Re: [libvirt] [PATCH] qemu: raise an error when trying to use readonly ide disks
Martin Kletzander <mkletzan(a)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