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vfio: Move vfio_device driver open/close code to a function

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This error unwind is getting complicated. Move all the code into two
pair'd function. The functions should be called when the open_count == 1
after incrementing/before decrementing.

Link: https://lore.kernel.org/r/1-v4-42cd2eb0e3eb+335a-vfio_iommufd_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yu He <yu.he@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
This commit is contained in:
Jason Gunthorpe 2022-11-29 16:31:46 -04:00
parent 2a54e347d9
commit 294aaccb50
1 changed files with 54 additions and 43 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

97
drivers/vfio/vfio_main.c
View File

@ -734,6 +734,51 @@ bool vfio_assert_device_open(struct vfio_device *device)
return !WARN_ON_ONCE(!READ_ONCE(device->open_count));
}
static int vfio_device_first_open(struct vfio_device *device)
{
int ret;
lockdep_assert_held(&device->dev_set->lock);
if (!try_module_get(device->dev->driver->owner))
return -ENODEV;
/*
* Here we pass the KVM pointer with the group under the lock. If the
* device driver will use it, it must obtain a reference and release it
* during close_device.
*/
mutex_lock(&device->group->group_lock);
device->kvm = device->group->kvm;
if (device->ops->open_device) {
ret = device->ops->open_device(device);
if (ret)
goto err_module_put;
}
vfio_device_container_register(device);
mutex_unlock(&device->group->group_lock);
return 0;
err_module_put:
device->kvm = NULL;
mutex_unlock(&device->group->group_lock);
module_put(device->dev->driver->owner);
return ret;
}
static void vfio_device_last_close(struct vfio_device *device)
{
lockdep_assert_held(&device->dev_set->lock);
mutex_lock(&device->group->group_lock);
vfio_device_container_unregister(device);
if (device->ops->close_device)
device->ops->close_device(device);
device->kvm = NULL;
mutex_unlock(&device->group->group_lock);
module_put(device->dev->driver->owner);
}
static struct file *vfio_device_open(struct vfio_device *device)
{
struct file *filep;
@ -745,29 +790,12 @@ static struct file *vfio_device_open(struct vfio_device *device)
if (ret)
return ERR_PTR(ret);
if (!try_module_get(device->dev->driver->owner)) {
ret = -ENODEV;
goto err_unassign_container;
}
mutex_lock(&device->dev_set->lock);
device->open_count++;
if (device->open_count == 1) {
/*
* Here we pass the KVM pointer with the group under the read
* lock. If the device driver will use it, it must obtain a
* reference and release it during close_device.
*/
mutex_lock(&device->group->group_lock);
device->kvm = device->group->kvm;
if (device->ops->open_device) {
ret = device->ops->open_device(device);
if (ret)
goto err_undo_count;
}
vfio_device_container_register(device);
mutex_unlock(&device->group->group_lock);
ret = vfio_device_first_open(device);
if (ret)
goto err_unassign_container;
}
mutex_unlock(&device->dev_set->lock);
@ -800,20 +828,11 @@ static struct file *vfio_device_open(struct vfio_device *device)
err_close_device:
mutex_lock(&device->dev_set->lock);
mutex_lock(&device->group->group_lock);
if (device->open_count == 1 && device->ops->close_device) {
device->ops->close_device(device);
vfio_device_container_unregister(device);
}
err_undo_count:
mutex_unlock(&device->group->group_lock);
device->open_count--;
if (device->open_count == 0 && device->kvm)
device->kvm = NULL;
mutex_unlock(&device->dev_set->lock);
module_put(device->dev->driver->owner);
if (device->open_count == 1)
vfio_device_last_close(device);
err_unassign_container:
device->open_count--;
mutex_unlock(&device->dev_set->lock);
vfio_device_unassign_container(device);
return ERR_PTR(ret);
}
@ -1016,19 +1035,11 @@ static int vfio_device_fops_release(struct inode *inode, struct file *filep)
mutex_lock(&device->dev_set->lock);
vfio_assert_device_open(device);
mutex_lock(&device->group->group_lock);
if (device->open_count == 1 && device->ops->close_device)
device->ops->close_device(device);
vfio_device_container_unregister(device);
mutex_unlock(&device->group->group_lock);
if (device->open_count == 1)
vfio_device_last_close(device);
device->open_count--;
if (device->open_count == 0)
device->kvm = NULL;
mutex_unlock(&device->dev_set->lock);
module_put(device->dev->driver->owner);
vfio_device_unassign_container(device);
vfio_device_put_registration(device);