diff options
| author | Jason Gunthorpe <jgg@nvidia.com> | 2022-05-11 13:19:07 -0600 |
|---|---|---|
| committer | Alex Williamson <alex.williamson@redhat.com> | 2022-05-11 13:32:56 -0600 |
| commit | ff806cbd90bd2cc3d08a026e26157e5b5a6b5e03 (patch) | |
| tree | 7819b677d8ec507c30674fab9e3e1f35df74fd95 /include/linux/vfio.h | |
| parent | 91be0bd6c6cf21328017e990d3ceeb00f03821fd (diff) | |
vfio/pci: Remove vfio_device_get_from_dev()
The last user of this function is in PCI callbacks that want to convert
their struct pci_dev to a vfio_device. Instead of searching use the
vfio_device available trivially through the drvdata.
When a callback in the device_driver is called, the caller must hold the
device_lock() on dev. The purpose of the device_lock is to prevent
remove() from being called (see __device_release_driver), and allow the
driver to safely interact with its drvdata without races.
The PCI core correctly follows this and holds the device_lock() when
calling error_detected (see report_error_detected) and
sriov_configure (see sriov_numvfs_store).
Further, since the drvdata holds a positive refcount on the vfio_device
any access of the drvdata, under the device_lock(), from a driver callback
needs no further protection or refcounting.
Thus the remark in the vfio_device_get_from_dev() comment does not apply
here, VFIO PCI drivers all call vfio_unregister_group_dev() from their
remove callbacks under the device_lock() and cannot race with the
remaining callers.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/2-v4-c841817a0349+8f-vfio_get_from_dev_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'include/linux/vfio.h')
| -rw-r--r-- | include/linux/vfio.h | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/include/linux/vfio.h b/include/linux/vfio.h index 6195edd2edcd..be1e7db4a314 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -125,8 +125,6 @@ void vfio_uninit_group_dev(struct vfio_device *device); int vfio_register_group_dev(struct vfio_device *device); int vfio_register_emulated_iommu_dev(struct vfio_device *device); void vfio_unregister_group_dev(struct vfio_device *device); -extern struct vfio_device *vfio_device_get_from_dev(struct device *dev); -extern void vfio_device_put(struct vfio_device *device); int vfio_assign_device_set(struct vfio_device *device, void *set_id); |