What were you trying to do that didn't work?

Cross migrate a KVM guest from 9.4 -> 9.5 for a guest with an attached virtio-gpu device.

Please provide the package NVR for which bug is seen:

qemu-kvm-9.0.0-3.el9.s390x

(source: qemu-kvm-8.2.0-11.el9_4.2.s390x)

How reproducible:

100%

Steps to reproduce

1. Define a VM with a virtio-gpu device on a host with RHEL 9.4, e.g.

   • # #qemu-kvm
       -vnc 127.0.0.1:0,audiodev=audio1
      -device {"driver":"virtio-gpu-ccw","id":"video0","max_outputs":1,"devno":"fe.0.0002"}
     

   •     <graphics type='vnc' port='-1' autoport='yes'>
           <listen type='address'/>
         </graphics>
         <audio id='1' type='none'/>
         <video>
           <model type='virtio' heads='1' primary='yes'/>
           <address type='ccw' cssid='0xfe' ssid='0x0' devno='0x0002'/>
         </video>
     

2. Migrate the VM to a host with RHEL 9.5, e.g.

   •  migrate --live --p2p --verbose --domain avocado-vt-vm1 --desturi qemu+ssh://<ip>/system

   • migrate --live --verbose --domain avocado-vt-vm1 --desturi qemu+ssh://<ip>/system --tls --postcopy-after-precopy --postcopy

Expected results

The migration finishes successfully

Actual results

The migration stops shortly before completion with error

emu-kvm: Missing section footer for /fe.0.0002/virtio-gpu2024-06-07T10:23:10.929189Z qemu-kvm: load of migration failed: Invalid argument


Additional notes

The migration succeeds when the virtio-gpu / video device is removed from the domain definition

Many automated test cases fail with this error, e.g. virsh.migrate_options_shared.positive_test.p2p_migration.disable_keepalive.on_both.without_postcopy

In some of the tests (virsh.migrate_options_shared.positive_test.native_tls.verify_client.post_after_precopy.with_postcopy) I see an additional error afterwards.

qemu-kvm: error while loading state section id 2(ram)qemu-kvm: ../util/oslib-posix.c:232: void qemu_socket_set_nonblock(int): Assertion `f == 0' failed.


or the migration just fails due to a connection reset (migrate --live --verbose --domain avocado-vt-vm1 --desturi qemu+ssh://<ip>/system --tls --postcopy-after-precopy --postcopy)

error: operation failed: job 'migration out' failed: Unable to read from socket: Connection reset by peer
}

Again, those tests pass without the graphic device.

I don't know yet if this only applies to s390x or if it is with virtio-gpu for all archs.