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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?NbKdG2WZJ3OfBRJKbPGndWCCjuUWLM3b9jhB4UFzgS2sAaH1xKKWw6teva5g?= =?us-ascii?Q?Ut4rb8wSszOjCFLfRsHMZ5yclo+23UiZGfiT5cHgjIH7iHiw9jFHJWbfm4E9?= =?us-ascii?Q?2NENp9b8PbFh/yfMHH9kD7TEaY3hxVA+OoSwodRsMm0htaSWReFwvH4AKvVw?= =?us-ascii?Q?ZRwJ29WygJvqkbwntzNJGAyWOBOC1LntgkwraTtuUecyFHFYu5NVDs4bx9eH?= =?us-ascii?Q?rP9NwogKIExu32RvmOHKEcJxriIu5l1V6qPoVQKggB0MBAKCY533J4q/pv5u?= =?us-ascii?Q?oqS1DyuUazMDYUCASSw7lgVsQRJUwc1l0B92RDCK9cWm3DWC3uMRw304kJ1U?= =?us-ascii?Q?xlmKALNSXEiCpRi0jRzvDa4h+6AIjosD5HAWfCCfL8ABZKdw8SX9HXaIKLzO?= =?us-ascii?Q?txiA+uqDHonS7eaBgVKZbLizXt4S/jEWnLzccpbescDMX1RhYx8FUB5hkZXO?= =?us-ascii?Q?wEJXn2rU6pq2IwUxYXUY1Sq5Ex9B9f8znxMT3sETG40MT875NCjb+CW2abfG?= =?us-ascii?Q?oSZ+h6zAmfBBTE17HohG9zriPA+uYHs24QjaiVhtueB1YBTdr5sQBJOiUxQo?= =?us-ascii?Q?JHc5Ksusyk7fukropAn3uhRg8E8NxzH1yk8zqQ1TsiImNZDT9vfxxiTSHvpd?= =?us-ascii?Q?GMQE+U1mdftAXQkEV+g1FvzjCbq0H7W3/tALRVmP4IGAoc3x1tl/2CYp02rV?= =?us-ascii?Q?rkZ+H5OzvQJxCWwyZxLjXxmfm1zctiYIe4KyE11fwd34G9P66dSj7m+yDbSf?= =?us-ascii?Q?rgH5jWAdfgTSbTyGKu82uu4o3E0J+SdzDnh3xFguTZaKv4VsTKH0PD9p1ioE?= =?us-ascii?Q?spAHp9SiO7nS6E/RaxCzp+Ou91kFaopRce81R8RDHpSOnqPKq9uDkCVCKZEb?= =?us-ascii?Q?WsOgo4gtTNAaPnhDLKdyBLRc+2mT55VqSeSxJaF+n8Cs4RgxpWHJa6qjLf/f?= =?us-ascii?Q?2COi8U1Q6f7g/E/Dqshmin0Awa6L0OXxQpJwNClCmYVf/7ljlZ67DOPu+UEM?= =?us-ascii?Q?T+KJTRk2pr1auU7NpkzImfV7/Prv+P6yz9YkCVgZ7G/Jxq/n+s7PNhVm918F?= =?us-ascii?Q?gwsF7dCNilyCaCPMvKDlzcSaw1Z0xT1/ua61ZkuX1Jjdb9foQ6js4bNrsyGk?= =?us-ascii?Q?BFDMBZt+q+1FAQUpff+mRcyVC8QGA5FcFlCrpljcVRW1W/l5eD+45a78UOdA?= =?us-ascii?Q?jWlEPvS+G4/iDXszyAUUrQ3oXXUr7Z4S30liaZ+yxj7zAx5l/8W7dZTVk7n8?= =?us-ascii?Q?iGOwyXGqxJazMh5kxL4fWY94dE0EAKmOymlf+R6tkZkKKwJRIKhAPNgARVeF?= =?us-ascii?Q?iRMKoNLOOiwfcMK0srKlyLGf+Bzz/5hWUIY8C3BeXDpUidknarsYNvoF+k8K?= =?us-ascii?Q?YpeumHpzwCVQ7HwZ7UVPQjgbp4vDyYDoK+RGjYg6wH5Zdzr7PUcXRGKyk0J8?= =?us-ascii?Q?p7MM4WcHuaIjADhA29oYg3aN9LGDQwRWQPtMj8PWdVMJw4jVEsjF9oWnx1Kk?= =?us-ascii?Q?zWMcpKf8n/jWl2rkwdJwusSfS2K2ht2cOOPb7kHypM2NAxl6i3+h/ha0K/B+?= =?us-ascii?Q?cugE5HBrMSVzQW45OZo/mJ2x8ugGUGdkCn5p5bcJPSWswhllm0rZ4zn6OSiL?= =?us-ascii?Q?noLUjkJqsaRD/pJpJE3ByoppcRPdngkTXt36RbqbWH2867Ka2iB1rtFMaHgL?= =?us-ascii?Q?kIvgIeVbT+7J9DQUKECyTNromCUsbBmBLZJRI3y5rIAe2aZ3xhahWz14fbYf?= =?us-ascii?Q?/tHpvSTvLg=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 310f1a72-9fb3-4b03-f00b-08de59cc7cf1 X-MS-Exchange-CrossTenant-AuthSource: LV8PR12MB9620.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 22 Jan 2026 15:39:53.9473 (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: HVyMvcKgQ8XKikMkr7bubfgL6r5O73WTnG2rY5pmmtdlpktwGVCYfMUDxMDLFnaN X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA0PR12MB4382 On Wed, Jan 21, 2026 at 05:18:46PM +0800, Wei Wang wrote: > On 1/21/26 12:41 AM, Jason Gunthorpe wrote: > > On Tue, Jan 20, 2026 at 02:11:30AM +0800, Wei Wang wrote: > > > Add support for the ACS (Access Control Services) Enhanced Capability, > > > introduced with PCIe Gen 5. These new configuration options can be > > > controlled via the config_acs= boot parameter. > > > > > > By default, the ACS Unclaimed Request Redirect Control (URRC) bit is > > > enabled if supported by the hardware (i.e., if the ACS Enhanced Capability > > > is present). This setting is particularly important for device passthrough > > > in virtualization scenarios. > > > > The memory target access bits should be set to request redirect as > > well. Linux's grouping logic effectively has assumed the enabled behavior > > forever. > > > Yes, sounds good, thanks. > I think the REQ_ACS_FLAGS also needs to include the check. That would make a mess, I think leave it alone. I tried to make some patches for it once but it is going to be problematic.. Jason