From patchwork Thu Oct 28 11:48:22 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Dovgalyuk X-Patchwork-Id: 12589923 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 4418FC433F5 for ; Thu, 28 Oct 2021 11:54:10 +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 0A01A60F21 for ; Thu, 28 Oct 2021 11:54:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 0A01A60F21 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]:50308 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mg3yz-0004xW-1J for qemu-devel@archiver.kernel.org; Thu, 28 Oct 2021 07:54:09 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:45030) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mg3tS-0001EC-S4 for qemu-devel@nongnu.org; Thu, 28 Oct 2021 07:48:28 -0400 Received: from mail.ispras.ru ([83.149.199.84]:45592) by eggs.gnu.org with esmtps (TLS1.2:DHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mg3tQ-0002ST-Tl for qemu-devel@nongnu.org; Thu, 28 Oct 2021 07:48:26 -0400 Received: from [127.0.1.1] (unknown [85.142.117.226]) by mail.ispras.ru (Postfix) with ESMTPSA id 5C72340D403D; Thu, 28 Oct 2021 11:48:23 +0000 (UTC) Subject: [PATCH 4/4] icount: preserve cflags when custom tb is about to execute From: Pavel Dovgalyuk To: qemu-devel@nongnu.org Date: Thu, 28 Oct 2021 14:48:22 +0300 Message-ID: <163542170287.2127597.18369415404458239885.stgit@pasha-ThinkPad-X280> In-Reply-To: <163542167953.2127597.8760651610734002929.stgit@pasha-ThinkPad-X280> References: <163542167953.2127597.8760651610734002929.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: 2.1.23 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 --- 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 c9764c1325..af1c6e6ba3 100644 --- a/accel/tcg/cpu-exec.c +++ b/accel/tcg/cpu-exec.c @@ -842,6 +842,16 @@ 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; }