Re: [kvm-devel] [PATCH]: Fake MSR_K7 performance counters

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

Chris Lalancette wrote:
> Attached is a patch that fixes a guest crash when booting older Linux kernels.
> The problem stems from the fact that we are currently emulating
> MSR_K7_EVNTSEL[0-3], but not emulating MSR_K7_PERFCTR[0-3].  Because of this,
> setup_k7_watchdog() in the Linux kernel receives a GPF when it attempts to write
> into MSR_K7_PERFCTR, which causes an OOPs.
> 
> The patch fixes it by just "fake" emulating the appropriate MSRs, throwing away
> the data in the process.  This causes the NMI watchdog to not actually work, but
> it's not such a big deal in a virtualized environment.
> 
> Tested by myself on a RHEL-4 guest, and Joerg Roedel on a Windows XP 64-bit guest.

Avi,
     Do you mind applying this patch for me (unless you see something wrong with
it, of course)?

Thanks,
Chris Lalancette