Re: [Qemu-devel] [PATCH v2 03/18] xen: introduce 'xen-block', 'xen-disk' and 'xen-cdrom'

[Anthony PERARD <anthony.perard@citrix.com>]

On Thu, Dec 06, 2018 at 03:08:29PM +0000, Paul Durrant wrote:
> +static char *disk_to_vbd_name(unsigned int disk)
> +{
> +    char *name, *prefix = (disk >= 26) ?
> +        disk_to_vbd_name((disk / 26) - 1) : g_strdup("");
> +
> +    name = g_strdup_printf("%s%c", prefix, 'a' + disk);

I don't think that works, if disk is 27, we do ('a' + 27) here. It's
probably missing a `disk % 26`.

> +    g_free(prefix);
> +
> +    return name;
> +}

[...]

> +static unsigned int vbd_name_to_disk(const char *name, const char **endp)
> +{
> +    unsigned int disk = 0;
> +
> +    while (*name != '\0') {
> +        if (!g_ascii_isalpha(*name) || !g_ascii_islower(*name)) {
> +            break;
> +        }
> +
> +        disk *= 26;
> +        disk += *name++ - 'a';
> +    }
> +    *endp = name;
> +
> +    return disk;
> +}
> +
> +static void xen_block_set_vdev(Object *obj, Visitor *v, const char *name,
> +                               void *opaque, Error **errp)
> +{

Setting vdev doesn't work. I've tried to add a disk `xvdaa', and it
result in `xvda', or `d0p0' (in the trace). (Same result with `xvdaaa',
and 'xvdba' gives 'xvdaa'/d26p0)

-- 
Anthony PERARD