[PATCH v3 4/7] drm/i915/gvt: hold reference of VFIO group during opening of vgpu

Yan Zhao
2020-02-24T08:57:23Z

hold reference count of the VFIO group for each vgpu at vgpu opening and
release the reference at vgpu releasing.

Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
---
drivers/gpu/drm/i915/gvt/gvt.h | 1 +
drivers/gpu/drm/i915/gvt/kvmgt.c | 13 +++++++++++++
2 files changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h
index 0081b051d3e0..5230ac80b84c 100644
--- a/drivers/gpu/drm/i915/gvt/gvt.h
+++ b/drivers/gpu/drm/i915/gvt/gvt.h
@@ -219,6 +219,7 @@ struct intel_vgpu {
struct work_struct release_work;
atomic_t released;
struct vfio_device *vfio_device;
+ struct vfio_group *vfio_group;
} vdev;
#endif

diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index bd79a9718cc7..ed4c79cc3e09 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -747,6 +747,7 @@ static int intel_vgpu_open(struct mdev_device *mdev)
struct intel_vgpu *vgpu = mdev_get_drvdata(mdev);
unsigned long events;
int ret;
+ struct vfio_group *vfio_group;

vgpu->vdev.iommu_notifier.notifier_call = intel_vgpu_iommu_notifier;
vgpu->vdev.group_notifier.notifier_call = intel_vgpu_group_notifier;
@@ -769,6 +770,14 @@ static int intel_vgpu_open(struct mdev_device *mdev)
goto undo_iommu;
}

+ vfio_group = vfio_group_get_external_user_from_dev(mdev_dev(mdev));
+ if (IS_ERR_OR_NULL(vfio_group)) {
+ ret = !vfio_group ? -EFAULT : PTR_ERR(vfio_group);
+ gvt_vgpu_err("vfio_group_get_external_user_from_dev failed\n");
+ goto undo_register_group;
+ }
+ vgpu->vdev.vfio_group = vfio_group;
+
/* Take a module reference as mdev core doesn't take
* a reference for vendor driver.
*/
@@ -785,6 +794,9 @@ static int intel_vgpu_open(struct mdev_device *mdev)
return ret;

undo_group:
+ vfio_group_put_external_user(vgpu->vdev.vfio_group);
+
+undo_register_group:
vfio_unregister_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY,
&vgpu->vdev.group_notifier);

@@ -834,6 +846,7 @@ static void __intel_vgpu_release(struct intel_vgpu *vgpu)
kvmgt_guest_exit(info);

intel_vgpu_release_msi_eventfd_ctx(vgpu);
+ vfio_group_put_external_user(vgpu->vdev.vfio_group);

vgpu->vdev.kvm = NULL;
vgpu->handle = 0;
--
2.17.1