Xen HVM Panic, HEAD

[Konstantin Belousov]

On Thu, Feb 19, 2015 at 11:50:49AM -0800, Neel Natu wrote:
> Hi Adrian,
> 
> On Wed, Feb 18, 2015 at 10:09 PM, Adrian Chadd <adrian at freebsd.org> wrote:
> > Hi,
> >
> > Since this is the (at least) second round of "x2apic support broke me"
> > changes, can we please either back them out or set it to default to
> > '0' for now?
> >
> 
> I don't think that is necessary.
> 
> This is -current and there is a tunable to disable x2apic on platforms
> that are experiencing issues. More importantly the issues that have
> been reported are being resolved in a timely manner (for e.g.,
> suspend/resume).

There is only one really enigmatic issue, it was reported that sandy
bridge laptop being unable to start APs. Koop stopped responding, so the
issue is not progresed.

My current idea is that a cause might be reduced intervals between
init/startup ipis due to x2apic not requiring wait for icr idle.

Anyway, I do not see it worth even discussing the revert or default'
frobbing for now.  The commit went mostly event-less for such kind
of change.