tcg: Avoid bouncing tb_lock between tb_gen_code() and tb_add_jump()

Backports commit 74d356dd48b64eaa2a6104ac1493ca64cb31fa16 from qemu
This commit is contained in:
Sergey Fedorov 2018-02-26 02:01:33 -05:00 committed by Lioncash
parent 09c3ef656e
commit 9b6f287488
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GPG key ID: 4E3C3CC1031BA9C7

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@ -140,7 +140,8 @@ static TranslationBlock *tb_find_physical(CPUState *cpu,
static TranslationBlock *tb_find_slow(CPUState *cpu, static TranslationBlock *tb_find_slow(CPUState *cpu,
target_ulong pc, target_ulong pc,
target_ulong cs_base, target_ulong cs_base,
uint32_t flags) uint32_t flags,
bool *have_tb_lock)
{ {
TranslationBlock *tb; TranslationBlock *tb;
@ -153,6 +154,7 @@ static TranslationBlock *tb_find_slow(CPUState *cpu,
mmap_lock(); mmap_lock();
// Unicorn: commented out // Unicorn: commented out
//tb_lock(); //tb_lock();
*have_tb_lock = true;
/* There's a chance that our desired tb has been translated while /* There's a chance that our desired tb has been translated while
* taking the locks so we check again inside the lock. * taking the locks so we check again inside the lock.
@ -180,6 +182,7 @@ static inline TranslationBlock *tb_find_fast(CPUState *cpu,
TranslationBlock *tb; TranslationBlock *tb;
target_ulong cs_base, pc; target_ulong cs_base, pc;
uint32_t flags; uint32_t flags;
bool have_tb_lock = false;
/* we record a subset of the CPU state. It will /* we record a subset of the CPU state. It will
always be the same before a given translated block always be the same before a given translated block
@ -189,7 +192,7 @@ static inline TranslationBlock *tb_find_fast(CPUState *cpu,
tb = atomic_read(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)]); tb = atomic_read(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)]);
if (unlikely(!tb || tb->pc != pc || tb->cs_base != cs_base || if (unlikely(!tb || tb->pc != pc || tb->cs_base != cs_base ||
tb->flags != flags)) { tb->flags != flags)) {
tb = tb_find_slow(cpu, pc, cs_base, flags); tb = tb_find_slow(cpu, pc, cs_base, flags, &have_tb_lock);
} }
#ifndef CONFIG_USER_ONLY #ifndef CONFIG_USER_ONLY
/* We don't take care of direct jumps when address mapping changes in /* We don't take care of direct jumps when address mapping changes in
@ -202,14 +205,19 @@ static inline TranslationBlock *tb_find_fast(CPUState *cpu,
#endif #endif
/* See if we can patch the calling TB. */ /* See if we can patch the calling TB. */
if (last_tb && !qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) { if (last_tb && !qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) {
// Unicorn: commented out if (!have_tb_lock) {
//tb_lock(); // Unicorn: commented out
//tb_lock();
have_tb_lock = true;
}
/* Check if translation buffer has been flushed */ /* Check if translation buffer has been flushed */
if (cpu->tb_flushed) { if (cpu->tb_flushed) {
cpu->tb_flushed = false; cpu->tb_flushed = false;
} else if (!tb->invalid) { } else if (!tb->invalid) {
tb_add_jump(last_tb, tb_exit, tb); tb_add_jump(last_tb, tb_exit, tb);
} }
}
if (have_tb_lock) {
// Unicorn: commented out // Unicorn: commented out
//tb_unlock(); //tb_unlock();
} }