From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 F12F24E77FF; Thu, 17 Sep 2026 15:41:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789659724; cv=none; b=CV6o+IJSQ384UTPOqVQrgtTfwvuOUZTMpb7mN5u/aVj7mZ40Im/sHmMB5GE+Ba3+V+4oFInj9Ax+rNkj/ietBdRJNdfmIR/ZotEMgb5LMc84pDrPJBbiX5Gp4Kv7HupcucVHlt6/5AQBBBhZSVz265uky50S3GuX0gbF5jy/41c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789659724; c=relaxed/simple; bh=z6vOf1YeyFgvkYj1yXXUS/3IwPf1k5+XK4OIOyQl4ec=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FmefRtSQLt+2D9TwBDgRAni7EUQt0oe8HrkljPzeTy6ogwyp46p348Q0g/BMA5f5j3CM8JygXsbv3WVlTkgksFqyyt9k/qmXwJkKAw1gJb2VAzTYxij/2oRZw3kV1nxOtL0M09+LDO40qm7Qyu+C2Z+JNoElV8GXQUCS7e7HzJg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=XdtJGMcp; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="XdtJGMcp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 05DB31F00893; Thu, 17 Sep 2026 15:41:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789659714; bh=aJpklFrE6M79BnX5F25M3E+INT5Or2RjJKH8FA3WtxU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=XdtJGMcpg0AzRZWBbrqDfAqQzrxBDvnW04scwrtJa2dLve8/3AHqHQBz+Hcl3y2r8 z16D6mnzYHI9guZnpp9RG2jRGenAA/kx524CeJiWCs+O43vJd75iahVw4r7azdpuoG ih4g/Bqj1kRABcLVXUizvnVYWf/0orFA2DNSfjCQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Michael S. Tsirkin" , Andrew Stellman , Sasha Levin Subject: [PATCH 7.2 349/733] virtio-pci: return IRQ_HANDLED after non-zero ISR Date: Thu, 17 Sep 2026 16:10:57 +0100 Message-ID: <20260917151400.266881868@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260917151350.597953846@linuxfoundation.org> References: <20260917151350.597953846@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andrew Stellman [ Upstream commit 93fa09455fb1a9624b73d42ac1f83771f4818e80 ] vp_interrupt() reads the ISR before dispatching config-change and vring handling. Reading the ISR also clears it, so once the read returns non-zero the interrupt was from this device and has already been consumed. Currently vp_interrupt() returns the result of vp_vring_interrupt(). For a config-change interrupt with no vring work, that can return IRQ_NONE even though the ISR was non-zero and the interrupt was handled. Call vp_vring_interrupt() for any queue work, but once the ISR is non-zero return IRQ_HANDLED. Tested with QEMU virtio-blk-pci forced to INTx using vectors=0 and pci=nomsi. On an idle device, 200 config-change interrupts were generated using QMP block_resize. Before this change, irq_handler_exit reported ret=unhandled and /proc/irq/11/spurious increased from 0 to 200 unhandled interrupts. After this change, irq_handler_exit reported ret=handled and the unhandled count remained at 0. The issue was found during an LLM-assisted Quality Playbook review. Fixes: 77cf524654a8 ("virtio_pci: split up vp_interrupt") Suggested-by: Michael S. Tsirkin Assisted-by: LLM Signed-off-by: Andrew Stellman Message-ID: <20260904141318.30278-1-astellman@stellman-greene.com> Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin --- drivers/virtio/virtio_pci_common.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c index 10371ecbc054c..b90c174450b20 100644 --- a/drivers/virtio/virtio_pci_common.c +++ b/drivers/virtio/virtio_pci_common.c @@ -120,7 +120,9 @@ static irqreturn_t vp_interrupt(int irq, void *opaque) if (isr & VIRTIO_PCI_ISR_CONFIG) vp_config_changed(irq, opaque); - return vp_vring_interrupt(irq, opaque); + vp_vring_interrupt(irq, opaque); + + return IRQ_HANDLED; } static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors, -- 2.53.0