[PATCH v4 11/29] KVM: PPC: Book3S PR: implement RFID TM behavior to suppress change from S0 to N0

[wei.guo.simon at gmail.com]

From: Simon Guo <wei.guo.simon at gmail.com>

Accordingly to ISA specification for RFID, in MSR TM disabled and TS
suspended state(S0), if the target MSR is TM disabled and TS state is
inactive(N0), rfid should suppress this update.

This patch make RFID emulation of PR KVM to be consistent with this.

Signed-off-by: Simon Guo <wei.guo.simon at gmail.com>
Reviewed-by: Paul Mackerras <paulus at ozlabs.org>
---
 arch/powerpc/kvm/book3s_emulate.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_emulate.c b/arch/powerpc/kvm/book3s_emulate.c
index 68d6898..2eb457b 100644
--- a/arch/powerpc/kvm/book3s_emulate.c
+++ b/arch/powerpc/kvm/book3s_emulate.c
@@ -117,11 +117,28 @@ int kvmppc_core_emulate_op_pr(struct kvm_run *run, struct kvm_vcpu *vcpu,
 	case 19:
 		switch (get_xop(inst)) {
 		case OP_19_XOP_RFID:
-		case OP_19_XOP_RFI:
+		case OP_19_XOP_RFI: {
+			unsigned long srr1 = kvmppc_get_srr1(vcpu);
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+			unsigned long cur_msr = kvmppc_get_msr(vcpu);
+
+			/*
+			 * add rules to fit in ISA specification regarding TM
+			 * state transistion in TM disable/Suspended state,
+			 * and target TM state is TM inactive(00) state. (the
+			 * change should be suppressed).
+			 */
+			if (((cur_msr & MSR_TM) == 0) &&
+				((srr1 & MSR_TM) == 0) &&
+				MSR_TM_SUSPENDED(cur_msr) &&
+				!MSR_TM_ACTIVE(srr1))
+				srr1 |= MSR_TS_S;
+#endif
 			kvmppc_set_pc(vcpu, kvmppc_get_srr0(vcpu));
-			kvmppc_set_msr(vcpu, kvmppc_get_srr1(vcpu));
+			kvmppc_set_msr(vcpu, srr1);
 			*advance = 0;
 			break;
+		}
 
 		default:
 			emulated = EMULATE_FAIL;
-- 
1.8.3.1