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| author |   Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> | 2022-07-24 22:34:28 -0500 |
|---|---|---|
| committer |   Paolo Bonzini <pbonzini@redhat.com> | 2022-07-28 13:51:42 -0400 |
| commit | 0a8735a6acf36ac35499563dc44f3e3d5034a2ce (patch) | |
| tree | e94f57ed33bae624ffbcaa50e636752a0b987bc8 /arch/x86/kvm | |
| parent | KVM: selftests: Verify VMX MSRs can be restored to KVM-supported values (diff) | |
| download | linux-dev-0a8735a6acf36ac35499563dc44f3e3d5034a2ce.tar.xz linux-dev-0a8735a6acf36ac35499563dc44f3e3d5034a2ce.zip | |
KVM: SVM: Do not virtualize MSR accesses for APIC LVTT register
AMD does not support APIC TSC-deadline timer mode. AVIC hardware
will generate GP fault when guest kernel writes 1 to bits [18]
of the APIC LVTT register (offset 0x32) to set the timer mode.
(Note: bit 18 is reserved on AMD system).
Therefore, always intercept and let KVM emulate the MSR accesses.
Fixes: f3d7c8aa6882 ("KVM: SVM: Fix x2APIC MSRs interception")
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Message-Id: <20220725033428.3699-1-suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm')
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index aef63aae922d..3e0639a68385 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -118,7 +118,14 @@ static const struct svm_direct_access_msrs { { .index = X2APIC_MSR(APIC_ESR), .always = false }, { .index = X2APIC_MSR(APIC_ICR), .always = false }, { .index = X2APIC_MSR(APIC_ICR2), .always = false }, - { .index = X2APIC_MSR(APIC_LVTT), .always = false }, + + /* + * Note: + * AMD does not virtualize APIC TSC-deadline timer mode, but it is + * emulated by KVM. When setting APIC LVTT (0x832) register bit 18, + * the AVIC hardware would generate GP fault. Therefore, always + * intercept the MSR 0x832, and do not setup direct_access_msr. + */ { .index = X2APIC_MSR(APIC_LVTTHMR), .always = false }, { .index = X2APIC_MSR(APIC_LVTPC), .always = false }, { .index = X2APIC_MSR(APIC_LVT0), .always = false }, |