Re: [PATCH] kvm: sync cpu state on internal error before dump

Gleb Natapov
2013-08-24T10:37:34Z

On Fri, Aug 23, 2013 at 02:41:13PM +0100, James Hogan wrote:
> On 23/08/13 13:58, Gleb Natapov wrote:
> > On Fri, Aug 23, 2013 at 01:26:00PM +0100, James Hogan wrote:
> >> When a KVM internal error occurs QEMU dumps the CPU state, however it
> >> doesn't synchronise the state from KVM first so the dumped state is out
> >> of date. Add the synchronisation calls before the dump in both locations
> >> (which is used depends on whether the arch says to stop or not).
> >>
> > x86_cpu_dump_state() calls cpu_synchronize_state() already.
>
> Ah yes, thanks. I hadn't noticed that.
>
> Out of the arches that support KVM only x86 and ppc call it. arm, mips
> (qemu support not upstream yet), and s390 don't. s390 never seems to
> emit that exit code, and arm only does so for unsupported exceptions
> (which should never happen).
>
> I'll fix in mips_cpu_dump_state() instead.
>
Moving cpu_synchronize_state() up to cpu_dump_state() would be better.

--
Gleb.