Re: [PATCH] target/i386: Export RFDS bit to guests

[Pawan Gupta <pawan.kumar.gupta@linux.intel.com>]

On Fri, Mar 15, 2024 at 03:50:18PM +0800, Zhao Liu wrote:
> > Make RFDS_CLEAR and RFDS_NO bits available to guests.
> 
> Are these two bits going to be supported by microcode updates to
> existing products?

RFDS_CLEAR is supported by the microcode update that is needed to
mitigate RFDS. RFDS_NO will be supported by future unaffected parts and
some of the existing parts. AFAIK, not all unaffected existing parts
will get RFDS_NO, for such parts KVM synthesizes RFDS_NO.

> (Let me aslo attach the related spec to make it easy for more people to
> learn about backgrounds: 
> https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/advisory-guidance/register-file-data-sampling.html)
> 
> > Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
> > ---
> >  target/i386/cpu.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> LGTM,
> 
> Reviewed-by: Zhao Liu <zhao1.liu@intel.com>

Thank you.