accel/tcg: Add CF_NO_GOTO_TB and CF_NO_GOTO_PTR
Move the -d nochain check to bits on tb->cflags.
These will be used for more than -d nochain shortly.
Set bits during curr_cflags, test them in translator_use_goto_tb,
assert we're not doing anything odd in tcg_gen_goto_tb. The test
in tcg_gen_exit_tb is redundant with the assert for goto_tb_issue_mask.
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20210717221851.2124573-4-richard.henderson@linaro.org>
diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
index ef4214d..d3232d5 100644
--- a/accel/tcg/cpu-exec.c
+++ b/accel/tcg/cpu-exec.c
@@ -147,7 +147,13 @@
uint32_t curr_cflags(CPUState *cpu)
{
- return cpu->tcg_cflags;
+ uint32_t cflags = cpu->tcg_cflags;
+
+ if (qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) {
+ cflags |= CF_NO_GOTO_TB | CF_NO_GOTO_PTR;
+ }
+
+ return cflags;
}
/* Might cause an exception, so have a longjmp destination ready */
diff --git a/accel/tcg/translator.c b/accel/tcg/translator.c
index 59804af..2ea5a74 100644
--- a/accel/tcg/translator.c
+++ b/accel/tcg/translator.c
@@ -33,6 +33,11 @@
bool translator_use_goto_tb(DisasContextBase *db, target_ulong dest)
{
+ /* Suppress goto_tb if requested. */
+ if (tb_cflags(db->tb) & CF_NO_GOTO_TB) {
+ return false;
+ }
+
/* Suppress goto_tb in the case of single-steping. */
if (db->singlestep_enabled || singlestep) {
return false;
diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
index ae7603c..6873cce 100644
--- a/include/exec/exec-all.h
+++ b/include/exec/exec-all.h
@@ -494,13 +494,15 @@
uint32_t cflags; /* compile flags */
/* Note that TCG_MAX_INSNS is 512; we validate this match elsewhere. */
-#define CF_COUNT_MASK 0x000001ff
-#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
-#define CF_INVALID 0x00040000 /* TB is stale. Set with @jmp_lock held */
-#define CF_PARALLEL 0x00080000 /* Generate code for a parallel context */
-#define CF_CLUSTER_MASK 0xff000000 /* Top 8 bits are cluster ID */
+#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_LAST_IO 0x00008000 /* Last insn may be an IO access. */
+#define CF_MEMI_ONLY 0x00010000 /* Only instrument memory ops */
+#define CF_USE_ICOUNT 0x00020000
+#define CF_INVALID 0x00040000 /* TB is stale. Set with @jmp_lock held */
+#define CF_PARALLEL 0x00080000 /* Generate code for a parallel context */
+#define CF_CLUSTER_MASK 0xff000000 /* Top 8 bits are cluster ID */
#define CF_CLUSTER_SHIFT 24
/* Per-vCPU dynamic tracing state used to generate this TB */
diff --git a/tcg/tcg-op.c b/tcg/tcg-op.c
index 75eaa91..c754396 100644
--- a/tcg/tcg-op.c
+++ b/tcg/tcg-op.c
@@ -2723,10 +2723,6 @@
seen this numbered exit before, via tcg_gen_goto_tb. */
tcg_debug_assert(tcg_ctx->goto_tb_issue_mask & (1 << idx));
#endif
- /* When not chaining, exit without indicating a link. */
- if (qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) {
- val = 0;
- }
} else {
/* This is an exit via the exitreq label. */
tcg_debug_assert(idx == TB_EXIT_REQUESTED);
@@ -2738,6 +2734,8 @@
void tcg_gen_goto_tb(unsigned idx)
{
+ /* We tested CF_NO_GOTO_TB in translator_use_goto_tb. */
+ tcg_debug_assert(!(tcg_ctx->tb_cflags & CF_NO_GOTO_TB));
/* We only support two chained exits. */
tcg_debug_assert(idx <= TB_EXIT_IDXMAX);
#ifdef CONFIG_DEBUG_TCG
@@ -2746,25 +2744,23 @@
tcg_ctx->goto_tb_issue_mask |= 1 << idx;
#endif
plugin_gen_disable_mem_helpers();
- /* When not chaining, we simply fall through to the "fallback" exit. */
- if (!qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) {
- tcg_gen_op1i(INDEX_op_goto_tb, idx);
- }
+ tcg_gen_op1i(INDEX_op_goto_tb, idx);
}
void tcg_gen_lookup_and_goto_ptr(void)
{
- if (!qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) {
- TCGv_ptr ptr;
+ TCGv_ptr ptr;
- plugin_gen_disable_mem_helpers();
- ptr = tcg_temp_new_ptr();
- gen_helper_lookup_tb_ptr(ptr, cpu_env);
- tcg_gen_op1i(INDEX_op_goto_ptr, tcgv_ptr_arg(ptr));
- tcg_temp_free_ptr(ptr);
- } else {
+ if (tcg_ctx->tb_cflags & CF_NO_GOTO_PTR) {
tcg_gen_exit_tb(NULL, 0);
+ return;
}
+
+ plugin_gen_disable_mem_helpers();
+ ptr = tcg_temp_new_ptr();
+ gen_helper_lookup_tb_ptr(ptr, cpu_env);
+ tcg_gen_op1i(INDEX_op_goto_ptr, tcgv_ptr_arg(ptr));
+ tcg_temp_free_ptr(ptr);
}
static inline MemOp tcg_canonicalize_memop(MemOp op, bool is64, bool st)
