target-s390x: PER instruction-fetch event support

For the PER instruction-fetch, we can't use the QEMU breakpoint infrastructure as it triggers for a single address and not a full address range, and as it actually stop before the instruction and not before. We therefore call an helper with the just fetched instruction address, which check if the address is within the PER address range. If it is the case, an event is recorded and will be signaled through an exception. Note that we implement here the PER-3 behaviour, that is an invalid opcode is not considered as an instruction fetch. Without PER-3 this behavious is undefined. Signed-off-by: Aurelien Jarno <[email protected]> Signed-off-by: Alexander Graf <[email protected]>
xlee · Jun 17, 2015 · f0e0d81 · f0e0d81
1 parent 2c2275e
commit f0e0d81
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diff --git a/target-s390x/helper.h b/target-s390x/helper.h
@@ -118,6 +118,7 @@ DEF_HELPER_FLAGS_3(stura, TCG_CALL_NO_WG, void, env, i64, i64)
 DEF_HELPER_FLAGS_3(sturg, TCG_CALL_NO_WG, void, env, i64, i64)
 DEF_HELPER_1(per_check_exception, void, env)
 DEF_HELPER_FLAGS_3(per_branch, TCG_CALL_NO_RWG, void, env, i64, i64)
+DEF_HELPER_FLAGS_2(per_ifetch, TCG_CALL_NO_RWG, void, env, i64)
 
 DEF_HELPER_2(xsch, void, env, i64)
 DEF_HELPER_2(csch, void, env, i64)

diff --git a/target-s390x/misc_helper.c b/target-s390x/misc_helper.c
@@ -619,4 +619,12 @@ void HELPER(per_branch)(CPUS390XState *env, uint64_t from, uint64_t to)
         }
     }
 }
+
+void HELPER(per_ifetch)(CPUS390XState *env, uint64_t addr)
+{
+    if ((env->cregs[9] & PER_CR9_EVENT_IFETCH) && get_per_in_range(env, addr)) {
+        env->per_address = addr;
+        env->per_perc_atmid = PER_CODE_EVENT_IFETCH | get_per_atmid(env);
+    }
+}
 #endif
diff --git a/target-s390x/translate.c b/target-s390x/translate.c
@@ -5187,6 +5187,14 @@ static ExitStatus translate_one(CPUS390XState *env, DisasContext *s)
         return EXIT_NORETURN;
     }
 
+#ifndef CONFIG_USER_ONLY
+    if (s->tb->flags & FLAG_MASK_PER) {
+        TCGv_i64 addr = tcg_const_i64(s->pc);
+        gen_helper_per_ifetch(cpu_env, addr);
+        tcg_temp_free_i64(addr);
+    }
+#endif
+
     /* Check for insn specification exceptions.  */
     if (insn->spec) {
         int spec = insn->spec, excp = 0, r;