Re: panic: xpq_flush_cache, err -22

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Thu, Aug 02, 2012 at 07:55:26PM +0000, Emmanuel Dreyfus wrote:
> On Thu, Aug 02, 2012 at 08:37:59PM +0200, Manuel Bouyer wrote:
> > With a xen-debug.gz hypervisor, do you have anything relevant in
> > xm dmesg ?
> 
> I have this. I don't know if it is relevant:
> 
> (XEN) Std. Loglevel: All
> (XEN) Guest Loglevel: All
> (XEN) Xen is relinquishing VGA console.
> (XEN) *** Serial input -> DOM0 (type \047CTRL-a\047 three times to switch 
> input 
> to Xen).
> (XEN) Freed 88kB init memory.
> (XEN) io_apic.c:2135: 
> (XEN) ioapic_guest_write: apic=0, pin=2, old_irq=0, new_irq=-1
> (XEN) ioapic_guest_write: old_entry=000009f0, new_entry=00010900
> (XEN) ioapic_guest_write: Attempt to remove IO-APIC pin of in-use IRQ!
> (XEN) traps.c:1747:d1 Domain attempted WRMSR c0000080 from 00000000:00000000 
> to 
> 00000000:00000800.
> (XEN) traps.c:1747:d3 Domain attempted WRMSR c0000080 from 00000000:00000000 
> to 
> 00000000:00000800.
> (XEN) mm.c:2256:d3 Non-physdev domain tried to FLUSH_CACHE.
> (XEN) traps.c:1747:d4 Domain attempted WRMSR c0000080 from 00000000:00000000 
> to 
> 00000000:00000800.

OK, so domUs are not allowed to flush the cache. Now we need to find what
causes this cross-call.
Watching what calls xc_lowpri() could help, but I'm not sure it's
called with xpq_flush_cache() directly. There may be an intermediate function
with a tail-call to xpq_flush_cache ...

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--