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authorPaolo Bonzini <pbonzini@redhat.com>2021-04-22 04:11:15 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2021-04-26 11:27:15 +0200
commitd9db0fd6c5c9fa7c9a462a2c54d5e91455a74fca (patch)
tree44ca9d2af91b6486a802b4f32d188f191f6b74e3 /arch/x86/kvm/svm/svm.c
parentKVM: SVM: Move SEV module params/variables to sev.c (diff)
downloadlinux-d9db0fd6c5c9fa7c9a462a2c54d5e91455a74fca.tar.xz
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KVM: SEV: Mask CPUID[0x8000001F].eax according to supported features
Add a reverse-CPUID entry for the memory encryption word, 0x8000001F.EAX, and use it to override the supported CPUID flags reported to userspace. Masking the reported CPUID flags avoids over-reporting KVM support, e.g. without the mask a SEV-SNP capable CPU may incorrectly advertise SNP support to userspace. Clear SEV/SEV-ES if their corresponding module parameters are disabled, and clear the memory encryption leaf completely if SEV is not fully supported in KVM. Advertise SME_COHERENT in addition to SEV and SEV-ES, as the guest can use SME_COHERENT to avoid CLFLUSH operations. Explicitly omit SME and VM_PAGE_FLUSH from the reporting. These features are used by KVM, but are not exposed to the guest, e.g. guest access to related MSRs will fault. Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210422021125.3417167-6-seanjc@google.com> 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.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index cbddcdb18d97..eed6f9455e1b 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -923,6 +923,9 @@ static __init void svm_set_cpu_caps(void)
if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) ||
boot_cpu_has(X86_FEATURE_AMD_SSBD))
kvm_cpu_cap_set(X86_FEATURE_VIRT_SSBD);
+
+ /* CPUID 0x8000001F (SME/SEV features) */
+ sev_set_cpu_caps();
}
static __init int svm_hardware_setup(void)