Martin Kletzander <mkletzan@redhat.com> writes:
If the user updates from QEMU without DRIVE_READONLY to newer one, that supports that flag, than XML with readonly IDE HDD will stop working even though it worked before the update *as requested*. That readonly flag does not reflect how the disk is exposed in the guest; as you said IDE does not have any readonly concept, that is only how the device reacts to writes.
Changing the behaviour to:
if (disk->readonly && virQEMUCapsGet(qemuCaps, QEMU_CAPS_DRIVE_READONLY) && !(disk->bus == VIR_DOMAIN_DISK_BUS_IDE && disk->device == VIR_DOMAIN_DISK_DEVICE_DISK)) virBufferAddLit(&opt, ",readonly=on");
would keep the backward compatibility. This behaviour makes more sense to me.
this behaves in a quite different way that my proposed patch but if <readonly/> affects also the SELinux label and we allow the process to run anyway by skipping readonly=on for IDE disks, wouldn't qemu fail in weird ways when trying to write to the file? Regards, Giuseppe