Re: [Qemu-devel] [PATCH] target-i386: GPF on invalid MSRs

[Alexander Graf]

On 26.05.2011, at 11:08, Josh Triplett wrote:

> qemu currently returns 0 for rdmsr on invalid MSRs, and ignores wrmsr on
> invalid MSRs.  Real x86 processors GPF on invalid MSRs, which allows
> software to detect unavailable MSRs.  Emulate this behavior correctly in
> qemu.
> 
> Bug discovered via the BIOS Implementation Test Suite
> <http://biosbits.org/>; fix tested the same way, for both 32-bit and
> 64-bit x86.

This would break a _lot_ of guests that work just fine today, as qemu doesn't 
handle all the necessary MSRs.


Alex