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From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	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: [PATCH v3 1/4] KVM: SVM: Inject #GP on guest MSR_TSC_AUX accesses if RDTSCP unsupported
Date: Fri, 23 Apr 2021 15:34:01 -0700	[thread overview]
Message-ID: <20210423223404.3860547-2-seanjc@google.com> (raw)
In-Reply-To: <20210423223404.3860547-1-seanjc@google.com>

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;
 		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
-- 
2.31.1.498.g6c1eba8ee3d-goog


  reply	other threads:[~2021-04-23 22:34 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 ` Sean Christopherson [this message]
2021-04-26  8:49   ` [PATCH v3 1/4] KVM: SVM: Inject #GP on guest MSR_TSC_AUX accesses if RDTSCP unsupported Vitaly Kuznetsov
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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