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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?USh2faYHQbF1+o+nFxakk1YTLK7HXAj5TWVkZZ+pt+U0B/B54vWPKGxQT9d4?= =?us-ascii?Q?C0ATaRoDQekluYgMi6I0mxt5HfFklYAnY7wNt3Dd4LAHZ0ogsAwCYuZoLR2B?= =?us-ascii?Q?sv45lvfvLa+Xo8lwl9nO89LtBzaBpFSbp7KMorEQzpnIFPJivxsGuI1N6COO?= =?us-ascii?Q?XIylubgxjnGe0lDi9ulMoG+CoLT+QTCNrgvKH6z6RxPXjTJ3OmydVQ5K1OpJ?= =?us-ascii?Q?JFq1igq9+EA6KTpeL/CkgT2Y4hSlG8kQClAkpravwYTUQZheDNw6X/iEdm61?= =?us-ascii?Q?PsXI/0Cj3EF/LgDGS5nTwLFlL5PQ3bsiNRKOXnR80OYxD1f4G2SxsZM+ky6B?= =?us-ascii?Q?Ug/vkqR99OAMhXhJ3p3uLlbJbJfK9QpZM5Ga8BFp7s6DM5nh6/bk6nr6EfDq?= =?us-ascii?Q?TLsUQSWb2kZPXrI8sOgXYWoFbIbgBckSILczYJWpRJWuZw4yor2/uKzYLjBJ?= =?us-ascii?Q?aNZB3qbrwmP2r3kmR8WRwR+ChhMR6gqHTh9ApWe+GvRlo+bJhD4gaUdbQcoT?= =?us-ascii?Q?/prAaySWHU8C+HDvTIdOCFqDVQG1kJ60V/9glFEkFr+8GhuYLzsF1TPRxsw2?= =?us-ascii?Q?1Y1SNhJyzqw2ddJdqmFDMIvA70TPiJA9rtLXpZoYg60bMonBQdC88VXaCn6C?= =?us-ascii?Q?ul1vuGu4Z+saG5TB3xYkxAcpthLfuaDHuMxrwpLH1jMuGjmeC9YD0GlxTUkJ?= =?us-ascii?Q?hk8+USsJaSIGX0hcL7CbhAijGBkhSoxae7IQ4UXQvTNhc+TcgNRmcrMC7T8H?= =?us-ascii?Q?aLevZLJCZ3rV6iht7zTJ2RmP9F/PvjvcHuOWna5wApBdOp7AGA1nLmmZHMKm?= =?us-ascii?Q?bXhxYtIF3HsUmhI0bMmwXYZHIhEFqHj1PI4Y3Vvg8VjoY5IBtF1988atA5Jv?= =?us-ascii?Q?XzcriEZZ0Vnh9KOLw1r197PhU+efZquC2kOsMkw2TCYaHBKxDqH2XzZCbeDL?= =?us-ascii?Q?EsvsceGVsLABhXtdG1UF6Aj4s1/vezuMV/2t4zrD4bOSObCe81wn3MThDph8?= =?us-ascii?Q?2aFQMJ+oUgyIUIEX83XgMCbUQD6u03O+mdkhSc9rBEFQ1aLLGgc6logTn+Sm?= =?us-ascii?Q?KjqIA5OJpdpaCC1D3/vuDSAtGT/ADYDYxEtqZpuNEyNVUep8AHqoGwrd/FxQ?= =?us-ascii?Q?//f8cYF7nPedG9Ds6OA6A+1NVqJauakw6d6QuT04ct7umOmWPML34WKqub6S?= =?us-ascii?Q?GAPgRTHFlh87tq4FzAnnNVjg9+OV148KZ2o70Frfs0e+zD8P4Mt9F5er6Cr6?= =?us-ascii?Q?IPf09fJ4IL9jY3bJj+MGWnylEDWObQkbZ9fQFE5bOnTQA2hVyewE2AVUs5Ep?= =?us-ascii?Q?C+S7YmxlxkWotE3w5bw8TdOGo+vx3+6xo+8hFMzkaf4kXO0wEpG1/JyLaKcr?= =?us-ascii?Q?XpGcg9TOgTifhCjpxPCRWVoWdS6UYkeRdeCWVyMNLNt0AKXEO32kippgzl+9?= =?us-ascii?Q?19ocVDXS5konyQMOyatVtuJDnZzs7gqS1/wkWSXS56yWN/yqOJ76Gl7OIeVN?= =?us-ascii?Q?DBE5WwY7qyxYibu1JnvEBdNzbn3aCobgZzcFQwjYjP8o+4eJnQsZfNIrpxyQ?= =?us-ascii?Q?xZiy1vVI5qkoQ58iANO4UiuE6+lWR/Qz+AANbouKHWmrGYKIWfebqW+vMGvJ?= =?us-ascii?Q?ARkDf0dni6/iuP7aVI0akxJCUOrCkZwmKqVFGNFYUcx757SXnCoF81iXydCT?= =?us-ascii?Q?7a6stXAFMzSCitaAV5xlkAaWCcOqlEVoLybrTlUjqWFTsCJ5?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 8e1a4042-9ddb-4296-824f-08defa20b52d X-MS-Exchange-CrossTenant-AuthSource: CH1PR12MB9573.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 14 Aug 2026 16:25:52.1129 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: +8bVlfvRAR6l6s902sZIoSgmXfksBALQe0QD6t9Qgx6178Rg+p4Z58ItdMRBFwiab42XwFE33SJOkg/kcUN4AQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS0PR12MB8319 When many virtio-blk devices are present, managed IRQ reservations can exhaust the per-CPU interrupt vector space and cause probe to fail with -ENOSPC: virtio_blk virtioNNN: probe with driver virtio_blk failed with error -28 On x86, the affinity masks of the managed request-queue interrupts collectively cover the possible CPUs. irq_matrix_reserve_managed() therefore reserves one vector slot per possible CPU for each device, even when the device has far fewer queues than CPUs. Once a CPU's vector space is exhausted, further managed reservations fail. Add use_irq_affinity, defaulting to true to keep existing behavior. Setting it to false makes the request-queue interrupts unmanaged, so each interrupt consumes a vector on only one CPU. The vector allocator places each unmanaged interrupt on the least-loaded CPU, allowing the interrupts to be spread across CPUs. For example, the reported 64-CPU system used one request queue per device, so each device needs two interrupts (config-change and request queue). With managed affinity disabled, 800 devices consume about 800 * 2 / 64 = 25 vector slots per CPU. This stays well below the per-CPU vector limit and allows more devices to probe. Signed-off-by: Liu, Changcheng Reviewed-by: Stefan Hajnoczi diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 32bf3ba07a9d..184f1c1f4485 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -41,6 +41,11 @@ static unsigned int poll_queues; module_param(poll_queues, uint, 0644); MODULE_PARM_DESC(poll_queues, "The number of dedicated virtqueues for polling I/O"); +static bool use_irq_affinity = true; +module_param(use_irq_affinity, bool, 0644); +MODULE_PARM_DESC(use_irq_affinity, + "Use managed IRQ affinity for virtqueues (default: true)"); + static int major; static DEFINE_IDA(vd_index_ida); @@ -1016,7 +1021,8 @@ static int init_vq(struct virtio_blk *vblk) } /* Discover virtqueues and write information to configuration. */ - err = virtio_find_vqs(vdev, num_vqs, vqs, vqs_info, &desc); + err = virtio_find_vqs(vdev, num_vqs, vqs, vqs_info, + use_irq_affinity ? &desc : NULL); if (err) goto out; -- 2.43.7