linux-kernel - [PATCH v3 27/62] KVM: x86: Nullify irqfd->producer after updating IRTEs

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Message-ID: <20250611224604.313496-29-seanjc@google.com>
Date: Wed, 11 Jun 2025 15:45:30 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Marc Zyngier <maz@...nel.org>, Oliver Upton <oliver.upton@...ux.dev>, 
	Sean Christopherson <seanjc@...gle.com>, Paolo Bonzini <pbonzini@...hat.com>, Joerg Roedel <joro@...tes.org>, 
	David Woodhouse <dwmw2@...radead.org>, Lu Baolu <baolu.lu@...ux.intel.com>
Cc: linux-arm-kernel@...ts.infradead.org, kvmarm@...ts.linux.dev, 
	kvm@...r.kernel.org, iommu@...ts.linux.dev, linux-kernel@...r.kernel.org, 
	Sairaj Kodilkar <sarunkod@....com>, Vasant Hegde <vasant.hegde@....com>, 
	Maxim Levitsky <mlevitsk@...hat.com>, Joao Martins <joao.m.martins@...cle.com>, 
	Francesco Lavra <francescolavra.fl@...il.com>, David Matlack <dmatlack@...gle.com>
Subject: [PATCH v3 27/62] KVM: x86: Nullify irqfd->producer after updating IRTEs

Nullify irqfd->producer (when it's going away) _after_ updating IRTEs so
that the producer can be queried during the update.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/irq.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c
index b9d3ec72037c..09f7a5cdca7d 100644
--- a/arch/x86/kvm/irq.c
+++ b/arch/x86/kvm/irq.c
@@ -549,7 +549,6 @@ void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
 	 * KVM must relinquish control of the IRTE.
 	 */
 	spin_lock_irq(&kvm->irqfds.lock);
-	irqfd->producer = NULL;
 
 	if (irqfd->irq_entry.type == KVM_IRQ_ROUTING_MSI) {
 		ret = kvm_x86_call(pi_update_irte)(irqfd, irqfd->kvm, prod->irq,
@@ -558,10 +557,10 @@ void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
 			pr_info("irq bypass consumer (token %p) unregistration fails: %d\n",
 				irqfd->consumer.token, ret);
 	}
+	irqfd->producer = NULL;
 
 	spin_unlock_irq(&kvm->irqfds.lock);
 
-
 	kvm_arch_end_assignment(irqfd->kvm);
 }
 
-- 
2.50.0.rc1.591.g9c95f17f64-goog