* Halil Pasic (pa...@linux.vnet.ibm.com) wrote:
>
>
> On 07/13/2017 02:27 PM, Cornelia Huck wrote:
> >> +static void kvm_flic_ais_pre_save(void *opaque)
> >> +{
> >> + KVMS390FLICStateMigTmp *tmp = opaque;
> >> + KVMS390FLICState *flic = tmp->parent;
> >> + struct kvm_s390_ais_all ais;
> >> + struct kvm_device_attr attr = {
> >> + .group = KVM_DEV_FLIC_AISM_ALL,
> >> + .addr = (uint64_t)&ais,
> >> + .attr = sizeof(ais),
> >> + };
> >> +
> >> + if (ioctl(flic->fd, KVM_GET_DEVICE_ATTR, &attr)) {
> >> + error_report("Failed to retrieve kvm flic ais states");
> > There's not much else we can do in that case, is there?
> >
>
> I think this is a very good question! The ioctl should not fail
> under any circumstances, but if it does we have a problem.
>
> Carrying on happily (what we do now) means effectively discarding
> ais state. In general just discarding state ain't a good idea.
>
> In particular it might be OK, but the patch should explain that!
>
> Regarding what could/should we do in such a case (instead
> of discarding state and carrying on happily) I don't know, so
> I tend to agree with you regarding 'not much else we can do'.
>
> Adding Dave and Juan. Maybe they can tell.
I keep meaning to make the pre_save give a return value for failure,
but it hasn't currently got one.
You could try something like:
qemu_file_set_error(migrate_get_current()->to_dst_file, -EINVAL);
I *think* the migration code should spot that before it finishes
but it might carry on for a little while before it does.
Dave
> Regards,
> Halil
>
> >> + return;
> >> + }
> >> +
> >> + tmp->simm = ais.simm;
> >> + tmp->nimm = ais.nimm;
> >> +}
> >> +
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
