Re: [Qemu-devel] [PATCH] x86/cpu: Enable CLDEMOTE(Demote Cache Line) cpu feature

[Eduardo Habkost <ehabkost@redhat.com>]

On Fri, May 04, 2018 at 11:57:33AM +0800, Jingqi Liu wrote:
> The CLDEMOTE instruction hints to hardware that the cache line that
> contains the linear address should be moved("demoted") from
> the cache(s) closest to the processor core to a level more distant
> from the processor core. This may accelerate subsequent accesses
> to the line by other cores in the same coherence domain,
> especially if the line was written by the core that demotes the line.
> 
> Intel Snow Ridge has added new cpu feature, CLDEMOTE.
> The new cpu feature needs to be exposed to guest VM.
> 
> The bit definition:
> CPUID.(EAX=7,ECX=0):ECX[bit 25] CLDEMOTE
> 
> The release document ref below link:
> https://software.intel.com/sites/default/files/managed/c5/15/\
> architecture-instruction-set-extensions-programming-reference.pdf
> 
> Signed-off-by: Jingqi Liu <jingqi.liu@intel.com>

Thanks.  Do you have a pointer to the corresponding
GET_SUPPORTED_CPUID patch in KVM?

-- 
Eduardo