[Intel-gfx] [PATCH v2 13/14] vfio/gvt: Fix open/close when multiple device FDs are open

Jason Gunthorpe
2021-07-20T17:43:35Z

The user can open multiple device FDs if it likes, however the open
function calls vfio_register_notifier() on device global state. Calling
vfio_register_notifier() twice will trigger a WARN_ON from
notifier_chain_register() and the first close will wrongly delete the
notifier and more.

Since these really want the new open/close_device() semantics just change
the function over.

Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
drivers/gpu/drm/i915/gvt/kvmgt.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index 1ac98f8aba31e6..7efa386449d104 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -885,7 +885,7 @@ static int intel_vgpu_group_notifier(struct notifier_block *nb,
return NOTIFY_OK;
}

-static int intel_vgpu_open(struct mdev_device *mdev)
+static int intel_vgpu_open_device(struct mdev_device *mdev)
{
struct intel_vgpu *vgpu = mdev_get_drvdata(mdev);
struct kvmgt_vdev *vdev = kvmgt_vdev(vgpu);
@@ -1004,7 +1004,7 @@ static void __intel_vgpu_release(struct intel_vgpu *vgpu)
vgpu->handle = 0;
}

-static void intel_vgpu_release(struct mdev_device *mdev)
+static void intel_vgpu_close_device(struct mdev_device *mdev)
{
struct intel_vgpu *vgpu = mdev_get_drvdata(mdev);

@@ -1753,8 +1753,8 @@ static struct mdev_parent_ops intel_vgpu_ops = {
.create = intel_vgpu_create,
.remove = intel_vgpu_remove,

- .open = intel_vgpu_open,
- .release = intel_vgpu_release,
+ .open_device = intel_vgpu_open_device,
+ .close_device = intel_vgpu_close_device,

.read = intel_vgpu_read,
.write = intel_vgpu_write,
--
2.32.0