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authorYi Liu <yi.l.liu@intel.com>2023-07-18 06:55:41 -0700
committerAlex Williamson <alex.williamson@redhat.com>2023-07-25 10:19:22 -0600
commit291872a533a2cdea8df1ae157987cd7ab3939421 (patch)
treea2ba5d3e9eec9927b729a699c57b9b0924d69ada /drivers/vfio
parent8cfa71860233652f8566bcdf55e77aefe0017b4a (diff)
vfio: Move vfio_device_group_unregister() to be the first operation in unregister
This avoids endless vfio_device refcount increment by userspace, which would keep blocking the vfio_unregister_group_dev(). Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> Tested-by: Yanting Jiang <yanting.jiang@intel.com> Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Tested-by: Terrence Xu <terrence.xu@intel.com> Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Link: https://lore.kernel.org/r/20230718135551.6592-17-yi.l.liu@intel.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/vfio')
-rw-r--r--drivers/vfio/vfio_main.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index c71c0d1a079f..6d45caa1f9a0 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -332,6 +332,12 @@ void vfio_unregister_group_dev(struct vfio_device *device)
bool interrupted = false;
long rc;
+ /*
+ * Prevent new device opened by userspace via the
+ * VFIO_GROUP_GET_DEVICE_FD in the group path.
+ */
+ vfio_device_group_unregister(device);
+
vfio_device_put_registration(device);
rc = try_wait_for_completion(&device->comp);
while (rc <= 0) {
@@ -355,8 +361,6 @@ void vfio_unregister_group_dev(struct vfio_device *device)
}
}
- vfio_device_group_unregister(device);
-
/* Balances device_add in register path */
device_del(&device->device);