[Qemu-devel] Re: [PATCH v2 1/2] Do not register kvmclock savevm section if kvmclock is disabled.

[Marcelo Tosatti]

On Mon, Dec 06, 2010 at 07:04:01PM -0200, Marcelo Tosatti wrote:
> On Mon, Dec 06, 2010 at 09:03:46AM -0500, Glauber Costa wrote:
> > Usually nobody usually thinks about that scenario (me included and 
> > specially),
> > but kvmclock can be actually disabled in the host.
> > 
> > It happens in two scenarios:
> >  1. host too old.
> >  2. we passed -kvmclock to our -cpu parameter.
> > 
> > In both cases, we should not register kvmclock savevm section. This patch
> > achives that by registering this section only if kvmclock is actually
> > currently enabled in cpuid.
> > 
> > The only caveat is that we have to register the savevm section a little bit
> > later, since we won't know the final kvmclock state before cpuid gets 
> > parsed.
> 
> What is the problem of registering the section? Restoring the value if
> the host does not support it returns an error?
> 
> Can't you ignore the error if kvmclock is not reported in cpuid, in the
> restore handler?
> 
> Also, please generate against uq/master.

Sorry, this is not upstream yet, so ignore the uq/master part.