diff options
| author | Sergey Fedorov <serge.fdrv@gmail.com> | 2016-07-15 20:58:43 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-09-13 19:08:42 +0200 |
| commit | 89a16b1e4294e3664667a151c2f70c84dfac6fd9 (patch) | |
| tree | dce042d3f42af47a13182a19786fcc4202b10705 | |
| parent | 4b7e69509df2fcbfdab8c62c294dbfcfdab8a6e1 (diff) | |
tcg: Prepare safe tb_jmp_cache lookup out of tb_lock
Ensure atomicity of CPU's 'tb_jmp_cache' access for future translation
block lookup out of 'tb_lock'.
Note that this patch does *not* make CPU's TLB invalidation safe if it
is done from some other thread while the CPU is in its execution loop.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20160715175852.30749-4-sergey.fedorov@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | cpu-exec.c | 4 | ||||
| -rw-r--r-- | translate-all.c | 10 |
2 files changed, 9 insertions, 5 deletions
diff --git a/cpu-exec.c b/cpu-exec.c index cf511f1b9a..32b58edb31 100644 --- a/cpu-exec.c +++ b/cpu-exec.c @@ -315,7 +315,7 @@ static TranslationBlock *tb_find_slow(CPUState *cpu, found: /* we add the TB in the virtual pc hash table */ - cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)] = tb; + atomic_set(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)], tb); return tb; } @@ -333,7 +333,7 @@ static inline TranslationBlock *tb_find_fast(CPUState *cpu, is executed. */ cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags); tb_lock(); - tb = cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)]; + tb = atomic_rcu_read(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)]); if (unlikely(!tb || tb->pc != pc || tb->cs_base != cs_base || tb->flags != flags)) { tb = tb_find_slow(cpu, pc, cs_base, flags); diff --git a/translate-all.c b/translate-all.c index 0dd6466e07..77ae59d7e9 100644 --- a/translate-all.c +++ b/translate-all.c @@ -851,7 +851,11 @@ void tb_flush(CPUState *cpu) tcg_ctx.tb_ctx.nb_tbs = 0; CPU_FOREACH(cpu) { - memset(cpu->tb_jmp_cache, 0, sizeof(cpu->tb_jmp_cache)); + int i; + + for (i = 0; i < TB_JMP_CACHE_SIZE; ++i) { + atomic_set(&cpu->tb_jmp_cache[i], NULL); + } cpu->tb_flushed = true; } @@ -1010,8 +1014,8 @@ void tb_phys_invalidate(TranslationBlock *tb, tb_page_addr_t page_addr) /* remove the TB from the hash list */ h = tb_jmp_cache_hash_func(tb->pc); CPU_FOREACH(cpu) { - if (cpu->tb_jmp_cache[h] == tb) { - cpu->tb_jmp_cache[h] = NULL; + if (atomic_read(&cpu->tb_jmp_cache[h]) == tb) { + atomic_set(&cpu->tb_jmp_cache[h], NULL); } } |