Re: [PATCH 1/9] vfio: Make vfio_(un)register_notifier accept a vfio_device

On Tue, 2022-04-12 at 12:53 -0300, Jason Gunthorpe wrote:

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.

Signed-off-by: Jason Gunthorpe jgg@nvidia.com

drivers/gpu/drm/i915/gvt/kvmgt.c | 15 +++++++++------ drivers/s390/cio/vfio_ccw_ops.c | 7 +++---- drivers/s390/crypto/vfio_ap_ops.c | 14 +++++++------- drivers/vfio/mdev/vfio_mdev.c | 12 ++++++++++++ drivers/vfio/vfio.c | 25 +++++++------------------ include/linux/mdev.h | 1 + include/linux/vfio.h | 4 ++-- 7 files changed, 41 insertions(+), 37 deletions(-)

For the -ccw bits:

Acked-by: Eric Farman farman@linux.ibm.com

diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c index 057ec449010458..bb59d21cf898ab 100644 --- a/drivers/gpu/drm/i915/gvt/kvmgt.c +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c @@ -904,6 +904,7 @@ static int intel_vgpu_group_notifier(struct notifier_block *nb,

static int intel_vgpu_open_device(struct mdev_device *mdev) {

• struct vfio_device *vfio_dev =

mdev_legacy_get_vfio_device(mdev); struct intel_vgpu *vgpu = mdev_get_drvdata(mdev); struct kvmgt_vdev *vdev = kvmgt_vdev(vgpu); unsigned long events; @@ -914,7 +915,7 @@ static int intel_vgpu_open_device(struct mdev_device *mdev) vdev->group_notifier.notifier_call = intel_vgpu_group_notifier;

events = VFIO_IOMMU_NOTIFY_DMA_UNMAP;

• ret = vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,

&events,

• ret = vfio_register_notifier(vfio_dev, VFIO_IOMMU_NOTIFY,

&events, &vdev->iommu_notifier); if (ret != 0) { gvt_vgpu_err("vfio_register_notifier for iommu failed: %d\n", @@ -923,7 +924,7 @@ static int intel_vgpu_open_device(struct mdev_device *mdev) }

events = VFIO_GROUP_NOTIFY_SET_KVM;

• ret = vfio_register_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY,

&events,

• ret = vfio_register_notifier(vfio_dev, VFIO_GROUP_NOTIFY,

&events, &vdev->group_notifier); if (ret != 0) { gvt_vgpu_err("vfio_register_notifier for group failed: %d\n", @@ -961,11 +962,11 @@ static int intel_vgpu_open_device(struct mdev_device *mdev) vdev->vfio_group = NULL;

undo_register:

• vfio_unregister_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY,

• vfio_unregister_notifier(vfio_dev, VFIO_GROUP_NOTIFY, &vdev->group_notifier);

undo_iommu:

• vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,

• vfio_unregister_notifier(vfio_dev, VFIO_IOMMU_NOTIFY, &vdev->iommu_notifier);

out: return ret; @@ -988,6 +989,7 @@ static void __intel_vgpu_release(struct intel_vgpu *vgpu) struct kvmgt_vdev *vdev = kvmgt_vdev(vgpu); struct drm_i915_private *i915 = vgpu->gvt->gt->i915; struct kvmgt_guest_info *info;

• struct vfio_device *vfio_dev; int ret;

  if (!handle_valid(vgpu->handle))

@@ -998,12 +1000,13 @@ static void __intel_vgpu_release(struct intel_vgpu *vgpu)

intel_gvt_ops->vgpu_release(vgpu);

• ret = vfio_unregister_notifier(mdev_dev(vdev->mdev),

VFIO_IOMMU_NOTIFY,

• vfio_dev = mdev_legacy_get_vfio_device(vdev->mdev);
• ret = vfio_unregister_notifier(vfio_dev, VFIO_IOMMU_NOTIFY, &vdev->iommu_notifier); drm_WARN(&i915->drm, ret, "vfio_unregister_notifier for iommu failed: %d\n",

ret);

• ret = vfio_unregister_notifier(mdev_dev(vdev->mdev),

VFIO_GROUP_NOTIFY,

• ret = vfio_unregister_notifier(vfio_dev, VFIO_GROUP_NOTIFY, &vdev->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 d8589afac272f1..e1ce24d8fb2555 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 6e08d04b605d6e..69768061cd7bd9 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/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c index a90e24b0c851d3..91605c1e8c8f94 100644 --- a/drivers/vfio/mdev/vfio_mdev.c +++ b/drivers/vfio/mdev/vfio_mdev.c @@ -17,6 +17,18 @@

#include "mdev_private.h"

+/*

• • Return the struct vfio_device for the mdev when using the legacy
• • vfio_mdev_dev_ops path. No new callers to this function should be

added.

• */

+struct vfio_device *mdev_legacy_get_vfio_device(struct mdev_device *mdev) +{

• if (WARN_ON(mdev->dev.driver != &vfio_mdev_driver.driver))

• return NULL;
  

• return dev_get_drvdata(&mdev->dev);

+} +EXPORT_SYMBOL_GPL(mdev_legacy_get_vfio_device);

static int vfio_mdev_open_device(struct vfio_device *core_vdev) { struct mdev_device *mdev = to_mdev_device(core_vdev->dev); 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/mdev.h b/include/linux/mdev.h index 15d03f6532d073..67d07220a28f29 100644 --- a/include/linux/mdev.h +++ b/include/linux/mdev.h @@ -29,6 +29,7 @@ static inline struct mdev_device *to_mdev_device(struct device *dev) unsigned int mdev_get_type_group_id(struct mdev_device *mdev); unsigned int mtype_get_type_group_id(struct mdev_type *mtype); struct device *mtype_get_parent_dev(struct mdev_type *mtype); +struct vfio_device *mdev_legacy_get_vfio_device(struct mdev_device *mdev);

/**

• struct mdev_parent_ops - Structure to be registered for each

parent device to 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);