---

yaml
---
r: 315834
b: refs/heads/master
c: b246dd5
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 1952639665e92481c34c34c3e2a71bf3e66ba362
+refs/heads/master: b246dd5df139501b974bd6b28f7815e53b3a792f

trunk/arch/x86/kvm/vmx.c

@@ -618,6 +618,10 @@ static void kvm_cpu_vmxon(u64 addr);
 static void kvm_cpu_vmxoff(void);
 static void vmx_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3);
 static int vmx_set_tss_addr(struct kvm *kvm, unsigned int addr);
+static void vmx_set_segment(struct kvm_vcpu *vcpu,
+			    struct kvm_segment *var, int seg);
+static void vmx_get_segment(struct kvm_vcpu *vcpu,
+			    struct kvm_segment *var, int seg);
 
 static DEFINE_PER_CPU(struct vmcs *, vmxarea);
 static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
@@ -2782,6 +2786,7 @@ static void enter_rmode(struct kvm_vcpu *vcpu)
 {
 	unsigned long flags;
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
+	struct kvm_segment var;
 
 	if (enable_unrestricted_guest)
 		return;
@@ -2825,20 +2830,23 @@ static void enter_rmode(struct kvm_vcpu *vcpu)
 	if (emulate_invalid_guest_state)
 		goto continue_rmode;
 
-	vmcs_write16(GUEST_SS_SELECTOR, vmcs_readl(GUEST_SS_BASE) >> 4);
-	vmcs_write32(GUEST_SS_LIMIT, 0xffff);
-	vmcs_write32(GUEST_SS_AR_BYTES, 0xf3);
+	vmx_get_segment(vcpu, &var, VCPU_SREG_SS);
+	vmx_set_segment(vcpu, &var, VCPU_SREG_SS);
+
+	vmx_get_segment(vcpu, &var, VCPU_SREG_CS);
+	vmx_set_segment(vcpu, &var, VCPU_SREG_CS);
+
+	vmx_get_segment(vcpu, &var, VCPU_SREG_ES);
+	vmx_set_segment(vcpu, &var, VCPU_SREG_ES);
 
-	vmcs_write32(GUEST_CS_AR_BYTES, 0xf3);
-	vmcs_write32(GUEST_CS_LIMIT, 0xffff);
-	if (vmcs_readl(GUEST_CS_BASE) == 0xffff0000)
-		vmcs_writel(GUEST_CS_BASE, 0xf0000);
-	vmcs_write16(GUEST_CS_SELECTOR, vmcs_readl(GUEST_CS_BASE) >> 4);
+	vmx_get_segment(vcpu, &var, VCPU_SREG_DS);
+	vmx_set_segment(vcpu, &var, VCPU_SREG_DS);
 
-	fix_rmode_seg(VCPU_SREG_ES, &vmx->rmode.es);
-	fix_rmode_seg(VCPU_SREG_DS, &vmx->rmode.ds);
-	fix_rmode_seg(VCPU_SREG_GS, &vmx->rmode.gs);
-	fix_rmode_seg(VCPU_SREG_FS, &vmx->rmode.fs);
+	vmx_get_segment(vcpu, &var, VCPU_SREG_GS);
+	vmx_set_segment(vcpu, &var, VCPU_SREG_GS);
+
+	vmx_get_segment(vcpu, &var, VCPU_SREG_FS);
+	vmx_set_segment(vcpu, &var, VCPU_SREG_FS);
 
 continue_rmode:
 	kvm_mmu_reset_context(vcpu);
@@ -3243,6 +3251,44 @@ static void vmx_set_segment(struct kvm_vcpu *vcpu,
 
 	vmcs_write32(sf->ar_bytes, ar);
 	__clear_bit(VCPU_EXREG_CPL, (ulong *)&vcpu->arch.regs_avail);
+
+	/*
+	 * Fix segments for real mode guest in hosts that don't have
+	 * "unrestricted_mode" or it was disabled.
+	 * This is done to allow migration of the guests from hosts with
+	 * unrestricted guest like Westmere to older host that don't have
+	 * unrestricted guest like Nehelem.
+	 */
+	if (!enable_unrestricted_guest && vmx->rmode.vm86_active) {
+		switch (seg) {
+		case VCPU_SREG_CS:
+			vmcs_write32(GUEST_CS_AR_BYTES, 0xf3);
+			vmcs_write32(GUEST_CS_LIMIT, 0xffff);
+			if (vmcs_readl(GUEST_CS_BASE) == 0xffff0000)
+				vmcs_writel(GUEST_CS_BASE, 0xf0000);
+			vmcs_write16(GUEST_CS_SELECTOR,
+				     vmcs_readl(GUEST_CS_BASE) >> 4);
+			break;
+		case VCPU_SREG_ES:
+			fix_rmode_seg(VCPU_SREG_ES, &vmx->rmode.es);
+			break;
+		case VCPU_SREG_DS:
+			fix_rmode_seg(VCPU_SREG_DS, &vmx->rmode.ds);
+			break;
+		case VCPU_SREG_GS:
+			fix_rmode_seg(VCPU_SREG_GS, &vmx->rmode.gs);
+			break;
+		case VCPU_SREG_FS:
+			fix_rmode_seg(VCPU_SREG_FS, &vmx->rmode.fs);
+			break;
+		case VCPU_SREG_SS:
+			vmcs_write16(GUEST_SS_SELECTOR,
+				     vmcs_readl(GUEST_SS_BASE) >> 4);
+			vmcs_write32(GUEST_SS_LIMIT, 0xffff);
+			vmcs_write32(GUEST_SS_AR_BYTES, 0xf3);
+			break;
+		}
+	}
 }
 
 static void vmx_get_cs_db_l_bits(struct kvm_vcpu *vcpu, int *db, int *l)