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While testing Hyper-V enabled Windows Server 2019 guests on Zen4 hardware
I noticed that with vCPU count large enough (> 16) they sometimes froze at
boot.
With vCPU count of 64 they never booted successfully - suggesting some kind
of a race condition.
Since adding "vnmi=0" module parameter made these guests boot successfully
it was clear that the problem is most likely (v)NMI-related.
Running kvm-unit-tests quickly showed failing NMI-related tests cases, like
"multiple nmi" and "pending nmi" from apic-split, x2apic and xapic tests
and the NMI parts of eventinj test.
The issue was that once one NMI was being serviced no other NMI was allowed
to be set pending (NMI limit = 0), which was traced to
svm_is_vnmi_pending() wrongly testing for the "NMI blocked" flag rather
than for the "NMI pending" flag.
Fix this by testing for the right flag in svm_is_vnmi_pending().
Once this is done, the NMI-related kvm-unit-tests pass successfully and
the Windows guest no longer freezes at boot.
Fixes: fa4c027a7956 ("KVM: x86: Add support for SVM's Virtual NMI")
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/be4ca192eb0c1e69a210db3009ca984e6a54ae69.1684495380.git.maciej.szmigiero@oracle.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Factor in the address space (non-SMM vs. SMM) of the target shadow page
when recovering potential NX huge pages, otherwise KVM will retrieve the
wrong memslot when zapping shadow pages that were created for SMM. The
bug most visibly manifests as a WARN on the memslot being non-NULL, but
the worst case scenario is that KVM could unaccount the shadow page
without ensuring KVM won't install a huge page, i.e. if the non-SMM slot
is being dirty logged, but the SMM slot is not.
------------[ cut here ]------------
WARNING: CPU: 1 PID: 3911 at arch/x86/kvm/mmu/mmu.c:7015
kvm_nx_huge_page_recovery_worker+0x38c/0x3d0 [kvm]
CPU: 1 PID: 3911 Comm: kvm-nx-lpage-re
RIP: 0010:kvm_nx_huge_page_recovery_worker+0x38c/0x3d0 [kvm]
RSP: 0018:ffff99b284f0be68 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff99b284edd000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff9271397024e0 R08: 0000000000000000 R09: ffff927139702450
R10: 0000000000000000 R11: 0000000000000001 R12: ffff99b284f0be98
R13: 0000000000000000 R14: ffff9270991fcd80 R15: 0000000000000003
FS: 0000000000000000(0000) GS:ffff927f9f640000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0aacad3ae0 CR3: 000000088fc2c005 CR4: 00000000003726e0
Call Trace:
<TASK>
__pfx_kvm_nx_huge_page_recovery_worker+0x10/0x10 [kvm]
kvm_vm_worker_thread+0x106/0x1c0 [kvm]
kthread+0xd9/0x100
ret_from_fork+0x2c/0x50
</TASK>
---[ end trace 0000000000000000 ]---
This bug was exposed by commit edbdb43fc96b ("KVM: x86: Preserve TDP MMU
roots until they are explicitly invalidated"), which allowed KVM to retain
SMM TDP MMU roots effectively indefinitely. Before commit edbdb43fc96b,
KVM would zap all SMM TDP MMU roots and thus all SMM TDP MMU shadow pages
once all vCPUs exited SMM, which made the window where this bug (recovering
an SMM NX huge page) could be encountered quite tiny. To hit the bug, the
NX recovery thread would have to run while at least one vCPU was in SMM.
Most VMs typically only use SMM during boot, and so the problematic shadow
pages were gone by the time the NX recovery thread ran.
Now that KVM preserves TDP MMU roots until they are explicitly invalidated
(e.g. by a memslot deletion), the window to trigger the bug is effectively
never closed because most VMMs don't delete memslots after boot (except
for a handful of special scenarios).
Fixes: eb298605705a ("KVM: x86/mmu: Do not recover dirty-tracked NX Huge Pages")
Reported-by: Fabio Coatti <fabio.coatti@gmail.com>
Closes: https://lore.kernel.org/all/CADpTngX9LESCdHVu_2mQkNGena_Ng2CphWNwsRGSMxzDsTjU2A@mail.gmail.com
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230602010137.784664-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Per Intel's SDM, unsupported ENCLS leafs result in a #GP, not a #UD.
SGX1 is a special snowflake as the SGX1 flag is used by the CPU as a
"soft" disable, e.g. if software disables machine check reporting, i.e.
having SGX but not SGX1 is effectively "SGX completely unsupported" and
and thus #UDs.
Fixes: 9798adbc04cf ("KVM: VMX: Frame in ENCLS handler for SGX virtualization")
Cc: Binbin Wu <binbin.wu@linux.intel.com>
Cc: Kai Huang <kai.huang@intel.com>
Tested-by: Kai Huang <kai.huang@intel.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/r/20230405234556.696927-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Inject a #GP when emulating/forwarding a valid ENCLS leaf if the vCPU has
paging disabled, e.g. if KVM is intercepting ECREATE to enforce additional
restrictions. The pseudocode in the SDM lists all #GP triggers, including
CR0.PG=0, as being checked after the ENLCS-exiting checks, i.e. the
VM-Exit will occur before the CPU performs the CR0.PG check.
Fixes: 70210c044b4e ("KVM: VMX: Add SGX ENCLS[ECREATE] handler to enforce CPUID restrictions")
Cc: Binbin Wu <binbin.wu@linux.intel.com>
Cc: Kai Huang <kai.huang@intel.com>
Tested-by: Kai Huang <kai.huang@intel.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/r/20230405234556.696927-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Commit 8bd200d23ec4 ("KVM: VMX: Flatten __vmx_vcpu_run()") changed
vmx_vmexit from SYM_FUNC_START to SYM_INNER_LABEL, accidentally
removing 16 byte alignment as SYM_FUNC_START uses SYM_A_ALIGN and
SYM_INNER_LABEL does not. Josh mentioned [1] this was unintentional.
Fix by changing to SYM_INNER_LABEL_ALIGN instead.
[1] https://lore.kernel.org/lkml/Y3adkSe%2FJ70PqUyt@p183
Fixes: 8bd200d23ec4 ("KVM: VMX: Flatten __vmx_vcpu_run()")
Signed-off-by: Jon Kohler <jon@nutanix.com>
Suggested-by: Alexey Dobriyan <adobriyan@gmail.com>
CC: Josh Poimboeuf <jpoimboe@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Reviewed-by: Jim Mattson <jmattson@google.com>
Link: https://lore.kernel.org/r/20230531155821.80590-1-jon@nutanix.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Update cpuid->nent if and only if kvm_vcpu_ioctl_get_cpuid2() succeeds.
The sole caller copies @cpuid to userspace only on success, i.e. the
existing code effectively does nothing.
Arguably, KVM should report the number of entries when returning -E2BIG so
that userspace doesn't have to guess the size, but all other similar KVM
ioctls() don't report the size either, i.e. userspace is conditioned to
guess.
Suggested-by: Takahiro Itazuri <itazur@amazon.com>
Link: https://lore.kernel.org/all/20230410141820.57328-1-itazur@amazon.com
Link: https://lore.kernel.org/r/20230526210340.2799158-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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After commit 2de154f541fc ("KVM: x86/pmu: Provide "error" semantics
for unsupported-but-known PMU MSRs"), the guest_cpuid_has(DS) check
is not necessary any more since if the guest supports X86_FEATURE_DS,
it never returns 1. And if the guest does not support this feature,
the set_msr handler will get false from kvm_pmu_is_valid_msr() before
reaching this point. Therefore, the check will not be true in all cases
and can be safely removed, which also simplifies the code and improves
its readability.
Signed-off-by: Jinrong Liang <cloudliang@tencent.com>
Link: https://lore.kernel.org/r/20230411130338.8592-1-cloudliang@tencent.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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According to the hardware manual, when the Poll command is issued, the
byte returned by the I/O read is 1 in Bit 7 when there is an interrupt,
and the highest priority binary code in Bits 2:0. The current pic
simulation code is not implemented strictly according to the above
expression.
Fix the implementation of pic_poll_read(), set Bit 7 when there is an
interrupt.
Signed-off-by: Jinliang Zheng <alexjlzheng@tencent.com>
Link: https://lore.kernel.org/r/20230419021924.1342184-1-alexjlzheng@tencent.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Move the common check-and-set handling of PAT MSR writes out of vendor
code and into kvm_set_msr_common(). This aligns writes with reads, which
are already handled in common code, i.e. makes the handling of reads and
writes symmetrical in common code.
Alternatively, the common handling in kvm_get_msr_common() could be moved
to vendor code, but duplicating code is generally undesirable (even though
the duplicatated code is trivial in this case), and guest writes to PAT
should be rare, i.e. the overhead of the extra function call is a
non-issue in practice.
Suggested-by: Kai Huang <kai.huang@intel.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/r/20230511233351.635053-9-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Make kvm_mtrr_valid() local to mtrr.c now that it's not used to check the
validity of a PAT MSR value.
Reviewed-by: Kai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/r/20230511233351.635053-8-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Drop handling of MSR_IA32_CR_PAT from mtrr.c now that SVM and VMX handle
writes without bouncing through kvm_set_msr_common(). PAT isn't truly an
MTRR even though it affects memory types, and more importantly KVM enables
hardware virtualization of guest PAT (by NOT setting "ignore guest PAT")
when a guest has non-coherent DMA, i.e. KVM doesn't need to zap SPTEs when
the guest PAT changes.
The read path is and always has been trivial, i.e. burying it in the MTRR
code does more harm than good.
WARN and continue for the PAT case in kvm_set_msr_common(), as that code
is _currently_ reached if and only if KVM is buggy. Defer cleaning up the
lack of symmetry between the read and write paths to a future patch.
Reviewed-by: Kai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/r/20230511233351.635053-7-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Use the MTRR macros to identify the ranges of possible MTRR MSRs instead
of bounding the ranges with a mismash of open coded values and unrelated
MSR indices. Carving out the gap for the machine check MSRs in particular
is confusing, as it's easy to incorrectly think the case statement handles
MCE MSRs instead of skipping them.
Drop the range-based funneling of MSRs between the end of the MCE MSRs
and MTRR_DEF_TYPE, i.e. 0x2A0-0x2FF, and instead handle MTTR_DEF_TYPE as
the one-off case that it is.
Extract PAT (0x277) as well in anticipation of dropping PAT "handling"
from the MTRR code.
Keep the range-based handling for the variable+fixed MTRRs even though
capturing unknown MSRs 0x214-0x24F is arguably "wrong". There is a gap in
the fixed MTRRs, 0x260-0x267, i.e. the MTRR code needs to filter out
unknown MSRs anyways, and using a single range generates marginally better
code for the big switch statement.
Reviewed-by: Kai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/r/20230511233351.635053-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Add a helper to dedup the logic for retrieving a variable MTRR range
structure given a variable MTRR MSR index.
No functional change intended.
Reviewed-by: Kai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/r/20230511233351.635053-5-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Add a helper to query whether a variable MTRR MSR is a base versus as mask
MSR. Replace the unnecessarily complex math with a simple check on bit 0;
base MSRs are even, mask MSRs are odd.
Link: https://lore.kernel.org/r/20230511233351.635053-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Use kvm_pat_valid() directly instead of bouncing through kvm_mtrr_valid().
The PAT is not an MTRR, and kvm_mtrr_valid() just redirects to
kvm_pat_valid(), i.e. is exempt from KVM's "zap SPTEs" logic that's
needed to honor guest MTRRs when the VM has a passthrough device with
non-coherent DMA (KVM does NOT set "ignore guest PAT" in this case, and so
enables hardware virtualization of the guest's PAT, i.e. doesn't need to
manually emulate the PAT memtype).
Signed-off-by: Ke Guo <guoke@uniontech.com>
[sean: massage changelog]
Reviewed-by: Kai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/r/20230511233351.635053-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Open code setting "vcpu->arch.pat" in vmx_set_msr() instead of bouncing
through kvm_set_msr_common() to get to the same code in kvm_mtrr_set_msr().
This aligns VMX with SVM, avoids hiding a very simple operation behind a
relatively complicated function call (finding the PAT MSR case in
kvm_set_msr_common() is non-trivial), and most importantly, makes it clear
that not unwinding the VMCS updates if kvm_set_msr_common() isn't a bug
(because kvm_set_msr_common() can never fail for PAT).
Opportunistically set vcpu->arch.pat before updating the VMCS info so that
a future patch can move the common bits (back) into kvm_set_msr_common()
without a functional change.
Note, MSR_IA32_CR_PAT is 0x277, and is very subtly handled by
case 0x200 ... MSR_IA32_MC0_CTL2 - 1:
in kvm_set_msr_common().
Cc: Kai Huang <kai.huang@intel.com>
Signed-off-by: Wenyao Hai <haiwenyao@uniontech.com>
[sean: massage changelog, hoist setting vcpu->arch.pat up]
Reviewed-by: Kai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/r/20230511233351.635053-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Remove the dedicated post-VMEXIT TSS reloading code now that KVM uses
VMLOAD to load host segment state, which includes TSS state.
Fixes: e79b91bb3c91 ("KVM: SVM: use vmsave/vmload for saving/restoring additional host state")
Reported-by: Venkatesh Srinivas <venkateshs@google.com>
Suggested-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Mingwei Zhang <mizhang@google.com>
Link: https://lore.kernel.org/r/20230523165635.4002711-1-mizhang@google.com
[sean: massage changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Use kvm_is_cr4_bit_set() to read guest CR4.UMIP when sanity checking that
a descriptor table VM-Exit occurs if and only if guest.CR4.UMIP=1. UMIP
can't be guest-owned, i.e. using kvm_read_cr4_bits() to decache guest-
owned bits isn't strictly necessary, but eliminating raw reads of
vcpu->arch.cr4 is desirable as it makes it easy to visually audit KVM for
correctness.
Opportunistically add a compile-time assertion that UMIP isn't guest-owned
as letting the guest own UMIP isn't compatible with emulation (or any CR4
bit that is emulated by KVM).
Opportunistically change the WARN_ON() to a ONCE variant. When the WARN
fires, it fires _a lot_, and spamming the kernel logs ends up doing more
harm than whatever led to KVM's unnecessary emulation.
Reported-by: Robert Hoo <robert.hu@intel.com>
Link: https://lore.kernel.org/all/20230310125718.1442088-4-robert.hu@intel.com
Link: https://lore.kernel.org/r/20230413231914.1482782-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Advertise UMIP as emulated if and only if the host doesn't natively
support UMIP, otherwise vmx_umip_emulated() is misleading when the host
_does_ support UMIP. Of the four users of vmx_umip_emulated(), two
already check for native support, and the logic in vmx_set_cpu_caps() is
relevant if and only if UMIP isn't natively supported as UMIP is set in
KVM's caps by kvm_set_cpu_caps() when UMIP is present in hardware.
That leaves KVM's stuffing of X86_CR4_UMIP into the default cr4_fixed1
value enumerated for nested VMX. In that case, checking for (lack of)
host support is actually a bug fix of sorts, as enumerating UMIP support
based solely on descriptor table exiting works only because KVM doesn't
sanity check MSR_IA32_VMX_CR4_FIXED1. E.g. if a (very theoretical) host
supported UMIP in hardware but didn't allow UMIP+VMX, KVM would advertise
UMIP but not actually emulate UMIP. Of course, KVM would explode long
before it could run a nested VM on said theoretical CPU, as KVM doesn't
modify host CR4 when enabling VMX, i.e. would load an "illegal" value into
vmcs.HOST_CR4.
Reported-by: Robert Hoo <robert.hu@intel.com>
Link: https://lore.kernel.org/all/20230310125718.1442088-2-robert.hu@intel.com
Link: https://lore.kernel.org/r/20230413231914.1482782-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Move the comment about keeping the hosts CR4.MCE loaded in hardware above
the code that actually modifies the hardware CR4 value.
No functional change indented.
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20230410125017.1305238-3-xiaoyao.li@intel.com
[sean: elaborate in changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Directly use vcpu->arch.cr4 is not recommended since it gets stale value
if the cr4 is not available.
Use kvm_read_cr4() instead to ensure correct value.
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20230410125017.1305238-2-xiaoyao.li@intel.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Add assertion to track that "mmu == vcpu->arch.mmu" is always true in the
context of __kvm_mmu_invalidate_addr(). for_each_shadow_entry_using_root()
and kvm_sync_spte() operate on vcpu->arch.mmu, but the only reason that
doesn't cause explosions is because handle_invept() frees roots instead of
doing a manual invalidation. As of now, there are no major roadblocks
to switching INVEPT emulation over to use kvm_mmu_invalidate_addr().
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Like Xu <likexu@tencent.com>
Link: https://lore.kernel.org/r/20230523032947.60041-1-likexu@tencent.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Commit aee98a6838d5 ("KVM: x86/mmu: Use try_cmpxchg64 in
tdp_mmu_set_spte_atomic") removed the comment that iter->old_spte is
updated when different logical CPU modifies the page table entry.
Although this is what try_cmpxchg does implicitly, it won't hurt
if this fact is explicitly mentioned in a restored comment.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: David Matlack <dmatlack@google.com>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Link: https://lore.kernel.org/r/20230425113932.3148-1-ubizjak@gmail.com
[sean: extend comment above try_cmpxchg64()]
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Add MSR_IA32_TSX_CTRL into msrs_to_save[] to explicitly tell userspace to
save/restore the register value during migration. Missing this may cause
userspace that relies on KVM ioctl(KVM_GET_MSR_INDEX_LIST) fail to port the
value to the target VM.
In addition, there is no need to add MSR_IA32_TSX_CTRL when
ARCH_CAP_TSX_CTRL_MSR is not supported in kvm_get_arch_capabilities(). So
add the checking in kvm_probe_msr_to_save().
Fixes: c11f83e0626b ("KVM: vmx: implement MSR_IA32_TSX_CTRL disable RTM functionality")
Reported-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Mingwei Zhang <mizhang@google.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <20230509032348.1153070-1-mizhang@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Drop KVM's manipulation of guest's CPUID.0x12.1 ECX and EDX, i.e. the
allowed XFRM of SGX enclaves, now that KVM explicitly checks the guest's
allowed XCR0 when emulating ECREATE.
Note, this could theoretically break a setup where userspace advertises
a "bad" XFRM and relies on KVM to provide a sane CPUID model, but QEMU
is the only known user of KVM SGX, and QEMU explicitly sets the SGX CPUID
XFRM subleaf based on the guest's XCR0.
Reviewed-by: Kai Huang <kai.huang@intel.com>
Tested-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230503160838.3412617-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Explicitly check the vCPU's supported XCR0 when determining whether or not
the XFRM for ECREATE is valid. Checking CPUID works because KVM updates
guest CPUID.0x12.1 to restrict the leaf to a subset of the guest's allowed
XCR0, but that is rather subtle and KVM should not modify guest CPUID
except for modeling true runtime behavior (allowed XFRM is most definitely
not "runtime" behavior).
Reviewed-by: Kai Huang <kai.huang@intel.com>
Tested-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230503160838.3412617-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Fix a long-standing flaw in x86's TDP MMU where unloading roots on a vCPU can
result in the root being freed even though the root is completely valid and
can be reused as-is (with a TLB flush).
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Pull kvm updates from Paolo Bonzini:
"s390:
- More phys_to_virt conversions
- Improvement of AP management for VSIE (nested virtualization)
ARM64:
- Numerous fixes for the pathological lock inversion issue that
plagued KVM/arm64 since... forever.
- New framework allowing SMCCC-compliant hypercalls to be forwarded
to userspace, hopefully paving the way for some more features being
moved to VMMs rather than be implemented in the kernel.
- Large rework of the timer code to allow a VM-wide offset to be
applied to both virtual and physical counters as well as a
per-timer, per-vcpu offset that complements the global one. This
last part allows the NV timer code to be implemented on top.
- A small set of fixes to make sure that we don't change anything
affecting the EL1&0 translation regime just after having having
taken an exception to EL2 until we have executed a DSB. This
ensures that speculative walks started in EL1&0 have completed.
- The usual selftest fixes and improvements.
x86:
- Optimize CR0.WP toggling by avoiding an MMU reload when TDP is
enabled, and by giving the guest control of CR0.WP when EPT is
enabled on VMX (VMX-only because SVM doesn't support per-bit
controls)
- Add CR0/CR4 helpers to query single bits, and clean up related code
where KVM was interpreting kvm_read_cr4_bits()'s "unsigned long"
return as a bool
- Move AMD_PSFD to cpufeatures.h and purge KVM's definition
- Avoid unnecessary writes+flushes when the guest is only adding new
PTEs
- Overhaul .sync_page() and .invlpg() to utilize .sync_page()'s
optimizations when emulating invalidations
- Clean up the range-based flushing APIs
- Revamp the TDP MMU's reaping of Accessed/Dirty bits to clear a
single A/D bit using a LOCK AND instead of XCHG, and skip all of
the "handle changed SPTE" overhead associated with writing the
entire entry
- Track the number of "tail" entries in a pte_list_desc to avoid
having to walk (potentially) all descriptors during insertion and
deletion, which gets quite expensive if the guest is spamming
fork()
- Disallow virtualizing legacy LBRs if architectural LBRs are
available, the two are mutually exclusive in hardware
- Disallow writes to immutable feature MSRs (notably
PERF_CAPABILITIES) after KVM_RUN, similar to CPUID features
- Overhaul the vmx_pmu_caps selftest to better validate
PERF_CAPABILITIES
- Apply PMU filters to emulated events and add test coverage to the
pmu_event_filter selftest
- AMD SVM:
- Add support for virtual NMIs
- Fixes for edge cases related to virtual interrupts
- Intel AMX:
- Don't advertise XTILE_CFG in KVM_GET_SUPPORTED_CPUID if
XTILE_DATA is not being reported due to userspace not opting in
via prctl()
- Fix a bug in emulation of ENCLS in compatibility mode
- Allow emulation of NOP and PAUSE for L2
- AMX selftests improvements
- Misc cleanups
MIPS:
- Constify MIPS's internal callbacks (a leftover from the hardware
enabling rework that landed in 6.3)
Generic:
- Drop unnecessary casts from "void *" throughout kvm_main.c
- Tweak the layout of "struct kvm_mmu_memory_cache" to shrink the
struct size by 8 bytes on 64-bit kernels by utilizing a padding
hole
Documentation:
- Fix goof introduced by the conversion to rST"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (211 commits)
KVM: s390: pci: fix virtual-physical confusion on module unload/load
KVM: s390: vsie: clarifications on setting the APCB
KVM: s390: interrupt: fix virtual-physical confusion for next alert GISA
KVM: arm64: Have kvm_psci_vcpu_on() use WRITE_ONCE() to update mp_state
KVM: arm64: Acquire mp_state_lock in kvm_arch_vcpu_ioctl_vcpu_init()
KVM: selftests: Test the PMU event "Instructions retired"
KVM: selftests: Copy full counter values from guest in PMU event filter test
KVM: selftests: Use error codes to signal errors in PMU event filter test
KVM: selftests: Print detailed info in PMU event filter asserts
KVM: selftests: Add helpers for PMC asserts in PMU event filter test
KVM: selftests: Add a common helper for the PMU event filter guest code
KVM: selftests: Fix spelling mistake "perrmited" -> "permitted"
KVM: arm64: vhe: Drop extra isb() on guest exit
KVM: arm64: vhe: Synchronise with page table walker on MMU update
KVM: arm64: pkvm: Document the side effects of kvm_flush_dcache_to_poc()
KVM: arm64: nvhe: Synchronise with page table walker on TLBI
KVM: arm64: Handle 32bit CNTPCTSS traps
KVM: arm64: nvhe: Synchronise with page table walker on vcpu run
KVM: arm64: vgic: Don't acquire its_lock before config_lock
KVM: selftests: Add test to verify KVM's supported XCR0
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull SMP cross-CPU function-call updates from Ingo Molnar:
- Remove diagnostics and adjust config for CSD lock diagnostics
- Add a generic IPI-sending tracepoint, as currently there's no easy
way to instrument IPI origins: it's arch dependent and for some major
architectures it's not even consistently available.
* tag 'smp-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
trace,smp: Trace all smp_function_call*() invocations
trace: Add trace_ipi_send_cpu()
sched, smp: Trace smp callback causing an IPI
smp: reword smp call IPI comment
treewide: Trace IPIs sent via smp_send_reschedule()
irq_work: Trace self-IPIs sent via arch_irq_work_raise()
smp: Trace IPIs sent via arch_send_call_function_ipi_mask()
sched, smp: Trace IPIs sent via send_call_function_single_ipi()
trace: Add trace_ipi_send_cpumask()
kernel/smp: Make csdlock_debug= resettable
locking/csd_lock: Remove per-CPU data indirection from CSD lock debugging
locking/csd_lock: Remove added data from CSD lock debugging
locking/csd_lock: Add Kconfig option for csd_debug default
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Preserve TDP MMU roots until they are explicitly invalidated by gifting
the TDP MMU itself a reference to a root when it is allocated. Keeping a
reference in the TDP MMU fixes a flaw where the TDP MMU exhibits terrible
performance, and can potentially even soft-hang a vCPU, if a vCPU
frequently unloads its roots, e.g. when KVM is emulating SMI+RSM.
When KVM emulates something that invalidates _all_ TLB entries, e.g. SMI
and RSM, KVM unloads all of the vCPUs roots (KVM keeps a small per-vCPU
cache of previous roots). Unloading roots is a simple way to ensure KVM
flushes and synchronizes all roots for the vCPU, as KVM flushes and syncs
when allocating a "new" root (from the vCPU's perspective).
In the shadow MMU, KVM keeps track of all shadow pages, roots included, in
a per-VM hash table. Unloading a shadow MMU root just wipes it from the
per-vCPU cache; the root is still tracked in the per-VM hash table. When
KVM loads a "new" root for the vCPU, KVM will find the old, unloaded root
in the per-VM hash table.
Unlike the shadow MMU, the TDP MMU doesn't track "inactive" roots in a
per-VM structure, where "active" in this case means a root is either
in-use or cached as a previous root by at least one vCPU. When a TDP MMU
root becomes inactive, i.e. the last vCPU reference to the root is put,
KVM immediately frees the root (asterisk on "immediately" as the actual
freeing may be done by a worker, but for all intents and purposes the root
is gone).
The TDP MMU behavior is especially problematic for 1-vCPU setups, as
unloading all roots effectively frees all roots. The issue is mitigated
to some degree in multi-vCPU setups as a different vCPU usually holds a
reference to an unloaded root and thus keeps the root alive, allowing the
vCPU to reuse its old root after unloading (with a flush+sync).
The TDP MMU flaw has been known for some time, as until very recently,
KVM's handling of CR0.WP also triggered unloading of all roots. The
CR0.WP toggling scenario was eventually addressed by not unloading roots
when _only_ CR0.WP is toggled, but such an approach doesn't Just Work
for emulating SMM as KVM must emulate a full TLB flush on entry and exit
to/from SMM. Given that the shadow MMU plays nice with unloading roots
at will, teaching the TDP MMU to do the same is far less complex than
modifying KVM to track which roots need to be flushed before reuse.
Note, preserving all possible TDP MMU roots is not a concern with respect
to memory consumption. Now that the role for direct MMUs doesn't include
information about the guest, e.g. CR0.PG, CR0.WP, CR4.SMEP, etc., there
are _at most_ six possible roots (where "guest_mode" here means L2):
1. 4-level !SMM !guest_mode
2. 4-level SMM !guest_mode
3. 5-level !SMM !guest_mode
4. 5-level SMM !guest_mode
5. 4-level !SMM guest_mode
6. 5-level !SMM guest_mode
And because each vCPU can track 4 valid roots, a VM can already have all
6 root combinations live at any given time. Not to mention that, in
practice, no sane VMM will advertise different guest.MAXPHYADDR values
across vCPUs, i.e. KVM won't ever use both 4-level and 5-level roots for
a single VM. Furthermore, the vast majority of modern hypervisors will
utilize EPT/NPT when available, thus the guest_mode=%true cases are also
unlikely to be utilized.
Reported-by: Jeremi Piotrowski <jpiotrowski@linux.microsoft.com>
Link: https://lore.kernel.org/all/959c5bce-beb5-b463-7158-33fc4a4f910c@linux.microsoft.com
Link: https://lkml.kernel.org/r/20220209170020.1775368-1-pbonzini%40redhat.com
Link: https://lore.kernel.org/all/20230322013731.102955-1-minipli@grsecurity.net
Link: https://lore.kernel.org/all/000000000000a0bc2b05f9dd7fab@google.com
Link: https://lore.kernel.org/all/000000000000eca0b905fa0f7756@google.com
Cc: Ben Gardon <bgardon@google.com>
Cc: David Matlack <dmatlack@google.com>
Cc: stable@vger.kernel.org
Tested-by: Jeremi Piotrowski <jpiotrowski@linux.microsoft.com>
Link: https://lore.kernel.org/r/20230426220323.3079789-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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KVM VMX changes for 6.4:
- Fix a bug in emulation of ENCLS in compatibility mode
- Allow emulation of NOP and PAUSE for L2
- Misc cleanups
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KVM SVM changes for 6.4:
- Add support for virtual NMIs
- Fixes for edge cases related to virtual interrupts
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KVM selftests, and an AMX/XCR0 bugfix, for 6.4:
- Don't advertise XTILE_CFG in KVM_GET_SUPPORTED_CPUID if XTILE_DATA is
not being reported due to userspace not opting in via prctl()
- Overhaul the AMX selftests to improve coverage and cleanup the test
- Misc cleanups
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KVM x86 PMU changes for 6.4:
- Disallow virtualizing legacy LBRs if architectural LBRs are available,
the two are mutually exclusive in hardware
- Disallow writes to immutable feature MSRs (notably PERF_CAPABILITIES)
after KVM_RUN, and overhaul the vmx_pmu_caps selftest to better
validate PERF_CAPABILITIES
- Apply PMU filters to emulated events and add test coverage to the
pmu_event_filter selftest
- Misc cleanups and fixes
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KVM x86 MMU changes for 6.4:
- Tweak FNAME(sync_spte) to avoid unnecessary writes+flushes when the
guest is only adding new PTEs
- Overhaul .sync_page() and .invlpg() to share the .sync_page()
implementation, i.e. utilize .sync_page()'s optimizations when emulating
invalidations
- Clean up the range-based flushing APIs
- Revamp the TDP MMU's reaping of Accessed/Dirty bits to clear a single
A/D bit using a LOCK AND instead of XCHG, and skip all of the "handle
changed SPTE" overhead associated with writing the entire entry
- Track the number of "tail" entries in a pte_list_desc to avoid having
to walk (potentially) all descriptors during insertion and deletion,
which gets quite expensive if the guest is spamming fork()
- Misc cleanups
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KVM x86 changes for 6.4:
- Optimize CR0.WP toggling by avoiding an MMU reload when TDP is enabled,
and by giving the guest control of CR0.WP when EPT is enabled on VMX
(VMX-only because SVM doesn't support per-bit controls)
- Add CR0/CR4 helpers to query single bits, and clean up related code
where KVM was interpreting kvm_read_cr4_bits()'s "unsigned long" return
as a bool
- Move AMD_PSFD to cpufeatures.h and purge KVM's definition
- Misc cleanups
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git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 updates for 6.4
- Numerous fixes for the pathological lock inversion issue that
plagued KVM/arm64 since... forever.
- New framework allowing SMCCC-compliant hypercalls to be forwarded
to userspace, hopefully paving the way for some more features
being moved to VMMs rather than be implemented in the kernel.
- Large rework of the timer code to allow a VM-wide offset to be
applied to both virtual and physical counters as well as a
per-timer, per-vcpu offset that complements the global one.
This last part allows the NV timer code to be implemented on
top.
- A small set of fixes to make sure that we don't change anything
affecting the EL1&0 translation regime just after having having
taken an exception to EL2 until we have executed a DSB. This
ensures that speculative walks started in EL1&0 have completed.
- The usual selftest fixes and improvements.
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git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto updates from Herbert Xu:
"API:
- Total usage stats now include all that returned errors (instead of
just some)
- Remove maximum hash statesize limit
- Add cloning support for hmac and unkeyed hashes
- Demote BUG_ON in crypto_unregister_alg to a WARN_ON
Algorithms:
- Use RIP-relative addressing on x86 to prepare for PIE build
- Add accelerated AES/GCM stitched implementation on powerpc P10
- Add some test vectors for cmac(camellia)
- Remove failure case where jent is unavailable outside of FIPS mode
in drbg
- Add permanent and intermittent health error checks in jitter RNG
Drivers:
- Add support for 402xx devices in qat
- Add support for HiSTB TRNG
- Fix hash concurrency issues in stm32
- Add OP-TEE firmware support in caam"
* tag 'v6.4-p1' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (139 commits)
i2c: designware: Add doorbell support for Mendocino
i2c: designware: Use PCI PSP driver for communication
powerpc: Move Power10 feature PPC_MODULE_FEATURE_P10
crypto: p10-aes-gcm - Remove POWER10_CPU dependency
crypto: testmgr - Add some test vectors for cmac(camellia)
crypto: cryptd - Add support for cloning hashes
crypto: cryptd - Convert hash to use modern init_tfm/exit_tfm
crypto: hmac - Add support for cloning
crypto: hash - Add crypto_clone_ahash/shash
crypto: api - Add crypto_clone_tfm
crypto: api - Add crypto_tfm_get
crypto: x86/sha - Use local .L symbols for code
crypto: x86/crc32 - Use local .L symbols for code
crypto: x86/aesni - Use local .L symbols for code
crypto: x86/sha256 - Use RIP-relative addressing
crypto: x86/ghash - Use RIP-relative addressing
crypto: x86/des3 - Use RIP-relative addressing
crypto: x86/crc32c - Use RIP-relative addressing
crypto: x86/cast6 - Use RIP-relative addressing
crypto: x86/cast5 - Use RIP-relative addressing
...
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Pull vfs fget updates from Al Viro:
"fget() to fdget() conversions"
* tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fuse_dev_ioctl(): switch to fdget()
cgroup_get_from_fd(): switch to fdget_raw()
bpf: switch to fdget_raw()
build_mount_idmapped(): switch to fdget()
kill the last remaining user of proc_ns_fget()
SVM-SEV: convert the rest of fget() uses to fdget() in there
convert sgx_set_attribute() to fdget()/fdput()
convert setns(2) to fdget()/fdput()
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git://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux
Pull RCU updates from Joel Fernandes:
- Updates and additions to MAINTAINERS files, with Boqun being added to
the RCU entry and Zqiang being added as an RCU reviewer.
I have also transitioned from reviewer to maintainer; however, Paul
will be taking over sending RCU pull-requests for the next merge
window.
- Resolution of hotplug warning in nohz code, achieved by fixing
cpu_is_hotpluggable() through interaction with the nohz subsystem.
Tick dependency modifications by Zqiang, focusing on fixing usage of
the TICK_DEP_BIT_RCU_EXP bitmask.
- Avoid needless calls to the rcu-lazy shrinker for CONFIG_RCU_LAZY=n
kernels, fixed by Zqiang.
- Improvements to rcu-tasks stall reporting by Neeraj.
- Initial renaming of k[v]free_rcu() to k[v]free_rcu_mightsleep() for
increased robustness, affecting several components like mac802154,
drbd, vmw_vmci, tracing, and more.
A report by Eric Dumazet showed that the API could be unknowingly
used in an atomic context, so we'd rather make sure they know what
they're asking for by being explicit:
https://lore.kernel.org/all/20221202052847.2623997-1-edumazet@google.com/
- Documentation updates, including corrections to spelling,
clarifications in comments, and improvements to the srcu_size_state
comments.
- Better srcu_struct cache locality for readers, by adjusting the size
of srcu_struct in support of SRCU usage by Christoph Hellwig.
- Teach lockdep to detect deadlocks between srcu_read_lock() vs
synchronize_srcu() contributed by Boqun.
Previously lockdep could not detect such deadlocks, now it can.
- Integration of rcutorture and rcu-related tools, targeted for v6.4
from Boqun's tree, featuring new SRCU deadlock scenarios, test_nmis
module parameter, and more
- Miscellaneous changes, various code cleanups and comment improvements
* tag 'rcu.6.4.april5.2023.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux: (71 commits)
checkpatch: Error out if deprecated RCU API used
mac802154: Rename kfree_rcu() to kvfree_rcu_mightsleep()
rcuscale: Rename kfree_rcu() to kfree_rcu_mightsleep()
ext4/super: Rename kfree_rcu() to kfree_rcu_mightsleep()
net/mlx5: Rename kfree_rcu() to kfree_rcu_mightsleep()
net/sysctl: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
lib/test_vmalloc.c: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
tracing: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
misc: vmw_vmci: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
drbd: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
rcu: Protect rcu_print_task_exp_stall() ->exp_tasks access
rcu: Avoid stack overflow due to __rcu_irq_enter_check_tick() being kprobe-ed
rcu-tasks: Report stalls during synchronize_srcu() in rcu_tasks_postscan()
rcu: Permit start_poll_synchronize_rcu_expedited() to be invoked early
rcu: Remove never-set needwake assignment from rcu_report_qs_rdp()
rcu: Register rcu-lazy shrinker only for CONFIG_RCU_LAZY=y kernels
rcu: Fix missing TICK_DEP_MASK_RCU_EXP dependency check
rcu: Fix set/clear TICK_DEP_BIT_RCU_EXP bitmask race
rcu/trace: use strscpy() to instead of strncpy()
tick/nohz: Fix cpu_is_hotpluggable() by checking with nohz subsystem
...
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Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Filter out XTILE_CFG from the supported XCR0 reported to userspace if the
current process doesn't have access to XTILE_DATA. Attempting to set
XTILE_CFG in XCR0 will #GP if XTILE_DATA is also not set, and so keeping
XTILE_CFG as supported results in explosions if userspace feeds
KVM_GET_SUPPORTED_CPUID back into KVM and the guest doesn't sanity check
CPUID.
Fixes: 445ecdf79be0 ("kvm: x86: Exclude unpermitted xfeatures at KVM_GET_SUPPORTED_CPUID")
Reported-by: Aaron Lewis <aaronlewis@google.com>
Reviewed-by: Aaron Lewis <aaronlewis@google.com>
Tested-by: Aaron Lewis <aaronlewis@google.com>
Link: https://lore.kernel.org/r/20230405004520.421768-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Add a helper, kvm_get_filtered_xcr0(), to dedup code that needs to account
for XCR0 features that require explicit opt-in on a per-process basis. In
addition to documenting when KVM should/shouldn't consult
xstate_get_guest_group_perm(), the helper will also allow sanitizing the
filtered XCR0 to avoid enumerating architecturally illegal XCR0 values,
e.g. XTILE_CFG without XTILE_DATA.
No functional changes intended.
Signed-off-by: Aaron Lewis <aaronlewis@google.com>
Reviewed-by: Mingwei Zhang <mizhang@google.com>
[sean: rename helper, move to x86.h, massage changelog]
Reviewed-by: Aaron Lewis <aaronlewis@google.com>
Tested-by: Aaron Lewis <aaronlewis@google.com>
Link: https://lore.kernel.org/r/20230405004520.421768-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Extend VMX's nested intercept logic for emulated instructions to handle
"pause" interception, in quotes because KVM's emulator doesn't filter out
NOPs when checking for nested intercepts. Failure to allow emulation of
NOPs results in KVM injecting a #UD into L2 on any NOP that collides with
the emulator's definition of PAUSE, i.e. on all single-byte NOPs.
For PAUSE itself, honor L1's PAUSE-exiting control, but ignore PLE to
avoid unnecessarily injecting a #UD into L2. Per the SDM, the first
execution of PAUSE after VM-Entry is treated as the beginning of a new
loop, i.e. will never trigger a PLE VM-Exit, and so L1 can't expect any
given execution of PAUSE to deterministically exit.
... the processor considers this execution to be the first execution of
PAUSE in a loop. (It also does so for the first execution of PAUSE at
CPL 0 after VM entry.)
All that said, the PLE side of things is currently a moot point, as KVM
doesn't expose PLE to L1.
Note, vmx_check_intercept() is still wildly broken when L1 wants to
intercept an instruction, as KVM injects a #UD instead of synthesizing a
nested VM-Exit. That issue extends far beyond NOP/PAUSE and needs far
more effort to fix, i.e. is a problem for the future.
Fixes: 07721feee46b ("KVM: nVMX: Don't emulate instructions in guest mode")
Cc: Mathias Krause <minipli@grsecurity.net>
Cc: stable@vger.kernel.org
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/r/20230405002359.418138-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Refresh the MMU's snapshot of the vCPU's CR0.WP prior to checking for
permission faults when emulating a guest memory access and CR0.WP may be
guest owned. If the guest toggles only CR0.WP and triggers emulation of
a supervisor write, e.g. when KVM is emulating UMIP, KVM may consume a
stale CR0.WP, i.e. use stale protection bits metadata.
Note, KVM passes through CR0.WP if and only if EPT is enabled as CR0.WP
is part of the MMU role for legacy shadow paging, and SVM (NPT) doesn't
support per-bit interception controls for CR0. Don't bother checking for
EPT vs. NPT as the "old == new" check will always be true under NPT, i.e.
the only cost is the read of vcpu->arch.cr4 (SVM unconditionally grabs CR0
from the VMCB on VM-Exit).
Reported-by: Mathias Krause <minipli@grsecurity.net>
Link: https://lkml.kernel.org/r/677169b4-051f-fcae-756b-9a3e1bb9f8fe%40grsecurity.net
Fixes: fb509f76acc8 ("KVM: VMX: Make CR0.WP a guest owned bit")
Tested-by: Mathias Krause <minipli@grsecurity.net>
Link: https://lore.kernel.org/r/20230405002608.418442-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Refactor Hyper-V's range-based TLB flushing API to take a gfn+nr_pages
pair instead of a struct, and bury said struct in Hyper-V specific code.
Passing along two params generates much better code for the common case
where KVM is _not_ running on Hyper-V, as forwarding the flush on to
Hyper-V's hv_flush_remote_tlbs_range() from kvm_flush_remote_tlbs_range()
becomes a tail call.
Cc: David Matlack <dmatlack@google.com>
Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20230405003133.419177-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Rename the Hyper-V hooks for TLB flushing to match the naming scheme used
by all the other TLB flushing hooks, e.g. in kvm_x86_ops, vendor code,
arch hooks from common code, etc.
Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20230405003133.419177-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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When counting "Instructions Retired" (0xc0) in a guest, KVM will
occasionally increment the PMU counter regardless of if that event is
being filtered. This is because some PMU events are incremented via
kvm_pmu_trigger_event(), which doesn't know about the event filter. Add
the event filter to kvm_pmu_trigger_event(), so events that are
disallowed do not increment their counters.
Fixes: 9cd803d496e7 ("KVM: x86: Update vPMCs when retiring instructions")
Signed-off-by: Aaron Lewis <aaronlewis@google.com>
Reviewed-by: Like Xu <likexu@tencent.com>
Link: https://lore.kernel.org/r/20230307141400.1486314-2-aaronlewis@google.com
[sean: prepend "pmc" to the new function]
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Fix a "reprogam" => "reprogram" typo in kvm_pmu_request_counter_reprogam().
Fixes: 68fb4757e867 ("KVM: x86/pmu: Defer reprogram_counter() to kvm_pmu_handle_event()")
Signed-off-by: Like Xu <likexu@tencent.com>
Link: https://lore.kernel.org/r/20230310113349.31799-1-likexu@tencent.com
[sean: trim the changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
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A valid pmc is always tested before using pmu->reprogram_pmi. Eliminate
this part of the redundancy by setting the counter's bitmask directly,
and in addition, trigger KVM_REQ_PMU only once to save more cpu cycles.
Signed-off-by: Like Xu <likexu@tencent.com>
Link: https://lore.kernel.org/r/20230214050757.9623-4-likexu@tencent.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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