[PATCH v3 02/18] target/s390x: Add ilen to unwind data

[Richard Henderson]

From: Richard Henderson <address@hidden>

Use ILEN_UNWIND to signal that we have in fact that
cpu_restore_state will have been called by the time
we arrive in do_program_interrupt.

Signed-off-by: Richard Henderson <address@hidden>
---
 target/s390x/cpu.h       |  4 +++-
 target/s390x/interrupt.c |  5 ++++-
 target/s390x/translate.c | 21 ++++++++++++++++++---
 3 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
index ce20dafd23..080ebcd6bb 100644
--- a/target/s390x/cpu.h
+++ b/target/s390x/cpu.h
@@ -30,7 +30,7 @@
 /* The z/Architecture has a strong memory model with some store-after-load 
re-ordering */
 #define TCG_GUEST_DEFAULT_MO      (TCG_MO_ALL & ~TCG_MO_ST_LD)
 
-#define TARGET_INSN_START_EXTRA_WORDS 1
+#define TARGET_INSN_START_EXTRA_WORDS 2
 
 #define MMU_MODE0_SUFFIX _primary
 #define MMU_MODE1_SUFFIX _secondary
@@ -814,6 +814,8 @@ int cpu_s390x_signal_handler(int host_signum, void *pinfo, 
void *puc);
 void s390_crw_mchk(void);
 void s390_io_interrupt(uint16_t subchannel_id, uint16_t subchannel_nr,
                        uint32_t io_int_parm, uint32_t io_int_word);
+/* instruction length set by unwind info */
+#define ILEN_UNWIND                 0
 /* automatically detect the instruction length */
 #define ILEN_AUTO                   0xff
 #define RA_IGNORED                  0
diff --git a/target/s390x/interrupt.c b/target/s390x/interrupt.c
index a841f7187d..30a9fb8852 100644
--- a/target/s390x/interrupt.c
+++ b/target/s390x/interrupt.c
@@ -28,7 +28,10 @@ void trigger_pgm_exception(CPUS390XState *env, uint32_t 
code, uint32_t ilen)
 
     cs->exception_index = EXCP_PGM;
     env->int_pgm_code = code;
-    env->int_pgm_ilen = ilen;
+    /* If ILEN_UNWIND, int_pgm_ilen already has the correct value.  */
+    if (ilen != ILEN_UNWIND) {
+        env->int_pgm_ilen = ilen;
+    }
 }
 
 void s390_program_interrupt(CPUS390XState *env, uint32_t code, int ilen,
diff --git a/target/s390x/translate.c b/target/s390x/translate.c
index e1c54ab03b..08f99454de 100644
--- a/target/s390x/translate.c
+++ b/target/s390x/translate.c
@@ -6309,6 +6309,9 @@ static DisasJumpType translate_one(CPUS390XState *env, 
DisasContext *s)
     /* Search for the insn in the table.  */
     insn = extract_insn(env, s, &f);
 
+    /* Emit insn_start now that we know the ILEN.  */
+    tcg_gen_insn_start(s->base.pc_next, s->cc_op, s->ilen);
+
     /* Not found means unimplemented/illegal opcode.  */
     if (insn == NULL) {
         qemu_log_mask(LOG_UNIMP, "unimplemented opcode 0x%02x%02x\n",
@@ -6457,9 +6460,6 @@ static void s390x_tr_tb_start(DisasContextBase *db, 
CPUState *cs)
 
 static void s390x_tr_insn_start(DisasContextBase *dcbase, CPUState *cs)
 {
-    DisasContext *dc = container_of(dcbase, DisasContext, base);
-
-    tcg_gen_insn_start(dc->base.pc_next, dc->cc_op);
 }
 
 static bool s390x_tr_breakpoint_check(DisasContextBase *dcbase, CPUState *cs,
@@ -6467,6 +6467,12 @@ static bool s390x_tr_breakpoint_check(DisasContextBase 
*dcbase, CPUState *cs,
 {
     DisasContext *dc = container_of(dcbase, DisasContext, base);
 
+    /*
+     * Emit an insn_start to accompany the breakpoint exception.
+     * The ILEN value is a dummy, since we didn't actually read an insn.
+     */
+    tcg_gen_insn_start(dc->base.pc_next, dc->cc_op, 0);
+
     dc->base.is_jmp = DISAS_PC_STALE;
     dc->do_debug = true;
     /* The address covered by the breakpoint must be included in
@@ -6561,8 +6567,17 @@ void restore_state_to_opc(CPUS390XState *env, 
TranslationBlock *tb,
                           target_ulong *data)
 {
     int cc_op = data[1];
+    int ilen = data[2];
+
     env->psw.addr = data[0];
+
+    /* Update the CC opcode if it is not already up-to-date.  */
     if ((cc_op != CC_OP_DYNAMIC) && (cc_op != CC_OP_STATIC)) {
         env->cc_op = cc_op;
     }
+
+    /* Update ILEN, except for breakpoint, where we didn't load an insn.  */
+    if (ilen) {
+        env->int_pgm_ilen = ilen;
+    }
 }
-- 
2.17.1