On 2022/10/26 02:17, Jason Gunthorpe wrote:
The only thing this function does is assert the group has an assigned
container and incrs refcounts.
The overall model we have is that once a conatiner_users refcount is
typo.
s/conatiner_users/container_users
incremented it cannot be de-assigned from the group -
vfio_group_ioctl_unset_container() will fail and the group FD cannot be
closed.
Thus we do not need to check this on evey device FD open, just the
s/evey/every
first. Reorganize the code so that only the first open and last close
manages the container.
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
---
drivers/vfio/container.c | 4 ++--
drivers/vfio/vfio_main.c | 18 ++++++++----------
2 files changed, 10 insertions(+), 12 deletions(-)
diff --git a/drivers/vfio/container.c b/drivers/vfio/container.c
index d74164abbf401d..dd79a66ec62cad 100644
--- a/drivers/vfio/container.c
+++ b/drivers/vfio/container.c
@@ -531,11 +531,11 @@ int vfio_device_assign_container(struct vfio_device *device)
void vfio_device_unassign_container(struct vfio_device *device)
{
- mutex_lock(&device->group->group_lock);
+ lockdep_assert_held_write(&device->group->group_lock);
+
WARN_ON(device->group->container_users <= 1);
device->group->container_users--;
fput(device->group->opened_file);
- mutex_unlock(&device->group->group_lock);
}
/*
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index d043383fc3ba2b..204443ba3b3cd9 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -749,16 +749,22 @@ static int vfio_device_first_open(struct vfio_device *device)
* it during close_device.
*/
mutex_lock(&device->group->group_lock);
+ ret = vfio_device_assign_container(device);
+ if (ret)
+ goto err_module_put;
+
device->kvm = device->group->kvm;
if (device->ops->open_device) {
ret = device->ops->open_device(device);
if (ret)
- goto err_module_put;
+ goto err_container;
}
vfio_device_container_register(device);
mutex_unlock(&device->group->group_lock);
return 0;
+err_container:
+ vfio_device_unassign_container(device);
err_module_put:
device->kvm = NULL;
mutex_unlock(&device->group->group_lock);
@@ -775,6 +781,7 @@ static void vfio_device_last_close(struct vfio_device *device)
if (device->ops->close_device)
device->ops->close_device(device);
device->kvm = NULL;
+ vfio_device_unassign_container(device);
mutex_unlock(&device->group->group_lock);
module_put(device->dev->driver->owner);
}
@@ -784,12 +791,6 @@ static struct file *vfio_device_open(struct vfio_device *device)
struct file *filep;
int ret;
- mutex_lock(&device->group->group_lock);
- ret = vfio_device_assign_container(device);
- mutex_unlock(&device->group->group_lock);
- if (ret)
- return ERR_PTR(ret);
-
mutex_lock(&device->dev_set->lock);
device->open_count++;
if (device->open_count == 1) {
@@ -833,7 +834,6 @@ static struct file *vfio_device_open(struct vfio_device *device)
err_unassign_container:
should the err_unassign_container be renamed to be err_dec_count?
other parts look good to me.
Reviewed-by: Yi Liu <yi.l.liu@xxxxxxxxx>
device->open_count--;
mutex_unlock(&device->dev_set->lock);
- vfio_device_unassign_container(device);
return ERR_PTR(ret);
}
@@ -1040,8 +1040,6 @@ static int vfio_device_fops_release(struct inode *inode, struct file *filep)
device->open_count--;
mutex_unlock(&device->dev_set->lock);
- vfio_device_unassign_container(device);
-
vfio_device_put_registration(device);
return 0;
--
Regards,
Yi Liu
