AMD K10 CPUs implement the FFXSR feature that gets enabled using EFER. Let's check if the virtual CPU description includes that CPUID feature bit and allow enabling it then. This is required for Windows Server 2008 in Hyper-V mode. Signed-off-by: Alexander Graf <agraf@xxxxxxx> --- arch/x86/kvm/svm.c | 3 +++ arch/x86/kvm/x86.c | 11 +++++++++++ 2 files changed, 14 insertions(+), 0 deletions(-) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index db5021b..1c4a018 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -417,6 +417,9 @@ static __init int svm_hardware_setup(void) if (boot_cpu_has(X86_FEATURE_NX)) kvm_enable_efer_bits(EFER_NX); + if (boot_cpu_has(X86_FEATURE_FXSR_OPT)) + kvm_enable_efer_bits(EFER_FFXSR); + if (nested) { printk(KERN_INFO "kvm: Nested Virtualization enabled\n"); kvm_enable_efer_bits(EFER_SVME); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index e96edda..cb3529d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -490,6 +490,17 @@ static void set_efer(struct kvm_vcpu *vcpu, u64 efer) return; } + if (efer & EFER_FFXSR) { + struct kvm_cpuid_entry2 *feat; + + feat = kvm_find_cpuid_entry(vcpu, 0x80000001, 0); + if (!feat || !(feat->edx & bit(X86_FEATURE_FXSR_OPT))) { + printk(KERN_DEBUG "set_efer: #GP, enable FFXSR w/o CPUID capability\n"); + kvm_inject_gp(vcpu, 0); + return; + } + } + if (efer & EFER_SVME) { struct kvm_cpuid_entry2 *feat; -- 1.6.0.2 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html