From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56600) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bKT3F-00078w-6q for qemu-devel@nongnu.org; Tue, 05 Jul 2016 12:18:22 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bKT3D-0001x9-3P for qemu-devel@nongnu.org; Tue, 05 Jul 2016 12:18:20 -0400 Received: from mail-wm0-x22d.google.com ([2a00:1450:400c:c09::22d]:34881) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bKT3C-0001wx-P5 for qemu-devel@nongnu.org; Tue, 05 Jul 2016 12:18:19 -0400 Received: by mail-wm0-x22d.google.com with SMTP id z126so81886837wme.0 for ; Tue, 05 Jul 2016 09:18:18 -0700 (PDT) From: =?UTF-8?q?Alex=20Benn=C3=A9e?= Date: Tue, 5 Jul 2016 17:18:14 +0100 Message-Id: <1467735496-16256-5-git-send-email-alex.bennee@linaro.org> In-Reply-To: <1467735496-16256-1-git-send-email-alex.bennee@linaro.org> References: <1467735496-16256-1-git-send-email-alex.bennee@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Qemu-devel] [PATCH v2 4/6] tcg: cpu-exec: factor out TB patching code List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: mttcg@listserver.greensocs.com, qemu-devel@nongnu.org, fred.konrad@greensocs.com, a.rigo@virtualopensystems.com, serge.fdrv@gmail.com, cota@braap.org, bobby.prani@gmail.com, rth@twiddle.net Cc: mark.burton@greensocs.com, pbonzini@redhat.com, jan.kiszka@siemens.com, peter.maydell@linaro.org, claudio.fontana@huawei.com, =?UTF-8?q?Alex=20Benn=C3=A9e?= , Peter Crosthwaite This is going to be useful in the next patch when rolling up the locking on the slow path into the TB patching. Signed-off-by: Alex Bennée --- cpu-exec.c | 59 +++++++++++++++++++++++++++++++++++++---------------------- 1 file changed, 37 insertions(+), 22 deletions(-) diff --git a/cpu-exec.c b/cpu-exec.c index dd0bd50..59c2ec5 100644 --- a/cpu-exec.c +++ b/cpu-exec.c @@ -278,6 +278,40 @@ static TranslationBlock *tb_find_physical(CPUState *cpu, return qht_lookup(&tcg_ctx.tb_ctx.htable, tb_cmp, &desc, h); } +/* + * Patch the last TB with a jump to the current TB. + * + * Modification of the TB has to be protected with tb_lock. + */ +static inline void maybe_patch_last_tb(CPUState *cpu, + TranslationBlock *tb, + TranslationBlock **last_tb, + int tb_exit) +{ + if (cpu->tb_flushed) { + /* Ensure that no TB jump will be modified as the + * translation buffer has been flushed. + */ + *last_tb = NULL; + cpu->tb_flushed = false; + } +#ifndef CONFIG_USER_ONLY + /* We don't take care of direct jumps when address mapping changes in + * system emulation. So it's not safe to make a direct jump to a TB + * spanning two pages because the mapping for the second page can change. + */ + if (tb->page_addr[1] != -1) { + *last_tb = NULL; + } +#endif + /* See if we can patch the calling TB. */ + if (*last_tb && !qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) { + tb_lock(); + tb_add_jump(*last_tb, tb_exit, tb); + tb_unlock(); + } +} + static TranslationBlock *tb_find_slow(CPUState *cpu, target_ulong pc, target_ulong cs_base, @@ -336,28 +370,9 @@ static inline TranslationBlock *tb_find_fast(CPUState *cpu, tb->flags != flags)) { tb = tb_find_slow(cpu, pc, cs_base, flags); } - if (cpu->tb_flushed) { - /* Ensure that no TB jump will be modified as the - * translation buffer has been flushed. - */ - *last_tb = NULL; - cpu->tb_flushed = false; - } -#ifndef CONFIG_USER_ONLY - /* We don't take care of direct jumps when address mapping changes in - * system emulation. So it's not safe to make a direct jump to a TB - * spanning two pages because the mapping for the second page can change. - */ - if (tb->page_addr[1] != -1) { - *last_tb = NULL; - } -#endif - /* See if we can patch the calling TB. */ - if (*last_tb && !qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) { - tb_lock(); - tb_add_jump(*last_tb, tb_exit, tb); - tb_unlock(); - } + + maybe_patch_last_tb(cpu, tb, last_tb, tb_exit); + return tb; } -- 2.7.4