Re: [PATCH 11/12] hw/xen: automatically assign device index to block devices

[Kevin Wolf]

Am 16.10.2023 um 17:19 hat David Woodhouse geschrieben:
> From: David Woodhouse <dwmw@amazon.co.uk>
> 
> There's no need to force the user to assign a vdev. We can automatically
> assign one, starting at xvda and searching until we find the first disk
> name that's unused.
> 
> This means we can now allow '-drive if=xen,file=xxx' to work without an
> explicit separate -driver argument, just like if=virtio.
> 
> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>

> @@ -34,6 +34,31 @@ static char *xen_block_get_name(XenDevice *xendev, Error 
> **errp)
>      XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
>      XenBlockVdev *vdev = &blockdev->props.vdev;
>  
> +    if (blockdev->props.vdev.type == XEN_BLOCK_VDEV_TYPE_INVALID) {
> +        char name[11];
> +        int disk = 0;
> +        unsigned long idx;
> +
> +        /* Find an unoccupied device name */
> +        while (disk < (1 << 20)) {

I like your optimism that we can handle a million disks. :-)

I haven't reviewed the Xen part in detail, but the patch looks fine on
the block layer side.

Acked-by: Kevin Wolf <kwolf@redhat.com>