aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorAlan Cox <alan@linux.intel.com>2012-05-14 18:41:09 +0100
committerH. Peter Anvin <hpa@linux.intel.com>2012-05-14 10:49:32 -0700
commitc3709e6734daa4d9b37fe31592ebb0eb57bae1bb (patch)
treeede4448a81dde842ca3af8a09077ce29235377af
parentb2a3477727c1d43b92a3e4223f10ad5bf639df06 (diff)
x86, kvm: KVM paravirt kernels don't check for CPUID being unavailable
We set cpuid_level to -1 if there is no CPUID instruction (only possible on i386). Signed-off-by: Alan Cox <alan@linux.intel.com> Link: http://lkml.kernel.org/r/20120514174059.30236.1064.stgit@bluebook Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?id=12122 Cc: Avi Kivity <avi@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
-rw-r--r--arch/x86/include/asm/kvm_para.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h
index 734c3767cfa..183922e13de 100644
--- a/arch/x86/include/asm/kvm_para.h
+++ b/arch/x86/include/asm/kvm_para.h
@@ -170,6 +170,9 @@ static inline int kvm_para_available(void)
unsigned int eax, ebx, ecx, edx;
char signature[13];
+ if (boot_cpu_data.cpuid_level < 0)
+ return 0; /* So we don't blow up on old processors */
+
cpuid(KVM_CPUID_SIGNATURE, &eax, &ebx, &ecx, &edx);
memcpy(signature + 0, &ebx, 4);
memcpy(signature + 4, &ecx, 4);