MIPS: KVM: Don't save/restore lo/hi for r6

MIPSr6 doesn't have lo/hi registers, so don't bother saving or
restoring them, and don't expose them to userland with the KVM ioctl
interface either.

In fact the lo/hi registers aren't callee saved in the MIPS ABIs anyway,
so there is no need to preserve the host lo/hi values at all when
transitioning to and from the guest (which happens via a function call).

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim KrÄmář <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index 7c76768..414b000 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -521,8 +521,10 @@
 	KVM_REG_MIPS_R30,
 	KVM_REG_MIPS_R31,
 
+#ifndef CONFIG_CPU_MIPSR6
 	KVM_REG_MIPS_HI,
 	KVM_REG_MIPS_LO,
+#endif
 	KVM_REG_MIPS_PC,
 
 	KVM_REG_MIPS_CP0_INDEX,
@@ -666,12 +668,14 @@
 	case KVM_REG_MIPS_R0 ... KVM_REG_MIPS_R31:
 		v = (long)vcpu->arch.gprs[reg->id - KVM_REG_MIPS_R0];
 		break;
+#ifndef CONFIG_CPU_MIPSR6
 	case KVM_REG_MIPS_HI:
 		v = (long)vcpu->arch.hi;
 		break;
 	case KVM_REG_MIPS_LO:
 		v = (long)vcpu->arch.lo;
 		break;
+#endif
 	case KVM_REG_MIPS_PC:
 		v = (long)vcpu->arch.pc;
 		break;
@@ -887,12 +891,14 @@
 	case KVM_REG_MIPS_R1 ... KVM_REG_MIPS_R31:
 		vcpu->arch.gprs[reg->id - KVM_REG_MIPS_R0] = v;
 		break;
+#ifndef CONFIG_CPU_MIPSR6
 	case KVM_REG_MIPS_HI:
 		vcpu->arch.hi = v;
 		break;
 	case KVM_REG_MIPS_LO:
 		vcpu->arch.lo = v;
 		break;
+#endif
 	case KVM_REG_MIPS_PC:
 		vcpu->arch.pc = v;
 		break;