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authorRichard Henderson <richard.henderson@linaro.org>2021-07-19 10:43:46 -1000
committerRichard Henderson <richard.henderson@linaro.org>2021-07-21 07:47:05 -1000
commitc2ffd7549b14373e9ca68eccd84fab141ffde646 (patch)
tree0362efe97ae88aa9d357b92c4ff052a142a55ca3
parentd40c5c79764db01cb7e495bfcec62df9be481bce (diff)
accel/tcg: Record singlestep_enabled in tb->cflags
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. Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
-rw-r--r--accel/tcg/cpu-exec.c7
-rw-r--r--accel/tcg/translate-all.c4
-rw-r--r--accel/tcg/translator.c7
-rw-r--r--cpu.c4
-rw-r--r--include/exec/exec-all.h1
5 files changed, 8 insertions, 15 deletions
diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
index 5cc6363f4c..fc895cf51e 100644
--- a/accel/tcg/cpu-exec.c
+++ b/accel/tcg/cpu-exec.c
@@ -150,10 +150,15 @@ uint32_t curr_cflags(CPUState *cpu)
uint32_t cflags = cpu->tcg_cflags;
/*
+ * Record gdb single-step. We should be exiting the TB by raising
+ * EXCP_DEBUG, but to simplify other tests, disable chaining too.
+ *
* For singlestep and -d nochain, suppress goto_tb so that
* we can log -d cpu,exec after every TB.
*/
- if (singlestep) {
+ if (unlikely(cpu->singlestep_enabled)) {
+ cflags |= CF_NO_GOTO_TB | CF_NO_GOTO_PTR | CF_SINGLE_STEP | 1;
+ } else if (singlestep) {
cflags |= CF_NO_GOTO_TB | 1;
} else if (qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) {
cflags |= CF_NO_GOTO_TB;
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
index bf82c15aab..bbfcfb698c 100644
--- a/accel/tcg/translate-all.c
+++ b/accel/tcg/translate-all.c
@@ -1432,10 +1432,6 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
}
QEMU_BUILD_BUG_ON(CF_COUNT_MASK + 1 != TCG_MAX_INSNS);
- if (cpu->singlestep_enabled) {
- max_insns = 1;
- }
-
buffer_overflow:
tb = tcg_tb_alloc(tcg_ctx);
if (unlikely(!tb)) {
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 d6ae5ae581..e1799a15bc 100644
--- a/cpu.c
+++ b/cpu.c
@@ -326,10 +326,6 @@ 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);
}
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