From patchwork Thu Nov 11 09:55:08 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Pavel Dovgalyuk X-Patchwork-Id: 12614523 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 507E5C433F5 for ; Thu, 11 Nov 2021 09:56:43 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EAE1E61207 for ; Thu, 11 Nov 2021 09:56:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org EAE1E61207 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=ispras.ru Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:41638 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ml6oz-0000sA-VY for qemu-devel@archiver.kernel.org; Thu, 11 Nov 2021 04:56:41 -0500 Received: from eggs.gnu.org ([209.51.188.92]:33960) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ml6nZ-0007JN-Ci for qemu-devel@nongnu.org; Thu, 11 Nov 2021 04:55:14 -0500 Received: from mail.ispras.ru ([83.149.199.84]:44968) by eggs.gnu.org with esmtps (TLS1.2:DHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ml6nX-0008OB-Dv for qemu-devel@nongnu.org; Thu, 11 Nov 2021 04:55:13 -0500 Received: from [127.0.1.1] (unknown [85.142.117.226]) by mail.ispras.ru (Postfix) with ESMTPSA id 1D48740755CE; Thu, 11 Nov 2021 09:55:09 +0000 (UTC) Subject: [PATCH v2 1/3] icount: preserve cflags when custom tb is about to execute From: Pavel Dovgalyuk To: qemu-devel@nongnu.org Date: Thu, 11 Nov 2021 12:55:08 +0300 Message-ID: <163662450891.125458.6706022775465303586.stgit@pasha-ThinkPad-X280> In-Reply-To: <163662450348.125458.5494710452733592356.stgit@pasha-ThinkPad-X280> References: <163662450348.125458.5494710452733592356.stgit@pasha-ThinkPad-X280> User-Agent: StGit/0.23 MIME-Version: 1.0 Received-SPF: pass client-ip=83.149.199.84; envelope-from=pavel.dovgalyuk@ispras.ru; helo=mail.ispras.ru X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: pavel.dovgalyuk@ispras.ru, david@redhat.com, richard.henderson@linaro.org, peterx@redhat.com, pbonzini@redhat.com, alex.bennee@linaro.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" When debugging with the watchpoints, qemu may need to create TB with single instruction. This is achieved by setting cpu->cflags_next_tb. But when this block is about to execute, it may be interrupted by another thread. In this case cflags will be lost and next executed TB will not be the special one. This patch checks TB exit reason and restores cflags_next_tb to allow finding the interrupted block. Signed-off-by: Pavel Dovgalyuk Signed-off-by: Alex Bennée --- accel/tcg/cpu-exec.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c index 2d14d02f6c..df12452b8f 100644 --- a/accel/tcg/cpu-exec.c +++ b/accel/tcg/cpu-exec.c @@ -846,6 +846,16 @@ static inline void cpu_loop_exec_tb(CPUState *cpu, TranslationBlock *tb, * cpu_handle_interrupt. cpu_handle_interrupt will also * clear cpu->icount_decr.u16.high. */ + if (cpu->cflags_next_tb == -1 + && (!use_icount || !(tb->cflags & CF_USE_ICOUNT) + || cpu_neg(cpu)->icount_decr.u16.low >= tb->icount)) { + /* + * icount is disabled or there are enough instructions + * in the budget, do not retranslate this block with + * different parameters. + */ + cpu->cflags_next_tb = tb->cflags; + } return; }