KVM: Add FFXSR support

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.

v2 adds CPUID capability exposure

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Alexander Graf 2009-02-02 16:23:51 +01:00 committed by Avi Kivity
parent d20626936d
commit 1b2fd70c4e
2 changed files with 15 additions and 0 deletions

View File

@ -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);

View File

@ -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;
@ -1240,6 +1251,7 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
#ifdef CONFIG_X86_64
bit(X86_FEATURE_LM) |
#endif
bit(X86_FEATURE_FXSR_OPT) |
bit(X86_FEATURE_MMXEXT) |
bit(X86_FEATURE_3DNOWEXT) |
bit(X86_FEATURE_3DNOW);