KVM: PPC: Support SC1 hypercalls for PAPR in PR mode

PAPR defines hypercalls as SC1 instructions. Using these, the guest modifies
page tables and does other privileged operations that it wouldn't be allowed
to do in supervisor mode.

This patch adds support for PR KVM to trap these instructions and route them
through the same PAPR hypercall interface that we already use for HV style
KVM.

Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index 78dcf65..48558f6 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -648,7 +648,27 @@
 		break;
 	}
 	case BOOK3S_INTERRUPT_SYSCALL:
-		if (vcpu->arch.osi_enabled &&
+		if (vcpu->arch.papr_enabled &&
+		    (kvmppc_get_last_inst(vcpu) == 0x44000022) &&
+		    !(vcpu->arch.shared->msr & MSR_PR)) {
+			/* SC 1 papr hypercalls */
+			ulong cmd = kvmppc_get_gpr(vcpu, 3);
+			int i;
+
+			if (kvmppc_h_pr(vcpu, cmd) == EMULATE_DONE) {
+				r = RESUME_GUEST;
+				break;
+			}
+
+			run->papr_hcall.nr = cmd;
+			for (i = 0; i < 9; ++i) {
+				ulong gpr = kvmppc_get_gpr(vcpu, 4 + i);
+				run->papr_hcall.args[i] = gpr;
+			}
+			run->exit_reason = KVM_EXIT_PAPR_HCALL;
+			vcpu->arch.hcall_needed = 1;
+			r = RESUME_HOST;
+		} else if (vcpu->arch.osi_enabled &&
 		    (((u32)kvmppc_get_gpr(vcpu, 3)) == OSI_SC_MAGIC_R3) &&
 		    (((u32)kvmppc_get_gpr(vcpu, 4)) == OSI_SC_MAGIC_R4)) {
 			/* MOL hypercalls */