kernel.git/drivers/vfio/pci, branch linux-6.15.y

vfio/mlx5: fix possible overflow in tracking max message size

2025-08-20T16:36:24Z

[ Upstream commit b3060198483bac43ec113c62ae3837076f61f5de ] MLX cap pg_track_log_max_msg_size consists of 5 bits, value of which is used as power of 2 for max_msg_size. This can lead to multiplication overflow between max_msg_size (u32) and integer constant, and afterwards incorrect value is being written to rq_size. Fix this issue by extending integer constant to u64 type. Found by Linux Verification Center (linuxtesting.org) with SVACE. Suggested-by: Alex Williamson Signed-off-by: Artem Sadovnikov Reviewed-by: Yishai Hadas Link: https://lore.kernel.org/r/20250701144017.2410-2-a.sadovnikov@ispras.ru Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin

vfio/pci: Do vf_token checks for VFIO_DEVICE_BIND_IOMMUFD

2025-08-15T10:16:56Z

[ Upstream commit 86624ba3b522b6512def25534341da93356c8da4 ] This was missed during the initial implementation. The VFIO PCI encodes the vf_token inside the device name when opening the device from the group FD, something like: "0000:04:10.0 vf_token=bd8d9d2b-5a5f-4f5a-a211-f591514ba1f3" This is used to control access to a VF unless there is co-ordination with the owner of the PF. Since we no longer have a device name in the cdev path, pass the token directly through VFIO_DEVICE_BIND_IOMMUFD using an optional field indicated by VFIO_DEVICE_BIND_FLAG_TOKEN. Fixes: 5fcc26969a16 ("vfio: Add VFIO_DEVICE_BIND_IOMMUFD") Tested-by: Shameer Kolothum Reviewed-by: Yi Liu Signed-off-by: Jason Gunthorpe Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/0-v3-bdd8716e85fe+3978a-vfio_token_jgg@nvidia.com Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin

vfio/pci: Separate SR-IOV VF dev_set

2025-08-15T10:16:55Z

[ Upstream commit e908f58b6beb337cbe4481d52c3f5c78167b1aab ] In the below noted Fixes commit we introduced a reflck mutex to allow better scaling between devices for open and close. The reflck was based on the hot reset granularity, device level for root bus devices which cannot support hot reset or bus/slot reset otherwise. Overlooked in this were SR-IOV VFs, where there's also no bus reset option, but the default for a non-root-bus, non-slot-based device is bus level reflck granularity. The reflck mutex has since become the dev_set mutex (via commit 2cd8b14aaa66 ("vfio/pci: Move to the device set infrastructure")) and is our defacto serialization for various operations and ioctls. It still seems to be the case though that sets of vfio-pci devices really only need serialization relative to hot resets affecting the entire set, which is not relevant to SR-IOV VFs. As described in the Closes link below, this serialization contributes to startup latency when multiple VFs sharing the same "bus" are opened concurrently. Mark the device itself as the basis of the dev_set for SR-IOV VFs. Reported-by: Aaron Lewis Closes: https://lore.kernel.org/all/20250626180424.632628-1-aaronlewis@google.com Tested-by: Aaron Lewis Fixes: e309df5b0c9e ("vfio/pci: Parallelize device open and release") Reviewed-by: Yi Liu Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Link: https://lore.kernel.org/r/20250626225623.1180952-1-alex.williamson@redhat.com Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin

vfio/pds: Fix missing detach_ioas op

2025-08-15T10:16:55Z

[ Upstream commit fe24d5bc635e103a517ec201c3cb571eeab8be2f ] When CONFIG_IOMMUFD is enabled and a device is bound to the pds_vfio_pci driver, the following WARN_ON() trace is seen and probe fails: WARNING: CPU: 0 PID: 5040 at drivers/vfio/vfio_main.c:317 __vfio_register_dev+0x130/0x140 [vfio] <...> pds_vfio_pci 0000:08:00.1: probe with driver pds_vfio_pci failed with error -22 This is because the driver's vfio_device_ops.detach_ioas isn't set. Fix this by using the generic vfio_iommufd_physical_detach_ioas function. Fixes: 38fe3975b4c2 ("vfio/pds: Initial support for pds VFIO driver") Signed-off-by: Brett Creeley Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20250702163744.69767-1-brett.creeley@amd.com Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin

hisi_acc_vfio_pci: bugfix live migration function without VF device driver

2025-06-19T13:39:55Z

[ Upstream commit 2777a40998deb36f96b6afc48bd397cf58a4edf0 ] If the VF device driver is not loaded in the Guest OS and we attempt to perform device data migration, the address of the migrated data will be NULL. The live migration recovery operation on the destination side will access a null address value, which will cause access errors. Therefore, live migration of VMs without added VF device drivers does not require device data migration. In addition, when the queue address data obtained by the destination is empty, device queue recovery processing will not be performed. Fixes: b0eed085903e ("hisi_acc_vfio_pci: Add support for VFIO live migration") Signed-off-by: Longfang Liu Reviewed-by: Shameer Kolothum Link: https://lore.kernel.org/r/20250510081155.55840-6-liulongfang@huawei.com Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin

hisi_acc_vfio_pci: bugfix the problem of uninstalling driver

2025-06-19T13:39:55Z

[ Upstream commit db6525a8573957faea28850392f4744e5f8f7a53 ] In a live migration scenario. If the number of VFs at the destination is greater than the source, the recovery operation will fail and qemu will not be able to complete the process and exit after shutting down the device FD. This will cause the driver to be unable to be unloaded normally due to abnormal reference counting of the live migration driver caused by the abnormal closing operation of fd. Therefore, make sure the migration file descriptor references are always released when the device is closed. Fixes: b0eed085903e ("hisi_acc_vfio_pci: Add support for VFIO live migration") Signed-off-by: Longfang Liu Reviewed-by: Shameer Kolothum Link: https://lore.kernel.org/r/20250510081155.55840-5-liulongfang@huawei.com Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin

hisi_acc_vfio_pci: bugfix cache write-back issue

2025-06-19T13:39:54Z

[ Upstream commit e63c466398731bb7867f42f44b76fa984de59db2 ] At present, cache write-back is placed in the device data copy stage after stopping the device operation. Writing back to the cache at this stage will cause the data obtained by the cache to be written back to be empty. In order to ensure that the cache data is written back successfully, the data needs to be written back into the stop device stage. Fixes: b0eed085903e ("hisi_acc_vfio_pci: Add support for VFIO live migration") Signed-off-by: Longfang Liu Reviewed-by: Shameer Kolothum Link: https://lore.kernel.org/r/20250510081155.55840-4-liulongfang@huawei.com Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin

hisi_acc_vfio_pci: add eq and aeq interruption restore

2025-06-19T13:39:54Z

[ Upstream commit 3495cec0787721ba7a9d5c19d0bbb66d182de584 ] In order to ensure that the task packets of the accelerator device are not lost during the migration process, it is necessary to send an EQ and AEQ command to the device after the live migration is completed and to update the completion position of the task queue. Let the device recheck the completed tasks data and if there are uncollected packets, device resend a task completion interrupt to the software. Fixes: b0eed085903e ("hisi_acc_vfio_pci: Add support for VFIO live migration") Signed-off-by: Longfang Liu Reviewed-by: Shameer Kolothum Link: https://lore.kernel.org/r/20250510081155.55840-3-liulongfang@huawei.com Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin

hisi_acc_vfio_pci: fix XQE dma address error

2025-06-19T13:39:54Z

[ Upstream commit 8bb7170c5a055ea17c6857c256ee73c10ff872eb ] The dma addresses of EQE and AEQE are wrong after migration and results in guest kernel-mode encryption services failure. Comparing the definition of hardware registers, we found that there was an error when the data read from the register was combined into an address. Therefore, the address combination sequence needs to be corrected. Even after fixing the above problem, we still have an issue where the Guest from an old kernel can get migrated to new kernel and may result in wrong data. In order to ensure that the address is correct after migration, if an old magic number is detected, the dma address needs to be updated. Fixes: b0eed085903e ("hisi_acc_vfio_pci: Add support for VFIO live migration") Signed-off-by: Longfang Liu Reviewed-by: Shameer Kolothum Link: https://lore.kernel.org/r/20250510081155.55840-2-liulongfang@huawei.com Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin

vfio/pci: Align huge faults to order

2025-05-06T18:59:12Z

The vfio-pci huge_fault handler doesn't make any attempt to insert a mapping containing the faulting address, it only inserts mappings if the faulting address and resulting pfn are aligned. This works in a lot of cases, particularly in conjunction with QEMU where DMA mappings linearly fault the mmap. However, there are configurations where we don't get that linear faulting and pages are faulted on-demand. The scenario reported in the bug below is such a case, where the physical address width of the CPU is greater than that of the IOMMU, resulting in a VM where guest firmware has mapped device MMIO beyond the address width of the IOMMU. In this configuration, the MMIO is faulted on demand and tracing indicates that occasionally the faults generate a VM_FAULT_OOM. Given the use case, this results in a "error: kvm run failed Bad address", killing the VM. The host is not under memory pressure in this test, therefore it's suspected that VM_FAULT_OOM is actually the result of a NULL return from __pte_offset_map_lock() in the get_locked_pte() path from insert_pfn(). This suggests a potential race inserting a pte concurrent to a pmd, and maybe indicates some deficiency in the mm layer properly handling such a case. Nevertheless, Peter noted the inconsistency of vfio-pci's huge_fault handler where our mapping granularity depends on the alignment of the faulting address relative to the order rather than aligning the faulting address to the order to more consistently insert huge mappings. This change not only uses the page tables more consistently and efficiently, but as any fault to an aligned page results in the same mapping, the race condition suspected in the VM_FAULT_OOM is avoided. Reported-by: Adolfo Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220057 Fixes: 09dfc8a5f2ce ("vfio/pci: Fallback huge faults for unaligned pfn") Cc: stable@vger.kernel.org Tested-by: Adolfo Co-developed-by: Peter Xu Signed-off-by: Peter Xu Link: https://lore.kernel.org/r/20250502224035.3183451-1-alex.williamson@redhat.com Signed-off-by: Alex Williamson