Re: [Qemu-devel] [PATCH V3 WIP 3/3] disable vhost_verify_ring_mappings check

[Michael S. Tsirkin]

On Tue, Mar 19, 2013 at 06:57:08PM -0700, Nicholas A. Bellinger wrote:
> On Tue, 2013-03-19 at 09:40 +0100, Stefan Hajnoczi wrote:
> > On Tue, Mar 19, 2013 at 08:34:45AM +0800, Asias He wrote:
> > > ---
> > >  hw/vhost.c | 2 ++
> > >  1 file changed, 2 insertions(+)
> > > 
> > > diff --git a/hw/vhost.c b/hw/vhost.c
> > > index 4d6aee3..0c52ec4 100644
> > > --- a/hw/vhost.c
> > > +++ b/hw/vhost.c
> > > @@ -421,10 +421,12 @@ static void vhost_set_memory(MemoryListener 
> > > *listener,
> > >          return;
> > >      }
> > >  
> > > +#if 0
> > >      if (dev->started) {
> > >          r = vhost_verify_ring_mappings(dev, start_addr, size);
> > >          assert(r >= 0);
> > >      }
> > > +#endif
> > 
> > Please add a comment to explain why.
> > 
> 
> Btw, the output that Asias added in the failure case at the behest of
> MST is here:
> 
> http://www.spinics.net/lists/target-devel/msg04077.html

Yes I suspected we could get l > ring_size, but this is
not the case here.

> MST seemed to think it may be a bug in cpu_physical_memory_map, but as
> this worked with the original vhost-scsi code it would seem to indicate
> something else at fault..
> 
> I'll be comparing what the original code did vs. vhost-scsi-pci to track
> this down, but any extra ideas to track is down is appreciated.  ;)
> 
> --nab