From 0ea3286e2df74c9ec2fadbf91170cd3edd14e3e5 Mon Sep 17 00:00:00 2001 From: Jingqi Liu Date: Tue, 22 May 2018 17:01:27 +0800 Subject: [PATCH] KVM: x86: Expose CLDEMOTE CPU feature to guest VM MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Wei Wang Signed-off-by: Radim Krčmář --- 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 82055b90a8b3..72d8c492d71d 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 =