From 25ef059e8bc51219f18fb7444aff1907960a3a53 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 11 Jun 2025 15:45:54 -0700 Subject: [PATCH] KVM: x86: WARN if IRQ bypass routing is updated without in-kernel local APIC 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. Link: https://lore.kernel.org/r/20250611224604.313496-53-seanjc@google.com Signed-off-by: Sean Christopherson --- arch/x86/kvm/irq.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c index 81a19d6afe44f..f87f63a53edeb 100644 --- a/arch/x86/kvm/irq.c +++ b/arch/x86/kvm/irq.c @@ -517,8 +517,8 @@ 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 (entry && entry->type == KVM_IRQ_ROUTING_MSI) { kvm_set_msi_irq(kvm, entry, &irq); -- 2.47.2