Re: [kvm-devel] [PATCH]: Fix MSR_K7_EVNTSEL{0,3} for SVM

[Chris L. <cla...@re...>]

Joerg Roedel wrote:
> We already discussed the emulation of the performance counter registers
> in the past. The conclusion is, that we loose live migration with that
> emulation because performance monitoring is implemented differently
> between AMD and Intel systems. Maybe discarding _any_ writes to
> the performance counter MSRs will fix the guest crash. What we should
> not do is injecting GPF on zero writes to the MSRs because that will
> break Windows XP 64bit installation.

     OK, yeah, I read some of those threads over the weekend.  It is a larger
problem than just this crash, and probably one to be solved later.
     I have attached a patch which just discards all writes, as you suggested;
this allows my RHEL-4 guest to successfully boot, although obviously the NMI
watchdog which it thinks it set up is not actually working.  Joerg, can you test
this on your 64-bit Windows XP guest to make sure it is still working?

Thanks,
Chris Lalancette