x86, kvm: Switch to use hypervisor_cpuid_base()

Switch to use hypervisor_cpuid_base() to detect KVM.

Cc: Gleb Natapov <gleb@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: http://lkml.kernel.org/r/1374742475-2485-3-git-send-email-jasowang@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h
index 695399f..0644129 100644 (file)
--- 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 bool kvm_para_available(void)
+static inline uint32_t kvm_cpuid_base(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 */
+               return 0;       /* 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 (cpu_has_hypervisor)
+               return hypervisor_cpuid_base("KVMKVMKVM\0\0\0", 0);
 
-               if (strcmp(signature, "KVMKVMKVM") == 0)
-                       return true;
-       }
+       return 0;
+}
 
-       return false;
+static inline bool kvm_para_available(void)
+{
+       return kvm_cpuid_base() != 0;
 }
 
 static inline unsigned int kvm_arch_para_features(void)