[PATCH 19/23] KVM: SVM: Skip intercepted PAUSE instructions after emulation

From: Paolo Bonzini
Date: Tue Mar 02 2021 - 17:38:35 EST


From: Sean Christopherson <seanjc@xxxxxxxxxx>

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@xxxxxxxxxx>
Message-Id: <20210205005750.3841462-10-seanjc@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
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 3725a4636930..1c62d3ec7e53 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2982,7 +2982,7 @@ 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)
--
2.26.2