diff options
| author | Jason Gunthorpe <jgg@nvidia.com> | 2022-09-23 11:26:52 +0200 |
|---|---|---|
| committer | Alex Williamson <alex.williamson@redhat.com> | 2022-10-04 12:06:58 -0600 |
| commit | 9c799c224d6ebc5be51065bd3217a2d7eea23b8f (patch) | |
| tree | d09166f170afc9fc32ecfe8205964a6257b81990 /drivers/vfio/mdev/mdev_sysfs.c | |
| parent | 685a1537f4c603cfcaf4b9be56ff6a571f7ddd08 (diff) | |
vfio/mdev: add mdev available instance checking to the core
Many of the mdev drivers use a simple counter for keeping track of the
available instances. Move this code to the core code and store the counter
in the mdev_parent. Implement it using correct locking, fixing mdpy.
Drivers just provide the value in the mdev_driver at registration time
and the core code takes care of maintaining it and exposing the value in
sysfs.
[hch: count instances per-parent instead of per-type, use an atomic_t
to avoid taking mdev_list_lock in the show method]
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-15-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/vfio/mdev/mdev_sysfs.c')
| -rw-r--r-- | drivers/vfio/mdev/mdev_sysfs.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/vfio/mdev/mdev_sysfs.c b/drivers/vfio/mdev/mdev_sysfs.c index 658b3bf5ed0b..abe3359dd477 100644 --- a/drivers/vfio/mdev/mdev_sysfs.c +++ b/drivers/vfio/mdev/mdev_sysfs.c @@ -108,7 +108,10 @@ static ssize_t available_instances_show(struct mdev_type *mtype, { struct mdev_driver *drv = mtype->parent->mdev_driver; - return sysfs_emit(buf, "%u\n", drv->get_available(mtype)); + if (drv->get_available) + return sysfs_emit(buf, "%u\n", drv->get_available(mtype)); + return sysfs_emit(buf, "%u\n", + atomic_read(&mtype->parent->available_instances)); } static MDEV_TYPE_ATTR_RO(available_instances); |