[PATCH 55/67] KVM: x86: WARN if IRQ bypass routing is updated without in-kernel local APIC

[Sean Christopherson]

Yell if kvm_pi_update_irte() is reached without an in-kernel local APIC,
as kvm_arch_irqfd_allowed() should prevent attaching an irqfd and thus any
and all postable IRQs to an APIC-less VM.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
 arch/x86/kvm/x86.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d05bffef88b7..49c3360eb4e8 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -13577,8 +13577,8 @@ static int kvm_pi_update_irte(struct kvm_kernel_irqfd *irqfd,
 	struct kvm_lapic_irq irq;
 	int r;
 
-	if (!irqchip_in_kernel(kvm) || WARN_ON_ONCE(!kvm_arch_has_irq_bypass()))
-		return 0;
+	if (WARN_ON_ONCE(!irqchip_in_kernel(kvm) || !kvm_arch_has_irq_bypass()))
+		return -EINVAL;
 
 	if (new && new->type == KVM_IRQ_ROUTING_MSI) {
 		kvm_set_msi_irq(kvm, new, &irq);
-- 
2.49.0.504.g3bcea36a83-goog