Re: [Qemu-devel] [PATCH v2 3/3] X86, mpx: Intel MPX xstate feature definition

[H. Peter Anvin]

On 12/06/2013 09:35 AM, Paolo Bonzini wrote:
> 
> Sorry for the back-and-forth, but I think this and the removal of
> XSTATE_FLEXIBLE (perhaps XSTATE_LAZY?) makes your v2 worse than v1.
> 
> Since Peter already said the same, please undo these changes.
> 
> Also, how is XSTATE_EAGER used?  Should MPX be disabled when xsaveopt is
> disabled on the kernel command line?  (Liu, how would this affect the
> KVM patches, too?)
> 

There are two options: we could disable MPX etc. or we could force eager
saving (using xsave) even if xsaveopt is disabled.  It is a hard call to
make, but I guess I'm leaning towards the latter; we could add an
"lazyxsave" option to explicitly disable all eager features if there is
use for that.

        -hpa