diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index b25a3f18b301cfbaf57e4c54b79d0c86609efb00..616b28802a198056b17ab25d8c170cc2e4ff903f 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -310,7 +310,7 @@ int kvmhv_run_single_vcpu(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu,
 void kvmhv_save_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr);
 void kvmhv_restore_hv_return_state(struct kvm_vcpu *vcpu,
 				   struct hv_guest_state *hr);
-long int kvmhv_nested_page_fault(struct kvm_vcpu *vcpu);
+long int kvmhv_nested_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu);
 
 void kvmppc_giveup_fac(struct kvm_vcpu *vcpu, ulong fac);
 
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index fac6f631ed29076ad5d5599d75c867d1325aede6..7a2483a139cffec24401255980101dac65f31961 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -793,6 +793,7 @@ struct kvm_vcpu_arch {
 	/* For support of nested guests */
 	struct kvm_nested_guest *nested;
 	u32 nested_vcpu_id;
+	gpa_t nested_io_gpr;
 #endif
 
 #ifdef CONFIG_KVM_BOOK3S_HV_EXIT_TIMING
@@ -827,6 +828,8 @@ struct kvm_vcpu_arch {
 #define KVM_MMIO_REG_FQPR	0x00c0
 #define KVM_MMIO_REG_VSX	0x0100
 #define KVM_MMIO_REG_VMX	0x0180
+#define KVM_MMIO_REG_NESTED_GPR	0xffc0
+
 
 #define __KVM_HAVE_ARCH_WQP
 #define __KVM_HAVE_CREATE_DEVICE
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index cef57b68dda1862603f9821fc021ca13638e8ea2..ca7de15f4a70bec7b049f76f56565ec09a2785d9 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -985,6 +985,10 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 			kvmppc_set_gpr(vcpu, 3, 0);
 			vcpu->arch.hcall_needed = 0;
 			return -EINTR;
+		} else if (ret == H_TOO_HARD) {
+			kvmppc_set_gpr(vcpu, 3, 0);
+			vcpu->arch.hcall_needed = 0;
+			return RESUME_HOST;
 		}
 		break;
 	case H_TLB_INVALIDATE:
@@ -1336,7 +1340,7 @@ static int kvmppc_handle_exit_hv(struct kvm_run *run, struct kvm_vcpu *vcpu,
 	return r;
 }
 
-static int kvmppc_handle_nested_exit(struct kvm_vcpu *vcpu)
+static int kvmppc_handle_nested_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
 {
 	int r;
 	int srcu_idx;
@@ -1394,7 +1398,7 @@ static int kvmppc_handle_nested_exit(struct kvm_vcpu *vcpu)
 	 */
 	case BOOK3S_INTERRUPT_H_DATA_STORAGE:
 		srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
-		r = kvmhv_nested_page_fault(vcpu);
+		r = kvmhv_nested_page_fault(run, vcpu);
 		srcu_read_unlock(&vcpu->kvm->srcu, srcu_idx);
 		break;
 	case BOOK3S_INTERRUPT_H_INST_STORAGE:
@@ -1404,7 +1408,7 @@ static int kvmppc_handle_nested_exit(struct kvm_vcpu *vcpu)
 		if (vcpu->arch.shregs.msr & HSRR1_HISI_WRITE)
 			vcpu->arch.fault_dsisr |= DSISR_ISSTORE;
 		srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
-		r = kvmhv_nested_page_fault(vcpu);
+		r = kvmhv_nested_page_fault(run, vcpu);
 		srcu_read_unlock(&vcpu->kvm->srcu, srcu_idx);
 		break;
 
@@ -4059,7 +4063,7 @@ int kvmhv_run_single_vcpu(struct kvm_run *kvm_run,
 		if (!nested)
 			r = kvmppc_handle_exit_hv(kvm_run, vcpu, current);
 		else
-			r = kvmppc_handle_nested_exit(vcpu);
+			r = kvmppc_handle_nested_exit(kvm_run, vcpu);
 	}
 	vcpu->arch.ret = r;
 
diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
index 6f9e1ad6052798265e50f3a7f7d24091f359bcb2..aeb0bb2075fad308063dd5b41a24ab71425e32ee 100644
--- a/arch/powerpc/kvm/book3s_hv_nested.c
+++ b/arch/powerpc/kvm/book3s_hv_nested.c
@@ -195,6 +195,26 @@ void kvmhv_restore_hv_return_state(struct kvm_vcpu *vcpu,
 	vcpu->arch.ppr = hr->ppr;
 }
 
+static void kvmhv_nested_mmio_needed(struct kvm_vcpu *vcpu, u64 regs_ptr)
+{
+	/* No need to reflect the page fault to L1, we've handled it */
+	vcpu->arch.trap = 0;
+
+	/*
+	 * Since the L2 gprs have already been written back into L1 memory when
+	 * we complete the mmio, store the L1 memory location of the L2 gpr
+	 * being loaded into by the mmio so that the loaded value can be
+	 * written there in kvmppc_complete_mmio_load()
+	 */
+	if (((vcpu->arch.io_gpr & KVM_MMIO_REG_EXT_MASK) == KVM_MMIO_REG_GPR)
+	    && (vcpu->mmio_is_write == 0)) {
+		vcpu->arch.nested_io_gpr = (gpa_t) regs_ptr +
+					   offsetof(struct pt_regs,
+						    gpr[vcpu->arch.io_gpr]);
+		vcpu->arch.io_gpr = KVM_MMIO_REG_NESTED_GPR;
+	}
+}
+
 long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
 {
 	long int err, r;
@@ -316,6 +336,11 @@ long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
 	if (r == -EINTR)
 		return H_INTERRUPT;
 
+	if (vcpu->mmio_needed) {
+		kvmhv_nested_mmio_needed(vcpu, regs_ptr);
+		return H_TOO_HARD;
+	}
+
 	return vcpu->arch.trap;
 }
 
@@ -1100,7 +1125,8 @@ static inline int kvmppc_radix_shift_to_level(int shift)
 }
 
 /* called with gp->tlb_lock held */
-static long int __kvmhv_nested_page_fault(struct kvm_vcpu *vcpu,
+static long int __kvmhv_nested_page_fault(struct kvm_run *run,
+					  struct kvm_vcpu *vcpu,
 					  struct kvm_nested_guest *gp)
 {
 	struct kvm *kvm = vcpu->kvm;
@@ -1181,9 +1207,14 @@ static long int __kvmhv_nested_page_fault(struct kvm_vcpu *vcpu,
 			kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
 			return RESUME_GUEST;
 		}
-		/* passthrough of emulated MMIO case... */
-		pr_err("emulated MMIO passthrough?\n");
-		return -EINVAL;
+
+		/* passthrough of emulated MMIO case */
+		if (kvmhv_on_pseries()) {
+			pr_err("emulated MMIO passthrough?\n");
+			return -EINVAL;
+		}
+
+		return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea, writing);
 	}
 	if (memslot->flags & KVM_MEM_READONLY) {
 		if (writing) {
@@ -1265,13 +1296,13 @@ static long int __kvmhv_nested_page_fault(struct kvm_vcpu *vcpu,
 	return RESUME_GUEST;
 }
 
-long int kvmhv_nested_page_fault(struct kvm_vcpu *vcpu)
+long int kvmhv_nested_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu)
 {
 	struct kvm_nested_guest *gp = vcpu->arch.nested;
 	long int ret;
 
 	mutex_lock(&gp->tlb_lock);
-	ret = __kvmhv_nested_page_fault(vcpu, gp);
+	ret = __kvmhv_nested_page_fault(run, vcpu, gp);
 	mutex_unlock(&gp->tlb_lock);
 	return ret;
 }
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index ec9cbf9db3645e5526fa68e5c41a8c22586172da..db61096ffcf7c69238b05f978fe280abe08dc8bc 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -1208,6 +1208,14 @@ static void kvmppc_complete_mmio_load(struct kvm_vcpu *vcpu,
 				KVMPPC_VMX_COPY_BYTE)
 			kvmppc_set_vmx_byte(vcpu, gpr);
 		break;
+#endif
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	case KVM_MMIO_REG_NESTED_GPR:
+		if (kvmppc_need_byteswap(vcpu))
+			gpr = swab64(gpr);
+		kvm_vcpu_write_guest(vcpu, vcpu->arch.nested_io_gpr, &gpr,
+				     sizeof(gpr));
+		break;
 #endif
 	default:
 		BUG();