diff options
| author | Jason Gunthorpe <jgg@nvidia.com> | 2022-08-16 16:13:04 -0300 |
|---|---|---|
| committer | Alex Williamson <alex.williamson@redhat.com> | 2022-09-01 15:29:11 -0600 |
| commit | 21c13829bc3b786bc5336470df023ae54e41d230 (patch) | |
| tree | 53c20b0afef514261db0874fc957e04b816fe599 /drivers | |
| parent | 453e6c98fd2bdae0df9adbc86af8d8bf1164edd5 (diff) | |
vfio: Remove vfio_group dev_counter
This counts the number of devices attached to a vfio_group, ie the number
of items in the group->device_list.
It is only read in vfio_pin_pages(), as some kind of protection against
limitations in type1.
However, with all the code cleanups in this area, now that
vfio_pin_pages() accepts a vfio_device directly it is redundant. All
drivers are already calling vfio_register_emulated_iommu_dev() which
directly creates a group specifically for the device and thus it is
guaranteed that there is a singleton group.
Leave a note in the comment about this requirement and remove the logic.
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/0-v2-d4374a7bf0c9+c4-vfio_dev_counter_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/vfio/vfio_main.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index 5edc49748013..77264d836d52 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -75,7 +75,6 @@ struct vfio_group { struct list_head vfio_next; struct list_head container_next; enum vfio_group_type type; - unsigned int dev_counter; struct rw_semaphore group_rwsem; struct kvm *kvm; struct file *opened_file; @@ -609,7 +608,6 @@ static int __vfio_register_dev(struct vfio_device *device, mutex_lock(&group->device_lock); list_add(&device->group_next, &group->device_list); - group->dev_counter++; mutex_unlock(&group->device_lock); return 0; @@ -697,7 +695,6 @@ void vfio_unregister_group_dev(struct vfio_device *device) mutex_lock(&group->device_lock); list_del(&device->group_next); - group->dev_counter--; mutex_unlock(&group->device_lock); if (group->type == VFIO_NO_IOMMU || group->type == VFIO_EMULATED_IOMMU) @@ -1991,6 +1988,9 @@ EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare); * @prot [in] : protection flags * @pages[out] : array of host pages * Return error or number of pages pinned. + * + * A driver may only call this function if the vfio_device was created + * by vfio_register_emulated_iommu_dev(). */ int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova, int npage, int prot, struct page **pages) @@ -2006,9 +2006,6 @@ int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova, if (npage > VFIO_PIN_PAGES_MAX_ENTRIES) return -E2BIG; - if (group->dev_counter > 1) - return -EINVAL; - /* group->container cannot change while a vfio device is open */ container = group->container; driver = container->iommu_driver; |