RE: [PATCH v2 1/2] vfio: Replace the DMA unmapping notifier with a callback

From: Jason Gunthorpe Sent: Wednesday, June 8, 2022 7:02 AM

Instead of having drivers register the notifier with explicit code just have them provide a dma_unmap callback op in their driver ops and rely on the core code to wire it up.

Suggested-by: Christoph Hellwig hch@lst.de Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Jason Gunthorpe jgg@nvidia.com

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

---

drivers/gpu/drm/i915/gvt/gvt.h | 1 - drivers/gpu/drm/i915/gvt/kvmgt.c | 75 ++++----------- drivers/s390/cio/vfio_ccw_ops.c | 41 ++------- drivers/s390/cio/vfio_ccw_private.h | 1 - drivers/s390/crypto/vfio_ap_ops.c | 53 ++--------- drivers/s390/crypto/vfio_ap_private.h | 3 - drivers/vfio/vfio.c | 126 +++++++++----------------- drivers/vfio/vfio.h | 5 + include/linux/vfio.h | 21 +---- 9 files changed, 87 insertions(+), 239 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h index aee1a45da74bcb..705689e6401197 100644 --- a/drivers/gpu/drm/i915/gvt/gvt.h +++ b/drivers/gpu/drm/i915/gvt/gvt.h @@ -226,7 +226,6 @@ struct intel_vgpu { unsigned long nr_cache_entries; struct mutex cache_lock;

• struct notifier_block iommu_notifier; atomic_t released;

  struct kvm_page_track_notifier_node track_node;

diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c index e2f6c56ab3420c..ecd5bb37b63a2a 100644 --- a/drivers/gpu/drm/i915/gvt/kvmgt.c +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c @@ -729,34 +729,25 @@ int intel_gvt_set_edid(struct intel_vgpu *vgpu, int port_num) return ret; }

-static int intel_vgpu_iommu_notifier(struct notifier_block *nb,

• 		     unsigned long action, void *data)
  

+static void intel_vgpu_dma_unmap(struct vfio_device *vfio_dev, u64 iova,

• 		 u64 length)
  

{

• struct intel_vgpu *vgpu =

• container_of(nb, struct intel_vgpu, iommu_notifier);
  

• if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP) {

• struct vfio_iommu_type1_dma_unmap *unmap = data;
  

• struct gvt_dma *entry;
  

• unsigned long iov_pfn, end_iov_pfn;
  

• struct intel_vgpu *vgpu = vfio_dev_to_vgpu(vfio_dev);
• struct gvt_dma *entry;
• u64 iov_pfn = iova >> PAGE_SHIFT;
• u64 end_iov_pfn = iov_pfn + length / PAGE_SIZE;

• iov_pfn = unmap->iova >> PAGE_SHIFT;
  

• end_iov_pfn = iov_pfn + unmap->size / PAGE_SIZE;
  

• mutex_lock(&vgpu->cache_lock);
• for (; iov_pfn < end_iov_pfn; iov_pfn++) {

• entry = __gvt_cache_find_gfn(vgpu, iov_pfn);
  

• if (!entry)
  

• 	continue;
  
  

• mutex_lock(&vgpu->cache_lock);
  

• for (; iov_pfn < end_iov_pfn; iov_pfn++) {
  

• 	entry = __gvt_cache_find_gfn(vgpu, iov_pfn);
  

• 	if (!entry)
  

• 		continue;
  

• 	gvt_dma_unmap_page(vgpu, entry->gfn, entry-
  

...

dma_addr,

• 			   entry->size);
  

• 	__gvt_cache_remove_entry(vgpu, entry);
  

• }
  

• mutex_unlock(&vgpu->cache_lock);
  

• gvt_dma_unmap_page(vgpu, entry->gfn, entry->dma_addr,
  

• 		   entry->size);
  

• __gvt_cache_remove_entry(vgpu, entry);
  

  }

• return NOTIFY_OK;

• mutex_unlock(&vgpu->cache_lock);

}

static bool __kvmgt_vgpu_exist(struct intel_vgpu *vgpu) @@ -783,36 +774,20 @@ static bool __kvmgt_vgpu_exist(struct intel_vgpu *vgpu) static int intel_vgpu_open_device(struct vfio_device *vfio_dev) { struct intel_vgpu *vgpu = vfio_dev_to_vgpu(vfio_dev);

• unsigned long events;

• int ret;

• vgpu->iommu_notifier.notifier_call = intel_vgpu_iommu_notifier;

• events = VFIO_IOMMU_NOTIFY_DMA_UNMAP;

• 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);
  

• goto out;
  

• }

• ret = -EEXIST; if (vgpu->attached)

• goto undo_iommu;
  

• return -EEXIST;
  
  

• ret = -ESRCH; if (!vgpu->vfio_device.kvm || vgpu->vfio_device.kvm->mm != current->mm) { gvt_vgpu_err("KVM is required to use Intel vGPU\n");

• goto undo_iommu;
  

• return -ESRCH;
  

  }

  kvm_get_kvm(vgpu->vfio_device.kvm);

• ret = -EEXIST; if (__kvmgt_vgpu_exist(vgpu))

• goto undo_iommu;
  

• return -EEXIST;
  
  

  vgpu->attached = true;

@@ -831,12 +806,6 @@ static int intel_vgpu_open_device(struct vfio_device *vfio_dev)

atomic_set(&vgpu->released, 0); return 0;

-undo_iommu:

• vfio_unregister_notifier(vfio_dev, VFIO_IOMMU_NOTIFY,

• 		 &vgpu->iommu_notifier);
  

-out:

• return ret;

}

static void intel_vgpu_release_msi_eventfd_ctx(struct intel_vgpu *vgpu) @@ -853,8 +822,6 @@ static void intel_vgpu_release_msi_eventfd_ctx(struct intel_vgpu *vgpu) static void intel_vgpu_close_device(struct vfio_device *vfio_dev) { struct intel_vgpu *vgpu = vfio_dev_to_vgpu(vfio_dev);

• struct drm_i915_private *i915 = vgpu->gvt->gt->i915;

• int ret;

  if (!vgpu->attached) return;

@@ -864,11 +831,6 @@ static void intel_vgpu_close_device(struct vfio_device *vfio_dev)

intel_gvt_release_vgpu(vgpu);

• 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);
  

• debugfs_remove(debugfs_lookup(KVMGT_DEBUGFS_FILENAME,

vgpu->debugfs));

kvm_page_track_unregister_notifier(vgpu->vfio_device.kvm, @@ -1610,6 +1572,7 @@ static const struct vfio_device_ops intel_vgpu_dev_ops = { .write = intel_vgpu_write, .mmap = intel_vgpu_mmap, .ioctl = intel_vgpu_ioctl,

• .dma_unmap = intel_vgpu_dma_unmap,

};

static int intel_vgpu_probe(struct mdev_device *mdev) diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c index b49e2e9db2dc6f..09e0ce7b72324c 100644 --- a/drivers/s390/cio/vfio_ccw_ops.c +++ b/drivers/s390/cio/vfio_ccw_ops.c @@ -44,31 +44,19 @@ static int vfio_ccw_mdev_reset(struct vfio_ccw_private *private) return ret; }

-static int vfio_ccw_mdev_notifier(struct notifier_block *nb,

• 		  unsigned long action,
  

• 		  void *data)
  

+static void vfio_ccw_dma_unmap(struct vfio_device *vdev, u64 iova, u64 length) { struct vfio_ccw_private *private =

• container_of(nb, struct vfio_ccw_private, nb);
  

• /*

• * Vendor drivers MUST unpin pages in response to an
  

• * invalidation.
  

• */
  

• if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP) {

• struct vfio_iommu_type1_dma_unmap *unmap = data;
  

• if (!cp_iova_pinned(&private->cp, unmap->iova))
  

• 	return NOTIFY_OK;
  

• container_of(vdev, struct vfio_ccw_private, vdev);
  
  

• if (vfio_ccw_mdev_reset(private))
  

• 	return NOTIFY_BAD;
  

• /* Drivers MUST unpin pages in response to an invalidation. */
• if (!cp_iova_pinned(&private->cp, iova))

• return;
  
  

• cp_free(&private->cp);
  

• return NOTIFY_OK;
  

• }

• if (vfio_ccw_mdev_reset(private))

• return;
  
  

• return NOTIFY_DONE;

• cp_free(&private->cp);

}

static ssize_t name_show(struct mdev_type *mtype, @@ -178,19 +166,11 @@ static int vfio_ccw_mdev_open_device(struct vfio_device *vdev) { struct vfio_ccw_private *private = container_of(vdev, struct vfio_ccw_private, vdev);

• unsigned long events = VFIO_IOMMU_NOTIFY_DMA_UNMAP; int ret;

• private->nb.notifier_call = vfio_ccw_mdev_notifier;

• ret = vfio_register_notifier(vdev, VFIO_IOMMU_NOTIFY,

• 		     &events, &private->nb);
  

• if (ret)

• return ret;
  

• ret = vfio_ccw_register_async_dev_regions(private); if (ret)

• goto out_unregister;
  

• return ret;
  
  

  ret = vfio_ccw_register_schib_dev_regions(private); if (ret)

@@ -204,7 +184,6 @@ static int vfio_ccw_mdev_open_device(struct vfio_device *vdev)

out_unregister: vfio_ccw_unregister_dev_regions(private);

• vfio_unregister_notifier(vdev, VFIO_IOMMU_NOTIFY, &private->nb); return ret;

}

@@ -222,7 +201,6 @@ 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, VFIO_IOMMU_NOTIFY, &private->nb);

}

static ssize_t vfio_ccw_mdev_read_io_region(struct vfio_ccw_private *private, @@ -645,6 +623,7 @@ static const struct vfio_device_ops vfio_ccw_dev_ops = { .write = vfio_ccw_mdev_write, .ioctl = vfio_ccw_mdev_ioctl, .request = vfio_ccw_mdev_request,

• .dma_unmap = vfio_ccw_dma_unmap,

};

struct mdev_driver vfio_ccw_mdev_driver = { diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h index 7272eb78861244..2627791c9006d4 100644 --- a/drivers/s390/cio/vfio_ccw_private.h +++ b/drivers/s390/cio/vfio_ccw_private.h @@ -98,7 +98,6 @@ struct vfio_ccw_private { struct completion *completion; atomic_t avail; struct mdev_device *mdev;

• struct notifier_block nb; struct ccw_io_region *io_region; struct mutex io_mutex; struct vfio_ccw_region *region;

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c index a7d2a95796d360..bb1a1677c5c230 100644 --- a/drivers/s390/crypto/vfio_ap_ops.c +++ b/drivers/s390/crypto/vfio_ap_ops.c @@ -1226,34 +1226,14 @@ static int vfio_ap_mdev_set_kvm(struct ap_matrix_mdev *matrix_mdev, return 0; }

-/**

• • vfio_ap_mdev_iommu_notifier - IOMMU notifier callback
• • @nb: The notifier block
• • @action: Action to be taken
• • @data: data associated with the request
• • For an UNMAP request, unpin the guest IOVA (the NIB guest address we
• • pinned before). Other requests are ignored.
• • Return: for an UNMAP request, NOFITY_OK; otherwise NOTIFY_DONE.
• */

-static int vfio_ap_mdev_iommu_notifier(struct notifier_block *nb,

• 		       unsigned long action, void *data)
  

+static void vfio_ap_mdev_dma_unmap(struct vfio_device *vdev, u64 iova,

• 		   u64 length)
  

{

• struct ap_matrix_mdev *matrix_mdev;
• matrix_mdev = container_of(nb, struct ap_matrix_mdev,

iommu_notifier);

• if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP) {

• struct vfio_iommu_type1_dma_unmap *unmap = data;
  

• unsigned long g_pfn = unmap->iova >> PAGE_SHIFT;
  

• vfio_unpin_pages(&matrix_mdev->vdev, &g_pfn, 1);
  

• return NOTIFY_OK;
  

• }

• struct ap_matrix_mdev *matrix_mdev =

• container_of(vdev, struct ap_matrix_mdev, vdev);
  

• unsigned long g_pfn = iova >> PAGE_SHIFT;

• return NOTIFY_DONE;

• vfio_unpin_pages(&matrix_mdev->vdev, &g_pfn, 1);

}

/** @@ -1380,27 +1360,11 @@ static int vfio_ap_mdev_open_device(struct vfio_device *vdev) { struct ap_matrix_mdev *matrix_mdev = container_of(vdev, struct ap_matrix_mdev, vdev);

• unsigned long events;

• int ret;

  if (!vdev->kvm) return -EINVAL;

• ret = vfio_ap_mdev_set_kvm(matrix_mdev, vdev->kvm);

• 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, VFIO_IOMMU_NOTIFY, &events,

• 		     &matrix_mdev->iommu_notifier);
  

• if (ret)

• goto err_kvm;
  

• return 0;

-err_kvm:

• vfio_ap_mdev_unset_kvm(matrix_mdev);
• return ret;

• return vfio_ap_mdev_set_kvm(matrix_mdev, vdev->kvm);

}

static void vfio_ap_mdev_close_device(struct vfio_device *vdev) @@ -1408,8 +1372,6 @@ 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, VFIO_IOMMU_NOTIFY,

• 		 &matrix_mdev->iommu_notifier);
  

  vfio_ap_mdev_unset_kvm(matrix_mdev);

}

@@ -1461,6 +1423,7 @@ static const struct vfio_device_ops vfio_ap_matrix_dev_ops = { .open_device = vfio_ap_mdev_open_device, .close_device = vfio_ap_mdev_close_device, .ioctl = vfio_ap_mdev_ioctl,

• .dma_unmap = vfio_ap_mdev_dma_unmap,

};

static struct mdev_driver vfio_ap_matrix_driver = { diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h index a26efd804d0df3..abb59d59f81b20 100644 --- a/drivers/s390/crypto/vfio_ap_private.h +++ b/drivers/s390/crypto/vfio_ap_private.h @@ -81,8 +81,6 @@ struct ap_matrix {

• @node: allows the ap_matrix_mdev struct to be added to a list
• @matrix: the adapters, usage domains and control domains assigned

to the

• mediated matrix device.
  

• • @iommu_notifier: notifier block used for specifying callback function for

• •     handling the VFIO_IOMMU_NOTIFY_DMA_UNMAP even
    

  • @kvm: the struct holding guest's state
  • @pqap_hook: the function pointer to the interception handler for

the

• PQAP(AQIC) instruction.
  

@@ -92,7 +90,6 @@ struct ap_matrix_mdev { struct vfio_device vdev; struct list_head node; struct ap_matrix matrix;

• struct notifier_block iommu_notifier; struct kvm *kvm; crypto_hook pqap_hook; struct mdev_device *mdev;

diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 61e71c1154be67..f005b644ab9e69 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -1077,8 +1077,20 @@ static void vfio_device_unassign_container(struct vfio_device *device) up_write(&device->group->group_rwsem); }

+static int vfio_iommu_notifier(struct notifier_block *nb, unsigned long action,

• 	       void *data)
  

+{

• struct vfio_device *vfio_device =

• container_of(nb, struct vfio_device, iommu_nb);
  

• struct vfio_iommu_type1_dma_unmap *unmap = data;
• vfio_device->ops->dma_unmap(vfio_device, unmap->iova, unmap-

...

size);

• return NOTIFY_OK;

+}

static struct file *vfio_device_open(struct vfio_device *device) {

• struct vfio_iommu_driver *iommu_driver; struct file *filep; int ret;

@@ -1109,6 +1121,18 @@ static struct file *vfio_device_open(struct vfio_device *device) if (ret) goto err_undo_count; }

• iommu_driver = device->group->container->iommu_driver;
  

• if (device->ops->dma_unmap && iommu_driver &&
  

•     iommu_driver->ops->register_notifier) {
  

• 	unsigned long events =
  

VFIO_IOMMU_NOTIFY_DMA_UNMAP;

• 	device->iommu_nb.notifier_call =
  

vfio_iommu_notifier;

• 	iommu_driver->ops->register_notifier(
  

• 		device->group->container->iommu_data,
  

&events,

• 		&device->iommu_nb);
  

• }
  

• up_read(&device->group->group_rwsem); } mutex_unlock(&device->dev_set->lock);

@@ -1143,8 +1167,16 @@ static struct file *vfio_device_open(struct vfio_device *device) err_close_device: mutex_lock(&device->dev_set->lock); down_read(&device->group->group_rwsem);

• if (device->open_count == 1 && device->ops->close_device)

• if (device->open_count == 1 && device->ops->close_device) { device->ops->close_device(device);

• iommu_driver = device->group->container->iommu_driver;
  

• if (device->ops->dma_unmap && iommu_driver &&
  

•     iommu_driver->ops->register_notifier)
  

• 	iommu_driver->ops->unregister_notifier(
  

• 		device->group->container->iommu_data,
  

• 		&device->iommu_nb);
  

• }

err_undo_count: device->open_count--; if (device->open_count == 0 && device->kvm) @@ -1339,12 +1371,20 @@ static const struct file_operations vfio_group_fops = { static int vfio_device_fops_release(struct inode *inode, struct file *filep) { struct vfio_device *device = filep->private_data;

• struct vfio_iommu_driver *iommu_driver;

  mutex_lock(&device->dev_set->lock); vfio_assert_device_open(device); down_read(&device->group->group_rwsem); if (device->open_count == 1 && device->ops->close_device) device->ops->close_device(device);

• iommu_driver = device->group->container->iommu_driver;

• if (device->ops->dma_unmap && iommu_driver &&

•    iommu_driver->ops->register_notifier)
  

• iommu_driver->ops->unregister_notifier(
  

• 	device->group->container->iommu_data,
  

• 	&device->iommu_nb);
  

  up_read(&device->group->group_rwsem); device->open_count--; if (device->open_count == 0)

@@ -2027,90 +2067,6 @@ int vfio_dma_rw(struct vfio_device *device, dma_addr_t user_iova, void *data, } EXPORT_SYMBOL(vfio_dma_rw);

-static int vfio_register_iommu_notifier(struct vfio_group *group,

• 			unsigned long *events,
  

• 			struct notifier_block *nb)
  

-{

• struct vfio_container *container;
• struct vfio_iommu_driver *driver;
• int ret;
• lockdep_assert_held_read(&group->group_rwsem);
• container = group->container;
• driver = container->iommu_driver;
• if (likely(driver && driver->ops->register_notifier))

• ret = driver->ops->register_notifier(container->iommu_data,
  

• 				     events, nb);
  

• else

• ret = -ENOTTY;
  

• return ret;

-}

-static int vfio_unregister_iommu_notifier(struct vfio_group *group,

• 			  struct notifier_block *nb)
  

-{

• struct vfio_container *container;
• struct vfio_iommu_driver *driver;
• int ret;
• lockdep_assert_held_read(&group->group_rwsem);
• container = group->container;
• driver = container->iommu_driver;
• if (likely(driver && driver->ops->unregister_notifier))

• ret = driver->ops->unregister_notifier(container-
  

...

iommu_data,

• 				       nb);
  

• else

• ret = -ENOTTY;
  

• return ret;

-}

-int vfio_register_notifier(struct vfio_device *device,

• 	   enum vfio_notify_type type, unsigned long *events,
  

• 	   struct notifier_block *nb)
  

-{

• struct vfio_group *group = device->group;
• int ret;
• if (!nb || !events || (*events == 0) ||

•    !vfio_assert_device_open(device))
  

• return -EINVAL;
  

• switch (type) {
• case VFIO_IOMMU_NOTIFY:

• ret = vfio_register_iommu_notifier(group, events, nb);
  

• break;
  

• default:

• ret = -EINVAL;
  

• }
• return ret;

-} -EXPORT_SYMBOL(vfio_register_notifier);

-int vfio_unregister_notifier(struct vfio_device *device,

• 	     enum vfio_notify_type type,
  

• 	     struct notifier_block *nb)
  

-{

• struct vfio_group *group = device->group;
• int ret;
• if (!nb || !vfio_assert_device_open(device))

• return -EINVAL;
  

• switch (type) {
• case VFIO_IOMMU_NOTIFY:

• ret = vfio_unregister_iommu_notifier(group, nb);
  

• break;
  

• default:

• ret = -EINVAL;
  

• }
• return ret;

-} -EXPORT_SYMBOL(vfio_unregister_notifier);

/*

• Module/class support

*/ diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h index a6713022115155..cb2e4e9baa8fe8 100644 --- a/drivers/vfio/vfio.h +++ b/drivers/vfio/vfio.h @@ -33,6 +33,11 @@ enum vfio_iommu_notify_type { VFIO_IOMMU_CONTAINER_CLOSE = 0, };

+/* events for register_notifier() */ +enum {

• VFIO_IOMMU_NOTIFY_DMA_UNMAP = 1,

+};

/**

• struct vfio_iommu_driver_ops - VFIO IOMMU driver callbacks

*/ diff --git a/include/linux/vfio.h b/include/linux/vfio.h index aa888cc517578e..b76623e3b92fca 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -44,6 +44,7 @@ struct vfio_device { unsigned int open_count; struct completion comp; struct list_head group_next;

• struct notifier_block iommu_nb;

};

/** @@ -60,6 +61,8 @@ struct vfio_device {

• @match: Optional device name match callback (return: 0 for no-match, >0

for

•     match, -errno for abort (ex. match with insufficient or incorrect
  

•     additional args)
  

• • @dma_unmap: Called when userspace unmaps IOVA from the container

• •         this device is attached to.
    

  • @device_feature: Optional, fill in the VFIO_DEVICE_FEATURE ioctl
  • @migration_set_state: Optional callback to change the migration state for

  •     devices that support migration. It's mandatory for
    

@@ -85,6 +88,7 @@ struct vfio_device_ops { int (*mmap)(struct vfio_device *vdev, struct vm_area_struct *vma); void (*request)(struct vfio_device *vdev, unsigned int count); int (*match)(struct vfio_device *vdev, char *buf);

• void (*dma_unmap)(struct vfio_device *vdev, u64 iova, u64

length); int (*device_feature)(struct vfio_device *device, u32 flags, void __user *arg, size_t argsz); struct file *(*migration_set_state)( @@ -154,23 +158,6 @@ extern int vfio_unpin_pages(struct vfio_device *device, unsigned long *user_pfn, extern int vfio_dma_rw(struct vfio_device *device, dma_addr_t user_iova, void *data, size_t len, bool write);

-/* each type has independent events */ -enum vfio_notify_type {

• VFIO_IOMMU_NOTIFY = 0,

-};

-/* events for VFIO_IOMMU_NOTIFY */ -#define VFIO_IOMMU_NOTIFY_DMA_UNMAP BIT(0)

-extern int vfio_register_notifier(struct vfio_device *device,

• 		  enum vfio_notify_type type,
  

• 		  unsigned long *required_events,
  

• 		  struct notifier_block *nb);
  

-extern int vfio_unregister_notifier(struct vfio_device *device,

• 		    enum vfio_notify_type type,
  

• 		    struct notifier_block *nb);
  

/*

• Sub-module helpers

*/

2.36.1