linux-kernel - Re: [PATCH RESEND 3/3] KVM: SVM: Reenable handle_fastpath_set_msr_irqoff() after complete

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Date:   Sat, 12 Sep 2020 08:15:46 +0200
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     Wanpeng Li <kernellwp@...il.com>, linux-kernel@...r.kernel.org,
        kvm@...r.kernel.org
Cc:     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>,
        "Paul K ." <kronenpj@...nenpj.dyndns.org>
Subject: Re: [PATCH RESEND 3/3] KVM: SVM: Reenable
 handle_fastpath_set_msr_irqoff() after complete_interrupts()

The overall patch is fairly simple:

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 03dd7bac8034..d6ce75e107c0 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2938,8 +2938,6 @@ static int handle_exit(struct kvm_vcpu *vcpu,
fastpath_t exit_fastpath)
 	if (npt_enabled)
 		vcpu->arch.cr3 = svm->vmcb->save.cr3;

-	svm_complete_interrupts(svm);
-
 	if (is_guest_mode(vcpu)) {
 		int vmexit;

@@ -3504,7 +3502,6 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct
kvm_vcpu *vcpu)
 	stgi();

 	/* Any pending NMI will happen here */
-	exit_fastpath = svm_exit_handlers_fastpath(vcpu);

 	if (unlikely(svm->vmcb->control.exit_code == SVM_EXIT_NMI))
 		kvm_after_interrupt(&svm->vcpu);
@@ -3537,6 +3534,9 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct
kvm_vcpu *vcpu)
 		     SVM_EXIT_EXCP_BASE + MC_VECTOR))
 		svm_handle_mce(svm);

+	svm_complete_interrupts(svm);
+	exit_fastpath = svm_exit_handlers_fastpath(vcpu);
+
 	vmcb_mark_all_clean(svm->vmcb);
 	return exit_fastpath;
 }

so I will just squash everything.

Paolo