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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: dBzYmG/CGJaEFUfYqRIWHJ0Enhh1aIU/T3V2l3A9didoz+WoNg79bj8mO5hkhSFNFI/W/zDYyn7yOQ/40Al+7Hm1tHQG3iY7sW4QIE1YZsxV2CNJT8XUKukSoyLcaQrNm2nizVshPgq0SNYJ4E2SYDdLjub20cO7+nbNH7bkYZY42euDOkrfXVsbRiFo0VgjaDaPcsv7qia7U8YBGKvtLJa8XqmLleQtBOjG0Fy3GW7Dh59TY6Z5dxwLETmnl4tfdVWGJufWvz1D1gl9Pzz4eZPON4y/seENUwfbsrWjcYWOuy+6M6Hq7Q7mkyrAD0HAgJJws7Ips0uZbsYRT/P9Ndoabo5VGH7yNT11sZKbySTbZZ/KqBtfpKL6ZY4jHPZmxWNS/4a1A2b5R5OSZLjpmk4I9UUiMTjzKAqcVXtJVhY/CVf4fWnNdirY/9wa5dTN X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 15 Apr 2026 15:13:18.1139 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 8083f892-e7d9-4c2e-0433-08de9b018641 X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[216.228.117.160];Helo=[mail.nvidia.com] X-MS-Exchange-CrossTenant-AuthSource: CH2PEPF0000009E.namprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA1PR12MB6185 On 14/04/2026 23:06, Alex Williamson wrote: > Jinhui Guo reported a mismatched spin_lock()/spin_unlock_irq() pair > in virtiovf_read_device_context_chunk() where spin_unlock_irq() would > unconditionally enable interrupts despite spin_lock() never having > disabled them. On closer inspection, the list_lock spinlock with IRQ > disabling was copied from the mlx5 variant driver where a hardirq > completion callback justifies it, but the virtio driver has no > interrupt context usage of list_lock. Patch 1 converts list_lock to > a mutex, fixing the mismatch and aligning with peer vfio-pci variant > drivers. Alex, How about staying with spin_lock but without the 'irq' variant, instead of replacing to mutex ? The scope of the lock is very small which can fit spin. We may potentially get a performance degradation compared to mutex as part of the hot path of STOP_COPY where this lock is used. Note: I don't see that other peer vfio-pci variant drivers maintain a list of buffers as of this driver, unless I missed that. > Patch 2 converts the list_lock acquisitions to guard()/scoped_guard() > where the lock scope aligns naturally with function or block scope. > This patch might not be applicable if we'll stay with spin_lock. > Patches 3 and 4 extend the same guard() conversion to the remaining > two mutexes in the driver (migf->lock and bar_mutex). These are > relatively independent of the list_lock fix but complete the > conversion across the driver. Thanks, > Those 2 patches seem fine to me. Reviewed-by: Yishai Hadas Yishai > Alex > > Alex Williamson (4): > vfio/virtio: Convert list_lock from spinlock to mutex > vfio/virtio: Use guard() for list_lock where applicable > vfio/virtio: Use guard() for migf->lock where applicable > vfio/virtio: Use guard() for bar_mutex in legacy I/O > > drivers/vfio/pci/virtio/common.h | 2 +- > drivers/vfio/pci/virtio/legacy_io.c | 17 +++--- > drivers/vfio/pci/virtio/migrate.c | 90 ++++++++++++----------------- > 3 files changed, 46 insertions(+), 63 deletions(-) >