KVM: PPC: Book3S PR: Expose TM registers

POWER8 introduces transactional memory which brings along a number of new
registers and MSR bits.

Implementing all of those is a pretty big headache, so for now let's at least
emulate enough to make Linux's context switching code happy.
Signed-off-by: Alexander Graf <agraf@suse.de>

arch/powerpc/kvm/book3s_emulate.c

@@ -451,6 +451,17 @@ int kvmppc_core_emulate_mtspr_pr(struct kvm_vcpu *vcpu, int sprn, ulong spr_val)
 	case SPRN_EBBRR:
 		vcpu->arch.ebbrr = spr_val;
 		break;
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	case SPRN_TFHAR:
+		vcpu->arch.tfhar = spr_val;
+		break;
+	case SPRN_TEXASR:
+		vcpu->arch.texasr = spr_val;
+		break;
+	case SPRN_TFIAR:
+		vcpu->arch.tfiar = spr_val;
+		break;
+#endif
 #endif
 	case SPRN_ICTC:
 	case SPRN_THRM1:
@@ -572,6 +583,17 @@ int kvmppc_core_emulate_mfspr_pr(struct kvm_vcpu *vcpu, int sprn, ulong *spr_val
 	case SPRN_EBBRR:
 		*spr_val = vcpu->arch.ebbrr;
 		break;
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	case SPRN_TFHAR:
+		*spr_val = vcpu->arch.tfhar;
+		break;
+	case SPRN_TEXASR:
+		*spr_val = vcpu->arch.texasr;
+		break;
+	case SPRN_TFIAR:
+		*spr_val = vcpu->arch.tfiar;
+		break;
+#endif
 #endif
 	case SPRN_THRM1:
 	case SPRN_THRM2:

arch/powerpc/kvm/book3s_pr.c

@@ -794,9 +794,27 @@ static void kvmppc_emulate_fac(struct kvm_vcpu *vcpu, ulong fac)
 /* Enable facilities (TAR, EBB, DSCR) for the guest */
 static int kvmppc_handle_fac(struct kvm_vcpu *vcpu, ulong fac)
 {
+	bool guest_fac_enabled;
 	BUG_ON(!cpu_has_feature(CPU_FTR_ARCH_207S));
 
-	if (!(vcpu->arch.fscr & (1ULL << fac))) {
+	/*
+	 * Not every facility is enabled by FSCR bits, check whether the
+	 * guest has this facility enabled at all.
+	 */
+	switch (fac) {
+	case FSCR_TAR_LG:
+	case FSCR_EBB_LG:
+		guest_fac_enabled = (vcpu->arch.fscr & (1ULL << fac));
+		break;
+	case FSCR_TM_LG:
+		guest_fac_enabled = kvmppc_get_msr(vcpu) & MSR_TM;
+		break;
+	default:
+		guest_fac_enabled = false;
+		break;
+	}
+
+	if (!guest_fac_enabled) {
 		/* Facility not enabled by the guest */
 		kvmppc_trigger_fac_interrupt(vcpu, fac);
 		return RESUME_GUEST;