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

Use the VM after a live dump.

Please provide the package NVR for which bug is seen:

qemu-kvm-9.0.0-10.el9_5.s390x

How reproducible:

10% if running a specific automated test case
0% when trying manually or with a bash script

Steps to reproduce

1. Take a live dump

   virsh dump --live avocado-vt-vm1 vm_dump

2. Access the VM via ssh or serial console

Expected results

I can log into the VM and use it as usual.

Actual results

I can't establish an ssh connection although this worked before the dump. The serial console doesn't show any output.

Additional info

1. The mentioned test case is tp-libvirt virsh.domjobinfo.normal_test.dump_action.live_dump.running_state.vm_id
2. Attaching dmesg and back traces for tasks in uninterruptible state
3. This is not a regression, since RHEL 8.8 it's been happening a few times.
4. I've seen similar hangs in cases of external live snapshots memory spec. Ref. RHEL-52635, more specifically this one:

   PID: 25       TASK: 720000            CPU: 1    COMMAND: "kworker/u10:0"
    #0 [37fffbf3578] __schedule at 3d3015c0
    #1 [37fffbf35f8] schedule at 3d3018e6
    #2 [37fffbf3628] io_schedule at 3d301a32
    #3 [37fffbf3658] rq_qos_wait at 3ce44800
    #4 [37fffbf36f8] wbt_wait at 3ce6eba8
    #5 [37fffbf3750] __rq_qos_throttle at 3ce4430e
    #6 [37fffbf3788] blk_mq_submit_bio at 3ce34068
    #7 [37fffbf3818] __submit_bio_noacct at 3ce2211c
    #8 [37fffbf3868] iomap_submit_ioend at 3cd2f48e
    #9 [37fffbf38a8] xfs_vm_writepages at 3ff7fd107ca [xfs]
   #10 [37fffbf3950] do_writepages at 3cbb3692
   #11 [37fffbf39d0] __writeback_single_inode at 3cce534c
   #12 [37fffbf3a28] writeback_sb_inodes at 3cce5c5c
   #13 [37fffbf3b20] __writeback_inodes_wb at 3cce601a
   #14 [37fffbf3b80] wb_writeback at 3cce635e
   #15 [37fffbf3c30] wb_workfn at 3cce76e8
   #16 [37fffbf3d10] process_one_work at 3c9ac892
   #17 [37fffbf3d98] worker_thread at 3c9ad77e
   #18 [37fffbf3e10] kthread at 3c9b6b40
   #19 [37fffbf3e68] __ret_from_fork at 3c936ebc
   #20 [37fffbf3e98] ret_from_fork at 3d308bf2