Bug#977721: Opening a block device as a file using the 'file' driver is deprecated

[Michael Tokarev]

19.12.2020 17:55, Marc Haber пишет:

Package: qemu-system-x86
Version: 1:5.2+dfsg-2
Severity: important

I have my VM images on individually encrypted LVs so that I can
individually lock and unlock VMs. This is what my block device looks
like:
[1/5386]mh@drop:~ $ ls -al /dev/mapper/centos
lrwxrwxrwx 1 root root 8 Dez 19 15:47 /dev/mapper/centos -> ../dm-13
[2/5387]mh@drop:~ $ ls -al /dev/dm-13
brw-rw---- 1 root root 254, 13 Dez 19 15:47 /dev/dm-13
[3/5388]mh@drop:~ $

When I create a storage device in virt-manager, this results in the
following XML:
     <disk type='file' device='disk'>
       <driver name='qemu' type='raw'/>
       <source file='/dev/mapper/centos' index='1'/>
       <backingStore/>
       <target dev='vda' bus='virtio'/>
       <alias name='virtio-disk0'/>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x08' 
function='0x0'/>
     </disk>

This VM won't start any more with qemu 5.2, saying "Opening a block
device as a file using the file drive is deprecated". It unfortunately
doesn't give a hint how block devices are to be opened, and it looks
like libvirt/virt-manager don't know either.

I don't know whether this is a libvirt, a virt-manager or a qemu issue,
but it should be properly reassigned and fixed (and conflicts added (and
conflicts added). In the man time, going back to qemu 5.1 has fixed the
issue for me.

Marc, what do you want we to do?

Should we revert qemu 5.2 to qemu 5.1 and stay there?

/mjt