qemu 6.0 breaks libvirt <7.2

[Christian Ehrhardt ]

With qemu 6.0 you'll see issues with hotplug on attach-device (there are more cases than the examples show)

attach-device hotplug-rng.xml+ uvt-kvm ssh --insecure impish-kvm 'virsh -c qemu:///system attach-device impish-2nd-hotplug hotplug-rng.xml'
error: Failed to attach device from hotplug-rng.xml
error: internal error: unable to execute QEMU command 'object-add': Parameter 'props' is unexpected

attach-device hotplug-mem64.xml+ uvt-kvm ssh --insecure impish-kvm 'virsh -c qemu:///system attach-device impish-2nd-hotplug hotplug-mem64.xml'
error: Failed to attach device from hotplug-mem64.xml
error: internal error: unable to execute QEMU command 'object-add': Parameter 'size' is missing

This is due to qemu
https://git.qemu.org/?p=qemu.git;a=commit;h=50243407457a9fb0ed17b9a9ba9fc9aee09495b1

It was reported and discussed in
https://bugzilla.redhat.com/show_bug.cgi?id=1944985

It is intentional and will stay that way, so higher layers need to adapt.
https://libvirt.org/git/?p=libvirt.git;a=commit;h=e0eeb2cc67d960a48937f99c659fb63dbd4049dc
https://libvirt.org/git/?p=libvirt.git;a=commit;h=96850dfe216f99019978a55027a1e763135ae88f
https://libvirt.org/git/?p=libvirt.git;a=commit;h=4f33b817b2926198ec626f10c3fca1c8aaececf6

That means >=7.2 is needed for qemu 6.0
Impish will eventually have that, but I think we need to add a Breaks to qemu d/control to ensure partial upgrades are not crashing unexpectedly.

[Launchpad Janitor (janitor)]

This bug was fixed in the package libvirt - 7.4.0-0ubuntu3

---------------
libvirt (7.4.0-0ubuntu3) impish; urgency=medium

  * d/t/smoke-lxc: skip if cgroup v1&v2 are present (systemd 248
    was not enough)

libvirt (7.4.0-0ubuntu2) impish; urgency=medium

  * d/t/smoke-lxc: skip before systemd 248 due to a known bug (LP: #1934966)

libvirt (7.4.0-0ubuntu1) impish; urgency=medium

  * Merge v7.4.0 from upstream,
    among a lot of new features and fixes this closes a few of issues
    reported against Ubuntu
    - Toleration for qemu >=6.0 handling of props (LP: #1932264)
    - Persistent vfio-ccw device assignments (LP: #1887929)
    - Drop patches that are upstream in v7.4.0
      - d/p/b/meson-Fix-cross-building-of-dtrace-probes.patch
      - d/p/b/apparmor-let-image-label-setting-loop-over-backing-files.patch
      - d/p/r/systemd-Revert-remote-Add-libvirtd-dependency-to-virt-gue.patch
      - d/p/u/lp-1913266-*: add vsock options to be usable with s390x
      - d/p/u/lp-1921754-*: EPYC-Rome-v2
      - d/p/u/lp-1921880-*: EPYC-Milan
    - d/libvirt-clients.install: completions no more are symlinked to vsh
    - Revert "disable firewalld support (universe dependency)"
      This does not add a runtime dependency and while firewalld isn't in
      main that way users can install and use it from universe.
      (LP: #1928113)
    - d/libvirt0.symbols: bump symbol versions for 7.4.0
    - d/rules: disable the now auto-built vstorage backend
    - not-installed: split daemon man pages are no yet installed

 -- Christian Ehrhardt <email address hidden> Thu, 08 Jul 2021 14:20:53 +0200

[Brian L. Somers (rodriques98)]

Unable to allow access for disk path /var/lib/libvirt/images/​qemu.img: No such file or directory, A guest ... exited, code=exited, status=6/​NOTCONFIGURED Sep 19 16:06:02 jsrh systemd[1]: Failed to start Virtualization daemon. ... Errors in these documents contain the file name of the broken document.
https://www.mypremiercreditcard.one/

[Christian Ehrhardt  (paelzer)]

Hi Brian,
that seems to be a different issue - maybe related but different.
I'd ask you to file a new bug and add all kind of info, how are things set up in detail, are there config changes that make it a good/bad case, does it only happen with new versions and on which release ...?

[Launchpad Janitor (janitor)]

This bug was fixed in the package qemu - 1:6.0+dfsg-1~ubuntu3

---------------
qemu (1:6.0+dfsg-1~ubuntu3) impish; urgency=medium

  * d/p/u/lp-1935617-target-ppc-Fix-load-endianness-for-lxvwsx-lxvdsx.patch:
    fix TCG emulation for ppc64 (LP: #1935617)

qemu (1:6.0+dfsg-1~ubuntu2) impish; urgency=medium

  * d/control: remove fuse2 trial-build (LP 1934510)

qemu (1:6.0+dfsg-1~ubuntu1) impish; urgency=medium

  * Merge with Debian experimental, Among many other things this fixes LP Bugs:
    (LP: #1907952) broken arrow keys in -display gtk on aarch64
    - qemu-kvm to systemd unit
      - d/qemu-kvm-init: script for QEMU KVM preparation modules, ksm,
        hugepages and architecture specifics
      - d/qemu-system-common.qemu-kvm.service: systemd unit to call
        qemu-kvm-init
      - d/qemu-system-common.install: install helper script
      - d/qemu-system-common.qemu-kvm.default: defaults for
        /etc/default/qemu-kvm
      - d/rules: call dh_installinit and dh_installsystemd for qemu-kvm
    - Distribution specific machine type
      (LP: 1304107 1621042 1776189 1761372 1761372 1776189)
      - d/p/ubuntu/define-ubuntu-machine-types.patch: define distro machine
        types containing release versioned machine attributes
      - d/qemu-system-x86.NEWS Info on fixed machine type defintions
        for host-phys-bits=true
      - Add an info about -hpb machine type in debian/qemu-system-x86.NEWS
      - ubuntu-q35 alias added to auto-select the most recent q35 ubuntu type
    - Enable nesting by default
      - d/p/ubuntu/enable-svm-by-default.patch: Enable nested svm by default
        in qemu64 on amd
        [ No more strictly needed, but required for backward compatibility ]
    - improved dependencies
      - Make qemu-system-common depend on qemu-block-extra
      - Make qemu-utils depend on qemu-block-extra
      - Let qemu-utils recommend sharutils
    - tolerate ipxe size change on migrations to >=18.04 (LP: 1713490)
      - d/p/ubuntu/pre-bionic-256k-ipxe-efi-roms.patch: old machine types
        reference 256k path
      - d/control-in: depend on ipxe-qemu-256k-compat-efi-roms to be able to
        handle incoming migrations from former releases.
    - d/control-in: Disable capstone disassembler library support (universe)
    - d/qemu-system-x86.README.Debian: add info about updated nesting changes
    - d/control*, d/rules: disable xen by default, but provide universe
      package qemu-system-x86-xen as alternative
      [includes compat links changes of 5.0-5ubuntu4]
    - Fix upgrade module handling (LP 1905377)
      --enable-module-upgrades for qemu-xen which doesn't exist in Debian
  * Dropped Changes [in 6.0]:
    - d/p/ubuntu/lp-1907789-build-no-pie-is-no-functional-liker-flag.patch: fix
      ld usage of -no-pie (LP 1907789)
    - d/p/u/lp-1916230-hw-s390x-fix-build-for-virtio-9p-ccw.patch: fix
      virtio-9p-ccw being missing (LP 1916230)
    - d/p/u/lp-1916705-disas-Fix-build-with-glib2.0-2.67.3.patch: Fix FTFBS due
      to glib2.0 >=2.67.3 (LP 1916705)
    - d/p/u/lp-1921754*: add EPYC-Rome-v2 as v1 missed IBRS and thereby fails
      on some HW/Guest combinations e.g. Windows 10 on Threadripper chips
  ...