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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?SxeMRXeyH5XtVkaecAzLhry7c2V+qBhgtt/UqhiT0NKvV9Wa2U8Vue/l2T7Y?= =?us-ascii?Q?ArG9oFANa2smlSjq7vlMkFenBv+6ucgEBFGn16ZaJv+M8k5xa4xdfuhSDW+b?= =?us-ascii?Q?9e/niHhx7u6msr56CK228953OT4XIEKcANRqgm2hdlT1jpHmuuF4fr1ojyCf?= =?us-ascii?Q?2BOAoOWiKoKROxBsosWrRqOQqEWBB+lyPszo3MMKwI9i1HwSbFAKnLlCf7Z4?= =?us-ascii?Q?yWMXP0xx4c1oLPu43VPoyjMNFXsEu7aOru8ph+GDg2H2za6OKyrVBaSZOOGM?= =?us-ascii?Q?G20Ai/njOUv4ufafaC/5lq5h+15KdTRIoLkx5YsIDDvOF9F5o5PoIMLf7hcB?= =?us-ascii?Q?byEpPxf774EGp+2sy+jT+KdtDFvDUZZv/CD4udh9LVDGS5uCKKpy1ceVgcZC?= =?us-ascii?Q?ygCtjL83Bx7nmz7TfIbTnlZ1rSobX3DYbzE9ltbIbJxMkcpoZWWgOofAi5gY?= =?us-ascii?Q?BD6xTGR6+HtY5RvW5UVqh1mrKcfQEO8GP9o6rKjr4jnOo9W6dk/IeE8cATVR?= =?us-ascii?Q?af1x9u+Gj/dVlj4Hjrl2HMyVCHoYnjClz9SlJtIy91qYqIlgvy2fCm1nDYed?= =?us-ascii?Q?mN8MYmejZbuG1AtCBcIS23fGB0589R8gwZ+M20bFZSE/RJeX8aF8Q0rPF3l3?= =?us-ascii?Q?ewarTY/SQW9rT0sNAA0UPHSG/bE1adkYo9pT7ag2H/VE3EmsDpeeTQY5GTyT?= =?us-ascii?Q?W0pOXQAipZ2lwwvORQSOuIX6U0a5a83zV/H6NQQUJlyfxDngz7zl1ikqUljH?= =?us-ascii?Q?EPMyl8LBeZGvD+GBgQ4YVNXpgb7WfApswMdycvNIKv7EKK9rwoFwWWzni5Ww?= =?us-ascii?Q?xt4+MIrgTFGZWiusQG0fxx5lGs3Q77UulGA16pVwb3nfN0MT1BzrGvZF+C6X?= =?us-ascii?Q?NizHvORdom2xGAtfX6C7EpsbtwlyOnzc1RGa2zhPQD/d6y5YCEn2+sAxLs6H?= =?us-ascii?Q?51MWbfsdJG/irmvuCdur/OMrz0T9Uau9aWCL30WfSxS1Pq/UD+q0ExFQXlCB?= =?us-ascii?Q?nNO3Gkq8mlXYv39CTLV9EK9ei0eFDttPcmSo9+8qmSId6hobCi6i/arauseE?= =?us-ascii?Q?8whkQz2U549JO2YeFY/JcDEGJUbvp4Kv1O9ddZrCPgUarGHtPqmQsxjZjv3+?= =?us-ascii?Q?2yhM8SRINLJ8ggLFGPM+hrL73rK2g93zeVafc/GSefL5Hee8TRc2bGJrtyRJ?= =?us-ascii?Q?QpXkg40SuZP6xmOxBqCuQBN1N5iu42Vhz9DSQpgFyAGK9EN2DD0/sgV/wg5f?= =?us-ascii?Q?OO47uCXNiwjMK0UGZaYK0l6y90+VGhF3lmCdoMLWH0UJfZdvO9FR8kldk2rz?= =?us-ascii?Q?q4S6EU8O2ILGmKIdLSqPZFAMuJNq+rQtCT3Oa7YTB5PodYi8WhWbOhakIy0B?= =?us-ascii?Q?LnSBxJMQh6TAo+rGnYkKzK2o0dTlmIFAquQqc7PLUF5Sip4exdAj1qI42aFD?= =?us-ascii?Q?8a5pYZqm7bQdyXlQ+3aTkFAysbLLm3REztNdZKXionaLtKcz0xAQick9O020?= =?us-ascii?Q?kJS49DgIu5vvzBoHfXPoWuzK3zEGQQ/CLSePOLTg3+sBFGfixzpMnQp+XnwR?= =?us-ascii?Q?s1XqR5yIfXWnyFx+A/iZXil4PkqslOAkH+FuLz+hM5JHJ1GCY3Z0jxW2n20D?= =?us-ascii?Q?soq3sTzpcGpZ4md2pZN48jTqtMW7KGKvDphW+i/kgsHMvSHZN+VU32m2HXWN?= =?us-ascii?Q?Uhlf9GQTXw9yqICXJkeJtThxD/h9L6kNf2J2XYRrIuMgIOnq8Hu9qx7f3319?= =?us-ascii?Q?uLboSvOSBA=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: d8a647b8-951d-4048-16c6-08deb2cde305 X-MS-Exchange-CrossTenant-AuthSource: LV3PR12MB9411.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 15 May 2026 22:04:08.0985 (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: AoU6cVY3ifr88iYb8gAQmR+RBNiG35LF8n67bHUDXO/8TIKygH5XHeIJn9/ctAS6kgAo8LUILsHtw4JzWsbqGA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA0PR12MB7751 The mix_and_match test intentionally submits TX descriptors with an unmapped source IOVA so that the DMA read fails. By default the 82576 re-sends the request after a PCIe completion timeout (datasheet section 8.6.1, GCR.Completion_Timeout_Resend, bit 16, initial value 1b). On real hardware this turns a single fault into a stream of retried reads, keeping PCIe AER and IOMMU error handling busy and interfering with subsequent reset recovery. Clear GCR.Completion_Timeout_Resend during device initialization so a faulted read fails once and stays failed. Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Alex Williamson --- tools/testing/selftests/vfio/lib/drivers/igb/igb.c | 12 ++++++++++++ .../selftests/vfio/lib/drivers/igb/registers.h | 2 ++ 2 files changed, 14 insertions(+) diff --git a/tools/testing/selftests/vfio/lib/drivers/igb/igb.c b/tools/testing/selftests/vfio/lib/drivers/igb/igb.c index 2297382d7c26..9f93ec7ba8bc 100644 --- a/tools/testing/selftests/vfio/lib/drivers/igb/igb.c +++ b/tools/testing/selftests/vfio/lib/drivers/igb/igb.c @@ -213,6 +213,18 @@ static void igb_init(struct vfio_pci_device *device) vfio_pci_config_writew(device, PCI_COMMAND, cmd_reg); } + /* + * Disable DMA re-send on PCIe completion timeout (82576 datasheet + * section 8.6.1, GCR.Completion_Timeout_Resend, bit 16). The + * mix_and_match test intentionally submits descriptors targeting + * unmapped IOVAs; with the default (set) value, the device keeps + * retrying the failed read indefinitely, which keeps PCIe AER and + * IOMMU error handling busy and interferes with reset recovery. + */ + ctrl = igb_read32(igb, IGB_GCR); + ctrl &= ~IGB_GCR_CMPL_TMOUT_RESEND; + igb_write32(igb, IGB_GCR, ctrl); + /* Configure PHY internal loopback for testing. */ if (igb_setup_loopback(igb)) return; diff --git a/tools/testing/selftests/vfio/lib/drivers/igb/registers.h b/tools/testing/selftests/vfio/lib/drivers/igb/registers.h index 139f1c2e6fdd..45f71dc26e24 100644 --- a/tools/testing/selftests/vfio/lib/drivers/igb/registers.h +++ b/tools/testing/selftests/vfio/lib/drivers/igb/registers.h @@ -73,6 +73,8 @@ #define IGB_RAH0 0x05404 /* Receive Address High 0 */ #define IGB_VMOLR0 0x05AD0 /* VM Offload Layout Register 0 */ +#define IGB_GCR 0x05B00 /* PCIe Control */ +#define IGB_GCR_CMPL_TMOUT_RESEND BIT(16) /* Re-send on completion timeout */ #define IGB_VMOLR_LPE 0x00010000 /* Long Packet Enable */ #define IGB_VMOLR_BAM 0x08000000 /* Broadcast Accept Mode */ -- 2.51.0