From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42305) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bPQSB-0003ZG-CM for qemu-devel@nongnu.org; Tue, 19 Jul 2016 04:32:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bPQS4-0002qG-Ax for qemu-devel@nongnu.org; Tue, 19 Jul 2016 04:32:34 -0400 Received: from mail-wm0-x244.google.com ([2a00:1450:400c:c09::244]:35331) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bPQS4-0002pu-5b for qemu-devel@nongnu.org; Tue, 19 Jul 2016 04:32:28 -0400 Received: by mail-wm0-x244.google.com with SMTP id i5so2011652wmg.2 for ; Tue, 19 Jul 2016 01:32:28 -0700 (PDT) Sender: Paolo Bonzini From: Paolo Bonzini Date: Tue, 19 Jul 2016 10:32:14 +0200 Message-Id: <1468917141-8155-4-git-send-email-pbonzini@redhat.com> In-Reply-To: <1468917141-8155-1-git-send-email-pbonzini@redhat.com> References: <1468917141-8155-1-git-send-email-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Qemu-devel] [PATCH 03/10] tcg: Prepare safe tb_jmp_cache lookup out of tb_lock List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: serge.fdrv@gmail.com, sergey.fedorov@linaro.org, alex.bennee@linaro.org From: Sergey Fedorov 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 Signed-off-by: Sergey Fedorov Signed-off-by: Sergey Fedorov Reviewed-by: Alex Bennée Message-Id: <20160715175852.30749-4-sergey.fedorov@linaro.org> Signed-off-by: Paolo Bonzini --- cpu-exec.c | 4 ++-- translate-all.c | 10 +++++++--- 2 files changed, 9 insertions(+), 5 deletions(-) diff --git a/cpu-exec.c b/cpu-exec.c index cf511f1..32b58ed 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_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 0d47c1c..fdf520a 100644 --- a/translate-all.c +++ b/translate-all.c @@ -848,7 +848,11 @@ 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; } @@ -1007,8 +1011,8 @@ 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); } } -- 2.7.4