---

yaml
---
r: 54104
b: refs/heads/master
c: e38aea3
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 2345df8c555ecb92c0c36172c07d5ac321a92dc7
+refs/heads/master: e38aea3e9330624d19a233c05f3e69c57519edd5

trunk/drivers/kvm/vmx.c

@@ -80,6 +80,9 @@ static const u32 vmx_msr_index[] = {
 
 #ifdef CONFIG_X86_64
 static unsigned msr_offset_kernel_gs_base;
+#define NR_64BIT_MSRS 4
+#else
+#define NR_64BIT_MSRS 0
 #endif
 
 static inline int is_page_fault(u32 intr_info)
@@ -300,6 +303,32 @@ static void vmx_inject_gp(struct kvm_vcpu *vcpu, unsigned error_code)
 		     INTR_INFO_VALID_MASK);
 }
 
+/*
+ * Set up the vmcs to automatically save and restore system
+ * msrs.  Don't touch the 64-bit msrs if the guest is in legacy
+ * mode, as fiddling with msrs is very expensive.
+ */
+static void setup_msrs(struct kvm_vcpu *vcpu)
+{
+	int nr_skip, nr_good_msrs;
+
+	if (is_long_mode(vcpu))
+		nr_skip = NR_BAD_MSRS;
+	else
+		nr_skip = NR_64BIT_MSRS;
+	nr_good_msrs = vcpu->nmsrs - nr_skip;
+
+	vmcs_writel(VM_ENTRY_MSR_LOAD_ADDR,
+		    virt_to_phys(vcpu->guest_msrs + nr_skip));
+	vmcs_writel(VM_EXIT_MSR_STORE_ADDR,
+		    virt_to_phys(vcpu->guest_msrs + nr_skip));
+	vmcs_writel(VM_EXIT_MSR_LOAD_ADDR,
+		    virt_to_phys(vcpu->host_msrs + nr_skip));
+	vmcs_write32(VM_EXIT_MSR_STORE_COUNT, nr_good_msrs); /* 22.2.2 */
+	vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, nr_good_msrs);  /* 22.2.2 */
+	vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, nr_good_msrs); /* 22.2.2 */
+}
+
 /*
  * reads and returns guest's timestamp counter "register"
  * guest_tsc = host_tsc + tsc_offset    -- 21.3
@@ -825,6 +854,7 @@ static void vmx_set_efer(struct kvm_vcpu *vcpu, u64 efer)
 
 		msr->data = efer & ~EFER_LME;
 	}
+	setup_msrs(vcpu);
 }
 
 #endif
@@ -988,7 +1018,6 @@ static int vmx_vcpu_setup(struct kvm_vcpu *vcpu)
 	struct descriptor_table dt;
 	int i;
 	int ret = 0;
-	int nr_good_msrs;
 	extern asmlinkage void kvm_vmx_return(void);
 
 	if (!init_rmode_tss(vcpu->kvm)) {
@@ -1140,19 +1169,10 @@ static int vmx_vcpu_setup(struct kvm_vcpu *vcpu)
 		++vcpu->nmsrs;
 	}
 
-	nr_good_msrs = vcpu->nmsrs - NR_BAD_MSRS;
-	vmcs_writel(VM_ENTRY_MSR_LOAD_ADDR,
-		    virt_to_phys(vcpu->guest_msrs + NR_BAD_MSRS));
-	vmcs_writel(VM_EXIT_MSR_STORE_ADDR,
-		    virt_to_phys(vcpu->guest_msrs + NR_BAD_MSRS));
-	vmcs_writel(VM_EXIT_MSR_LOAD_ADDR,
-		    virt_to_phys(vcpu->host_msrs + NR_BAD_MSRS));
+	setup_msrs(vcpu);
+
 	vmcs_write32_fixedbits(MSR_IA32_VMX_EXIT_CTLS, VM_EXIT_CONTROLS,
 		     	       (HOST_IS_64 << 9));  /* 22.2,1, 20.7.1 */
-	vmcs_write32(VM_EXIT_MSR_STORE_COUNT, nr_good_msrs); /* 22.2.2 */
-	vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, nr_good_msrs);  /* 22.2.2 */
-	vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, nr_good_msrs); /* 22.2.2 */
-
 
 	/* 22.2.1, 20.8.1 */
 	vmcs_write32_fixedbits(MSR_IA32_VMX_ENTRY_CTLS,
@@ -1769,9 +1789,11 @@ static int vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 	fx_restore(vcpu->guest_fx_image);
 
 #ifdef CONFIG_X86_64
-	save_msrs(vcpu->host_msrs + msr_offset_kernel_gs_base, 1);
+	if (is_long_mode(vcpu)) {
+		save_msrs(vcpu->host_msrs + msr_offset_kernel_gs_base, 1);
+		load_msrs(vcpu->guest_msrs, NR_BAD_MSRS);
+	}
 #endif
-	load_msrs(vcpu->guest_msrs, NR_BAD_MSRS);
 
 	asm (
 		/* Store host registers */
@@ -1915,8 +1937,12 @@ static int vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 	}
 	++kvm_stat.exits;
 
-	save_msrs(vcpu->guest_msrs, NR_BAD_MSRS);
-	load_msrs(vcpu->host_msrs, NR_BAD_MSRS);
+#ifdef CONFIG_X86_64
+	if (is_long_mode(vcpu)) {
+		save_msrs(vcpu->guest_msrs, NR_BAD_MSRS);
+		load_msrs(vcpu->host_msrs, NR_BAD_MSRS);
+	}
+#endif
 
 	fx_save(vcpu->guest_fx_image);
 	fx_restore(vcpu->host_fx_image);