kernel/linux.git/include/linux/vfio.h, branch v6.18.21

vfio/pci: Do vf_token checks for VFIO_DEVICE_BIND_IOMMUFD

2025-08-05T21:41:14+00:00

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

vfio-iommufd: Support pasid [at|de]tach for physical VFIO devices

2025-03-25T13:18:31+00:00

This adds pasid_at|de]tach_ioas ops for attaching hwpt to pasid of a device and the helpers for it. For now, only vfio-pci supports pasid attach/detach. Link: https://patch.msgid.link/r/20250321180143.8468-3-yi.l.liu@intel.com Signed-off-by: Kevin Tian Reviewed-by: Jason Gunthorpe Reviewed-by: Alex Williamson Tested-by: Nicolin Chen Signed-off-by: Yi Liu Signed-off-by: Jason Gunthorpe

vfio: Create vfio_fs_type with inode per device

2024-05-31T21:15:51+00:00

By linking all the device fds we provide to userspace to an address space through a new pseudo fs, we can use tools like unmap_mapping_range() to zap all vmas associated with a device. Suggested-by: Jason Gunthorpe Reviewed-by: Jason Gunthorpe Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20240530045236.1005864-2-alex.williamson@redhat.com Signed-off-by: Alex Williamson

vfio: Introduce interface to flush virqfd inject workqueue

2024-03-11T19:08:52+00:00

In order to synchronize changes that can affect the thread callback, introduce an interface to force a flush of the inject workqueue. The irqfd pointer is only valid under spinlock, but the workqueue cannot be flushed under spinlock. Therefore the flush work for the irqfd is queued under spinlock. The vfio_irqfd_cleanup_wq workqueue is re-used for queuing this work such that flushing the workqueue is also ordered relative to shutdown. Reviewed-by: Kevin Tian Reviewed-by: Reinette Chatre Reviewed-by: Eric Auger Link: https://lore.kernel.org/r/20240308230557.805580-4-alex.williamson@redhat.com Signed-off-by: Alex Williamson

vfio/migration: Add debugfs to live migration driver

2023-12-04T21:29:08+00:00

There are multiple devices, software and operational steps involved in the process of live migration. An error occurred on any node may cause the live migration operation to fail. This complex process makes it very difficult to locate and analyze the cause when the function fails. In order to quickly locate the cause of the problem when the live migration fails, I added a set of debugfs to the vfio live migration driver. +-------------------------------------------+ | | | | | QEMU | | | | | +---+----------------------------+----------+ | ^ | ^ | | | | | | | | v | v | +---------+--+ +---------+--+ |src vfio_dev| |dst vfio_dev| +--+---------+ +--+---------+ | ^ | ^ | | | | v | | | +-----------+----+ +-----------+----+ |src dev debugfs | |dst dev debugfs | +----------------+ +----------------+ The entire debugfs directory will be based on the definition of the CONFIG_DEBUG_FS macro. If this macro is not enabled, the interfaces in vfio.h will be empty definitions, and the creation and initialization of the debugfs directory will not be executed. vfio | +--- | +---migration | +--state | +--- +---migration +--state debugfs will create a public root directory "vfio" file. then create a dev_name() file for each live migration device. First, create a unified state acquisition file of "migration" in this device directory. Then, create a public live migration state lookup file "state". Signed-off-by: Longfang Liu Reviewed-by: Cédric Le Goater Link: https://lore.kernel.org/r/20231106072225.28577-2-liulongfang@huawei.com Signed-off-by: Alex Williamson

vfio: Drop vfio_file_iommu_group() stub to fudge around a KVM wart

2023-11-30T18:27:17+00:00

Drop the vfio_file_iommu_group() stub and instead unconditionally declare the function to fudge around a KVM wart where KVM tries to do symbol_get() on vfio_file_iommu_group() (and other VFIO symbols) even if CONFIG_VFIO=n. Ensuring the symbol is always declared fixes a PPC build error when modules are also disabled, in which case symbol_get() simply points at the address of the symbol (with some attributes shenanigans). Because KVM does symbol_get() instead of directly depending on VFIO, the lack of a fully defined symbol is not problematic (ugly, but "fine"). arch/powerpc/kvm/../../../virt/kvm/vfio.c:89:7: error: attribute declaration must precede definition [-Werror,-Wignored-attributes] fn = symbol_get(vfio_file_iommu_group); ^ include/linux/module.h:805:60: note: expanded from macro 'symbol_get' #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak,visibility("hidden"))); &(x); }) ^ include/linux/vfio.h:294:35: note: previous definition is here static inline struct iommu_group *vfio_file_iommu_group(struct file *file) ^ arch/powerpc/kvm/../../../virt/kvm/vfio.c:89:7: error: attribute declaration must precede definition [-Werror,-Wignored-attributes] fn = symbol_get(vfio_file_iommu_group); ^ include/linux/module.h:805:65: note: expanded from macro 'symbol_get' #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak,visibility("hidden"))); &(x); }) ^ include/linux/vfio.h:294:35: note: previous definition is here static inline struct iommu_group *vfio_file_iommu_group(struct file *file) ^ 2 errors generated. Although KVM is firmly in the wrong (there is zero reason for KVM to build virt/kvm/vfio.c when VFIO is disabled), fudge around the error in VFIO as the stub is unnecessary and doesn't serve its intended purpose (KVM is the only external user of vfio_file_iommu_group()), and there is an in-flight series to clean up the entire KVM<->VFIO interaction, i.e. fixing this in KVM would result in more churn in the long run, and the stub needs to go away regardless. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202308251949.5IiaV0sz-lkp@intel.com Closes: https://lore.kernel.org/oe-kbuild-all/202309030741.82aLACDG-lkp@intel.com Closes: https://lore.kernel.org/oe-kbuild-all/202309110914.QLH0LU6L-lkp@intel.com Link: https://lore.kernel.org/all/0-v1-08396538817d+13c5-vfio_kvm_kconfig_jgg@nvidia.com Link: https://lore.kernel.org/all/20230916003118.2540661-1-seanjc@google.com Cc: Nick Desaulniers Cc: Jason Gunthorpe Tested-by: Michael Ellerman Fixes: c1cce6d079b8 ("vfio: Compile vfio_group infrastructure optionally") Signed-off-by: Sean Christopherson Reviewed-by: Jason Gunthorpe Link: https://lore.kernel.org/r/20231130001000.543240-1-seanjc@google.com Signed-off-by: Alex Williamson

vfio: Commonize combine_ranges for use in other VFIO drivers

2023-08-16T16:52:23+00:00

Currently only Mellanox uses the combine_ranges function. The new pds_vfio driver also needs this function. So, move it to a common location for other vendor drivers to use. Also, fix RCT ordering while moving/renaming the function. Cc: Yishai Hadas Signed-off-by: Brett Creeley Signed-off-by: Shannon Nelson Reviewed-by: Simon Horman Reviewed-by: Jason Gunthorpe Reviewed-by: Kevin Tian Reviewed-by: Shameer Kolothum Link: https://lore.kernel.org/r/20230807205755.29579-2-brett.creeley@amd.com Signed-off-by: Alex Williamson

vfio: Compile vfio_group infrastructure optionally

2023-07-25T16:20:50+00:00

vfio_group is not needed for vfio device cdev, so with vfio device cdev introduced, the vfio_group infrastructures can be compiled out if only cdev is needed. Reviewed-by: Jason Gunthorpe Tested-by: Nicolin Chen Tested-by: Matthew Rosato Tested-by: Yanting Jiang Tested-by: Shameer Kolothum Tested-by: Terrence Xu Tested-by: Zhenzhong Duan Signed-off-by: Yi Liu Link: https://lore.kernel.org/r/20230718135551.6592-26-yi.l.liu@intel.com Signed-off-by: Alex Williamson

vfio: Add VFIO_DEVICE_BIND_IOMMUFD

2023-07-25T16:20:32+00:00

This adds ioctl for userspace to bind device cdev fd to iommufd. VFIO_DEVICE_BIND_IOMMUFD: bind device to an iommufd, hence gain DMA control provided by the iommufd. open_device op is called after bind_iommufd op. Tested-by: Nicolin Chen Tested-by: Matthew Rosato Tested-by: Yanting Jiang Tested-by: Shameer Kolothum Tested-by: Terrence Xu Tested-by: Zhenzhong Duan Signed-off-by: Yi Liu Reviewed-by: Jason Gunthorpe Link: https://lore.kernel.org/r/20230718135551.6592-23-yi.l.liu@intel.com Signed-off-by: Alex Williamson

vfio: Add cdev for vfio_device

2023-07-25T16:19:40+00:00

This adds cdev support for vfio_device. It allows the user to directly open a vfio device w/o using the legacy container/group interface, as a prerequisite for supporting new iommu features like nested translation and etc. The device fd opened in this manner doesn't have the capability to access the device as the fops open() doesn't open the device until the successful VFIO_DEVICE_BIND_IOMMUFD ioctl which will be added in a later patch. With this patch, devices registered to vfio core would have both the legacy group and the new device interfaces created. - group interface : /dev/vfio/$groupID - device interface: /dev/vfio/devices/vfioX - normal device ("X" is a unique number across vfio devices) For a given device, the user can identify the matching vfioX by searching the vfio-dev folder under the sysfs path of the device. Take PCI device (0000:6a:01.0) as an example, /sys/bus/pci/devices/0000\:6a\:01.0/vfio-dev/vfioX implies the matching vfioX under /dev/vfio/devices/, and vfio-dev/vfioX/dev contains the major:minor number of the matching /dev/vfio/devices/vfioX. The user can get device fd by opening the /dev/vfio/devices/vfioX. The vfio_device cdev logic in this patch: *) __vfio_register_dev() path ends up doing cdev_device_add() for each vfio_device if VFIO_DEVICE_CDEV configured. *) vfio_unregister_group_dev() path does cdev_device_del(); cdev interface does not support noiommu devices, so VFIO only creates the legacy group interface for the physical devices that do not have IOMMU. noiommu users should use the legacy group interface. Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Tested-by: Terrence Xu Tested-by: Nicolin Chen Tested-by: Matthew Rosato Tested-by: Yanting Jiang Tested-by: Shameer Kolothum Tested-by: Zhenzhong Duan Signed-off-by: Yi Liu Link: https://lore.kernel.org/r/20230718135551.6592-19-yi.l.liu@intel.com Signed-off-by: Alex Williamson