RE: [PATCH v2 1/7] vfio: Make vfio_(un)register_notifier accept a vfio_device

Tian, Kevin
2022-04-22T01:39:21Z

> From: Jason Gunthorpe
> Sent: Friday, April 22, 2022 12:29 AM
>
> All callers have a struct vfio_device trivially available, pass it in
> directly and avoid calling the expensive vfio_group_get_from_dev().
>
> To support the unconverted kvmgt mdev driver add
> mdev_legacy_get_vfio_device() which will return the vfio_device pointer
> vfio_mdev.c puts in the drv_data.

stale comment

>
> Acked-by: Eric Farman <farman@linux.ibm.com>
> Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
> Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

Reviewed-by: Kevin Tian <kevin.tian@intel.com>

> ---
> drivers/gpu/drm/i915/gvt/kvmgt.c | 24 ++++++++++++------------
> drivers/s390/cio/vfio_ccw_ops.c | 7 +++----
> drivers/s390/crypto/vfio_ap_ops.c | 14 +++++++-------
> drivers/vfio/vfio.c | 25 +++++++------------------
> include/linux/vfio.h | 4 ++--
> 5 files changed, 31 insertions(+), 43 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c
> b/drivers/gpu/drm/i915/gvt/kvmgt.c
> index 0787ba5c301f5e..1cec4f1fdfaced 100644
> --- a/drivers/gpu/drm/i915/gvt/kvmgt.c
> +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
> @@ -810,8 +810,8 @@ static int intel_vgpu_open_device(struct vfio_device
> *vfio_dev)
> vgpu->group_notifier.notifier_call = intel_vgpu_group_notifier;
>
> events = VFIO_IOMMU_NOTIFY_DMA_UNMAP;
> - ret = vfio_register_notifier(vfio_dev->dev, VFIO_IOMMU_NOTIFY,
> &events,
> - &vgpu->iommu_notifier);
> + ret = vfio_register_notifier(vfio_dev, VFIO_IOMMU_NOTIFY, &events,
> + &vgpu->iommu_notifier);
> if (ret != 0) {
> gvt_vgpu_err("vfio_register_notifier for iommu failed: %d\n",
> ret);
> @@ -819,8 +819,8 @@ static int intel_vgpu_open_device(struct vfio_device
> *vfio_dev)
> }
>
> events = VFIO_GROUP_NOTIFY_SET_KVM;
> - ret = vfio_register_notifier(vfio_dev->dev, VFIO_GROUP_NOTIFY,
> &events,
> - &vgpu->group_notifier);
> + ret = vfio_register_notifier(vfio_dev, VFIO_GROUP_NOTIFY, &events,
> + &vgpu->group_notifier);
> if (ret != 0) {
> gvt_vgpu_err("vfio_register_notifier for group failed: %d\n",
> ret);
> @@ -873,12 +873,12 @@ static int intel_vgpu_open_device(struct
> vfio_device *vfio_dev)
> vgpu->vfio_group = NULL;
>
> undo_register:
> - vfio_unregister_notifier(vfio_dev->dev, VFIO_GROUP_NOTIFY,
> - &vgpu->group_notifier);
> + vfio_unregister_notifier(vfio_dev, VFIO_GROUP_NOTIFY,
> + &vgpu->group_notifier);
>
> undo_iommu:
> - vfio_unregister_notifier(vfio_dev->dev, VFIO_IOMMU_NOTIFY,
> - &vgpu->iommu_notifier);
> + vfio_unregister_notifier(vfio_dev, VFIO_IOMMU_NOTIFY,
> + &vgpu->iommu_notifier);
> out:
> return ret;
> }
> @@ -907,13 +907,13 @@ static void __intel_vgpu_release(struct intel_vgpu
> *vgpu)
>
> intel_gvt_release_vgpu(vgpu);
>
> - ret = vfio_unregister_notifier(vgpu->vfio_device.dev,
> VFIO_IOMMU_NOTIFY,
> - &vgpu->iommu_notifier);
> + ret = vfio_unregister_notifier(&vgpu->vfio_device,
> VFIO_IOMMU_NOTIFY,
> + &vgpu->iommu_notifier);
> drm_WARN(&i915->drm, ret,
> "vfio_unregister_notifier for iommu failed: %d\n", ret);
>
> - ret = vfio_unregister_notifier(vgpu->vfio_device.dev,
> VFIO_GROUP_NOTIFY,
> - &vgpu->group_notifier);
> + ret = vfio_unregister_notifier(&vgpu->vfio_device,
> VFIO_GROUP_NOTIFY,
> + &vgpu->group_notifier);
> drm_WARN(&i915->drm, ret,
> "vfio_unregister_notifier for group failed: %d\n", ret);
>
> diff --git a/drivers/s390/cio/vfio_ccw_ops.c
> b/drivers/s390/cio/vfio_ccw_ops.c
> index c4d60cdbf247bf..b49e2e9db2dc6f 100644
> --- a/drivers/s390/cio/vfio_ccw_ops.c
> +++ b/drivers/s390/cio/vfio_ccw_ops.c
> @@ -183,7 +183,7 @@ static int vfio_ccw_mdev_open_device(struct
> vfio_device *vdev)
>
> private->nb.notifier_call = vfio_ccw_mdev_notifier;
>
> - ret = vfio_register_notifier(vdev->dev, VFIO_IOMMU_NOTIFY,
> + ret = vfio_register_notifier(vdev, VFIO_IOMMU_NOTIFY,
> &events, &private->nb);
> if (ret)
> return ret;
> @@ -204,8 +204,7 @@ static int vfio_ccw_mdev_open_device(struct
> vfio_device *vdev)
>
> out_unregister:
> vfio_ccw_unregister_dev_regions(private);
> - vfio_unregister_notifier(vdev->dev, VFIO_IOMMU_NOTIFY,
> - &private->nb);
> + vfio_unregister_notifier(vdev, VFIO_IOMMU_NOTIFY, &private->nb);
> return ret;
> }
>
> @@ -223,7 +222,7 @@ static void vfio_ccw_mdev_close_device(struct
> vfio_device *vdev)
>
> cp_free(&private->cp);
> vfio_ccw_unregister_dev_regions(private);
> - vfio_unregister_notifier(vdev->dev, VFIO_IOMMU_NOTIFY, &private-
> >nb);
> + vfio_unregister_notifier(vdev, VFIO_IOMMU_NOTIFY, &private->nb);
> }
>
> static ssize_t vfio_ccw_mdev_read_io_region(struct vfio_ccw_private
> *private,
> diff --git a/drivers/s390/crypto/vfio_ap_ops.c
> b/drivers/s390/crypto/vfio_ap_ops.c
> index ee0a3bf8f476ca..bfa7ee6ef532d9 100644
> --- a/drivers/s390/crypto/vfio_ap_ops.c
> +++ b/drivers/s390/crypto/vfio_ap_ops.c
> @@ -1406,21 +1406,21 @@ static int vfio_ap_mdev_open_device(struct
> vfio_device *vdev)
> matrix_mdev->group_notifier.notifier_call =
> vfio_ap_mdev_group_notifier;
> events = VFIO_GROUP_NOTIFY_SET_KVM;
>
> - ret = vfio_register_notifier(vdev->dev, VFIO_GROUP_NOTIFY,
> - &events, &matrix_mdev->group_notifier);
> + ret = vfio_register_notifier(vdev, VFIO_GROUP_NOTIFY, &events,
> + &matrix_mdev->group_notifier);
> if (ret)
> return ret;
>
> matrix_mdev->iommu_notifier.notifier_call =
> vfio_ap_mdev_iommu_notifier;
> events = VFIO_IOMMU_NOTIFY_DMA_UNMAP;
> - ret = vfio_register_notifier(vdev->dev, VFIO_IOMMU_NOTIFY,
> - &events, &matrix_mdev->iommu_notifier);
> + ret = vfio_register_notifier(vdev, VFIO_IOMMU_NOTIFY, &events,
> + &matrix_mdev->iommu_notifier);
> if (ret)
> goto out_unregister_group;
> return 0;
>
> out_unregister_group:
> - vfio_unregister_notifier(vdev->dev, VFIO_GROUP_NOTIFY,
> + vfio_unregister_notifier(vdev, VFIO_GROUP_NOTIFY,
> &matrix_mdev->group_notifier);
> return ret;
> }
> @@ -1430,9 +1430,9 @@ static void vfio_ap_mdev_close_device(struct
> vfio_device *vdev)
> struct ap_matrix_mdev *matrix_mdev =
> container_of(vdev, struct ap_matrix_mdev, vdev);
>
> - vfio_unregister_notifier(vdev->dev, VFIO_IOMMU_NOTIFY,
> + vfio_unregister_notifier(vdev, VFIO_IOMMU_NOTIFY,
> &matrix_mdev->iommu_notifier);
> - vfio_unregister_notifier(vdev->dev, VFIO_GROUP_NOTIFY,
> + vfio_unregister_notifier(vdev, VFIO_GROUP_NOTIFY,
> &matrix_mdev->group_notifier);
> vfio_ap_mdev_unset_kvm(matrix_mdev);
> }
> diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
> index a4555014bd1e72..8a5c46aa2bef61 100644
> --- a/drivers/vfio/vfio.c
> +++ b/drivers/vfio/vfio.c
> @@ -2484,19 +2484,15 @@ static int vfio_unregister_group_notifier(struct
> vfio_group *group,
> return ret;
> }
>
> -int vfio_register_notifier(struct device *dev, enum vfio_notify_type type,
> +int vfio_register_notifier(struct vfio_device *dev, enum vfio_notify_type
> type,
> unsigned long *events, struct notifier_block *nb)
> {
> - struct vfio_group *group;
> + struct vfio_group *group = dev->group;
> int ret;
>
> - if (!dev || !nb || !events || (*events == 0))
> + if (!nb || !events || (*events == 0))
> return -EINVAL;
>
> - group = vfio_group_get_from_dev(dev);
> - if (!group)
> - return -ENODEV;
> -
> switch (type) {
> case VFIO_IOMMU_NOTIFY:
> ret = vfio_register_iommu_notifier(group, events, nb);
> @@ -2507,25 +2503,20 @@ int vfio_register_notifier(struct device *dev,
> enum vfio_notify_type type,
> default:
> ret = -EINVAL;
> }
> -
> - vfio_group_put(group);
> return ret;
> }
> EXPORT_SYMBOL(vfio_register_notifier);
>
> -int vfio_unregister_notifier(struct device *dev, enum vfio_notify_type type,
> +int vfio_unregister_notifier(struct vfio_device *dev,
> + enum vfio_notify_type type,
> struct notifier_block *nb)
> {
> - struct vfio_group *group;
> + struct vfio_group *group = dev->group;
> int ret;
>
> - if (!dev || !nb)
> + if (!nb)
> return -EINVAL;
>
> - group = vfio_group_get_from_dev(dev);
> - if (!group)
> - return -ENODEV;
> -
> switch (type) {
> case VFIO_IOMMU_NOTIFY:
> ret = vfio_unregister_iommu_notifier(group, nb);
> @@ -2536,8 +2527,6 @@ int vfio_unregister_notifier(struct device *dev,
> enum vfio_notify_type type,
> default:
> ret = -EINVAL;
> }
> -
> - vfio_group_put(group);
> return ret;
> }
> EXPORT_SYMBOL(vfio_unregister_notifier);
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index 66dda06ec42d1b..748ec0e0293aea 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -178,11 +178,11 @@ enum vfio_notify_type {
> /* events for VFIO_GROUP_NOTIFY */
> #define VFIO_GROUP_NOTIFY_SET_KVM BIT(0)
>
> -extern int vfio_register_notifier(struct device *dev,
> +extern int vfio_register_notifier(struct vfio_device *dev,
> enum vfio_notify_type type,
> unsigned long *required_events,
> struct notifier_block *nb);
> -extern int vfio_unregister_notifier(struct device *dev,
> +extern int vfio_unregister_notifier(struct vfio_device *dev,
> enum vfio_notify_type type,
> struct notifier_block *nb);
>
> --
> 2.36.0