Hi Paolo, Thanks. Will you help to modify the Signed-off-by chain ? Or do I need to submit the second version after modifying the Signed-off-by chain ? Thanks, Jingqi Liu -----Original Message----- From: Paolo Bonzini [mailto:pbonzini@xxxxxxxxxx] Sent: Tuesday, May 8, 2018 12:30 AM To: Liu, Jingqi <jingqi.liu@xxxxxxxxx>; kvm@xxxxxxxxxxxxxxx Cc: rkrcmar@xxxxxxxxxx; tglx@xxxxxxxxxxxxx; mingo@xxxxxxxxxx; hpa@xxxxxxxxx; x86@xxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Wang, Wei W <wei.w.wang@xxxxxxxxx> Subject: Re: [PATCH] KVM: x86: Expose CLDEMOTE CPU feature to guest VM 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.liu@xxxxxxxxx> > Signed-off-by: Wei Wang <wei.w.wang@xxxxxxxxx> 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 = >
