From 1085ba7f552d84aa8ac0ae903fa8d0cc2ff9f79d Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Thu, 25 Jul 2013 16:54:34 +0800 Subject: [PATCH] x86, kvm: Switch to use hypervisor_cpuid_base() Switch to use hypervisor_cpuid_base() to detect KVM. Cc: Gleb Natapov Cc: Paolo Bonzini Signed-off-by: Jason Wang Link: http://lkml.kernel.org/r/1374742475-2485-3-git-send-email-jasowang@redhat.com Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/kvm_para.h | 30 ++++++++++++------------------ 1 file changed, 12 insertions(+), 18 deletions(-) diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h index 695399f2d5eb..0644129a5333 100644 --- a/arch/x86/include/asm/kvm_para.h +++ b/arch/x86/include/asm/kvm_para.h @@ -85,26 +85,20 @@ static inline long kvm_hypercall4(unsigned int nr, unsigned long p1, return ret; } +static inline uint32_t kvm_cpuid_base(void) +{ + if (boot_cpu_data.cpuid_level < 0) + return 0; /* So we don't blow up on old processors */ + + if (cpu_has_hypervisor) + return hypervisor_cpuid_base("KVMKVMKVM\0\0\0", 0); + + return 0; +} + static inline bool kvm_para_available(void) { - unsigned int eax, ebx, ecx, edx; - char signature[13]; - - if (boot_cpu_data.cpuid_level < 0) - return false; /* So we don't blow up on old processors */ - - if (cpu_has_hypervisor) { - cpuid(KVM_CPUID_SIGNATURE, &eax, &ebx, &ecx, &edx); - memcpy(signature + 0, &ebx, 4); - memcpy(signature + 4, &ecx, 4); - memcpy(signature + 8, &edx, 4); - signature[12] = 0; - - if (strcmp(signature, "KVMKVMKVM") == 0) - return true; - } - - return false; + return kvm_cpuid_base() != 0; } static inline unsigned int kvm_arch_para_features(void)