[PATCH 56/67] KVM: SVM: WARN if ir_list is non-empty at vCPU free

[Sean Christopherson]

Now that AVIC IRTE tracking is in a mostly sane state, WARN if a vCPU is
freed with ir_list entries, i.e. if KVM leaves a dangling IRTE.

Initialize the per-vCPU interrupt remapping list and its lock even if AVIC
is disabled so that the WARN doesn't hit false positives (and so that KVM
doesn't need to call into AVIC code for a simple sanity check).

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
 arch/x86/kvm/svm/avic.c | 5 +++--
 arch/x86/kvm/svm/svm.c  | 2 ++
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index a932eba1f42c..d2cbb7ac91f4 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -713,6 +713,9 @@ int avic_init_vcpu(struct vcpu_svm *svm)
 	int ret;
 	struct kvm_vcpu *vcpu = &svm->vcpu;
 
+	INIT_LIST_HEAD(&svm->ir_list);
+	spin_lock_init(&svm->ir_list_lock);
+
 	if (!enable_apicv || !irqchip_in_kernel(vcpu->kvm))
 		return 0;
 
@@ -720,8 +723,6 @@ int avic_init_vcpu(struct vcpu_svm *svm)
 	if (ret)
 		return ret;
 
-	INIT_LIST_HEAD(&svm->ir_list);
-	spin_lock_init(&svm->ir_list_lock);
 	svm->dfr_reg = APIC_DFR_FLAT;
 
 	return ret;
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 43c4933d7da6..71b52ad13577 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1499,6 +1499,8 @@ static void svm_vcpu_free(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
 
+	WARN_ON_ONCE(!list_empty(&svm->ir_list));
+
 	/*
 	 * The vmcb page can be recycled, causing a false negative in
 	 * svm_vcpu_load(). So, ensure that no logical CPU has this
-- 
2.49.0.504.g3bcea36a83-goog