From a0ca34bb1aad0c72e3fe7b9377c7ac87fa3b7098 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 11 Jun 2025 15:45:10 -0700 Subject: [PATCH] KVM: SVM: Delete IRTE link from previous vCPU irrespective of new routing Delete the IRTE link from the previous vCPU irrespective of the new routing state, i.e. even if the IRTE won't be configured to post IRQs to a vCPU. Whether or not the new route is postable as no bearing on the *old* route. Failure to delete the link can result in KVM incorrectly updating the IRTE, e.g. if the "old" vCPU is scheduled in/out. Fixes: 411b44ba80ab ("svm: Implements update_pi_irte hook to setup posted interrupt") Tested-by: Sairaj Kodilkar Link: https://lore.kernel.org/r/20250611224604.313496-9-seanjc@google.com Signed-off-by: Sean Christopherson --- arch/x86/kvm/svm/avic.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c index 38cdfb052a3a9..d7478a62de632 100644 --- a/arch/x86/kvm/svm/avic.c +++ b/arch/x86/kvm/svm/avic.c @@ -862,6 +862,12 @@ int avic_pi_update_irte(struct kvm_kernel_irqfd *irqfd, struct kvm *kvm, if (!kvm_arch_has_assigned_device(kvm) || !kvm_arch_has_irq_bypass()) return 0; + /* + * If the IRQ was affined to a different vCPU, remove the IRTE metadata + * from the *previous* vCPU's list. + */ + svm_ir_list_del(irqfd); + pr_debug("SVM: %s: host_irq=%#x, guest_irq=%#x, set=%#x\n", __func__, host_irq, guest_irq, set); @@ -884,8 +890,6 @@ int avic_pi_update_irte(struct kvm_kernel_irqfd *irqfd, struct kvm *kvm, WARN_ON_ONCE(new && memcmp(e, new, sizeof(*new))); - svm_ir_list_del(irqfd); - /** * Here, we setup with legacy mode in the following cases: * 1. When cannot target interrupt to a specific vcpu. -- 2.47.2