diff options
| -rw-r--r-- | arch/x86/kvm/vmx.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 284f5c2fdf0b..0d25fc16d98b 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1662,8 +1662,14 @@ static bool update_transition_efer(struct vcpu_vmx *vmx, int efer_offset) vmx->guest_msrs[efer_offset].mask = ~ignore_bits; clear_atomic_switch_msr(vmx, MSR_EFER); - /* On ept, can't emulate nx, and must switch nx atomically */ - if (enable_ept && ((vmx->vcpu.arch.efer ^ host_efer) & EFER_NX)) { + + /* + * On EPT, we can't emulate NX, so we must switch EFER atomically. + * On CPUs that support "load IA32_EFER", always switch EFER + * atomically, since it's faster than switching it manually. + */ + if (cpu_has_load_ia32_efer || + (enable_ept && ((vmx->vcpu.arch.efer ^ host_efer) & EFER_NX))) { guest_efer = vmx->vcpu.arch.efer; if (!(guest_efer & EFER_LMA)) guest_efer &= ~EFER_LME; |