From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Reiji Watanabe <reijiw@google.com>
Subject: Re: [PATCH v3 1/4] KVM: SVM: Inject #GP on guest MSR_TSC_AUX accesses if RDTSCP unsupported
Date: Mon, 26 Apr 2021 10:49:15 +0200 [thread overview]
Message-ID: <87mttlfn1w.fsf@vitty.brq.redhat.com> (raw)
In-Reply-To: <20210423223404.3860547-2-seanjc@google.com>
Sean Christopherson <seanjc@google.com> writes:
> 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>
> ---
> arch/x86/kvm/svm/svm.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> 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;
Super-nit: a blank like before and after the condition would make this
consistent with the hunk you add to svm_set_msr() below.
> 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
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
--
Vitaly
next prev parent reply other threads:[~2021-04-26 8:49 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-23 22:34 [PATCH v3 0/4] KVM: x86: MSR_TSC_AUX fixes and improvements Sean Christopherson
2021-04-23 22:34 ` [PATCH v3 1/4] KVM: SVM: Inject #GP on guest MSR_TSC_AUX accesses if RDTSCP unsupported Sean Christopherson
2021-04-26 8:49 ` Vitaly Kuznetsov [this message]
2021-04-23 22:34 ` [PATCH v3 2/4] KVM: SVM: Clear MSR_TSC_AUX[63:32] on write Sean Christopherson
2021-04-26 8:57 ` Vitaly Kuznetsov
2021-04-26 19:18 ` Sean Christopherson
2021-04-26 19:44 ` Sean Christopherson
2021-04-23 22:34 ` [PATCH v3 3/4] KVM: x86: Tie Intel and AMD behavior for MSR_TSC_AUX to guest CPU model Sean Christopherson
2021-04-24 7:19 ` Reiji Watanabe
2021-04-26 19:38 ` Sean Christopherson
2021-04-27 4:42 ` Reiji Watanabe
2021-04-27 21:58 ` Sean Christopherson
2021-04-23 22:34 ` [PATCH v3 4/4] KVM: SVM: Delay restoration of host MSR_TSC_AUX until return to userspace Sean Christopherson
2021-04-26 9:26 ` [PATCH v3 0/4] KVM: x86: MSR_TSC_AUX fixes and improvements Paolo Bonzini
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