The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 6f2b296aa6432d8274e258cc3220047ca04f5de0 Mon Sep 17 00:00:00 2001

From: Sean Christopherson seanjc@google.com Date: Fri, 23 Apr 2021 15:34:01 -0700 Subject: [PATCH] KVM: SVM: Inject #GP on guest MSR_TSC_AUX accesses if RDTSCP unsupported

Inject #GP on guest accesses to MSR_TSC_AUX if RDTSCP is unsupported in the guest's CPUID model.

Fixes: 46896c73c1a4 ("KVM: svm: add support for RDTSCP") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson seanjc@google.com Message-Id: 20210423223404.3860547-2-seanjc@google.com Reviewed-by: Vitaly Kuznetsov vkuznets@redhat.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index cd8c333ed2dc..9ed9c7bd7cfd 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -2674,6 +2674,9 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) case MSR_TSC_AUX: if (!boot_cpu_has(X86_FEATURE_RDTSCP)) return 1; + if (!msr_info->host_initiated && + !guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP)) + return 1; msr_info->data = svm->tsc_aux; break; /* @@ -2892,6 +2895,10 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) if (!boot_cpu_has(X86_FEATURE_RDTSCP)) return 1;

+ if (!msr->host_initiated && + !guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP)) + return 1; + /* * This is rare, so we update the MSR here instead of using * direct_access_msrs. Doing that would require a rdmsr in