* [Intel-gfx] [PATCH v2 1/2] vfio: Replace the DMA unmapping notifier with a callback
@ 2022-06-07 23:02 ` Jason Gunthorpe
0 siblings, 0 replies; 34+ messages in thread
From: Jason Gunthorpe @ 2022-06-07 23:02 UTC (permalink / raw)
To: Alexander Gordeev, David Airlie, Tony Krowiak, Alex Williamson,
Christian Borntraeger, Cornelia Huck, Daniel Vetter, dri-devel,
Eric Farman, Harald Freudenberger, Vasily Gorbik, Heiko Carstens,
intel-gfx, intel-gvt-dev, Jani Nikula, Jason Herne,
Joonas Lahtinen, kvm, linux-s390, Matthew Rosato,
Peter Oberparleiter, Halil Pasic, Rodrigo Vivi, Sven Schnelle,
Tvrtko Ursulin, Vineeth Vijayan, Zhenyu Wang, Zhi Wang
Cc: Christoph Hellwig
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>
---
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
^ permalink raw reply related [flat|nested] 34+ messages in thread* RE: [PATCH v2 1/2] vfio: Replace the DMA unmapping notifier with a callback
2022-06-07 23:02 ` [Intel-gfx] " Jason Gunthorpe
@ 2022-06-08 3:37 ` Tian, Kevin
-1 siblings, 0 replies; 34+ messages in thread
From: Tian, Kevin @ 2022-06-08 3:37 UTC (permalink / raw)
To: Jason Gunthorpe, Alexander Gordeev, David Airlie, Tony Krowiak,
Alex Williamson, Christian Borntraeger, Cornelia Huck,
Daniel Vetter, dri-devel, Eric Farman, Harald Freudenberger,
Vasily Gorbik, Heiko Carstens, intel-gfx, intel-gvt-dev,
Jani Nikula, Jason Herne, Joonas Lahtinen, kvm, linux-s390,
Matthew Rosato, Peter Oberparleiter, Halil Pasic, Vivi, Rodrigo,
Sven Schnelle, Tvrtko Ursulin, Vineeth Vijayan, Zhenyu Wang,
Wang, Zhi A
Cc: Christoph Hellwig
> 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
^ permalink raw reply [flat|nested] 34+ messages in thread* Re: [Intel-gfx] [PATCH v2 1/2] vfio: Replace the DMA unmapping notifier with a callback
@ 2022-06-08 3:37 ` Tian, Kevin
0 siblings, 0 replies; 34+ messages in thread
From: Tian, Kevin @ 2022-06-08 3:37 UTC (permalink / raw)
To: Jason Gunthorpe, Alexander Gordeev, David Airlie, Tony Krowiak,
Alex Williamson, Christian Borntraeger, Cornelia Huck,
Daniel Vetter, dri-devel, Eric Farman, Harald Freudenberger,
Vasily Gorbik, Heiko Carstens, intel-gfx, intel-gvt-dev,
Jani Nikula, Jason Herne, Joonas Lahtinen, kvm, linux-s390,
Matthew Rosato, Peter Oberparleiter, Halil Pasic, Vivi, Rodrigo,
Sven Schnelle, Tvrtko Ursulin, Vineeth Vijayan, Zhenyu Wang,
Wang, Zhi A
Cc: Christoph Hellwig
> 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
^ permalink raw reply [flat|nested] 34+ messages in thread
* Re: [PATCH v2 1/2] vfio: Replace the DMA unmapping notifier with a callback
2022-06-07 23:02 ` [Intel-gfx] " Jason Gunthorpe
(?)
(?)
@ 2022-06-08 15:50 ` Eric Farman
2022-06-09 14:43 ` Jason Gunthorpe
-1 siblings, 1 reply; 34+ messages in thread
From: Eric Farman @ 2022-06-08 15:50 UTC (permalink / raw)
To: Jason Gunthorpe, Alexander Gordeev, David Airlie, Tony Krowiak,
Alex Williamson, Christian Borntraeger, Cornelia Huck,
Daniel Vetter, dri-devel, Harald Freudenberger, Vasily Gorbik,
Heiko Carstens, intel-gfx, intel-gvt-dev, Jani Nikula,
Jason Herne, Joonas Lahtinen, kvm, linux-s390, Matthew Rosato,
Peter Oberparleiter, Halil Pasic, Rodrigo Vivi, Sven Schnelle,
Tvrtko Ursulin, Vineeth Vijayan, Zhenyu Wang, Zhi Wang
Cc: Christoph Hellwig
On Tue, 2022-06-07 at 20:02 -0300, Jason Gunthorpe wrote:
> 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>
> ---
> 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(-)
>
>
...snip...
> 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;
Could you also remove this from the comment block above the struct?
Besides that, this is fine for -ccw.
Reviewed-by: Eric Farman <farman@linux.ibm.com>
> struct ccw_io_region *io_region;
> struct mutex io_mutex;
> struct vfio_ccw_region *region;
>
...snip...
^ permalink raw reply [flat|nested] 34+ messages in thread* Re: [PATCH v2 1/2] vfio: Replace the DMA unmapping notifier with a callback
2022-06-08 15:50 ` Eric Farman
2022-06-09 14:43 ` Jason Gunthorpe
@ 2022-06-09 14:43 ` Jason Gunthorpe
0 siblings, 0 replies; 34+ messages in thread
From: Jason Gunthorpe @ 2022-06-09 14:43 UTC (permalink / raw)
To: Eric Farman
Cc: Alexander Gordeev, David Airlie, Tony Krowiak, Alex Williamson,
Christian Borntraeger, Cornelia Huck, Daniel Vetter, dri-devel,
Harald Freudenberger, Vasily Gorbik, Heiko Carstens, intel-gfx,
intel-gvt-dev, Jani Nikula, Jason Herne, Joonas Lahtinen, kvm,
linux-s390, Matthew Rosato, Peter Oberparleiter, Halil Pasic,
Rodrigo Vivi, Sven Schnelle, Tvrtko Ursulin, Vineeth Vijayan,
Zhenyu Wang, Zhi Wang, Christoph Hellwig
On Wed, Jun 08, 2022 at 11:50:31AM -0400, Eric Farman wrote:
> > --- 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;
>
> Could you also remove this from the comment block above the struct?
> Besides that, this is fine for -ccw.
Done, thanks
Jason
^ permalink raw reply [flat|nested] 34+ messages in thread* Re: [Intel-gfx] [PATCH v2 1/2] vfio: Replace the DMA unmapping notifier with a callback
@ 2022-06-09 14:43 ` Jason Gunthorpe
0 siblings, 0 replies; 34+ messages in thread
From: Jason Gunthorpe @ 2022-06-09 14:43 UTC (permalink / raw)
To: Eric Farman
Cc: kvm, David Airlie, dri-devel, Vineeth Vijayan, Alexander Gordeev,
Christoph Hellwig, linux-s390, Matthew Rosato, Halil Pasic,
Christian Borntraeger, intel-gfx, Jason Herne, Vasily Gorbik,
Heiko Carstens, Harald Freudenberger, Rodrigo Vivi,
intel-gvt-dev, Tony Krowiak, Cornelia Huck, Peter Oberparleiter,
Sven Schnelle
On Wed, Jun 08, 2022 at 11:50:31AM -0400, Eric Farman wrote:
> > --- 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;
>
> Could you also remove this from the comment block above the struct?
> Besides that, this is fine for -ccw.
Done, thanks
Jason
^ permalink raw reply [flat|nested] 34+ messages in thread* Re: [PATCH v2 1/2] vfio: Replace the DMA unmapping notifier with a callback
@ 2022-06-09 14:43 ` Jason Gunthorpe
0 siblings, 0 replies; 34+ messages in thread
From: Jason Gunthorpe @ 2022-06-09 14:43 UTC (permalink / raw)
To: Eric Farman
Cc: kvm, David Airlie, dri-devel, Vineeth Vijayan, Alexander Gordeev,
Christoph Hellwig, linux-s390, Matthew Rosato, Halil Pasic,
Christian Borntraeger, intel-gfx, Zhi Wang, Jason Herne,
Vasily Gorbik, Heiko Carstens, Alex Williamson,
Harald Freudenberger, Rodrigo Vivi, intel-gvt-dev, Tony Krowiak,
Tvrtko Ursulin, Cornelia Huck, Peter Oberparleiter,
Sven Schnelle
On Wed, Jun 08, 2022 at 11:50:31AM -0400, Eric Farman wrote:
> > --- 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;
>
> Could you also remove this from the comment block above the struct?
> Besides that, this is fine for -ccw.
Done, thanks
Jason
^ permalink raw reply [flat|nested] 34+ messages in thread
* Re: [PATCH v2 1/2] vfio: Replace the DMA unmapping notifier with a callback
2022-06-07 23:02 ` [Intel-gfx] " Jason Gunthorpe
@ 2022-06-09 13:21 ` Tony Krowiak
-1 siblings, 0 replies; 34+ messages in thread
From: Tony Krowiak @ 2022-06-09 13:21 UTC (permalink / raw)
To: Jason Gunthorpe, Alexander Gordeev, David Airlie,
Alex Williamson, Christian Borntraeger, Cornelia Huck,
Daniel Vetter, dri-devel, Eric Farman, Harald Freudenberger,
Vasily Gorbik, Heiko Carstens, intel-gfx, intel-gvt-dev,
Jani Nikula, Jason Herne, Joonas Lahtinen, kvm, linux-s390,
Matthew Rosato, Peter Oberparleiter, Halil Pasic, Rodrigo Vivi,
Sven Schnelle, Tvrtko Ursulin, Vineeth Vijayan, Zhenyu Wang,
Zhi Wang
Cc: Christoph Hellwig
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
On 6/7/22 7:02 PM, Jason Gunthorpe wrote:
> 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>
> ---
> 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
> */
^ permalink raw reply [flat|nested] 34+ messages in thread* Re: [Intel-gfx] [PATCH v2 1/2] vfio: Replace the DMA unmapping notifier with a callback
@ 2022-06-09 13:21 ` Tony Krowiak
0 siblings, 0 replies; 34+ messages in thread
From: Tony Krowiak @ 2022-06-09 13:21 UTC (permalink / raw)
To: Jason Gunthorpe, Alexander Gordeev, David Airlie,
Alex Williamson, Christian Borntraeger, Cornelia Huck,
Daniel Vetter, dri-devel, Eric Farman, Harald Freudenberger,
Vasily Gorbik, Heiko Carstens, intel-gfx, intel-gvt-dev,
Jani Nikula, Jason Herne, Joonas Lahtinen, kvm, linux-s390,
Matthew Rosato, Peter Oberparleiter, Halil Pasic, Rodrigo Vivi,
Sven Schnelle, Tvrtko Ursulin, Vineeth Vijayan, Zhenyu Wang,
Zhi Wang
Cc: Christoph Hellwig
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
On 6/7/22 7:02 PM, Jason Gunthorpe wrote:
> 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>
> ---
> 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
> */
^ permalink raw reply [flat|nested] 34+ messages in thread
* Re: [PATCH v2 1/2] vfio: Replace the DMA unmapping notifier with a callback
2022-06-07 23:02 ` [Intel-gfx] " Jason Gunthorpe
(?)
@ 2022-06-17 22:42 ` Alex Williamson
-1 siblings, 0 replies; 34+ messages in thread
From: Alex Williamson @ 2022-06-17 22:42 UTC (permalink / raw)
To: Jason Gunthorpe
Cc: Alexander Gordeev, David Airlie, Tony Krowiak,
Christian Borntraeger, Cornelia Huck, Daniel Vetter, dri-devel,
Eric Farman, Harald Freudenberger, Vasily Gorbik, Heiko Carstens,
intel-gfx, intel-gvt-dev, Jani Nikula, Jason Herne,
Joonas Lahtinen, kvm, linux-s390, Matthew Rosato,
Peter Oberparleiter, Halil Pasic, Rodrigo Vivi, Sven Schnelle,
Tvrtko Ursulin, Vineeth Vijayan, Zhenyu Wang, Zhi Wang,
Christoph Hellwig
On Tue, 7 Jun 2022 20:02:11 -0300
Jason Gunthorpe <jgg@nvidia.com> wrote:
> 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)
Test for register_notifier callback...
> + iommu_driver->ops->unregister_notifier(
> + device->group->container->iommu_data,
> + &device->iommu_nb);
use unregister_notifier callback. Same below.
> + }
> 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,
> +};
Can't say I understand why this changed from BIT(0) to an enum, the
event mask is meant to be a bitfield. Using the notifier all the way
to the device was meant to avoid future callbacks on the device. If we
now have a dma_unmap on the device, should the whole infrastructure be
tailored to that one task? For example a dma_unmap_nb on the device,
{un}register_dma_unmap_notifier on the iommu ops,
vfio_dma_unmap_notifier, etc? Thanks,
Alex
> +
> /**
> * 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
> */
^ permalink raw reply [flat|nested] 34+ messages in thread* Re: [Intel-gfx] [PATCH v2 1/2] vfio: Replace the DMA unmapping notifier with a callback
@ 2022-06-17 22:42 ` Alex Williamson
0 siblings, 0 replies; 34+ messages in thread
From: Alex Williamson @ 2022-06-17 22:42 UTC (permalink / raw)
To: Jason Gunthorpe
Cc: kvm, David Airlie, dri-devel, Vineeth Vijayan, Alexander Gordeev,
Christoph Hellwig, linux-s390, Matthew Rosato, Halil Pasic,
Christian Borntraeger, intel-gfx, Jason Herne, Eric Farman,
Vasily Gorbik, Heiko Carstens, Harald Freudenberger,
Rodrigo Vivi, intel-gvt-dev, Tony Krowiak, Cornelia Huck,
Peter Oberparleiter, Sven Schnelle
On Tue, 7 Jun 2022 20:02:11 -0300
Jason Gunthorpe <jgg@nvidia.com> wrote:
> 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)
Test for register_notifier callback...
> + iommu_driver->ops->unregister_notifier(
> + device->group->container->iommu_data,
> + &device->iommu_nb);
use unregister_notifier callback. Same below.
> + }
> 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,
> +};
Can't say I understand why this changed from BIT(0) to an enum, the
event mask is meant to be a bitfield. Using the notifier all the way
to the device was meant to avoid future callbacks on the device. If we
now have a dma_unmap on the device, should the whole infrastructure be
tailored to that one task? For example a dma_unmap_nb on the device,
{un}register_dma_unmap_notifier on the iommu ops,
vfio_dma_unmap_notifier, etc? Thanks,
Alex
> +
> /**
> * 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
> */
^ permalink raw reply [flat|nested] 34+ messages in thread* Re: [PATCH v2 1/2] vfio: Replace the DMA unmapping notifier with a callback
@ 2022-06-17 22:42 ` Alex Williamson
0 siblings, 0 replies; 34+ messages in thread
From: Alex Williamson @ 2022-06-17 22:42 UTC (permalink / raw)
To: Jason Gunthorpe
Cc: kvm, David Airlie, dri-devel, Vineeth Vijayan, Alexander Gordeev,
Christoph Hellwig, linux-s390, Matthew Rosato, Halil Pasic,
Christian Borntraeger, intel-gfx, Zhi Wang, Jason Herne,
Eric Farman, Vasily Gorbik, Heiko Carstens, Harald Freudenberger,
Rodrigo Vivi, intel-gvt-dev, Tony Krowiak, Tvrtko Ursulin,
Cornelia Huck, Peter Oberparleiter, Sven Schnelle
On Tue, 7 Jun 2022 20:02:11 -0300
Jason Gunthorpe <jgg@nvidia.com> wrote:
> 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)
Test for register_notifier callback...
> + iommu_driver->ops->unregister_notifier(
> + device->group->container->iommu_data,
> + &device->iommu_nb);
use unregister_notifier callback. Same below.
> + }
> 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,
> +};
Can't say I understand why this changed from BIT(0) to an enum, the
event mask is meant to be a bitfield. Using the notifier all the way
to the device was meant to avoid future callbacks on the device. If we
now have a dma_unmap on the device, should the whole infrastructure be
tailored to that one task? For example a dma_unmap_nb on the device,
{un}register_dma_unmap_notifier on the iommu ops,
vfio_dma_unmap_notifier, etc? Thanks,
Alex
> +
> /**
> * 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
> */
^ permalink raw reply [flat|nested] 34+ messages in thread* Re: [PATCH v2 1/2] vfio: Replace the DMA unmapping notifier with a callback
2022-06-17 22:42 ` Alex Williamson
(?)
@ 2022-06-17 22:47 ` Alex Williamson
-1 siblings, 0 replies; 34+ messages in thread
From: Alex Williamson @ 2022-06-17 22:47 UTC (permalink / raw)
To: Jason Gunthorpe
Cc: Alexander Gordeev, David Airlie, Tony Krowiak,
Christian Borntraeger, Cornelia Huck, Daniel Vetter, dri-devel,
Eric Farman, Harald Freudenberger, Vasily Gorbik, Heiko Carstens,
intel-gfx, intel-gvt-dev, Jani Nikula, Jason Herne,
Joonas Lahtinen, kvm, linux-s390, Matthew Rosato,
Peter Oberparleiter, Halil Pasic, Rodrigo Vivi, Sven Schnelle,
Tvrtko Ursulin, Vineeth Vijayan, Zhenyu Wang, Zhi Wang,
Christoph Hellwig
On Fri, 17 Jun 2022 16:42:30 -0600
Alex Williamson <alex.williamson@redhat.com> wrote:
> On Tue, 7 Jun 2022 20:02:11 -0300
> Jason Gunthorpe <jgg@nvidia.com> wrote:
> > 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)
>
> Test for register_notifier callback...
>
> > + iommu_driver->ops->unregister_notifier(
> > + device->group->container->iommu_data,
> > + &device->iommu_nb);
>
> use unregister_notifier callback. Same below.
>
> > + }
> > 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,
> > +};
>
> Can't say I understand why this changed from BIT(0) to an enum, the
> event mask is meant to be a bitfield. Using the notifier all the way
> to the device was meant to avoid future callbacks on the device. If we
> now have a dma_unmap on the device, should the whole infrastructure be
> tailored to that one task? For example a dma_unmap_nb on the device,
> {un}register_dma_unmap_notifier on the iommu ops,
> vfio_dma_unmap_notifier, etc? Thanks,
Ok, this all seems cleared up in the next patch, maybe there's a better
intermediate step, but not worth bike shedding. Thanks,
Alex
> > +
> > /**
> > * 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
> > */
>
^ permalink raw reply [flat|nested] 34+ messages in thread* Re: [Intel-gfx] [PATCH v2 1/2] vfio: Replace the DMA unmapping notifier with a callback
@ 2022-06-17 22:47 ` Alex Williamson
0 siblings, 0 replies; 34+ messages in thread
From: Alex Williamson @ 2022-06-17 22:47 UTC (permalink / raw)
To: Jason Gunthorpe
Cc: kvm, David Airlie, dri-devel, Vineeth Vijayan, Alexander Gordeev,
Christoph Hellwig, linux-s390, Matthew Rosato, Halil Pasic,
Christian Borntraeger, intel-gfx, Jason Herne, Eric Farman,
Vasily Gorbik, Heiko Carstens, Harald Freudenberger,
Rodrigo Vivi, intel-gvt-dev, Tony Krowiak, Cornelia Huck,
Peter Oberparleiter, Sven Schnelle
On Fri, 17 Jun 2022 16:42:30 -0600
Alex Williamson <alex.williamson@redhat.com> wrote:
> On Tue, 7 Jun 2022 20:02:11 -0300
> Jason Gunthorpe <jgg@nvidia.com> wrote:
> > 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)
>
> Test for register_notifier callback...
>
> > + iommu_driver->ops->unregister_notifier(
> > + device->group->container->iommu_data,
> > + &device->iommu_nb);
>
> use unregister_notifier callback. Same below.
>
> > + }
> > 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,
> > +};
>
> Can't say I understand why this changed from BIT(0) to an enum, the
> event mask is meant to be a bitfield. Using the notifier all the way
> to the device was meant to avoid future callbacks on the device. If we
> now have a dma_unmap on the device, should the whole infrastructure be
> tailored to that one task? For example a dma_unmap_nb on the device,
> {un}register_dma_unmap_notifier on the iommu ops,
> vfio_dma_unmap_notifier, etc? Thanks,
Ok, this all seems cleared up in the next patch, maybe there's a better
intermediate step, but not worth bike shedding. Thanks,
Alex
> > +
> > /**
> > * 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
> > */
>
^ permalink raw reply [flat|nested] 34+ messages in thread* Re: [PATCH v2 1/2] vfio: Replace the DMA unmapping notifier with a callback
@ 2022-06-17 22:47 ` Alex Williamson
0 siblings, 0 replies; 34+ messages in thread
From: Alex Williamson @ 2022-06-17 22:47 UTC (permalink / raw)
To: Jason Gunthorpe
Cc: kvm, David Airlie, dri-devel, Vineeth Vijayan, Alexander Gordeev,
Christoph Hellwig, linux-s390, Matthew Rosato, Halil Pasic,
Christian Borntraeger, intel-gfx, Zhi Wang, Jason Herne,
Eric Farman, Vasily Gorbik, Heiko Carstens, Harald Freudenberger,
Rodrigo Vivi, intel-gvt-dev, Tony Krowiak, Tvrtko Ursulin,
Cornelia Huck, Peter Oberparleiter, Sven Schnelle
On Fri, 17 Jun 2022 16:42:30 -0600
Alex Williamson <alex.williamson@redhat.com> wrote:
> On Tue, 7 Jun 2022 20:02:11 -0300
> Jason Gunthorpe <jgg@nvidia.com> wrote:
> > 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)
>
> Test for register_notifier callback...
>
> > + iommu_driver->ops->unregister_notifier(
> > + device->group->container->iommu_data,
> > + &device->iommu_nb);
>
> use unregister_notifier callback. Same below.
>
> > + }
> > 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,
> > +};
>
> Can't say I understand why this changed from BIT(0) to an enum, the
> event mask is meant to be a bitfield. Using the notifier all the way
> to the device was meant to avoid future callbacks on the device. If we
> now have a dma_unmap on the device, should the whole infrastructure be
> tailored to that one task? For example a dma_unmap_nb on the device,
> {un}register_dma_unmap_notifier on the iommu ops,
> vfio_dma_unmap_notifier, etc? Thanks,
Ok, this all seems cleared up in the next patch, maybe there's a better
intermediate step, but not worth bike shedding. Thanks,
Alex
> > +
> > /**
> > * 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
> > */
>
^ permalink raw reply [flat|nested] 34+ messages in thread