Now that the iommu core takes care of isolation there is no race between
driver attach and container unset. Once iommu_group_release_dma_owner()
returns the device can immediately be re-used.
Remove this mechanism.
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
---
drivers/vfio/vfio.c | 20 --------------------
1 file changed, 20 deletions(-)
This was missed in Baolu's series, and applies on top of "iommu: Remove iommu
group changes notifier"
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 0c766384cee0f8..4a1847f50c9289 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -74,7 +74,6 @@ struct vfio_group {
struct list_head vfio_next;
struct list_head container_next;
atomic_t opened;
- wait_queue_head_t container_q;
enum vfio_group_type type;
unsigned int dev_counter;
struct kvm *kvm;
@@ -363,7 +362,6 @@ static struct vfio_group *vfio_group_alloc(struct iommu_group *iommu_group,
refcount_set(&group->users, 1);
INIT_LIST_HEAD(&group->device_list);
mutex_init(&group->device_lock);
- init_waitqueue_head(&group->container_q);
group->iommu_group = iommu_group;
/* put in vfio_group_release() */
iommu_group_ref_get(iommu_group);
@@ -723,23 +721,6 @@ void vfio_unregister_group_dev(struct vfio_device *device)
group->dev_counter--;
mutex_unlock(&group->device_lock);
- /*
- * In order to support multiple devices per group, devices can be
- * plucked from the group while other devices in the group are still
- * in use. The container persists with this group and those remaining
- * devices still attached. If the user creates an isolation violation
- * by binding this device to another driver while the group is still in
- * use, that's their fault. However, in the case of removing the last,
- * or potentially the only, device in the group there can be no other
- * in-use devices in the group. The user has done their due diligence
- * and we should lay no claims to those devices. In order to do that,
- * we need to make sure the group is detached from the container.
- * Without this stall, we're potentially racing with a user process
- * that may attempt to immediately bind this device to another driver.
- */
- if (list_empty(&group->device_list))
- wait_event(group->container_q, !group->container);
-
if (group->type == VFIO_NO_IOMMU || group->type == VFIO_EMULATED_IOMMU)
iommu_group_remove_device(device->dev);
@@ -984,7 +965,6 @@ static void __vfio_group_unset_container(struct vfio_group *group)
iommu_group_release_dma_owner(group->iommu_group);
group->container = NULL;
- wake_up(&group->container_q);
list_del(&group->container_next);
/* Detaching the last group deprivileges a container, remove iommu */
base-commit: 46788c84354d07f8b1e5df87e805500611fd04fb
--
2.36.0
