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Subject[PATCH V2 3/4] kvm: switch to use hypervisor_cpuid_base()
Date
Switch to use hypervisor_cpuid_base() to detect KVM.

Cc: Gleb Natapov <gleb@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
Changes from V1:
- Introduce kvm_cpuid_base() which will be used by next patch.
---
arch/x86/include/asm/kvm_para.h | 24 +++++++++---------------
1 files changed, 9 insertions(+), 15 deletions(-)

diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h
index 695399f..0644129 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 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)
--
1.7.1


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