[Pkg-libvirt-maintainers] Bug#993712: file driver no longer supported with block devices in qemu

[Marc Haber]

Package: libvirt-daemon-driver-qemu
Version: 7.6.0-1
Severity: normal

Hi,

this is an incompatibility of current libvirt in unstable with current
qemu in unstable, documented upstream as https://gitlab.com/libvirt/libvirt/-/issues/212

In a nutstell, it seems no longer possible to add a storage device
pointing to, for example, /dev/sda6 od /dev/mapper/lvname. A VM with
such a definition:

    <disk type='file' device='disk'>
      <driver name='qemu' type='raw'/>
      <source file='/dev/mapper/cryptodevice'/>
      <target dev='vda' bus='virtio'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x>
    </disk>                                                                                      ,
will no longer start:

+{"driver":"file","filename":"/dev/mapper/cryptodevice","node-name":"libvirt-1-storage","auto-read-only":true,"discard":"unmap"}: 'file' driver requires '/dev/mapper/cryptodevice' to be a regular file

Especially virt-manager users will be bitten by this since they don't
know how to write proper XML to make their VM work again.

I don't know whether this needs to be fixed in libvirt or virt-manager
(I suspect in both), since this seems to be an intended change in qemu.

For the time being, I recommend adding versioned dependencies, breaks
and/or conflicts with qemu 6.x to libvirt to avoid people updating into
unusable libvirt/qemu. The appropriate bug to qemu is #Bug#993688

Please forward appropriately to virt-manager in case virt-manager needs
to do things as well.

Greetings
Marc

-- System Information:
Debian Release: bookworm/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)

Kernel: Linux 5.14.1-zgws1 (SMP w/12 CPU threads)
Locale: LANG=de_DE.utf8, LC_CTYPE=de_DE.utf8 (charmap=UTF-8), LANGUAGE=en
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages libvirt-daemon-driver-qemu depends on:
ii  libc6         2.31-17
ii  libgcc-s1     11.2.0-4
ii  libglib2.0-0  2.68.4-1
ii  libgnutls30   3.7.2-2
ii  libselinux1   3.1-3
ii  libvirt0      7.6.0-1
ii  libxml2       2.9.12+dfsg-3

libvirt-daemon-driver-qemu recommends no packages.

libvirt-daemon-driver-qemu suggests no packages.

-- no debconf information