diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 1cc901e..a1a96a5 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -37,12 +37,14 @@
 #define CR3_L_MODE_RESERVED_BITS (CR3_NONPAE_RESERVED_BITS |	\
 				  0xFFFFFF0000000000ULL)
 
-#define KVM_GUEST_CR0_MASK				   \
-	(X86_CR0_PG | X86_CR0_PE | X86_CR0_WP | X86_CR0_NE \
-	 | X86_CR0_NW | X86_CR0_CD)
+#define KVM_GUEST_CR0_MASK_UNRESTRICTED_GUEST				\
+	(X86_CR0_WP | X86_CR0_NE | X86_CR0_NW | X86_CR0_CD)
+#define KVM_GUEST_CR0_MASK						\
+	(KVM_GUEST_CR0_MASK_UNRESTRICTED_GUEST | X86_CR0_PG | X86_CR0_PE)
+#define KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST				\
+	(X86_CR0_WP | X86_CR0_NE | X86_CR0_TS | X86_CR0_MP)
 #define KVM_VM_CR0_ALWAYS_ON						\
-	(X86_CR0_PG | X86_CR0_PE | X86_CR0_WP | X86_CR0_NE | X86_CR0_TS \
-	 | X86_CR0_MP)
+	(KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST | X86_CR0_PG | X86_CR0_PE)
 #define KVM_GUEST_CR4_MASK						\
 	(X86_CR4_VME | X86_CR4_PSE | X86_CR4_PAE | X86_CR4_PGE | X86_CR4_VMXE)
 #define KVM_PMODE_VM_CR4_ALWAYS_ON (X86_CR4_PAE | X86_CR4_VMXE)
diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index 11be5ad..e7927a6 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -55,6 +55,7 @@
 #define SECONDARY_EXEC_ENABLE_EPT               0x00000002
 #define SECONDARY_EXEC_ENABLE_VPID              0x00000020
 #define SECONDARY_EXEC_WBINVD_EXITING		0x00000040
+#define SECONDARY_EXEC_UNRESTRICTED_GUEST	0x00000080
 
 
 #define PIN_BASED_EXT_INTR_MASK                 0x00000001
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 959cb59..f0f9773 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -51,6 +51,10 @@ module_param_named(flexpriority, flexpriority_enabled, bool, S_IRUGO);
 static int __read_mostly enable_ept = 1;
 module_param_named(ept, enable_ept, bool, S_IRUGO);
 
+static int __read_mostly enable_unrestricted_guest = 1;
+module_param_named(unrestricted_guest,
+			enable_unrestricted_guest, bool, S_IRUGO);
+
 static int __read_mostly emulate_invalid_guest_state = 0;
 module_param(emulate_invalid_guest_state, bool, S_IRUGO);
 
@@ -279,6 +283,12 @@ static inline int cpu_has_vmx_ept(void)
 		SECONDARY_EXEC_ENABLE_EPT;
 }
 
+static inline int cpu_has_vmx_unrestricted_guest(void)
+{
+	return vmcs_config.cpu_based_2nd_exec_ctrl &
+		SECONDARY_EXEC_UNRESTRICTED_GUEST;
+}
+
 static inline int vm_need_virtualize_apic_accesses(struct kvm *kvm)
 {
 	return flexpriority_enabled &&
@@ -1210,7 +1220,8 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf)
 		opt2 = SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
 			SECONDARY_EXEC_WBINVD_EXITING |
 			SECONDARY_EXEC_ENABLE_VPID |
-			SECONDARY_EXEC_ENABLE_EPT;
+			SECONDARY_EXEC_ENABLE_EPT |
+			SECONDARY_EXEC_UNRESTRICTED_GUEST;
 		if (adjust_vmx_controls(min2, opt2,
 					MSR_IA32_VMX_PROCBASED_CTLS2,
 					&_cpu_based_2nd_exec_control) < 0)
@@ -1340,8 +1351,13 @@ static __init int hardware_setup(void)
 	if (!cpu_has_vmx_vpid())
 		enable_vpid = 0;
 
-	if (!cpu_has_vmx_ept())
+	if (!cpu_has_vmx_ept()) {
 		enable_ept = 0;
+		enable_unrestricted_guest = 0;
+	}
+
+	if (!cpu_has_vmx_unrestricted_guest())
+		enable_unrestricted_guest = 0;
 
 	if (!cpu_has_vmx_flexpriority())
 		flexpriority_enabled = 0;
@@ -1440,6 +1456,9 @@ static void enter_rmode(struct kvm_vcpu *vcpu)
 	unsigned long flags;
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 
+	if (enable_unrestricted_guest)
+		return;
+
 	vmx->emulation_required = 1;
 	vcpu->arch.rmode.vm86_active = 1;
 
@@ -1593,7 +1612,6 @@ static void ept_update_paging_mode_cr0(unsigned long *hw_cr0,
 			      CPU_BASED_CR3_STORE_EXITING));
 		vcpu->arch.cr0 = cr0;
 		vmx_set_cr4(vcpu, vcpu->arch.cr4);
-		*hw_cr0 |= X86_CR0_PE | X86_CR0_PG;
 		*hw_cr0 &= ~X86_CR0_WP;
 	} else if (!is_paging(vcpu)) {
 		/* From nonpaging to paging */
@@ -1620,8 +1638,13 @@ static void ept_update_paging_mode_cr4(unsigned long *hw_cr4,
 
 static void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
 {
-	unsigned long hw_cr0 = (cr0 & ~KVM_GUEST_CR0_MASK) |
-				KVM_VM_CR0_ALWAYS_ON;
+	unsigned long hw_cr0;
+
+	if (enable_unrestricted_guest)
+		hw_cr0 = (cr0 & ~KVM_GUEST_CR0_MASK_UNRESTRICTED_GUEST)
+			| KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST;
+	else
+		hw_cr0 = (cr0 & ~KVM_GUEST_CR0_MASK) | KVM_VM_CR0_ALWAYS_ON;
 
 	vmx_fpu_deactivate(vcpu);
 
@@ -1786,6 +1809,21 @@ static void vmx_set_segment(struct kvm_vcpu *vcpu,
 		ar = 0xf3;
 	} else
 		ar = vmx_segment_access_rights(var);
+
+	/*
+	 *   Fix the "Accessed" bit in AR field of segment registers for older
+	 * qemu binaries.
+	 *   IA32 arch specifies that at the time of processor reset the
+	 * "Accessed" bit in the AR field of segment registers is 1. And qemu
+	 * is setting it to 0 in the usedland code. This causes invalid guest
+	 * state vmexit when "unrestricted guest" mode is turned on.
+	 *    Fix for this setup issue in cpu_reset is being pushed in the qemu
+	 * tree. Newer qemu binaries with that qemu fix would not need this
+	 * kvm hack.
+	 */
+	if (enable_unrestricted_guest && (seg != VCPU_SREG_LDTR))
+		ar |= 0x1; /* Accessed */
+
 	vmcs_write32(sf->ar_bytes, ar);
 }
 
@@ -2082,11 +2120,19 @@ out:
 static void seg_setup(int seg)
 {
 	struct kvm_vmx_segment_field *sf = &kvm_vmx_segment_fields[seg];
+	unsigned int ar;
 
 	vmcs_write16(sf->selector, 0);
 	vmcs_writel(sf->base, 0);
 	vmcs_write32(sf->limit, 0xffff);
-	vmcs_write32(sf->ar_bytes, 0xf3);
+	if (enable_unrestricted_guest) {
+		ar = 0x93;
+		if (seg == VCPU_SREG_CS)
+			ar |= 0x08; /* code segment */
+	} else
+		ar = 0xf3;
+
+	vmcs_write32(sf->ar_bytes, ar);
 }
 
 static int alloc_apic_access_page(struct kvm *kvm)
@@ -2229,6 +2275,8 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
 			exec_control &= ~SECONDARY_EXEC_ENABLE_VPID;
 		if (!enable_ept)
 			exec_control &= ~SECONDARY_EXEC_ENABLE_EPT;
+		if (!enable_unrestricted_guest)
+			exec_control &= ~SECONDARY_EXEC_UNRESTRICTED_GUEST;
 		vmcs_write32(SECONDARY_VM_EXEC_CONTROL, exec_control);
 	}
 
