Set CF_SINGLE_STEP when single-stepping is enabled.
This avoids the need to flush all tb's when turning
single-stepping on or off.
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
include/exec/exec-all.h | 1 +
accel/tcg/cpu-exec.c | 12 ++++++++++++
accel/tcg/translator.c | 7 +------
cpu.c | 4 ----
4 files changed, 14 insertions(+), 10 deletions(-)
diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
index 6873cce8df..5d1b6d80fb 100644
--- a/include/exec/exec-all.h
+++ b/include/exec/exec-all.h
@@ -497,6 +497,7 @@ struct TranslationBlock {
#define CF_COUNT_MASK 0x000001ff
#define CF_NO_GOTO_TB 0x00000200 /* Do not chain with goto_tb */
#define CF_NO_GOTO_PTR 0x00000400 /* Do not chain with goto_ptr */
+#define CF_SINGLE_STEP 0x00000800 /* gdbstub single-step in effect */
#define CF_LAST_IO 0x00008000 /* Last insn may be an IO access. */
#define CF_MEMI_ONLY 0x00010000 /* Only instrument memory ops */
#define CF_USE_ICOUNT 0x00020000
diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
index 6710e15d8b..30a3be9ea7 100644
--- a/accel/tcg/cpu-exec.c
+++ b/accel/tcg/cpu-exec.c
@@ -272,6 +272,14 @@ static uint32_t cflags_for_breakpoints(CPUState *cpu,
target_ulong pc,
}
}
+ if (unlikely(cpu->singlestep_enabled)) {
+ /*
+ * Record gdb single-step. We should be exiting the TB by raising
+ * EXCP_DEBUG, but to simplify other tests, disable chaining too.
+ */
+ bflags = CF_NO_GOTO_TB | CF_NO_GOTO_PTR | CF_SINGLE_STEP | 1;
+ }
+
if (unlikely(bflags)) {
cflags = (cflags & ~CF_COUNT_MASK) | bflags;
}
@@ -409,7 +417,11 @@ void cpu_exec_step_atomic(CPUState *cpu)
* We only arrive in cpu_exec_step_atomic after beginning execution
* of an insn that includes an atomic operation we can't handle.
* Any breakpoint for this insn will have been recognized earlier.
+ * But do record single-stepping.
*/
+ if (unlikely(cpu->singlestep_enabled)) {
+ cflags |= CF_SINGLE_STEP;
+ }
tb = tb_lookup(cpu, pc, cs_base, flags, cflags);
if (tb == NULL) {
diff --git a/accel/tcg/translator.c b/accel/tcg/translator.c
index b45337f3ba..c53a7f8e44 100644
--- a/accel/tcg/translator.c
+++ b/accel/tcg/translator.c
@@ -38,11 +38,6 @@ bool translator_use_goto_tb(DisasContextBase *db,
target_ulong dest)
return false;
}
- /* Suppress goto_tb in the case of single-steping. */
- if (db->singlestep_enabled) {
- return false;
- }
-
/* Check for the dest on the same page as the start of the TB. */
return ((db->pc_first ^ dest) & TARGET_PAGE_MASK) == 0;
}
@@ -60,7 +55,7 @@ void translator_loop(const TranslatorOps *ops,
DisasContextBase *db,
db->is_jmp = DISAS_NEXT;
db->num_insns = 0;
db->max_insns = max_insns;
- db->singlestep_enabled = cpu->singlestep_enabled;
+ db->singlestep_enabled = cflags & CF_SINGLE_STEP;
ops->init_disas_context(db, cpu);
tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */
diff --git a/cpu.c b/cpu.c
index 660b56f431..addcb5db9c 100644
--- a/cpu.c
+++ b/cpu.c
@@ -316,10 +316,6 @@ void cpu_single_step(CPUState *cpu, int enabled)
cpu->singlestep_enabled = enabled;
if (kvm_enabled()) {
kvm_update_guest_debug(cpu, 0);
- } else {
- /* must flush all the translated code to avoid inconsistencies */
- /* XXX: only flush what is necessary */
- tb_flush(cpu);
}
trace_breakpoint_singlestep(cpu->cpu_index, enabled);
}
--
2.25.1
