Re: [Xen-devel] Xen 4.3 development update RC2 imminent

[George Dunlap <george.dunlap@xxxxxxxxxxxxx>]

On 05/21/2013 03:31 PM, Andrew Cooper wrote:
> On 21/05/13 15:06, Anthony PERARD wrote:
> > On 20/05/13 11:33, George Dunlap wrote:
> > > * qxl not actually working
> > >    > qxl apparently not enabled during compile by default
> > >    > Appear to be some other bugs even when it is working:
> > >    >   http://lists.xen.org/archives/html/xen-devel/2012-11/msg00713.html
> > >    owner: ? (Anthony was going to take a look)
> > >    We need to either fix both of these problems or disable qxl for 4.3
> > I've been able to track down this error:
> > > Spice-CRITICAL **: red_memslots.c:123:get_virt: slot_id 194 too big,
> > addr=c2c2c2c2c2c2c2c2
> >
> > This little patch fix it:
> > diff --git a/hw/qxl.c b/hw/qxl.c
> > index 96887c4..db2e02e 100644
> > --- a/hw/qxl.c
> > +++ b/hw/qxl.c
> > @@ -390,6 +390,7 @@ static void init_qxl_ram(PCIQXLDevice *d)
> >       d->ram->int_pending = cpu_to_le32(0);
> >       d->ram->int_mask    = cpu_to_le32(0);
> >       d->ram->update_surface = 0;
> > +    d->ram->monitors_config = 0;
> >       SPICE_RING_INIT(&d->ram->cmd_ring);
> >       SPICE_RING_INIT(&d->ram->cursor_ring);
> >       SPICE_RING_INIT(&d->ram->release_ring);
> >
> > But then, once this applied, qxl is still not able to start. Xorg crash
> > (in the guest), and here is why:
> >
> > (XEN) emulate.c:88:d18 bad mmio size 16
> > (XEN) io.c:201:d18 MMIO emulation failed @ 0033:7fd2de390430: f3 0f 6f
> > 19 41 83 e8 403
> > (XEN) emulate.c:88:d18 bad mmio size 16
> > (XEN) io.c:201:d18 MMIO emulation failed @ 0033:7fd2de390430: f3 0f 6f
> > 19 41 83 e8 403
> Disassembly of section .data:
>
> 0000000000000000 <.data>:
>     0:    f3 0f 6f 19              movdqu (%rcx),%xmm3
>
> Xen does not support emulating SSE instructions.  We have sporadically
> seen similar errors from Windows guests.  The best guess I have managed
> to get so far is that %rcx is a pointer to something which Xen thinks is
> an MMIO page.
>
> In this case, it looks like X is copying from MMIO into an xmm register,
> scraping the framebuffer perhaps?  In the windows failure, it was the
> pagescrub trying to zero ram, which clearly indicated something wonky in
> the combined idea of the memory map.
>
> If Spice is doing something valid and sensible, then Xen will likely
> need extending to be able to emulate SSE instructions.
>
> Not that this helps much with the problem for 4.3
Hmm, is there any way to disable the SSE instructions in X and/or the 
qxl driver?
I'll take a quick look around to see what I can see...

 -George


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel