diff options
| author | Sean Christopherson <seanjc@google.com> | 2021-05-04 20:17:26 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-05-07 13:06:17 +0300 |
| commit | 36fa06f9ff39f23e03cd8206dc6bbb7711c23be6 (patch) | |
| tree | 061a01f384438101cb391e99db0f213fb0cfdf75 /arch/x86/kvm/svm | |
| parent | 0caa0a77c2f6fcd0830cdcd018db1af98fe35e28 (diff) | |
| download | linux-36fa06f9ff39f23e03cd8206dc6bbb7711c23be6.tar.xz | |
KVM: x86: Add support for RDPID without RDTSCP
Allow userspace to enable RDPID for a guest without also enabling RDTSCP.
Aside from checking for RDPID support in the obvious flows, VMX also needs
to set ENABLE_RDTSCP=1 when RDPID is exposed.
For the record, there is no known scenario where enabling RDPID without
RDTSCP is desirable. But, both AMD and Intel architectures allow for the
condition, i.e. this is purely to make KVM more architecturally accurate.
Fixes: 41cd02c6f7f6 ("kvm: x86: Expose RDPID in KVM_GET_SUPPORTED_CPUID")
Cc: stable@vger.kernel.org
Reported-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210504171734.1434054-8-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/svm')
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 13e4dd128177..0ba0a00f8dc6 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -2669,7 +2669,8 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) if (tsc_aux_uret_slot < 0) return 1; if (!msr_info->host_initiated && - !guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP)) + !guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP) && + !guest_cpuid_has(vcpu, X86_FEATURE_RDPID)) return 1; msr_info->data = svm->tsc_aux; break; @@ -2891,7 +2892,8 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) return 1; if (!msr->host_initiated && - !guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP)) + !guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP) && + !guest_cpuid_has(vcpu, X86_FEATURE_RDPID)) return 1; /* |