[PATCH 24/29] drm/i915/gvt: remove the extra vfio_device refcounting for dmabufs

From: Christoph Hellwig
Date: Tue Nov 02 2021 - 03:09:11 EST


All the dmabufs are torn down when th VGPU is released, so there is
no need for extra refcounting here.

Based on an patch from Jason Gunthorpe.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/gpu/drm/i915/gvt/dmabuf.c | 12 ------------
drivers/gpu/drm/i915/gvt/gvt.h | 1 -
2 files changed, 13 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/dmabuf.c b/drivers/gpu/drm/i915/gvt/dmabuf.c
index eacfe7beaaf67..88c4f8b02ffb6 100644
--- a/drivers/gpu/drm/i915/gvt/dmabuf.c
+++ b/drivers/gpu/drm/i915/gvt/dmabuf.c
@@ -134,7 +134,6 @@ static void dmabuf_gem_object_free(struct kref *kref)
struct intel_vgpu_dmabuf_obj, list);
if (dmabuf_obj == obj) {
list_del(pos);
- vfio_device_put(vgpu->vfio_device);
idr_remove(&vgpu->object_idr,
dmabuf_obj->dmabuf_id);
kfree(dmabuf_obj->info);
@@ -474,16 +473,6 @@ int intel_vgpu_query_plane(struct intel_vgpu *vgpu, void *args)

kref_init(&dmabuf_obj->kref);

- mutex_lock(&vgpu->dmabuf_lock);
- vgpu->vfio_device = vfio_device_get_from_dev(mdev_dev(vgpu->mdev));
- if (!vgpu->vfio_device) {
- gvt_vgpu_err("failed to get vfio device\n");
- mutex_unlock(&vgpu->dmabuf_lock);
- ret = -ENODEV;
- goto out_free_info;
- }
- mutex_unlock(&vgpu->dmabuf_lock);
-
update_fb_info(gfx_plane_info, &fb_info);

INIT_LIST_HEAD(&dmabuf_obj->list);
@@ -589,7 +578,6 @@ void intel_vgpu_dmabuf_cleanup(struct intel_vgpu *vgpu)
dmabuf_obj->vgpu = NULL;

idr_remove(&vgpu->object_idr, dmabuf_obj->dmabuf_id);
- vfio_device_put(vgpu->vfio_device);
list_del(pos);

/* dmabuf_obj might be freed in dmabuf_obj_put */
diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h
index 7c87d7638e6b2..fa83365227514 100644
--- a/drivers/gpu/drm/i915/gvt/gvt.h
+++ b/drivers/gpu/drm/i915/gvt/gvt.h
@@ -230,7 +230,6 @@ struct intel_vgpu {
struct kvm *kvm;
struct work_struct release_work;
atomic_t released;
- struct vfio_device *vfio_device;
struct vfio_group *vfio_group;

struct kvm_page_track_notifier_node track_node;
--
2.30.2