[dimerr]

test-grainmedia.py's migration check ("and loaded back") fails intermittently, about one run in three. It fails on master since #208's CI passed, and it blocks #211.

Cause: the save never completed. Switchover failed with bdrv_inactivate_all() failed: -1, so the stream stopped after RAM, and whether the truncated stream loaded was down to timing.

flash-file opens the image with blk_new_open() and passes that BlockBackend to the flash device's drive property. The property refers to an anonymous BlockBackend by its node name and creates a new BlockBackend on that node for the device. The machine's original one stayed attached to the node, writable and with no device, so blk_can_inactivate() refuses it.

Fix: the Grain Media and Fullhan machines drop their reference once the device has its own; the device's BlockBackend still writes the image back.

Testing:

• 72 save/load cycles under 12-way parallel load all succeed; 12 of 72 failed before.
• query-migrate now reports completed.
• test-grainmedia.py and test-fullhan.py pass.

[qodo-free-for-open-source-projects]

PR Summary by Qodo

Fix flash-file migration for Grain Media and Fullhan machines

🐞 Bug fix 🕐 Less than 10 minutes

AI Description

• Release the machines’ temporary flash backends after device realization so migration can
 inactivate the image.
• Preserve flash-image writes through each device’s backend, fixing intermittent save/load failures.

Diagram

graph TD
  GM["Grain Media"] --> TEMP["Temporary backend"] --> PROP["Drive property"] --> DEV["Device backend"] --> IMAGE[("Flash image")]
  FH["Fullhan"] --> TEMP
  TEMP -. "unref after realization" .-> MIG["Migration"] --> DEV

Loading

High-Level Assessment

Release the machine-created backend after the device has acquired its own. This fixes the ownership problem locally without changing QEMU’s drive-property behavior or the legacy-drive path; a broader property API change is unnecessary for this bug.

Files changed (2) +18 / -0

Bug fix (2) +18 / -0

fullhan.cRelease Fullhan’s temporary flash-file backend +9/-0

Release Fullhan’s temporary flash-file backend

• After realizing the flash device, unref the backend opened for flash-file. This removes the unattached writable backend that prevents block inactivation during migration; legacy-drive handling is unchanged.

qemu/hw/arm/fullhan.c

grainmedia.cRelease Grain Media’s temporary flash-file backend +9/-0

Release Grain Media’s temporary flash-file backend

• After realizing the flash device, unref the backend opened for flash-file. The device retains its own backend for image writes, while migration no longer encounters the machine’s unattached writable backend.

qemu/hw/arm/grainmedia.c

[qodo-free-for-open-source-projects]

Code Review by Qodo

🐞 Bugs (0) 📘 Rule violations (0) 📎 Requirement gaps (0)

Great, no issues found!

Qodo reviewed your code and found no material issues that require review

Tip of the day

💡 Did you know, you can type 'qodo, fix this' on a finding and the fix lands right on your PR

More tips ↗ | Customize Qodo ↗ | Qodo docs ↗