From 5a4f55cde81f1633cb7ae9f0963b722e47acdc36 Mon Sep 17 00:00:00 2001 From: Eugene Korenevsky Date: Sun, 29 Mar 2015 23:56:12 +0300 Subject: KVM: x86: cache maxphyaddr CPUID leaf in struct kvm_vcpu cpuid_maxphyaddr(), which performs lot of memory accesses is called extensively across KVM, especially in nVMX code. This patch adds a cached value of maxphyaddr to vcpu.arch to reduce the pressure onto CPU cache and simplify the code of cpuid_maxphyaddr() callers. The cached value is initialized in kvm_arch_vcpu_init() and reloaded every time CPUID is updated by usermode. It is obvious that these reloads occur infrequently. Signed-off-by: Eugene Korenevsky Message-Id: <20150329205612.GA1223@gnote> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/cpuid.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch/x86/kvm/cpuid.h') diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h index 26228466f3f8..c3b1ad9fca81 100644 --- a/arch/x86/kvm/cpuid.h +++ b/arch/x86/kvm/cpuid.h @@ -20,6 +20,12 @@ int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 __user *entries); void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx); +int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu); + +static inline int cpuid_maxphyaddr(struct kvm_vcpu *vcpu) +{ + return vcpu->arch.maxphyaddr; +} static inline bool guest_cpuid_has_xsave(struct kvm_vcpu *vcpu) { -- cgit v1.2.3