> From: Christoph Hellwig <hch@xxxxxx>
> Sent: Thursday, August 26, 2021 12:19 AM
>
> Factor out a helper to find or allocate the vfio_group to reduce the
> spagetthi code in vfio_register_group_dev a little.
this will need an update if my comment on patch01 is correct.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> drivers/vfio/vfio.c | 51 ++++++++++++++++++++++++++-------------------
> 1 file changed, 30 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
> index 00aeef5bb29abd..207c1bbac1829a 100644
> --- a/drivers/vfio/vfio.c
> +++ b/drivers/vfio/vfio.c
> @@ -833,10 +833,34 @@ void vfio_uninit_group_dev(struct vfio_device
> *device)
> }
> EXPORT_SYMBOL_GPL(vfio_uninit_group_dev);
>
> +struct vfio_group *vfio_group_find_or_alloc(struct device *dev)
> +{
> + struct iommu_group *iommu_group;
> + struct vfio_group *group;
> +
> + iommu_group = vfio_iommu_group_get(dev);
> + if (!iommu_group)
> + return ERR_PTR(-EINVAL);
> +
> + /* a found vfio_group already holds a reference to the iommu_group
> */
> + group = vfio_group_get_from_iommu(iommu_group);
> + if (group)
> + goto out_put;
> +
> + /* a newly created vfio_group keeps the reference. */
> + group = vfio_create_group(iommu_group);
> + if (IS_ERR(group))
> + goto out_put;
> + return group;
> +
> +out_put:
> + vfio_iommu_group_put(iommu_group, dev);
> + return group;
> +}
> +
> int vfio_register_group_dev(struct vfio_device *device)
> {
> struct vfio_device *existing_device;
> - struct iommu_group *iommu_group;
> struct vfio_group *group;
>
> /*
> @@ -846,31 +870,16 @@ int vfio_register_group_dev(struct vfio_device
> *device)
> if (!device->dev_set)
> vfio_assign_device_set(device, device);
>
> - iommu_group = vfio_iommu_group_get(device->dev);
> - if (!iommu_group)
> - return -EINVAL;
> -
> - group = vfio_group_get_from_iommu(iommu_group);
> - if (!group) {
> - group = vfio_create_group(iommu_group);
> - if (IS_ERR(group)) {
> - vfio_iommu_group_put(iommu_group, device->dev);
> - return PTR_ERR(group);
> - }
> - } else {
> - /*
> - * A found vfio_group already holds a reference to the
> - * iommu_group. A created vfio_group keeps the reference.
> - */
> - vfio_iommu_group_put(iommu_group, device->dev);
> - }
> + group = vfio_group_find_or_alloc(device->dev);
> + if (IS_ERR(group))
> + return PTR_ERR(group);
>
> existing_device = vfio_group_get_device(group, device->dev);
> if (existing_device) {
> dev_WARN(device->dev, "Device already exists on
> group %d\n",
> - iommu_group_id(iommu_group));
> + iommu_group_id(group->iommu_group));
> vfio_device_put(existing_device);
> - vfio_iommu_group_put(iommu_group, device->dev);
> + vfio_iommu_group_put(group->iommu_group, device->dev);
> return -EBUSY;
> }
>
> --
> 2.30.2
