Re: machine check support in HVM guests

[Keir Fraser <keir@xensource.com>]

On 27/11/06 14:59, "Jan Beulich" <jbeulich@novell.com> wrote:

>> No, I'm not saying that. I was simply expecting that it would be easy to
>> fake out a very minimal machine-check emulation where nothing ever goes
>> wrong. :-) If that involves GPFing on some MSR accesses, those are easy to
>> inject into an HVM guest I believe.
> 
> That wasn't my concern, I know that's simple. But the guest may not be
> prepared to handle a GP fault here - after all, if CPUID says MCA is
> supported, there is no reason the guest should use recovery methods
> around accessing the respective MSRs. Likewise, if returning zero, the
> guest may BUG(), as it may (validly) assert there's at least one bank of
> MSRs supported. And so on...

Then we support one bank of MSRs, store writes to those (so the contents can
be read back) but do not act on the writes? I never got the impression
machine check setup was very complicated.

 -- Keir