[libvirt] [PATCH] send default USB controller in xml to destination during migration on PPC64

[Shivaprasad bhat]

Thanks Cole.. Here is the XML for a PPC64 guest.
https://paste.fedoraproject.org/360574/61826548/
You can see the slot 1 is free as I unplugged a device there.

On X86, Q35 seems to use the model ich9-ehci1 by default. So, may not be
applicable there.
For pc-i440fx, I couldn't force USB to occupy any place other than slot 1
function 2. So, might not be applicable there too.

Regards,
Shiva

On Wed, Apr 27, 2016 at 9:27 PM, Cole Robinson <crobinso at redhat.com> wrote:

> On 03/02/2016 10:09 AM, Shivaprasad G Bhat wrote:
> > The default USB controller is not sent to destination as the older
> versions
> > of libvirt(0.9.4 or earlier as I see in commit log of 409b5f54) didn't
> > support them. For some archs where the support started much later can
> > safely send the USB controllers without this worry. For now, changing the
> > checks to allow PPC64 here. If we can track the historical support for
> > other archs, the changes can be extrapolated to them too.
> >
> > The patch fixes a bug that, if the USB controller happens to occupy
> > a slot after disks/interfaces and one of them is hot-unplugged, then
> > the default USB controller added on destination takes the smallest slot
> > number and that would lead to savestate mismatch and migration
> > failure.
> >
> > Signed-off-by: Shivaprasad G Bhat <sbhat at linux.vnet.ibm.com>
> > ---
> >  src/qemu/qemu_domain.c |    2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
> > index 9044792..6ecc0e2 100644
> > --- a/src/qemu/qemu_domain.c
> > +++ b/src/qemu/qemu_domain.c
> > @@ -2226,7 +2226,7 @@ qemuDomainDefFormatBuf(virQEMUDriverPtr driver,
> >                  usb = def->controllers[i];
> >              }
> >          }
> > -        if (usb && usb->idx == 0 && usb->model == -1) {
> > +        if (!ARCH_IS_PPC64(def->os.arch) && usb && usb->idx == 0 &&
> usb->model == -1) {
> >              VIR_DEBUG("Removing default USB controller from domain '%s'"
> >                        " for migration compatibility", def->name);
> >              toremove++;
> >
>
> Sorry this didn't receive a timely response. Can you provide the XML config
> that reproduces this? I wonder if this is something that affects x86 too.
> And
> if so we may want to fix it in a different way
>
> Thanks,
> Cole
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20160428/a7fc4351/attachment-0001.htm>