From: Maxim Levitsky <mlevitsk@redhat.com>
To: kvm@vger.kernel.org
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Borislav Petkov <bp@alien8.de>, Bandan Das <bsd@redhat.com>,
linux-kernel@vger.kernel.org (open list),
Joerg Roedel <joro@8bytes.org>, Ingo Molnar <mingo@redhat.com>,
Wei Huang <wei.huang2@amd.com>,
Sean Christopherson <seanjc@google.com>,
linux-kselftest@vger.kernel.org (open list:KERNEL SELFTEST
FRAMEWORK), Maxim Levitsky <mlevitsk@redhat.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Jim Mattson <jmattson@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
Shuah Khan <shuah@kernel.org>, Wanpeng Li <wanpengli@tencent.com>
Subject: [PATCH 07/14] KVM: x86: SVM: add warning for CVE-2021-3656
Date: Tue, 14 Sep 2021 18:48:18 +0300 [thread overview]
Message-ID: <20210914154825.104886-8-mlevitsk@redhat.com> (raw)
In-Reply-To: <20210914154825.104886-1-mlevitsk@redhat.com>
Just in case, add a warning ensuring that on guest entry,
either both VMLOAD and VMSAVE intercept is enabled or
vVMLOAD/VMSAVE is enabled.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
---
arch/x86/kvm/svm/svm.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 861ac9f74331..deeebd05f682 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3784,6 +3784,12 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu)
WARN_ON_ONCE(kvm_apicv_activated(vcpu->kvm) != kvm_vcpu_apicv_active(vcpu));
+ /* Check that CVE-2021-3656 can't happen again */
+ if (!svm_is_intercept(svm, INTERCEPT_VMSAVE) ||
+ !svm_is_intercept(svm, INTERCEPT_VMSAVE))
+ WARN_ON(!(svm->vmcb->control.virt_ext &
+ VIRTUAL_VMLOAD_VMSAVE_ENABLE_MASK));
+
sync_lapic_to_cr8(vcpu);
if (unlikely(svm->asid != svm->vmcb->control.asid)) {
--
2.26.3
next prev parent reply other threads:[~2021-09-14 15:50 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-14 15:48 [PATCH 00/14] nSVM fixes and optional features Maxim Levitsky
2021-09-14 15:48 ` [PATCH 01/14] KVM: x86: nSVM: restore int_vector in svm_clear_vintr Maxim Levitsky
2021-09-23 14:04 ` Paolo Bonzini
2021-09-14 15:48 ` [PATCH 02/14] KVM: x86: selftests: test simultaneous uses of V_IRQ from L1 and L0 Maxim Levitsky
2021-09-23 14:05 ` Paolo Bonzini
2021-09-14 15:48 ` [PATCH 03/14] KVM: x86: nSVM: test eax for 4K alignment for GP errata workaround Maxim Levitsky
2021-09-23 14:05 ` Paolo Bonzini
2021-09-14 15:48 ` [PATCH 04/14] KVM: x86: nSVM: don't copy pause related settings Maxim Levitsky
2021-09-14 15:48 ` [PATCH 05/14] KVM: x86: nSVM: don't copy virt_ext from vmcb12 Maxim Levitsky
2021-09-23 14:06 ` Paolo Bonzini
2021-09-14 15:48 ` [PATCH 06/14] KVM: x86: SVM: don't set VMLOAD/VMSAVE intercepts on vCPU reset Maxim Levitsky
2021-09-23 16:40 ` Paolo Bonzini
2021-09-14 15:48 ` Maxim Levitsky [this message]
2021-09-23 16:44 ` [PATCH 07/14] KVM: x86: SVM: add warning for CVE-2021-3656 Paolo Bonzini
2021-10-12 0:21 ` Sean Christopherson
2021-10-11 17:30 ` Xiaoyao Li
2021-10-12 7:51 ` Maxim Levitsky
2021-09-14 15:48 ` [PATCH 08/14] KVM: x86: SVM: add module param to control LBR virtualization Maxim Levitsky
2021-09-14 15:48 ` [PATCH 09/14] KVM: x86: nSVM: correctly virtualize LBR msrs when L2 is running Maxim Levitsky
2021-09-14 15:48 ` [PATCH 10/14] KVM: x86: nSVM: implement nested LBR virtualization Maxim Levitsky
2021-09-14 15:48 ` [PATCH 11/14] KVM: x86: nSVM: implement nested VMLOAD/VMSAVE Maxim Levitsky
2021-09-14 15:48 ` [PATCH 12/14] KVM: x86: SVM: add module param to control TSC scaling Maxim Levitsky
2021-09-14 15:48 ` [PATCH 13/14] KVM: x86: nSVM: implement nested " Maxim Levitsky
2021-09-14 15:48 ` [PATCH 14/14] KVM: x86: nSVM: support PAUSE filter threshold and count Maxim Levitsky
2021-09-23 16:54 ` [PATCH 00/14] nSVM fixes and optional features Paolo Bonzini
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