From a4429e53c9b3082b05e51224c3d58dbdd39306c5 Mon Sep 17 00:00:00 2001 From: Wanpeng Li Date: Tue, 13 Feb 2018 09:05:40 +0800 Subject: KVM: Introduce paravirtualization hints and KVM_HINTS_DEDICATED MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch introduces kvm_para_has_hint() to query for hints about the configuration of the guests. The first hint KVM_HINTS_DEDICATED, is set if the guest has dedicated physical CPUs for each vCPU (i.e. pinning and no over-commitment). This allows optimizing spinlocks and tells the guest to avoid PV TLB flush. Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Eduardo Habkost Signed-off-by: Wanpeng Li Signed-off-by: Paolo Bonzini Signed-off-by: Radim Krčmář --- arch/x86/include/uapi/asm/kvm_para.h | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'arch/x86/include/uapi') diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h index 6cfa9c8cb7d6..68a41b6ba3da 100644 --- a/arch/x86/include/uapi/asm/kvm_para.h +++ b/arch/x86/include/uapi/asm/kvm_para.h @@ -10,8 +10,10 @@ */ #define KVM_CPUID_SIGNATURE 0x40000000 -/* This CPUID returns a feature bitmap in eax. Before enabling a particular - * paravirtualization, the appropriate feature bit should be checked. +/* This CPUID returns two feature bitmaps in eax, edx. Before enabling + * a particular paravirtualization, the appropriate feature bit should + * be checked in eax. The performance hint feature bit should be checked + * in edx. */ #define KVM_CPUID_FEATURES 0x40000001 #define KVM_FEATURE_CLOCKSOURCE 0 @@ -28,6 +30,8 @@ #define KVM_FEATURE_PV_TLB_FLUSH 9 #define KVM_FEATURE_ASYNC_PF_VMEXIT 10 +#define KVM_HINTS_DEDICATED 0 + /* The last 8 bits are used to indicate how to interpret the flags field * in pvclock structure. If no bits are set, all flags are ignored. */ -- cgit v1.2.3