Thread (113 messages) 113 messages, 9 authors, 2026-01-24
STALE187d LANDED

[PATCH v3 49/62] KVM: x86: Drop superfluous "has assigned device" check in kvm_pi_update_irte()

From: Sean Christopherson <seanjc@google.com>
Date: 2025-06-11 22:48:21
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

Don't bother checking if the VM has an assigned device when updating
IRTE entries.  kvm_arch_irq_bypass_add_producer() explicitly increments
the assigned device count, kvm_arch_irq_bypass_del_producer() explicitly
decrements the count before invoking kvm_pi_update_irte(), and
kvm_irq_routing_update() only updates IRTE entries if there's an active
IRQ bypass producer.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/kvm/irq.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c
index 4119c1e880e7..45cb9f1ee618 100644
--- a/arch/x86/kvm/irq.c
+++ b/arch/x86/kvm/irq.c
@@ -517,9 +517,7 @@ static int kvm_pi_update_irte(struct kvm_kernel_irqfd *irqfd,
 	struct kvm_lapic_irq irq;
 	int r;
 
-	if (!irqchip_in_kernel(kvm) ||
-	    !kvm_arch_has_irq_bypass() ||
-	    !kvm_arch_has_assigned_device(kvm))
+	if (!irqchip_in_kernel(kvm) || !kvm_arch_has_irq_bypass())
 		return 0;
 
 	if (entry && entry->type == KVM_IRQ_ROUTING_MSI) {
-- 
2.50.0.rc1.591.g9c95f17f64-goog

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