[PATCH v3 07/62] KVM: SVM: Delete IRTE link from previous vCPU irrespective of new routing
From: Sean Christopherson <seanjc@google.com>
Date: 2025-06-11 22:47:08
Also in:
kvm, kvmarm, linux-iommu, lkml
Subsystem:
kernel virtual machine for x86 (kvm/x86), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Sean Christopherson, Paolo Bonzini, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
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 <redacted>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
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 4e8380d2f017..c981ce764b45 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c@@ -861,6 +861,12 @@ 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);
@@ -883,8 +889,6 @@ 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.
--
2.50.0.rc1.591.g9c95f17f64-goog