fyi, what I tested in Comment #35 was upstream QEMU (@ aceeaa69d2) with a port of the patch in Comment #34 applied. I've attached that patch here. While it did avoid the issue in my testing, I agree with Rafael's Comment #36 that it does not appear to address the root cause (as I understand it), and is therefore unlikely something we'd ship in Ubuntu.
fyi, what I tested in Comment #35 was upstream QEMU (@ aceeaa69d2) with a port of the patch in Comment #34 applied. I've attached that patch here. While it did avoid the issue in my testing, I agree with Rafael's Comment #36 that it does not appear to address the root cause (as I understand it), and is therefore unlikely something we'd ship in Ubuntu.