From c3709e6734daa4d9b37fe31592ebb0eb57bae1bb Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Mon, 14 May 2012 18:41:09 +0100 Subject: [PATCH] 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 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 Cc: Marcelo Tosatti Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/kvm_para.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h index 734c3767cfac..183922e13de1 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);