linux-kernel - [PATCH] KVM: SVM: Analyze is_guest_mode() in svm_vcpu

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Message-Id: <1600066548-4343-1-git-send-email-wanpengli@tencent.com>
Date:   Mon, 14 Sep 2020 14:55:48 +0800
From:   Wanpeng Li <kernellwp@...il.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     Paolo Bonzini <pbonzini@...hat.com>,
        Sean Christopherson <sean.j.christopherson@...el.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>
Subject: [PATCH] KVM: SVM: Analyze is_guest_mode() in svm_vcpu_run()

From: Wanpeng Li <wanpengli@...cent.com>

Analyze is_guest_mode() in svm_vcpu_run() instead of svm_exit_handlers_fastpath()
in conformity with VMX version.

Suggested-by: Vitaly Kuznetsov <vkuznets@...hat.com>
Signed-off-by: Wanpeng Li <wanpengli@...cent.com>
---
 arch/x86/kvm/svm/svm.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 3da5b2f..009035a 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3393,8 +3393,7 @@ static void svm_cancel_injection(struct kvm_vcpu *vcpu)
 
 static fastpath_t svm_exit_handlers_fastpath(struct kvm_vcpu *vcpu)
 {
-	if (!is_guest_mode(vcpu) &&
-	    to_svm(vcpu)->vmcb->control.exit_code == SVM_EXIT_MSR &&
+	if (to_svm(vcpu)->vmcb->control.exit_code == SVM_EXIT_MSR &&
 	    to_svm(vcpu)->vmcb->control.exit_info_1)
 		return handle_fastpath_set_msr_irqoff(vcpu);
 
@@ -3580,6 +3579,10 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu)
 		svm_handle_mce(svm);
 
 	svm_complete_interrupts(svm);
+
+	if (is_guest_mode(vcpu))
+		return EXIT_FASTPATH_NONE;
+
 	exit_fastpath = svm_exit_handlers_fastpath(vcpu);
 	return exit_fastpath;
 }
-- 
2.7.4