linux-kernel - [PATCH 3/5] KVM: x86: Check for in-kernel xAPIC when querying APICv for directed yield

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Date:   Tue, 14 Jun 2022 23:05:46 +0000
From:   Sean Christopherson <seanjc@...gle.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH 3/5] KVM: x86: Check for in-kernel xAPIC when querying APICv
 for directed yield

Use kvm_vcpu_apicv_active() to check if APICv is active when seeing if a
vCPU is a candidate for directed yield due to a pending ACPIv interrupt.
This will allow moving apicv_active into kvm_lapic without introducing a
potential NULL pointer deref (kvm_vcpu_apicv_active() effectively adds a
pre-check on the vCPU having an in-kernel APIC).

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/x86.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2318a99139fa..cd554a62eb0f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -12375,7 +12375,8 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)
 
 bool kvm_arch_dy_has_pending_interrupt(struct kvm_vcpu *vcpu)
 {
-	if (vcpu->arch.apicv_active && static_call(kvm_x86_dy_apicv_has_pending_interrupt)(vcpu))
+	if (kvm_vcpu_apicv_active(vcpu) &&
+	    static_call(kvm_x86_dy_apicv_has_pending_interrupt)(vcpu))
 		return true;
 
 	return false;
-- 
2.36.1.476.g0c4daa206d-goog