[pve-devel] [RFC storage 1/3] plugin: add method to get qemu blockdevice options for volume

[Fiona Ebner]

Am 23.05.25 um 11:34 schrieb DERUMIER, Alexandre:
>>> I intentionally do not handle CD-ROMs, qemu-server should be
>>> concerned
>>> with doing that. There is a comment about this ;)
> 
> I mean, could it better to have something like this ? :
> 
> 
> sub qemu_blockdev_options {
>     my ($cfg, $volid, $snapname) = @_;
> 
>     my ($storeid, $volname) = parse_volume_id($volid, 1);
> 
>     if($storeid) {
>         my $scfg = storage_config($cfg, $storeid);
> 
>         my $plugin = PVE::Storage::Plugin->lookup($scfg->{type});
>         my ($vtype) = $plugin->parse_volname($volname);
> 
>         die "cannot use volume of type '$vtype' as a QEMU
> blockdevice\n"
>             if $vtype ne 'images' && $vtype ne 'iso' && $vtype ne
> 'import';
> 
>         die "QEMU blockdevice - 'snapname' argument is not supported
> for vtype '$vtype'"
>             if $snapname && $vtype ne 'images';
>     } elsif ($volid =~ m|^/|) {
>         my $st = File::stat::stat($volid);
>         my $driver = (S_ISCHR($st->mode) || S_ISBLK($st->mode)) ?
> 'host_device' : 'file';
>         return { driver => $driver, filename => $volid };
>     }
> 
>     return $plugin->qemu_blockdev_options($scfg, $storeid, $volname,
> $snapname);
> }

Yes, it would be possible, and it is a close call. But I briefly chatted
with Fabian off-list and we think it's better to do this in qemu-server,
together with the CD-ROM handling. Since the whole use-case is related
to a QEMU-specific interface already.