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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: LInZe9dg+h2cRR4XljGXMGYvCffaB6EJErEJm+RnleRKuKuT5GgZbkdDGQRGmoNTa0RhNRgQwvZwY21XA64kW3HKFuc5zM4NM/LmS9LXjP8fQonH1YjTCojN6MIoiLZ/VnOD42lg88ZhX4YX9wSVqxeOBDcdqgRs1a82h0aYrRTqu6AdPrjAY7Zt+jFHeCVnKitLRxZVjxxkzPAmjCX5ysGKSY0jeNIAAWNyN4S8QRKlh9sJjQ87LWmjoaNIstbsUvowI4i8ERJ4RGZeSjNQGmjm9DvUn2/mGnWw13oudlW0ZxjOjP3AdNyFTV9nWTH4sN/CjsdRoNwrXrlsXRekBb2Fxd2bTuXwKEHAxJuj6ZNNS5ozeT/cBe+v9eQSuzswN881O879Fmvap97Umm8sdC2mUPJ8IhfCKx7zuIkr2na/QmoDC6KCWwEeIHq5txU1 X-OriginatorOrg: arm.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 13 Mar 2026 10:41:26.0485 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: b0fde794-dd25-4b44-35d3-08de80ed13d4 X-MS-Exchange-CrossTenant-Id: f34e5979-57d9-4aaa-ad4d-b122a662184d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=f34e5979-57d9-4aaa-ad4d-b122a662184d;Ip=[4.158.2.129];Helo=[outbound-uk1.az.dlp.m.darktrace.com] X-MS-Exchange-CrossTenant-AuthSource: DB1PEPF000509F1.eurprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: VE1PR08MB5728 On 10/03/2026 12:49, Sebastian Ene wrote: > From: Mostafa Saleh > > Add a function to donate MMIO to the hypervisor so IOMMU hypervisor > drivers can use that to protect the MMIO of IOMMU. > The initial attempt to implement this was to have a new flag to > "___pkvm_host_donate_hyp" to accept MMIO. However that had many problems, > it was quite intrusive for host/hyp to check/set page state to make it > aware of MMIO and to encode the state in the page table in that case. > Which is called in paths that can be sensitive to performance (FFA, VMs..) > > As donating MMIO is very rare, and we don’t need to encode the full > state, it’s reasonable to have a separate function to do this. > It will init the host s2 page table with an invalid leaf with the owner ID > to prevent the host from mapping the page on faults. > > Also, prevent kvm_pgtable_stage2_unmap() from removing owner ID from > stage-2 PTEs, as this can be triggered from recycle logic under memory > pressure. There is no code relying on this, as all ownership changes is > done via kvm_pgtable_stage2_set_owner() > > For error path in IOMMU drivers, add a function to donate MMIO back > from hyp to host. > > Signed-off-by: Mostafa Saleh nit: Your Signed-off-by: is missing. Even if you haven't made any changes, when you are sending something, you need your S-o-B. Suzuki