Virtual_disk: add new case for dpofua attribute

[meinaLi]

Automate case:
VIRT-306602 - [virtual_disks] Start guest or hotplug disk with dpofua attribute

Summary by CodeRabbit

• Tests
  • Added comprehensive test suite for virtual disk dpofua attribute handling, covering both hot-plug and cold-plug attachment scenarios. Tests validate dpofua configuration in guest XML and QEMU command-line representations, and verify proper attribute removal during disk detachment.

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[coderabbitai]

Walkthrough

This pull request introduces a new test for Libvirt's dpofua attribute handling on virtual disks. It adds two new files: a configuration file that defines disk characteristics and test variants for dpofua and hotplug/coldplug scenarios, and a corresponding Python test script that validates dpofua behavior through XML verification and QEMU command-line inspection in both hotplug and standard attachment modes.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly describes the main change: adding a new test case for the dpofua attribute in virtual disks. It directly relates to the changeset which introduces both a configuration file and test script for dpofua attribute handling.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

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✨ Finishing touches

• 📝 Generate docstrings

---

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[meinaLi]

# avocado run --vt-type libvirt --vt-omit-data-loss --vt-machine-type q35 virtual_disks.dpofua
JOB ID     : 3cfedd39e584039f51f6e7d0011a39b77a9fb871
JOB LOG    : /var/log/avocado/job-results/job-2026-01-27T02.22-3cfedd3/job.log
 (1/4) type_specific.io-github-autotest-libvirt.virtual_disks.dpofua.coldplug.dpofua_on: STARTED
 (1/4) type_specific.io-github-autotest-libvirt.virtual_disks.dpofua.coldplug.dpofua_on: PASS (60.15 s)
 (2/4) type_specific.io-github-autotest-libvirt.virtual_disks.dpofua.coldplug.dpofua_off: STARTED
 (2/4) type_specific.io-github-autotest-libvirt.virtual_disks.dpofua.coldplug.dpofua_off: PASS (61.66 s)
 (3/4) type_specific.io-github-autotest-libvirt.virtual_disks.dpofua.hotplug.dpofua_on: STARTED
 (3/4) type_specific.io-github-autotest-libvirt.virtual_disks.dpofua.hotplug.dpofua_on: PASS (69.72 s)
 (4/4) type_specific.io-github-autotest-libvirt.virtual_disks.dpofua.hotplug.dpofua_off: STARTED
 (4/4) type_specific.io-github-autotest-libvirt.virtual_disks.dpofua.hotplug.dpofua_off: PASS (62.92 s)
RESULTS    : PASS 4 | ERROR 0 | FAIL 0 | SKIP 0 | WARN 0 | INTERRUPT 0 | CANCEL 0
JOB HTML   : /var/log/avocado/job-results/job-2026-01-27T02.22-3cfedd3/results.html
JOB TIME   : 258.96 s