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From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>, Jiri Kosina <trivial@kernel.org>
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
Subject: [PATCH 9/9] KVM: SVM: Skip intercepted PAUSE instructions after emulation
Date: Thu,  4 Feb 2021 16:57:50 -0800	[thread overview]
Message-ID: <20210205005750.3841462-10-seanjc@google.com> (raw)
In-Reply-To: <20210205005750.3841462-1-seanjc@google.com>

Skip PAUSE after interception to avoid unnecessarily re-executing the
instruction in the guest, e.g. after regaining control post-yield.
This is a benign bug as KVM disables PAUSE interception if filtering is
off, including the case where pause_filter_count is set to zero.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/kvm/svm/svm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index b6acc73d356a..ac634b9eba8a 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2992,7 +2992,7 @@ static int pause_interception(struct kvm_vcpu *vcpu)
 		grow_ple_window(vcpu);
 
 	kvm_vcpu_on_spin(vcpu, in_kernel);
-	return 1;
+	return kvm_skip_emulated_instruction(vcpu);
 }
 
 static int invpcid_interception(struct kvm_vcpu *vcpu)
-- 
2.30.0.365.g02bc693789-goog


  parent reply	other threads:[~2021-02-05  1:02 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-05  0:57 [PATCH 0/9] KVM: x86: Move common exit handlers to x86.c Sean Christopherson
2021-02-05  0:57 ` [PATCH 1/9] KVM: SVM: Move AVIC vCPU kicking snippet to helper function Sean Christopherson
2021-02-05  0:57 ` [PATCH 2/9] KVM: SVM: Remove an unnecessary forward declaration Sean Christopherson
2021-02-05  0:57 ` [PATCH 3/9] KVM: SVM: Pass @vcpu to exit handlers (and many, many other places) Sean Christopherson
2021-02-05  0:57 ` [PATCH 4/9] KVM: nSVM: Add VMLOAD/VMSAVE helper to deduplicate code Sean Christopherson
2021-02-05  0:57 ` [PATCH 5/9] KVM: x86: Move XSETBV emulation to common code Sean Christopherson
2021-02-05  0:57 ` [PATCH 6/9] KVM: x86: Move trivial instruction-based exit handlers " Sean Christopherson
2021-02-05  0:57 ` [PATCH 7/9] KVM: x86: Move RDPMC emulation " Sean Christopherson
2021-02-05  0:57 ` [PATCH 8/9] KVM: SVM: Don't manually emulate RDPMC if nrips=0 Sean Christopherson
2021-02-05  0:57 ` Sean Christopherson [this message]
2021-02-05  8:20 ` [PATCH 0/9] KVM: x86: Move common exit handlers to x86.c Paolo Bonzini

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