Libvirt_rng: syncing vmxml after attaching rng device

[rh-jugraham]

Issue:
Failed to check rng file on guest. The virtio device is not the current rng device.

More specifically:

L0333 DEBUG| rng avail:tpm-rng-0 virtio_rng.0, current:tpm-rng-0

Fix:
The above debug message shows that the virtio device is available, it is not the current rng device. The fix therefore is to run sync() on the vmxml to ensure that the most up-to-date version of the xml (with the rng device attached) is being used.

Tests passing:

(.libvirt-ci-venv-ci-runtest-1BjoYw) [root@ampere-one-01 ~]# avocado run --vt-type libvirt --vt-omit-data-loss libvirt_rng.backend_builtin.hotplug_unplug.positive --vt-connect-uri qemu:///system
No python imaging library installed. Screendump and Windows guest BSOD detection are disabled. In order to enable it, please install python-imaging or the equivalent for your distro.
No python imaging library installed. PPM image conversion to JPEG disabled. In order to enable it, please install python-imaging or the equivalent for your distro.
No python imaging library installed. Screendump and Windows guest BSOD detection are disabled. In order to enable it, please install python-imaging or the equivalent for your distro.
No python imaging library installed. PPM image conversion to JPEG disabled. In order to enable it, please install python-imaging or the equivalent for your distro.
JOB ID     : 12fe5b56be85943360211c6763f8cf688919ebd7
JOB LOG    : /var/log/avocado/job-results/job-2024-10-24T16.15-12fe5b5/job.log
 (01/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.no_options: STARTED
 (01/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.no_options: PASS (37.88 s)
 (02/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.persistent: STARTED
 (02/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.persistent: PASS (39.61 s)
 (03/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.no_options: STARTED
 (03/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.no_options: PASS (39.38 s)
 (04/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.persistent: STARTED
 (04/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.persistent: PASS (39.33 s)
 (05/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.no_options: STARTED
 (05/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.no_options: PASS (39.25 s)
 (06/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.persistent: STARTED
 (06/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.persistent: PASS (42.24 s)
 (07/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.no_options: STARTED
 (07/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.no_options: PASS (41.93 s)
 (08/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.persistent: STARTED
 (08/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.persistent: PASS (42.68 s)
 (09/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.no_options: STARTED
 (09/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.no_options: PASS (41.96 s)
 (10/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.persistent: STARTED
 (10/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.persistent: PASS (41.88 s)
 (11/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.no_options: STARTED
 (11/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.no_options: PASS (42.12 s)
 (12/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.persistent: STARTED
 (12/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.persistent: PASS (42.00 s)
 (13/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.no_options: STARTED
 (13/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.no_options: PASS (41.88 s)
 (14/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.persistent: STARTED
 (14/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_builtin.hotplug_unplug.positive.persistent: PASS (42.00 s)
RESULTS    : PASS 14 | ERROR 0 | FAIL 0 | SKIP 0 | WARN 0 | INTERRUPT 0 | CANCEL 0
JOB HTML   : /var/log/avocado/job-results/job-2024-10-24T16.15-12fe5b5/results.html
JOB TIME   : 584.03 s

AND

(.libvirt-ci-venv-ci-runtest-1BjoYw) [root@ampere-one-01 ~]# avocado run --vt-type libvirt --vt-omit-data-loss libvirt_rng.backend_rdm.default.hotplug_unplug.positive --vt-connect-uri qemu:///syste
m
No python imaging library installed. Screendump and Windows guest BSOD detection are disabled. In order to enable it, please install python-imaging or the equivalent for your distro.
No python imaging library installed. PPM image conversion to JPEG disabled. In order to enable it, please install python-imaging or the equivalent for your distro.
No python imaging library installed. Screendump and Windows guest BSOD detection are disabled. In order to enable it, please install python-imaging or the equivalent for your distro.
No python imaging library installed. PPM image conversion to JPEG disabled. In order to enable it, please install python-imaging or the equivalent for your distro.
JOB ID     : 4bbdceab9c7f5124f91319fce07404c054d04746
JOB LOG    : /var/log/avocado/job-results/job-2024-10-24T16.29-4bbdcea/job.log
 (01/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.no_options: STARTED
 (01/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.no_options: PASS (42.69 s)
 (02/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.persistent: STARTED
 (02/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.persistent: PASS (38.57 s)
 (03/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.no_options: STARTED
 (03/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.no_options: PASS (38.88 s)
 (04/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.persistent: STARTED
 (04/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.persistent: PASS (38.71 s)
 (05/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.no_options: STARTED
 (05/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.no_options: PASS (37.98 s)
 (06/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.persistent: STARTED
 (06/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.persistent: PASS (41.11 s)
 (07/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.no_options: STARTED
 (07/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.no_options: PASS (41.26 s)
 (08/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.persistent: STARTED
 (08/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.persistent: PASS (41.71 s)
 (09/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.no_options: STARTED
 (09/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.no_options: PASS (41.76 s)
 (10/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.persistent: STARTED
 (10/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.persistent: PASS (41.59 s)
 (11/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.no_options: STARTED
 (11/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.no_options: PASS (41.60 s)
 (12/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.persistent: STARTED
 (12/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.persistent: PASS (42.20 s)
 (13/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.no_options: STARTED
 (13/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.no_options: PASS (41.31 s)
 (14/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.persistent: STARTED
 (14/14) type_specific.io-github-autotest-libvirt.libvirt_rng.backend_rdm.default.hotplug_unplug.positive.persistent: PASS (41.78 s)
RESULTS    : PASS 14 | ERROR 0 | FAIL 0 | SKIP 0 | WARN 0 | INTERRUPT 0 | CANCEL 0
JOB HTML   : /var/log/avocado/job-results/job-2024-10-24T16.29-4bbdcea/results.html
JOB TIME   : 580.62 s