KVM: PPC: e500: Add support for EPTCFG register

EPTCFG register defined by E.PT is accessed unconditionally by Linux guests
in the presence of MAV 2.0. Emulate it now.

Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/arch/powerpc/kvm/e500_mmu.c b/arch/powerpc/kvm/e500_mmu.c
index a863dc1..1c1c5cb 100644
--- a/arch/powerpc/kvm/e500_mmu.c
+++ b/arch/powerpc/kvm/e500_mmu.c
@@ -624,6 +624,9 @@
 	case KVM_REG_PPC_MMUCFG:
 		*val = get_reg_val(id, vcpu->arch.mmucfg);
 		break;
+	case KVM_REG_PPC_EPTCFG:
+		*val = get_reg_val(id, vcpu->arch.eptcfg);
+		break;
 	case KVM_REG_PPC_TLB0CFG:
 	case KVM_REG_PPC_TLB1CFG:
 	case KVM_REG_PPC_TLB2CFG:
@@ -678,6 +681,12 @@
 			r = -EINVAL;
 		break;
 	}
+	case KVM_REG_PPC_EPTCFG: {
+		u32 reg = set_reg_val(id, *val);
+		if (reg != vcpu->arch.eptcfg)
+			r = -EINVAL;
+		break;
+	}
 	case KVM_REG_PPC_TLB0CFG:
 	case KVM_REG_PPC_TLB1CFG:
 	case KVM_REG_PPC_TLB2CFG:
@@ -875,6 +884,9 @@
 	if (has_feature(vcpu, VCPU_FTR_MMU_V2)) {
 		vcpu->arch.tlbps[0] = mfspr(SPRN_TLB0PS);
 		vcpu->arch.tlbps[1] = mfspr(SPRN_TLB1PS);
+
+		/* Guest mmu emulation currently doesn't handle E.PT */
+		vcpu->arch.eptcfg = 0;
 	}
 
 	return 0;