On 04/05/2018 05:55, 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.
>
> This patch exposes the cldemote feature to the guest.
>
> The release document ref below link:
> https://software.intel.com/sites/default/files/managed/c5/15/\
> architecture-instruction-set-extensions-programming-reference.pdf
> This patch has a dependency on https://lkml.org/lkml/2018/4/23/928
>
> Signed-off-by: Jingqi Liu <jingqi....@intel.com>
> Signed-off-by: Wei Wang <wei.w.w...@intel.com>
Thanks. Note that the Signed-off-by chain for the patch looks strange,
the submitter should be the last (because it is a chain).
In the meanwhile, Ingo, Thomas, would it be possible to get a topic
branch for that patch ("[PATCH] x86/cpufeatures: Enumerate cldemote
instruction")?
Thanks,
Paolo
> ---
> arch/x86/kvm/cpuid.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
> index 82055b9..72d8c49 100644
> --- a/arch/x86/kvm/cpuid.c
> +++ b/arch/x86/kvm/cpuid.c
> @@ -403,7 +403,8 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2
> *entry, u32 function,
> const u32 kvm_cpuid_7_0_ecx_x86_features =
> F(AVX512VBMI) | F(LA57) | F(PKU) | 0 /*OSPKE*/ |
> F(AVX512_VPOPCNTDQ) | F(UMIP) | F(AVX512_VBMI2) | F(GFNI) |
> - F(VAES) | F(VPCLMULQDQ) | F(AVX512_VNNI) | F(AVX512_BITALG);
> + F(VAES) | F(VPCLMULQDQ) | F(AVX512_VNNI) | F(AVX512_BITALG) |
> + F(CLDEMOTE);
>
> /* cpuid 7.0.edx*/
> const u32 kvm_cpuid_7_0_edx_x86_features =
>
