[PULL,01/22] target/s390x: Do not use unwind for per_check_exception

Commit Message

Thomas Huth May 29, 2024, 10:54 a.m. UTC

From: Richard Henderson <[e-mail]>

Using exception unwind via tcg_s390_program_interrupt,
we discard the current value of psw.addr, which discards
the result of a branch.

Pass in the address of the next instruction, which may
not be sequential.  Pass in ilen, which we would have
gotten from unwind and is passed to the exception handler.
Sync cc_op before the call, which we would have gotten
from unwind.

Signed-off-by: Richard Henderson <[e-mail]>
Reviewed-by: Ilya Leoshkevich <[e-mail]>
Message-ID: <[e-mail]>
[thuth: Silence checkpatch.pl errors]
Signed-off-by: Thomas Huth <[e-mail]>
---
 target/s390x/helper.h          |  2 +-
 target/s390x/tcg/excp_helper.c |  2 +-
 target/s390x/tcg/misc_helper.c | 23 ++++++++++++++++++++---
 target/s390x/tcg/translate.c   | 11 ++++++-----
 4 files changed, 28 insertions(+), 10 deletions(-)

Patch

diff --git a/target/s390x/helper.h b/target/s390x/helper.h
index cc1c20e9e3..96ab71e877 100644
--- a/target/s390x/helper.h
+++ b/target/s390x/helper.h
@@ -359,7 +359,7 @@  DEF_HELPER_FLAGS_4(ipte, TCG_CALL_NO_RWG, void, env, i64, i64, i32)
 DEF_HELPER_FLAGS_1(ptlb, TCG_CALL_NO_RWG, void, env)
 DEF_HELPER_FLAGS_1(purge, TCG_CALL_NO_RWG, void, env)
 DEF_HELPER_3(lra, i64, env, i64, i64)
-DEF_HELPER_1(per_check_exception, void, env)
+DEF_HELPER_FLAGS_3(per_check_exception, TCG_CALL_NO_WG, void, env, i64, i32)
 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_FLAGS_1(per_store_real, TCG_CALL_NO_RWG, void, env)
diff --git a/target/s390x/tcg/excp_helper.c b/target/s390x/tcg/excp_helper.c
index f1c33f7967..4c0b692c9e 100644
--- a/target/s390x/tcg/excp_helper.c
+++ b/target/s390x/tcg/excp_helper.c
@@ -209,7 +209,7 @@  static void do_program_interrupt(CPUS390XState *env)
 
     switch (env->int_pgm_code) {
     case PGM_PER:
-        advance = !(env->per_perc_atmid & PER_CODE_EVENT_NULLIFICATION);
+        /* advance already handled */
         break;
     case PGM_ASCE_TYPE:
     case PGM_REG_FIRST_TRANS:
diff --git a/target/s390x/tcg/misc_helper.c b/target/s390x/tcg/misc_helper.c
index 8764846ce8..7c94468392 100644
--- a/target/s390x/tcg/misc_helper.c
+++ b/target/s390x/tcg/misc_helper.c
@@ -20,6 +20,7 @@ 
 
 #include "qemu/osdep.h"
 #include "qemu/cutils.h"
+#include "qemu/log.h"
 #include "cpu.h"
 #include "s390x-internal.h"
 #include "qemu/host-utils.h"
@@ -590,10 +591,26 @@  void HELPER(chsc)(CPUS390XState *env, uint64_t inst)
 #endif
 
 #ifndef CONFIG_USER_ONLY
-void HELPER(per_check_exception)(CPUS390XState *env)
+static G_NORETURN void per_raise_exception(CPUS390XState *env)
 {
-    if (env->per_perc_atmid) {
-        tcg_s390_program_interrupt(env, PGM_PER, GETPC());
+    trigger_pgm_exception(env, PGM_PER);
+    cpu_loop_exit(env_cpu(env));
+}
+
+static G_NORETURN void per_raise_exception_log(CPUS390XState *env)
+{
+    qemu_log_mask(CPU_LOG_INT, "PER interrupt after 0x%" PRIx64 "\n",
+                  env->per_address);
+    per_raise_exception(env);
+}
+
+void HELPER(per_check_exception)(CPUS390XState *env, uint64_t next_pc,
+                                 uint32_t ilen)
+{
+    if (unlikely(env->per_perc_atmid)) {
+        env->psw.addr = next_pc;
+        env->int_pgm_ilen = ilen;
+        per_raise_exception_log(env);
     }
 }
 
diff --git a/target/s390x/tcg/translate.c b/target/s390x/tcg/translate.c
index ebd96abe6c..4c3ff1931b 100644
--- a/target/s390x/tcg/translate.c
+++ b/target/s390x/tcg/translate.c
@@ -6424,13 +6424,14 @@  static DisasJumpType translate_one(CPUS390XState *env, DisasContext *s)
 
 #ifndef CONFIG_USER_ONLY
     if (s->base.tb->flags & FLAG_MASK_PER) {
-        /* An exception might be triggered, save PSW if not already done.  */
+        TCGv_i64 next_pc = psw_addr;
+
         if (ret == DISAS_NEXT || ret == DISAS_TOO_MANY) {
-            tcg_gen_movi_i64(psw_addr, s->pc_tmp);
+            next_pc = tcg_constant_i64(s->pc_tmp);
         }
-
-        /* Call the helper to check for a possible PER exception.  */
-        gen_helper_per_check_exception(tcg_env);
+        update_cc_op(s);
+        gen_helper_per_check_exception(tcg_env, next_pc,
+                                       tcg_constant_i32(s->ilen));
     }
 #endif