linux-kernel - [PATCH v4 2/7] KVM: X86: Enable fastpath when APICv is enabled

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Message-Id: <1588055009-12677-3-git-send-email-wanpengli@tencent.com>
Date:   Tue, 28 Apr 2020 14:23:24 +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>,
        Haiwei Li <lihaiwei@...cent.com>
Subject: [PATCH v4 2/7] KVM: X86: Enable fastpath when APICv is enabled

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

We can't observe benefit from single target IPI fastpath when APICv is
disabled, let's just enable IPI and Timer fastpath when APICv is enabled
for now.

Tested-by: Haiwei Li <lihaiwei@...cent.com>
Cc: Haiwei Li <lihaiwei@...cent.com>
Signed-off-by: Wanpeng Li <wanpengli@...cent.com>
---
 arch/x86/kvm/svm/svm.c | 2 +-
 arch/x86/kvm/vmx/vmx.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 8f8fc65..1e7220e 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3344,7 +3344,7 @@ static void svm_cancel_injection(struct kvm_vcpu *vcpu)
 
 static enum exit_fastpath_completion svm_exit_handlers_fastpath(struct kvm_vcpu *vcpu)
 {
-	if (!is_guest_mode(vcpu) &&
+	if (!is_guest_mode(vcpu) && vcpu->arch.apicv_active &&
 	    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);
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 9b5adb4..f207004 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6585,7 +6585,7 @@ void vmx_update_host_rsp(struct vcpu_vmx *vmx, unsigned long host_rsp)
 
 static enum exit_fastpath_completion vmx_exit_handlers_fastpath(struct kvm_vcpu *vcpu)
 {
-	if (!is_guest_mode(vcpu)) {
+	if (!is_guest_mode(vcpu) && vcpu->arch.apicv_active) {
 		switch (to_vmx(vcpu)->exit_reason) {
 		case EXIT_REASON_MSR_WRITE:
 			return handle_fastpath_set_msr_irqoff(vcpu);
-- 
2.7.4