From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Date: Tue, 12 Sep 2017 10:42:42 -0500
Subject: KVM: SVM: Add irqchip_split() checks before enabling AVIC
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Patch-mainline: v4.14-rc1
Git-commit: 67034bb9dd5ecc0171bdacfbd31ebf7c2634df98
References: bsc#1044503

SVM AVIC hardware accelerates guest write to APIC_EOI register
(for edge-trigger interrupt), which means it does not trap to KVM.

So, only enable SVM AVIC only in split irqchip mode.
(e.g. launching qemu w/ option '-machine kernel_irqchip=split').

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Fixes: 44a95dae1d22 ("KVM: x86: Detect and Initialize AVIC support")
[Removed pr_debug - Radim.]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
---
 arch/x86/kvm/svm.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1162,7 +1162,6 @@ static void avic_init_vmcb(struct vcpu_s
 	vmcb->control.avic_physical_id = ppa & AVIC_HPA_MASK;
 	vmcb->control.avic_physical_id |= AVIC_MAX_PHYSICAL_ID_COUNT;
 	vmcb->control.int_ctl |= AVIC_ENABLE_MASK;
-	svm->vcpu.arch.apicv_active = true;
 }
 
 static void init_vmcb(struct vcpu_svm *svm)
@@ -1278,7 +1277,7 @@ static void init_vmcb(struct vcpu_svm *s
 		set_intercept(svm, INTERCEPT_PAUSE);
 	}
 
-	if (avic)
+	if (kvm_vcpu_apicv_active(&svm->vcpu))
 		avic_init_vmcb(svm);
 
 	/*
@@ -1577,7 +1576,7 @@ static int avic_init_vcpu(struct vcpu_sv
 {
 	int ret;
 
-	if (!avic)
+	if (!kvm_vcpu_apicv_active(&svm->vcpu))
 		return 0;
 
 	ret = avic_init_backing_page(&svm->vcpu);
@@ -4337,7 +4336,7 @@ static void svm_set_virtual_x2apic_mode(
 
 static bool svm_get_enable_apicv(struct kvm_vcpu *vcpu)
 {
-	return avic;
+	return avic && irqchip_split(vcpu->kvm);
 }
 
 static void svm_hwapic_irr_update(struct kvm_vcpu *vcpu, int max_irr)
@@ -4354,7 +4353,7 @@ static void svm_refresh_apicv_exec_ctrl(
 	struct vcpu_svm *svm = to_svm(vcpu);
 	struct vmcb *vmcb = svm->vmcb;
 
-	if (!avic)
+	if (!kvm_vcpu_apicv_active(&svm->vcpu))
 		return;
 
 	vmcb->control.int_ctl &= ~AVIC_ENABLE_MASK;