nov 2024 18:22:21 +0000 (08:22 -1000)]
Merge tag 'timers-urgent-2024-11-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Thomas Gleixner:
"A single fix for posix CPU timers.
When a thread is cloned, the posix CPU timers are not inherited.
If the parent has a CPU timer armed the corresponding tick dependency
in the tasks tick_dep_mask is set and copied to the new thread, which
means the new thread and all decendants will prevent the system to go
into full NOHZ operation.
Clear the tick dependency mask in copy_process() to fix this"
* tag 'timers-urgent-2024-11-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
posix-cpu-timers: Clear TICK_DEP_BIT_POSIX_TIMER on clone
Linus Torvalds [Sun, 3 Nov 2024 18:18:28 +0000 (08:18 -1000)]
Merge tag 'sched-urgent-2024-11-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Thomas Gleixner:
- Plug a race between pick_next_task_fair() and try_to_wake_up() where
both try to write to the same task, even though both paths hold a
runqueue lock, but obviously from different runqueues.
The problem is that the store to task::on_rq in __block_task() is
visible to try_to_wake_up() which assumes that the task is not
queued. Both sides then operate on the same task.
Cure it by rearranging __block_task() so the the store to task::on_rq
is the last operation on the task.
- Prevent a potential NULL pointer dereference in task_numa_work()
task_numa_work() iterates the VMAs of a process. A concurrent unmap
of the address space can result in a NULL pointer return from
vma_next() which is unchecked.
Add the missing NULL pointer check to prevent this.
- Operate on the correct scheduler policy in task_should_scx()
task_should_scx() returns true when a task should be handled by sched
EXT. It checks the tasks scheduling policy.
This fails when the check is done before a policy has been set.
Cure it by handing the policy into task_should_scx() so it operates
on the requested value.
- Add the missing handling of sched EXT in the delayed dequeue
mechanism. This was simply forgotten.
* tag 'sched-urgent-2024-11-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/ext: Fix scx vs sched_delayed
sched: Pass correct scheduling policy to __setscheduler_class
sched/numa: Fix the potential null pointer dereference in task_numa_work()
sched: Fix pick_next_task_fair() vs try_to_wake_up() race
Linus Torvalds [Sun, 3 Nov 2024 18:13:52 +0000 (08:13 -1000)]
Merge tag 'perf-urgent-2024-11-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fix from Thomas Gleixner:
"perf_event_clear_cpumask() uses list_for_each_entry_rcu() without
being in a RCU read side critical section, which triggers a
'suspicious RCU usage' warning.
It turns out that the list walk does not be RCU protected because the
write side lock is held in this context.
Change it to a regular list walk"
* tag 'perf-urgent-2024-11-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Fix missing RCU reader protection in perf_event_clear_cpumask()
Linus Torvalds [Sun, 3 Nov 2024 18:09:25 +0000 (08:09 -1000)]
Merge tag 'irq-urgent-2024-11-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Thomas Gleixner:
- Fix an off-by-one error in the failure path of msi_domain_alloc(),
which causes the cleanup loop to terminate early and leaking the
first allocated interrupt.
- Handle a corner case in GIC-V4 versus a lazily mapped Virtual
Processing Element (VPE). If the VPE has not been mapped because the
guest has not yet emitted a mapping command, then the set_affinity()
callback returns an error code, which causes the vCPU management to
fail.
Return success in this case without touching the hardware. This will
be done later when the guest issues the mapping command.
* tag 'irq-urgent-2024-11-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/gic-v4: Correctly deal with set_affinity on lazily-mapped VPEs
genirq/msi: Fix off-by-one error in msi_domain_alloc()
When building a 64-bit kernel, BITS_PER_LONG is defined as 64. However,
on a 32-bit build machine, the constant 1L is a signed 32-bit value.
Left-shifting it beyond 32 bits causes wraparound, and shifting by 31
or 63 bits makes it a negative value.
The fix in commit e0e92632715f ("[PATCH] PATCH: 1 line 2.6.18 bugfix:
modpost-64bit-fix.patch") is incorrect; it only addresses cases where
a 64-bit kernel is built on a 64-bit build machine, overlooking cases
on a 32-bit build machine.
Using 1ULL ensures a 64-bit width on both 32-bit and 64-bit machines,
avoiding the wraparound issue.
Dmitry Torokhov [Mon, 28 Oct 2024 05:31:15 +0000 (22:31 -0700)]
Input: fix regression when re-registering input handlers
Commit d469647bafd9 ("Input: simplify event handling logic") introduced
code that would set handler->events() method to either
input_handler_events_filter() or input_handler_events_default() or
input_handler_events_null(), depending on the kind of input handler
(a filter or a regular one) we are dealing with. Unfortunately this
breaks cases when we try to re-register the same filter (as is the case
with sysrq handler): after initial registration the handler will have 2
event handling methods defined, and will run afoul of the check in
input_handler_check_methods():
input: input_handler_check_methods: only one event processing method can be defined (sysrq)
sysrq: Failed to register input handler, error -22
Fix this by adding handle_events() method to input_handle structure and
setting it up when registering a new input handle according to event
handling methods defined in associated input_handler structure, thus
avoiding modifying the input_handler structure.
Reported-by: "Ned T. Crigler" <crigler@gmail.com> Reported-by: Christian Heusel <christian@heusel.eu> Tested-by: "Ned T. Crigler" <crigler@gmail.com> Tested-by: Peter Seiderer <ps.report@gmx.net> Fixes: d469647bafd9 ("Input: simplify event handling logic") Link: https://lore.kernel.org/r/Zx2iQp6csn42PJA7@xavtug Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Linus Torvalds [Sat, 2 Nov 2024 19:27:11 +0000 (09:27 -1000)]
Merge tag 'nfsd-6.12-3' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux
Pull nfsd fixes from Chuck Lever:
- Fix two async COPY bugs found during NFS bake-a-thon
- Fix an svcrdma memory leak
* tag 'nfsd-6.12-3' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
rpcrdma: Always release the rpcrdma_device's xa_array
NFSD: Never decrement pending_async_copies on error
NFSD: Initialize struct nfsd4_copy earlier
Linus Torvalds [Sat, 2 Nov 2024 19:22:16 +0000 (09:22 -1000)]
Merge tag 'xfs-6.12-fixes-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs fixes from Carlos Maiolino:
- fix a sysbot reported crash on filestreams
- Reduce cpu time spent searching for extents in a very fragmented FS
- Check for delayed allocations before setting extsize
* tag 'xfs-6.12-fixes-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: streamline xfs_filestream_pick_ag
xfs: fix finding a last resort AG in xfs_filestream_pick_ag
xfs: Reduce unnecessary searches when searching for the best extents
xfs: Check for delayed allocations before setting extsize
- fix idmap_mount_tree_invalid test failure due to incorrect argument
- fix watchdog-test run leaving the watchdog timer enabled causing
system reboot. With this fix, the test disables the watchdog timer
when it gets terminated with SIGTERM, SIGKILL, and SIGQUIT in
addition to SIGINT
* tag 'linux_kselftest-fixes-6.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
selftests/watchdog-test: Fix system accidentally reset after watchdog-test
selftests/intel_pstate: check if cpupower is installed
selftests/intel_pstate: fix operand expected error
selftests/mount_setattr: fix idmap_mount_tree_invalid failed to run
Linus Torvalds [Sat, 2 Nov 2024 01:59:46 +0000 (15:59 -1000)]
Merge tag 'rust-fixes-6.12-3' of https://github.com/Rust-for-Linux/linux
Pull rust fixes from Miguel Ojeda:
"Toolchain and infrastructure:
- Avoid build errors with old 'rustc's without LLVM patch version
(important since it impacts people that do not even enable Rust)
- Update LLVM version for 'HAVE_CFI_ICALL_NORMALIZE_INTEGERS' in
'depends on' condition (the fix was eventually backported rather
than land in LLVM 19)"
* tag 'rust-fixes-6.12-3' of https://github.com/Rust-for-Linux/linux:
cfi: tweak llvm version for HAVE_CFI_ICALL_NORMALIZE_INTEGERS
kbuild: rust: avoid errors with old `rustc`s without LLVM patch version
Linus Torvalds [Sat, 2 Nov 2024 01:44:23 +0000 (15:44 -1000)]
Merge tag 'pci-v6.12-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci
Pull pci fix from Bjorn Helgaas:
- Enable device-specific ACS-like functionality even if the device
doesn't advertise an ACS capability, which got broken when adding
fancy ACS kernel parameter (Jason Gunthorpe)
* tag 'pci-v6.12-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci:
PCI: Fix pci_enable_acs() support for the ACS quirks
Linus Torvalds [Sat, 2 Nov 2024 01:37:09 +0000 (15:37 -1000)]
Merge tag 'drm-fixes-2024-11-02' of https://gitlab.freedesktop.org/drm/kernel
Pull drm fixes from Dave Airlie:
"Regular fixes pull, nothing too out of the ordinary, the mediatek
fixes came in a batch that I might have preferred a bit earlier but
all seem fine, otherwise regular xe/amdgpu and a few misc ones.
xe:
- Fix missing HPD interrupt enabling, bringing one PM refactor with it
- Workaround LNL GGTT invalidation not being visible to GuC
- Avoid getting jobs stuck without a protecting timeout
ivpu:
- Fix firewall IRQ handling
panthor:
- Fix firmware initialization wrt page sizes
- Fix handling and reporting of dead job groups
sched:
- Guarantee forward progress via WC_MEM_RECLAIM
tests:
- Fix memory leak in drm_display_mode_from_cea_vic()
mediatek:
- Fix degradation problem of alpha blending
- Fix color format MACROs in OVL
- Fix get efuse issue for MT8188 DPTX
- Fix potential NULL dereference in mtk_crtc_destroy()
- Correct dpi power-domains property
- Add split subschema property constraints"
* tag 'drm-fixes-2024-11-02' of https://gitlab.freedesktop.org/drm/kernel: (27 commits)
drm/xe: Don't short circuit TDR on jobs not started
drm/xe: Add mmio read before GGTT invalidate
drm/tests: hdmi: Fix memory leaks in drm_display_mode_from_cea_vic()
drm/connector: hdmi: Fix memory leak in drm_display_mode_from_cea_vic()
drm/tests: helpers: Add helper for drm_display_mode_from_cea_vic()
drm/panthor: Report group as timedout when we fail to properly suspend
drm/panthor: Fail job creation when the group is dead
drm/panthor: Fix firmware initialization on systems with a page size > 4k
accel/ivpu: Fix NOC firewall interrupt handling
drm/xe/display: Add missing HPD interrupt enabling during non-d3cold RPM resume
drm/xe/display: Separate the d3cold and non-d3cold runtime PM handling
drm/xe: Remove runtime argument from display s/r functions
drm/amdgpu/smu13: fix profile reporting
drm/amd/pm: Vangogh: Fix kernel memory out of bounds write
Revert "drm/amd/display: update DML2 policy EnhancedPrefetchScheduleAccelerationFinal DCN35"
drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM
drm/tegra: Fix NULL vs IS_ERR() check in probe()
dt-bindings: display: mediatek: split: add subschema property constraints
dt-bindings: display: mediatek: dpi: correct power-domains property
drm/mediatek: Fix potential NULL dereference in mtk_crtc_destroy()
...
Linus Torvalds [Sat, 2 Nov 2024 01:22:57 +0000 (15:22 -1000)]
Merge tag 'cxl-fixes-6.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl
Pull cxl fixes from Ira Weiny:
"The bulk of these fixes center around an initialization order bug
reported by Gregory Price and some additional fall out from the
debugging effort.
In summary, cxl_acpi and cxl_mem race and previously worked because of
a bus_rescan_devices() while testing without modules built in.
Unfortunately with modules built in the rescan would fail due to the
cxl_port driver being registered late via the build order. Furthermore
it was found bus_rescan_devices() did not guarantee a probe barrier
which CXL was expecting. Additional fixes to cxl-test and decoder
allocation came along as they were found in this debugging effort.
The other fixes are pretty minor but one affects trace point data seen
by user space.
Summary:
- Fix crashes when running with cxl-test code
- Fix Trace DRAM Event Record field decodes
- Fix module/built in initialization order errors
- Fix use after free on decoder shutdowns
- Fix out of order decoder allocations
- Improve cxl-test to better reflect real world systems"
* tag 'cxl-fixes-6.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl:
cxl/test: Improve init-order fidelity relative to real-world systems
cxl/port: Prevent out-of-order decoder allocation
cxl/port: Fix use-after-free, permit out-of-order decoder shutdown
cxl/acpi: Ensure ports ready at cxl_acpi_probe() return
cxl/port: Fix cxl_bus_rescan() vs bus_rescan_devices()
cxl/port: Fix CXL port initialization order when the subsystem is built-in
cxl/events: Fix Trace DRAM Event Record
cxl/core: Return error when cxl_endpoint_gather_bandwidth() handles a non-PCI device
Linus Torvalds [Fri, 1 Nov 2024 23:41:55 +0000 (13:41 -1000)]
Merge tag 'block-6.12-20241101' of git://git.kernel.dk/linux
Pull block fixes from Jens Axboe:
- Fixup for a recent blk_rq_map_user_bvec() patch
- NVMe pull request via Keith:
- Spec compliant identification fix (Keith)
- Module parameter to enable backward compatibility on unusual
namespace formats (Keith)
- Target double free fix when using keys (Vitaliy)
- Passthrough command error handling fix (Keith)
* tag 'block-6.12-20241101' of git://git.kernel.dk/linux:
nvme: re-fix error-handling for io_uring nvme-passthrough
nvmet-auth: assign dh_key to NULL after kfree_sensitive
nvme: module parameter to disable pi with offsets
block: fix queue limits checks in blk_rq_map_user_bvec for real
nvme: enhance cns version checking
Linus Torvalds [Fri, 1 Nov 2024 23:38:01 +0000 (13:38 -1000)]
Merge tag 'io_uring-6.12-20241101' of git://git.kernel.dk/linux
Pull io_uring fix from Jens Axboe:
- Fix not honoring IOCB_NOWAIT for starting buffered writes in terms of
calling sb_start_write(), leading to a deadlock if someone is
attempting to freeze the file system with writes in progress, as each
side will end up waiting for the other to make progress.
* tag 'io_uring-6.12-20241101' of git://git.kernel.dk/linux:
io_uring/rw: fix missing NOWAIT check for O_DIRECT start write
Linus Torvalds [Fri, 1 Nov 2024 19:04:23 +0000 (09:04 -1000)]
Merge tag 'acpi-6.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI fix from Rafael Wysocki:
"Make the ACPI CPPC library use a raw spinlock for operations carried
out in scheduler context via the schedutil governor and the ACPI CPPC
cpufreq driver (Pierre Gondois)"
* tag 'acpi-6.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI: CPPC: Make rmw_lock a raw_spin_lock
Dave Airlie [Fri, 1 Nov 2024 18:44:02 +0000 (04:44 +1000)]
Merge tag 'drm-xe-fixes-2024-10-31' of https://gitlab.freedesktop.org/drm/xe/kernel into drm-fixes
Driver Changes:
- Fix missing HPD interrupt enabling, bringing one PM refactor with it
(Imre / Maarten)
- Workaround LNL GGTT invalidation not being visible to GuC
(Matthew Brost)
- Avoid getting jobs stuck without a protecting timeout (Matthew Brost)
Linus Torvalds [Fri, 1 Nov 2024 18:26:38 +0000 (08:26 -1000)]
Merge tag 'riscv-for-linus-6.11-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V fixes from Palmer Dabbelt:
- Avoid accessing the early boot ACPI tables via unsafe memory
attributes, which can result in incorrect ACPI table data appearing.
This can cause all sorts of bad behavior.
- Avoid compiler-inserted library calls in the VDSO.
- GCC+Rust builds have been disabled, to avoid issues related to ISA
string mismatched between the GCC and LLVM Rust implementations.
- The NX flag is now set in the EFI PE/COFF headers, which is necessary
for some distro GRUB versions to boot images.
- A fix to avoid leaking DT node reference counts on ACPI systems
during cache info parsing.
- CPU numbers are now printed as unsigned values during hotplug.
- A pair of build fixes for usused macros, which can trigger warnings
on some configurations.
* tag 'riscv-for-linus-6.11-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
riscv: Remove duplicated GET_RM
riscv: Remove unused GENERATING_ASM_OFFSETS
riscv: Use '%u' to format the output of 'cpu'
riscv: Prevent a bad reference count on CPU nodes
riscv: efi: Set NX compat flag in PE/COFF header
RISC-V: disallow gcc + rust builds
riscv: Do not use fortify in early code
RISC-V: ACPI: fix early_ioremap to early_memremap
riscv: vdso: Prevent the compiler from inserting calls to memset()
Linus Torvalds [Fri, 1 Nov 2024 17:54:11 +0000 (07:54 -1000)]
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Will Deacon:
"The important one is a change to the way in which we handle protection
keys around signal delivery so that we're more closely aligned with
the x86 behaviour, however there is also a revert of the previous fix
to disable software tag-based KASAN with GCC, since a workaround
materialised shortly afterwards.
I'd love to say we're done with 6.12, but we're aware of some
longstanding fpsimd register corruption issues that we're almost at
the bottom of resolving.
Summary:
- Fix handling of POR_EL0 during signal delivery so that pushing the
signal context doesn't fail based on the pkey configuration of the
interrupted context and align our user-visible behaviour with that
of x86.
- Fix a bogus pointer being passed to the CPU hotplug code from the
Arm SDEI driver.
- Re-enable software tag-based KASAN with GCC by using an alternative
implementation of '__no_sanitize_address'"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: signal: Improve POR_EL0 handling to avoid uaccess failures
firmware: arm_sdei: Fix the input parameter of cpuhp_remove_state()
Revert "kasan: Disable Software Tag-Based KASAN with GCC"
kasan: Fix Software Tag-Based KASAN with GCC
Linus Torvalds [Fri, 1 Nov 2024 17:45:00 +0000 (07:45 -1000)]
Merge tag 'vfs-6.12-rc6.iomap' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs
Pull iomap fixes from Christian Brauner:
"Fixes for iomap to prevent data corruption bugs in the fallocate
unshare range implementation of fsdax and a small cleanup to turn
iomap_want_unshare_iter() into an inline function"
* tag 'vfs-6.12-rc6.iomap' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs:
iomap: turn iomap_want_unshare_iter into an inline function
fsdax: dax_unshare_iter needs to copy entire blocks
fsdax: remove zeroing code from dax_unshare_iter
iomap: share iomap_unshare_iter predicate code with fsdax
xfs: don't allocate COW extents when unsharing a hole
Linus Torvalds [Fri, 1 Nov 2024 17:37:10 +0000 (07:37 -1000)]
Merge tag 'vfs-6.12-rc6.fixes' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs
Pull filesystem fixes from Christian Brauner:
"VFS:
- Fix copy_page_from_iter_atomic() if KMAP_LOCAL_FORCE_MAP=y is set
- Add a get_tree_bdev_flags() helper that allows to modify e.g.,
whether errors are logged into the filesystem context during
superblock creation. This is used by erofs to fix a userspace
regression where an error is currently logged when its used on a
regular file which is an new allowed mode in erofs.
netfs:
- Fix the sysfs debug path in the documentation.
- Fix iov_iter_get_pages*() for folio queues by skipping the page
extracation if we're at the end of a folio.
afs:
- Fix moving subdirectories to different parent directory.
autofs:
- Fix handling of AUTOFS_DEV_IOCTL_TIMEOUT_CMD ioctl in
validate_dev_ioctl(). The actual ioctl number, not the ioctl
command needs to be checked for autofs"
* tag 'vfs-6.12-rc6.fixes' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs:
iov_iter: fix copy_page_from_iter_atomic() if KMAP_LOCAL_FORCE_MAP
autofs: fix thinko in validate_dev_ioctl()
iov_iter: Fix iov_iter_get_pages*() for folio_queue
afs: Fix missing subdir edit when renamed between parent dirs
doc: correcting the debug path for cachefiles
erofs: use get_tree_bdev_flags() to avoid misleading messages
fs/super.c: introduce get_tree_bdev_flags()
Linus Torvalds [Fri, 1 Nov 2024 17:31:47 +0000 (07:31 -1000)]
Merge tag 'for-6.12-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"A few more stability fixes. There's one patch adding export of MIPS
cmpxchg helper, used in the error propagation fix.
- fix error propagation from split bios to the original btrfs bio
- fix merging of adjacent extents (normal operation, defragmentation)
- fix potential use after free after freeing btrfs device structures"
* tag 'for-6.12-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix defrag not merging contiguous extents due to merged extent maps
btrfs: fix extent map merging not happening for adjacent extents
btrfs: fix use-after-free of block device file in __btrfs_free_extra_devids()
btrfs: fix error propagation of split bios
MIPS: export __cmpxchg_small()
Linus Torvalds [Fri, 1 Nov 2024 17:21:03 +0000 (07:21 -1000)]
Merge tag 'bcachefs-2024-10-31' of git://evilpiepirate.org/bcachefs
Pull bcachefs fixes from Kent Overstreet:
"Various syzbot fixes, and the more notable ones:
- Fix for pointers in an extent overflowing the max (16) on a
filesystem with many devices: we were creating too many cached
copies when moving data around. Now, we only create at most one
cached copy if there's a promote target set.
Caching will be a bit broken for reflinked data until 6.13: I have
larger series queued up which significantly improves the plumbing
for data options down into the extent (bch_extent_rebalance) to fix
this.
- Fix for deadlock on -ENOSPC on tiny filesystems
Allocation from the partial open_bucket list wasn't correctly
accounting partial open_buckets as free: this fixes the main cause
of tests timing out in the automated tests"
* tag 'bcachefs-2024-10-31' of git://evilpiepirate.org/bcachefs:
bcachefs: Fix NULL ptr dereference in btree_node_iter_and_journal_peek
bcachefs: fix possible null-ptr-deref in __bch2_ec_stripe_head_get()
bcachefs: Fix deadlock on -ENOSPC w.r.t. partial open buckets
bcachefs: Don't filter partial list buckets in open_buckets_to_text()
bcachefs: Don't keep tons of cached pointers around
bcachefs: init freespace inited bits to 0 in bch2_fs_initialize
bcachefs: Fix unhandled transaction restart in fallocate
bcachefs: Fix UAF in bch2_reconstruct_alloc()
bcachefs: fix null-ptr-deref in have_stripes()
bcachefs: fix shift oob in alloc_lru_idx_fragmentation
bcachefs: Fix invalid shift in validate_sb_layout()
KVM: selftests: Ensure KVM supports AVX for SEV-ES VMSA FPU test
Verify that KVM's supported XCR0 includes AVX (and earlier features) when
running the SEV-ES VMSA XSAVE test. In practice, the issue will likely
never pop up, since KVM support for AVX predates KVM support for SEV-ES,
but checking for KVM support makes the requirement more obvious.
KVM: selftests: Drop manual XCR0 configuration from SEV smoke test
Now that CR4.OSXSAVE and XCR0 are setup by default, drop the manual
enabling from the SEV smoke test that validates FPU state can be
transferred into the VMSA.
In guest_code_xsave(), explicitly set the Requested-Feature Bitmask (RFBM)
to exactly XFEATURE_MASK_X87_AVX instead of relying on the host side of
things to enable only X87_AVX features in guest XCR0. I.e. match the RFBM
for the host XSAVE.
KVM: selftests: Verify XCR0 can be "downgraded" and "upgraded"
Now that KVM selftests enable all supported XCR0 features by default, add
a testcase to the XCR0 vs. CPUID test to verify that the guest can disable
everything except the legacy FPU in XCR0, and then re-enable the full
feature set, which is kinda sorta what the test did before XCR0 was setup
by default.
KVM: selftests: Configure XCR0 to max supported value by default
To play nice with compilers generating AVX instructions, set CR4.OSXSAVE
and configure XCR0 by default when creating selftests vCPUs. Some distros
have switched gcc to '-march=x86-64-v3' by default, and while it's hard to
find a CPU which doesn't support AVX today, many KVM selftests fail with
==== Test Assertion Failure ====
lib/x86_64/processor.c:570: Unhandled exception in guest
pid=72747 tid=72747 errno=4 - Interrupted system call
Unhandled exception '0x6' at guest RIP '0x4104f7'
due to selftests not enabling AVX by default for the guest. The failure
is easy to reproduce elsewhere with:
$ make clean && CFLAGS='-march=x86-64-v3' make -j && ./x86_64/kvm_pv_test
E.g. gcc-13 with -march=x86-64-v3 compiles this chunk from selftests'
kvm_fixup_exception():
Alternatively, KVM selftests could explicitly restrict the compiler to
-march=x86-64-v2, but odds are very good that punting on AVX enabling will
simply result in tests that "need" AVX doing their own thing, e.g. there
are already three or so additional cleanups that can be done on top.
KVM: selftests: Rework OSXSAVE CR4=>CPUID test to play nice with AVX insns
Rework the CR4/CPUID sync test to clear CR4.OSXSAVE, do CPUID, and restore
CR4.OSXSAVE in assembly, so that there is zero chance of AVX instructions
being executed while CR4.OSXSAVE is disabled. This will allow enabling
CR4.OSXSAVE by default for selftests vCPUs as a general means of playing
nice with AVX instructions.
KVM: selftests: Mask off OSPKE and OSXSAVE when comparing CPUID entries
Mask off OSPKE and OSXSAVE, which are toggled based on corresponding CR4
enabling bits, when comparing vCPU CPUID against KVM's supported CPUID.
This will allow setting OSXSAVE by default when creating vCPUs, without
causing test failures (KVM doesn't enumerate OSXSAVE=1).
KVM: selftests: Precisely mask off dynamic fields in CPUID test
When comparing vCPU CPUID entries against KVM's supported CPUID, mask off
only the dynamic fields/bits instead of skipping the entire entry.
Precisely masking bits isn't meaningfully more difficult than skipping
entire entries, and will be necessary to maintain test coverage when a
future commit enables OSXSAVE by default, i.e. makes one bit in all of
CPUID.0x1 dynamic.
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