3 files changed, 71 insertions, 21 deletions

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index c252efed49d9..db2bc6f168cd 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -255,6 +255,7 @@ struct kvm_stat {
         u32 request_irq_exits;
         u32 irq_exits;
         u32 light_exits;
+        u32 efer_reload;
 };
 
 struct kvm_vcpu {
@@ -289,6 +290,7 @@ struct kvm_vcpu {
         u64 ia32_misc_enable_msr;
         int nmsrs;
         int save_nmsrs;
+        int msr_offset_efer;
 #ifdef CONFIG_X86_64
         int msr_offset_kernel_gs_base;
 #endif
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 095d673b9efb..af07cd539bba 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -73,6 +73,7 @@ static struct kvm_stats_debugfs_item {
         { "request_irq", STAT_OFFSET(request_irq_exits) },
         { "irq_exits", STAT_OFFSET(irq_exits) },
         { "light_exits", STAT_OFFSET(light_exits) },
+        { "efer_reload", STAT_OFFSET(efer_reload) },
         { NULL }
 };
 
@@ -2378,6 +2379,27 @@ out:
         return r;
 }
 
+static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
+{
+        u64 efer;
+        int i;
+        struct kvm_cpuid_entry *e, *entry;
+
+        rdmsrl(MSR_EFER, efer);
+        entry = NULL;
+        for (i = 0; i < vcpu->cpuid_nent; ++i) {
+                e = &vcpu->cpuid_entries[i];
+                if (e->function == 0x80000001) {
+                        entry = e;
+                        break;
+                }
+        }
+        if (entry && (entry->edx & EFER_NX) && !(efer & EFER_NX)) {
+                entry->edx &= ~(1 << 20);
+                printk(KERN_INFO ": guest NX capability removed\n");
+        }
+}
+
 static int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
                                     struct kvm_cpuid *cpuid,
                                     struct kvm_cpuid_entry __user *entries)
@@ -2392,6 +2414,7 @@ static int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
                            cpuid->nent * sizeof(struct kvm_cpuid_entry)))
                 goto out;
         vcpu->cpuid_nent = cpuid->nent;
+        cpuid_fix_nx_cap(vcpu);
         return 0;
 
 out:
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index dc99191dbb4a..93e5bb2c40e3 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -42,6 +42,7 @@ static struct page *vmx_io_bitmap_b;
 #else
 #define HOST_IS_64 0
 #endif
+#define EFER_SAVE_RESTORE_BITS ((u64)EFER_SCE)
 
 static struct vmcs_descriptor {
         int size;
@@ -85,6 +86,18 @@ static const u32 vmx_msr_index[] = {
 };
 #define NR_VMX_MSR ARRAY_SIZE(vmx_msr_index)
 
+static inline u64 msr_efer_save_restore_bits(struct vmx_msr_entry msr)
+{
+        return (u64)msr.data & EFER_SAVE_RESTORE_BITS;
+}
+
+static inline int msr_efer_need_save_restore(struct kvm_vcpu *vcpu)
+{
+        int efer_offset = vcpu->msr_offset_efer;
+        return msr_efer_save_restore_bits(vcpu->host_msrs[efer_offset]) !=
+                msr_efer_save_restore_bits(vcpu->guest_msrs[efer_offset]);
+}
+
 static inline int is_page_fault(u32 intr_info)
 {
         return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VECTOR_MASK |
@@ -265,6 +278,19 @@ static void reload_tss(void)
 #endif
 }
 
+static void load_transition_efer(struct kvm_vcpu *vcpu)
+{
+        u64 trans_efer;
+        int efer_offset = vcpu->msr_offset_efer;
+
+        trans_efer = vcpu->host_msrs[efer_offset].data;
+        trans_efer &= ~EFER_SAVE_RESTORE_BITS;
+        trans_efer |= msr_efer_save_restore_bits(
+                                vcpu->guest_msrs[efer_offset]);
+        wrmsrl(MSR_EFER, trans_efer);
+        vcpu->stat.efer_reload++;
+}
+
 static void vmx_save_host_state(struct kvm_vcpu *vcpu)
 {
         struct vmx_host_state *hs = &vcpu->vmx_host_state;
@@ -308,6 +334,8 @@ static void vmx_save_host_state(struct kvm_vcpu *vcpu)
         }
 #endif
         load_msrs(vcpu->guest_msrs, vcpu->save_nmsrs);
+        if (msr_efer_need_save_restore(vcpu))
+                load_transition_efer(vcpu);
 }
 
 static void vmx_load_host_state(struct kvm_vcpu *vcpu)
@@ -336,6 +364,8 @@ static void vmx_load_host_state(struct kvm_vcpu *vcpu)
         }
         save_msrs(vcpu->guest_msrs, vcpu->save_nmsrs);
         load_msrs(vcpu->host_msrs, vcpu->save_nmsrs);
+        if (msr_efer_need_save_restore(vcpu))
+                load_msrs(vcpu->host_msrs + vcpu->msr_offset_efer, 1);
 }
 
 /*
@@ -477,11 +507,13 @@ void move_msr_up(struct kvm_vcpu *vcpu, int from, int to)
  */
 static void setup_msrs(struct kvm_vcpu *vcpu)
 {
-        int index, save_nmsrs;
+        int save_nmsrs;
 
         save_nmsrs = 0;
 #ifdef CONFIG_X86_64
         if (is_long_mode(vcpu)) {
+                int index;
+
                 index = __find_msr_index(vcpu, MSR_SYSCALL_MASK);
                 if (index >= 0)
                         move_msr_up(vcpu, index, save_nmsrs++);
@@ -509,22 +541,7 @@ static void setup_msrs(struct kvm_vcpu *vcpu)
         vcpu->msr_offset_kernel_gs_base =
                 __find_msr_index(vcpu, MSR_KERNEL_GS_BASE);
 #endif
-        index = __find_msr_index(vcpu, MSR_EFER);
-        if (index >= 0)
-                save_nmsrs = 1;
-        else {
-                save_nmsrs = 0;
-                index = 0;
-        }
-        vmcs_writel(VM_ENTRY_MSR_LOAD_ADDR,
-                    virt_to_phys(vcpu->guest_msrs + index));
-        vmcs_writel(VM_EXIT_MSR_STORE_ADDR,
-                    virt_to_phys(vcpu->guest_msrs + index));
-        vmcs_writel(VM_EXIT_MSR_LOAD_ADDR,
-                    virt_to_phys(vcpu->host_msrs + index));
-        vmcs_write32(VM_EXIT_MSR_STORE_COUNT, save_nmsrs);
-        vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, save_nmsrs);
-        vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, save_nmsrs);
+        vcpu->msr_offset_efer = __find_msr_index(vcpu, MSR_EFER);
 }
 
 /*
@@ -611,10 +628,15 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)
 static int vmx_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
 {
         struct vmx_msr_entry *msr;
+        int ret = 0;
+
         switch (msr_index) {
 #ifdef CONFIG_X86_64
         case MSR_EFER:
-                return kvm_set_msr_common(vcpu, msr_index, data);
+                ret = kvm_set_msr_common(vcpu, msr_index, data);
+                if (vcpu->vmx_host_state.loaded)
+                        load_transition_efer(vcpu);
+                break;
         case MSR_FS_BASE:
                 vmcs_writel(GUEST_FS_BASE, data);
                 break;
@@ -639,13 +661,13 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
                 if (msr) {
                         msr->data = data;
                         if (vcpu->vmx_host_state.loaded)
-                                load_msrs(vcpu->guest_msrs,vcpu->save_nmsrs);
+                                load_msrs(vcpu->guest_msrs, vcpu->save_nmsrs);
                         break;
                 }
-                return kvm_set_msr_common(vcpu, msr_index, data);
+                ret = kvm_set_msr_common(vcpu, msr_index, data);
         }
 
-        return 0;
+        return ret;
 }
 
 /*
@@ -1326,6 +1348,9 @@ static int vmx_vcpu_setup(struct kvm_vcpu *vcpu)
 
         asm ("mov $.Lkvm_vmx_return, %0" : "=r"(kvm_vmx_return));
         vmcs_writel(HOST_RIP, kvm_vmx_return); /* 22.2.5 */
+        vmcs_write32(VM_EXIT_MSR_STORE_COUNT, 0);
+        vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, 0);
+        vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, 0);
 
         rdmsr(MSR_IA32_SYSENTER_CS, host_sysenter_cs, junk);
         vmcs_write32(HOST_IA32_SYSENTER_CS, host_sysenter_cs);