1 files changed, 30 insertions, 0 deletions

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 736f83955ce9..a713c69bfcee 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -191,6 +191,8 @@ static unsigned long *vmx_io_bitmap_b;
 static unsigned long *vmx_msr_bitmap_legacy;
 static unsigned long *vmx_msr_bitmap_longmode;
 
+static bool cpu_has_load_ia32_efer;
+
 static DECLARE_BITMAP(vmx_vpid_bitmap, VMX_NR_VPIDS);
 static DEFINE_SPINLOCK(vmx_vpid_lock);
 
@@ -664,6 +666,12 @@ static void clear_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr)
         unsigned i;
         struct msr_autoload *m = &vmx->msr_autoload;
 
+        if (msr == MSR_EFER && cpu_has_load_ia32_efer) {
+                vmcs_clear_bits(VM_ENTRY_CONTROLS, VM_ENTRY_LOAD_IA32_EFER);
+                vmcs_clear_bits(VM_EXIT_CONTROLS, VM_EXIT_LOAD_IA32_EFER);
+                return;
+        }
+
         for (i = 0; i < m->nr; ++i)
                 if (m->guest[i].index == msr)
                         break;
@@ -683,6 +691,14 @@ static void add_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr,
         unsigned i;
         struct msr_autoload *m = &vmx->msr_autoload;
 
+        if (msr == MSR_EFER && cpu_has_load_ia32_efer) {
+                vmcs_write64(GUEST_IA32_EFER, guest_val);
+                vmcs_write64(HOST_IA32_EFER, host_val);
+                vmcs_set_bits(VM_ENTRY_CONTROLS, VM_ENTRY_LOAD_IA32_EFER);
+                vmcs_set_bits(VM_EXIT_CONTROLS, VM_EXIT_LOAD_IA32_EFER);
+                return;
+        }
+
         for (i = 0; i < m->nr; ++i)
                 if (m->guest[i].index == msr)
                         break;
@@ -1418,6 +1434,14 @@ static __init int adjust_vmx_controls(u32 ctl_min, u32 ctl_opt,
         return 0;
 }
 
+static __init bool allow_1_setting(u32 msr, u32 ctl)
+{
+        u32 vmx_msr_low, vmx_msr_high;
+
+        rdmsr(msr, vmx_msr_low, vmx_msr_high);
+        return vmx_msr_high & ctl;
+}
+
 static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf)
 {
         u32 vmx_msr_low, vmx_msr_high;
@@ -1532,6 +1556,12 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf)
         vmcs_conf->vmexit_ctrl         = _vmexit_control;
         vmcs_conf->vmentry_ctrl        = _vmentry_control;
 
+        cpu_has_load_ia32_efer =
+                allow_1_setting(MSR_IA32_VMX_ENTRY_CTLS,
+                                VM_ENTRY_LOAD_IA32_EFER)
+                && allow_1_setting(MSR_IA32_VMX_EXIT_CTLS,
+                                   VM_EXIT_LOAD_IA32_EFER);
+
         return 0;
 }