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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?SIzLxcoMZS6WwUlmyB+R1Fn37YD0nGa7gRfqt97TobFgLpS4bWDOR2me6YIg?= =?us-ascii?Q?AiUMrUYp5ypLrlu31Kk5aqmPinhBiecDSPJvwjQEEuM/MRPpEHFudcMV9ORt?= =?us-ascii?Q?RRNnmHhE3k0nFi8BWcwYafO2vbulOpLTArMPx2O1r/imcfB2vVMtNJUZ6wAh?= =?us-ascii?Q?N0HLgk3oZULJh7Ir0Nvm9HZlczWA0zzhQUdwW0tg/HxmSMtAT8berLrakyqH?= =?us-ascii?Q?OYryZTleHt4PMGSowNQVaYwPxIRc481XJV35da1FAZBKYGgu1FqUaMM+peZp?= =?us-ascii?Q?3rxibqUbdVhNvY/aKzurifye7k8QFIpkq0upUOzqC5jctdgEKRRhuIA+RMGD?= =?us-ascii?Q?YKBsokFY81pMqCm/LY6EreIWumYpvcFerb0Z2g1RjzVltfG2s7IcceS4GHLs?= =?us-ascii?Q?eEchZkpf6eu1e8Mu49Ey/dDLQoPSzGTnG6G3tWZOszh5CoCeYwt9oB32S/GZ?= =?us-ascii?Q?rF2YG5FonwZmzEua3rtZa5/8RnkdpmLaN8yihVN2NudBJrTq4TW3CLS3gORn?= =?us-ascii?Q?pFe6vESkv6tqF61Kw1HKRZtkiT5f7rys8P6Cc7Wo9+xoCTW2PBQqHvUd2ue6?= =?us-ascii?Q?V7DIN8WIj7W84Z0V6mSTe60bnLHtX8wGWEPOYOO0KAMfqB7wp0ELGMhEZSNR?= =?us-ascii?Q?u3B9jF/YBEAdj8BUJC0R/0goG/N4c/onxFag4aeq1ixd6CyUNQeqapczW+Oy?= =?us-ascii?Q?hYinEaYiEUa200MD+PyPtQkYZjIkd9HhAq0P6RLCly9bYbTle+tSPH0xUjyy?= =?us-ascii?Q?uOPSQHVvVsx19T1RFiXQc3MHGu4Jw1LknCrAiOjubQi5m963yYTCfrqoI2q2?= =?us-ascii?Q?ShkT+MhS4HZbMkkbirxNvptcZrzSuw+bflMJbxNrGdLolhC6u6T4SEI+lvUZ?= =?us-ascii?Q?ezbopFtqP/c+Wa/fgRjXYGkSmqfQvnzC2uDZgoDVlYg+HwuFSfRvTCDeIKDl?= =?us-ascii?Q?YKbXlEdFuMAuFLMn72asytqjXt7CgB6sE48Yjaa6MoIRKu2uBziFEej4lVpF?= =?us-ascii?Q?nuWE0YygNjNzXStxsPCkkAO1g8vGNvTBCyTQGHDZp12GBPlbQyFZhh4vv8ar?= =?us-ascii?Q?Y71z/pJbuq+6uMyvs8afOwRZlohLCO4wm0F4E7Gckcg30wnYEGkeoBRZJHil?= =?us-ascii?Q?tr0iO+7h3ZliT9etL4+IWIPjGTKT1MDOmauyPAJn6vkYAnK4dSRfopxd7wyn?= =?us-ascii?Q?e71WWXxEmyPliZKO+ZlTU2Mm7LX4XzBzgru5fJsaERSvcT5e+J5D9PvJXd8R?= =?us-ascii?Q?kD0UiZ/si6Opbq8jNuYlYRtvpqVAy5DpwMcEvpwvw987gLiW14A7WxoSTDaU?= =?us-ascii?Q?Se+Rqzq4GlnxNxLBjhLrvLj2b4GG6wvHkrknjLhRolTU4Zfe3uqQ5rQtF6jg?= =?us-ascii?Q?hjeOpoislXMd/NYtDFqgNb9Q3sErPkeQzDWwoHrUBJ5iuEKIqjgCzNverNf9?= =?us-ascii?Q?Pznd2NVd6h5dbnSGytQW/vD8k4ltbNxmxvFLVBlrtDPPfaB+tH8cn9sdIqeT?= =?us-ascii?Q?vHQqT/6rueJIjxK++DbubgZNWpMPt0RhOP+xkVpCibWb9XGdaUN9ep6MLrZE?= =?us-ascii?Q?VZvVxn8bN8bR317yDwA=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 6d01b779-94e1-4514-31ba-08ddf456f017 X-MS-Exchange-CrossTenant-AuthSource: PH7PR12MB5757.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 15 Sep 2025 12:53:59.2168 (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: L/e3Z82iHxMU6YMiwYeyxkyq5iCH0VT7YVc0GX21OwYq/IpZ3oIe/3IBPu5BkVE3 X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN7PR12MB7346 On Fri, Sep 12, 2025 at 09:49:13AM +0000, Tian, Kevin wrote: > > There are two corner cases that won't work: > > 1. Alias devices that share the same RID > > Blocking one device also blocks the other alias devices that might not > > want a reset. Given that it's very rare for an alias device to support > > ATS, simply skip the blocking routine. > > it also applies to the devices in the same iommu group. While one device > is being reset, all other devices in the group cannot change the domain. > This needs to be documented in the attach uAPI. I think we should just exclude multi-device groups for the first version of this. We really need to fixup multi-device groups to distinguish between cases where the group is there for aliases and we must have consistent domains across the whole group and cases where the group is there just for representing isolation and different domains are fine. We are now having workloads where this difference matters, ATS reset is one case, but I'm interesting in seeing iommufd able to control domains per-device within a group. We have some HW that wants this. 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charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-rockchip" Errors-To: linux-rockchip-bounces+linux-rockchip=archiver.kernel.org@lists.infradead.org On Fri, Sep 12, 2025 at 09:49:13AM +0000, Tian, Kevin wrote: > > There are two corner cases that won't work: > > 1. Alias devices that share the same RID > > Blocking one device also blocks the other alias devices that might not > > want a reset. Given that it's very rare for an alias device to support > > ATS, simply skip the blocking routine. > > it also applies to the devices in the same iommu group. While one device > is being reset, all other devices in the group cannot change the domain. > This needs to be documented in the attach uAPI. I think we should just exclude multi-device groups for the first version of this. We really need to fixup multi-device groups to distinguish between cases where the group is there for aliases and we must have consistent domains across the whole group and cases where the group is there just for representing isolation and different domains are fine. We are now having workloads where this difference matters, ATS reset is one case, but I'm interesting in seeing iommufd able to control domains per-device within a group. We have some HW that wants this. Jason _______________________________________________ Linux-rockchip mailing list Linux-rockchip@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-rockchip From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id EE40BCAC592 for ; Mon, 15 Sep 2025 12:54:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:In-Reply-To:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; 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charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Fri, Sep 12, 2025 at 09:49:13AM +0000, Tian, Kevin wrote: > > There are two corner cases that won't work: > > 1. Alias devices that share the same RID > > Blocking one device also blocks the other alias devices that might not > > want a reset. Given that it's very rare for an alias device to support > > ATS, simply skip the blocking routine. > > it also applies to the devices in the same iommu group. While one device > is being reset, all other devices in the group cannot change the domain. > This needs to be documented in the attach uAPI. I think we should just exclude multi-device groups for the first version of this. We really need to fixup multi-device groups to distinguish between cases where the group is there for aliases and we must have consistent domains across the whole group and cases where the group is there just for representing isolation and different domains are fine. We are now having workloads where this difference matters, ATS reset is one case, but I'm interesting in seeing iommufd able to control domains per-device within a group. We have some HW that wants this. Jason _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv