UMONITOR, UMWAIT, and TPAUSE are a set of user wait instructions. UMONITOR arms address monitoring hardware using an address. A store to an address within the specified address range triggers the monitoring hardware to wake up the processor waiting in umwait. UMWAIT instructs the processor to enter an implementation-dependent optimized state while monitoring a range of addresses. The optimized state may be either a light-weight power/performance optimized state (c0.1 state) or an improved power/performance optimized state (c0.2 state). TPAUSE instructs the processor to enter an implementation-dependent optimized state c0.1 or c0.2 state and wake up when time-stamp counter reaches specified timeout. Availability of the user wait instructions is indicated by the presence of the CPUID feature flag WAITPKG CPUID.0x07.0x0:ECX[5]. This patch exposes the umonitor,umwait, and tpause features 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/2018/6/15/657. Signed-off-by: Jingqi Liu <jingqi.liu@xxxxxxxxx> --- arch/x86/kvm/cpuid.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 7e042e3..e16c05e 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -406,7 +406,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, 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(CLDEMOTE); + F(CLDEMOTE) | F(WAITPKG); /* cpuid 7.0.edx*/ const u32 kvm_cpuid_7_0_edx_x86_features = -- 1.8.3.1