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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?Tu60XNF7RmrT9YafleRktlDa9jlk+VW2V9HhLpwcpu0MFDkz7CHv5eOOnfYt?= =?us-ascii?Q?Qr+x9QkAwjRezJp6R5pxJelOJQGkVpgex2qUbTsdB+ibNbAhzH+EcwqM1PuP?= =?us-ascii?Q?eCAliTSl2gE/fleuRkYy3GXw4sf1nBNQRfTOnxVAJ2/m2CWRDlXIRnGWLQ5K?= =?us-ascii?Q?FZ+KlK2P4LWNzITsIekNLsZCn5qelpqc0Vlxmdws7LGxFOcaKR5u1pfAKgmU?= =?us-ascii?Q?wee0f/oCqzmXcpImJHev38e0LUb1kDNGkfpP4LMs97PNj9PPZGfqvGkCfn47?= =?us-ascii?Q?g+zy/+J9bHxYIeI6tvzECl7SeZYP63148yI9shbfBjzmAPkwYmv6KpEx3TN8?= =?us-ascii?Q?r5Lr1FV+6odx9gFAtit9E/5QzwSpEA4JGWD+k/d167ZvcZ0EqzFfEgwg4MLk?= =?us-ascii?Q?NpzViK6Q41e1JdpaNGEeS8z9A9mtqFalD6ZLqV/oOkMpFNEWjeie9RLjMO3E?= =?us-ascii?Q?k2TJGb4x2GwbbDdV2eXfjdHusfTp6Ni0LWXHrO7uYJsy7X7myIRgIAxGQURo?= =?us-ascii?Q?1I0VpSG8pR4OPWFm65lyOM5iQqlf5LWV6aFZhcCVPDwHrpm4QvLDov/vDaMt?= =?us-ascii?Q?bqyumI0/kIY3eb0DHg2/zVAO9J5Gi+kzsRuz9+CMtEgxugL1Sb+Xvd5i6J0U?= =?us-ascii?Q?Gpe1tcgHRI2ka4ZaFkcOogeYNjFNWnz63iQVkufbUHJahlTcbYwz8o4hywaw?= =?us-ascii?Q?RWx8e0seLzYtPLwRpcA4q9kdCSN+0AR4BdO1Ud6ZuDurVUNeYhMN67UslhSm?= =?us-ascii?Q?Zd3FsTaNLRCClo8HF9aT1stLDirXCSA/VSzz0bytBCVz6Y5qpMjX0bkWYO4N?= =?us-ascii?Q?b3cTLqAojcejN5MUSLY3nWp/hINb4qWKv4yOyrS5EgM/wvnhadZjG/628ZpY?= =?us-ascii?Q?T49KYjn1O2E1x53pCkklXRmcRe9z51ntEjh9lFg+TaakRmp/boK8QqNvMSUT?= =?us-ascii?Q?9W2OkiypHFQJi7zyVJaYOW+EI3m11kjnosivUxn/C/zfQjRgAhVQEr3f9xtJ?= =?us-ascii?Q?O0m9/v3TaBGZt03TeWzTXxmny4LddGprOelILZoCu4DZ8TML1VJiJ/GKfNZo?= =?us-ascii?Q?N3oVo6V8QEnEH+yJhV5h35CcwlJ5wfzw+4MFN417gk2SCtMICamwts9DH2Gf?= =?us-ascii?Q?Zh4AQkbpjK9JmAKMVfEaqORsPZAFUWkuy3L+4Uyvp9tsnmeOXtNLGkuagYCT?= =?us-ascii?Q?AJuxeAuzPVsJCqv5gIqhkqBNlBM8EZQ91JxXxHbdwab6Pu0ykc/Jhzhr8rLk?= =?us-ascii?Q?9JFmldQ5Qn6QESWYR7CurOZHMk49fj1aUABLsBD1iAdQu8f6K2Yx1UDpFkdP?= =?us-ascii?Q?kJ3neehb8veKqWe9TIoKiGEsjlJXwCg6AVUuw8G+DyVlbeuM7JedBqWKgypY?= =?us-ascii?Q?0zFcC+XdsxYSToYW8szffFMK0Ns1lJydbjjcdit576FtutgFqY/AKl7SdYvW?= =?us-ascii?Q?Bb9Rqk2+51bbOVPOihGytKmBxwN0R8oBrZmQ4vu6g6NRlwUdhzzWRc8mFgo5?= =?us-ascii?Q?saYXsTrmuXi/B6Zgmh4NMVegy6gqPPpoEFWlXOkrXLHb7ZMqijxg+t/4oBoU?= =?us-ascii?Q?4Ld7v149HWuD0Xcj31Y=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: af7fc3e6-071a-4433-ee3b-08de260daa8a X-MS-Exchange-CrossTenant-AuthSource: MN2PR12MB3613.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 17 Nov 2025 19:15:27.2861 (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: 0bgz7aLxGHoFFdc42NMjtT1Plia4Md8ziR2Kqu3a8NwmXlbb1Sb+pcFj2v8OWYP2 X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH1PR12MB9621 On Thu, Nov 13, 2025 at 11:54:06PM +0800, Wei Wang wrote: > AMD Secure Memory Encryption (SME) marks individual memory pages as > encrypted by setting the C-bit in page table entries. According to the > AMD APM,any pages corresponding to MMIO addresses must be configured > with the C-bit clear. > > The current *_iommu_set_prot() implementation sets the C-bit on all PTEs > in the IOMMU page tables. This is incorrect for PTEs backed by MMIO, and > can break PCIe peer-to-peer communication when IOVA is used. Fix this by > avoiding the C-bit for MMIO-backed mappings. > > For amdv2 IOMMU page tables, there is a usage scenario for GVA->GPA > mappings, and for the trusted MMIO in the TEE-IO case, the C-bit will need > to be added to GPA. However, SNP guests do not yet support vIOMMU, and the > trusted MMIO support is not ready in upstream. Adding the C-bit for trusted > MMIO can be considered once those features land. > > Fixes: 879ced2bab1b ("iommupt: Add the AMD IOMMU v1 page table format") > Fixes: aef5de756ea8 ("iommupt: Add the x86 64 bit page table format") > Suggested-by: Jason Gunthorpe > Signed-off-by: Wei Wang > --- > drivers/iommu/generic_pt/fmt/amdv1.h | 3 ++- > drivers/iommu/generic_pt/fmt/x86_64.h | 3 ++- > 2 files changed, 4 insertions(+), 2 deletions(-) Reviewed-by: Jason Gunthorpe Jason