RE: [PATCH v1 0/2] Virtio: fix some vq allocation issues

[Wang, Wei W]

On Friday, December 28, 2018 3:57 PM, Christian Borntraeger wrote:
> On 28.12.2018 03:26, Wei Wang wrote:
> > Some vqs don't need to be allocated when the related feature bits are
> > disabled. Callers notice the vq allocation layer by setting the
> > related names[i] to be NULL.
> >
> > This patch series fixes the find_vqs implementations to handle this case.
> 
> So the random crashes during boot are gone.
> What still does not work is actually using the balloon.
> 
> So in the qemu monitor using lets say "balloon 1000"  will hang the guest.
> Seems to be a deadlock in the virtio-ccw code.  We seem to call the config
> code in the interrupt handler.

Yes. It reads a config register from the interrupt handler. Do you know why ccw doesn't support it and has some internal lock that caused the deadlock issue?
 
Best,
Wei