From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0ED551E1E00 for ; Sat, 6 Sep 2025 14:57:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757170640; cv=none; b=Tbbb73l6nLlj7dMj8NwUvLxzQGH8PVwycPalHX9CxuNg4HkFL33jIZLcsOO0RzGsIjpmpXvJWxtlqhNTIjN7ASpNfRN4SkMEgbapELfP+b+LqXCqKXsPO7DHi62Zt5Xm9nUBFyxuNMJ2esQZJXByLzGlAfwfDE78YHNwNjqa7Do= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757170640; c=relaxed/simple; bh=EHFNCV0S3VAKHCpV2Xg24af7gNkaf9317963pqrWujM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TIiUqPj+w3+AV24cgrm+qkLQIO8i+JtMJ+AIhLQRDtJwK4HxJd6RiwewxC+9uECVmVNsBvuOvegVpqmrUg812tf2mN4ZIZobHC+S3IVlI6uKO4YoCnPrDcEdnBC/yoF55LS9P6xIBEQP6jOJ0rYV35UMD9FaLlJWYY4x7JlOVmo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=p2NoCe2F; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="p2NoCe2F" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 07555C4CEE7; Sat, 6 Sep 2025 14:57:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1757170639; bh=EHFNCV0S3VAKHCpV2Xg24af7gNkaf9317963pqrWujM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=p2NoCe2FJTt+8VBeCbKfYLe5K/dc2+Cl3WKSPiT065950grG5UfyNQjLXKlh/rBvY oaauKvW1af6b6QaA9O71BN+Wxt29ih4hYawoL03/g9lTiU8fDzlzqde8tQlM0UKP+1 a6bW88qK8s6gLgmOv+DPxkllPLTRs5t0xjy1/ITxOW3J1JJwWtr4VGqb+KGxshaCry akzyXBMP1Tu8DI5AFyFfVJz0F3hgWx4a1KVpH1CrfBf9motdpjI1mK8vAiAJmqLikS u8HhBNPgDSIRFlBMYfAIybAjlp4cplfSfzMIyCRyOz6pIEDjGTLj0KTBHJC3Y5I8sf VfKzk1KJu9w4Q== From: Sasha Levin To: stable@vger.kernel.org Cc: Sean Christopherson , Paolo Bonzini , Sasha Levin Subject: [PATCH 5.10.y] KVM: x86: Take irqfds.lock when adding/deleting IRQ bypass producer Date: Sat, 6 Sep 2025 10:57:16 -0400 Message-ID: <20250906145716.57721-1-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <2025042806-economic-dexterous-1dcd@gregkh> References: <2025042806-economic-dexterous-1dcd@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Sean Christopherson [ Upstream commit f1fb088d9cecde5c3066d8ff8846789667519b7d ] Take irqfds.lock when adding/deleting an IRQ bypass producer to ensure irqfd->producer isn't modified while kvm_irq_routing_update() is running. The only lock held when a producer is added/removed is irqbypass's mutex. Fixes: 872768800652 ("KVM: x86: select IRQ_BYPASS_MANAGER") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson Message-ID: <20250404193923.1413163-5-seanjc@google.com> Signed-off-by: Paolo Bonzini [ Adjust context ] Signed-off-by: Sasha Levin --- arch/x86/kvm/x86.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 63df6c33e3a47..8952f3567b69a 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -11417,16 +11417,22 @@ int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons, { struct kvm_kernel_irqfd *irqfd = container_of(cons, struct kvm_kernel_irqfd, consumer); + struct kvm *kvm = irqfd->kvm; int ret; - irqfd->producer = prod; kvm_arch_start_assignment(irqfd->kvm); + + spin_lock_irq(&kvm->irqfds.lock); + irqfd->producer = prod; + ret = kvm_x86_ops.update_pi_irte(irqfd->kvm, prod->irq, irqfd->gsi, 1); - if (ret) kvm_arch_end_assignment(irqfd->kvm); + spin_unlock_irq(&kvm->irqfds.lock); + + return ret; } @@ -11436,9 +11442,9 @@ void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons, int ret; struct kvm_kernel_irqfd *irqfd = container_of(cons, struct kvm_kernel_irqfd, consumer); + struct kvm *kvm = irqfd->kvm; WARN_ON(irqfd->producer != prod); - irqfd->producer = NULL; /* * When producer of consumer is unregistered, we change back to @@ -11446,11 +11452,17 @@ void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons, * when the irq is masked/disabled or the consumer side (KVM * int this case doesn't want to receive the interrupts. */ + spin_lock_irq(&kvm->irqfds.lock); + irqfd->producer = NULL; + ret = kvm_x86_ops.update_pi_irte(irqfd->kvm, prod->irq, irqfd->gsi, 0); if (ret) printk(KERN_INFO "irq bypass consumer (token %p) unregistration" " fails: %d\n", irqfd->consumer.token, ret); + spin_unlock_irq(&kvm->irqfds.lock); + + kvm_arch_end_assignment(irqfd->kvm); } -- 2.51.0