Re: [Qemu-devel] [PATCH] x86: Implement SMEP and SMAP

[H. Peter Anvin]

On 09/26/2012 12:50 PM, Anthony Liguori wrote:
> 
> The patch looks good except for these two chunks.  This would break live
> migration from a new QEMU to an old one because CPUs are currently not
> versioned.
> 
> If you just remove these two chunks, the patch can be applied and you
> can still test with:
> 
> qemu-system-x86_64 -cpu qemu64,+smep,+smap
> 
> We're working vcpu versioning and will hopefully have it in place for
> 1.3.  If we get there, we can enable these features unconditionally and
> add the appropriate backwards compatibility code.
> 

OK.  I had to add a chunk to up the minimum CPUID level to 7 if any of
the level 7 features were enabled, however.
> 
> scripts/checkpatch.pl will complain about lack of curly braces with ifs.
> 
> I know this file does not use them consistently.  Since you have to
> respin anyway, please run checkpatch and fixup the errors.
> 


Actually, several of the files are very consistent about *not* using
them.  I'll respin the patch, but it ain't pretty.

        -hpa