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| author | Babu Moger <babu.moger@amd.com> | 2022-04-19 15:54:44 -0500 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-04-29 12:49:15 -0400 |
| commit | 296d5a17e793956f7b914336422043c939263409 (patch) | |
| tree | e6dae9614be53367fac2eec0fe49eaaa5ceb13da /arch/x86/kvm/svm/svm.c | |
| parent | f30903394eb62316dddea8801b357f5cec4df187 (diff) | |
| download | linux-296d5a17e793956f7b914336422043c939263409.tar.bz2 | |
KVM: SEV-ES: Use V_TSC_AUX if available instead of RDTSC/MSR_TSC_AUX intercepts
The TSC_AUX virtualization feature allows AMD SEV-ES guests to securely use
TSC_AUX (auxiliary time stamp counter data) in the RDTSCP and RDPID
instructions. The TSC_AUX value is set using the WRMSR instruction to the
TSC_AUX MSR (0xC0000103). It is read by the RDMSR, RDTSCP and RDPID
instructions. If the read/write of the TSC_AUX MSR is intercepted, then
RDTSCP and RDPID must also be intercepted when TSC_AUX virtualization
is present. However, the RDPID instruction can't be intercepted. This means
that when TSC_AUX virtualization is present, RDTSCP and TSC_AUX MSR
read/write must not be intercepted for SEV-ES (or SEV-SNP) guests.
Signed-off-by: Babu Moger <babu.moger@amd.com>
Message-Id: <165040164424.1399644.13833277687385156344.stgit@bmoger-ubuntu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/svm/svm.c')
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 22bbd69495ad..b83af9ecf85a 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -99,6 +99,7 @@ static const struct svm_direct_access_msrs { { .index = MSR_EFER, .always = false }, { .index = MSR_IA32_CR_PAT, .always = false }, { .index = MSR_AMD64_SEV_ES_GHCB, .always = true }, + { .index = MSR_TSC_AUX, .always = false }, { .index = MSR_INVALID, .always = false }, }; |