From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4C84FC2B9F8 for ; Tue, 25 May 2021 06:41:27 +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 EE6E6613F9 for ; Tue, 25 May 2021 06:41:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EE6E6613F9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=ispras.ru Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:42006 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1llQko-0004aO-0y for qemu-devel@archiver.kernel.org; Tue, 25 May 2021 02:41:26 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:58346) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1llQjz-0003Gr-Do for qemu-devel@nongnu.org; Tue, 25 May 2021 02:40:35 -0400 Received: from mail.ispras.ru ([83.149.199.84]:52040) by eggs.gnu.org with esmtps (TLS1.2:DHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1llQjx-0002Ni-Dj for qemu-devel@nongnu.org; Tue, 25 May 2021 02:40:35 -0400 Received: from [192.168.0.92] (unknown [62.118.138.151]) by mail.ispras.ru (Postfix) with ESMTPSA id 887A54076B44; Tue, 25 May 2021 06:40:24 +0000 (UTC) Subject: Re: [PATCH] replay: fix watchpoint processing for reverse debugging To: qemu-devel@nongnu.org References: <162072430303.827403.7379783546934958566.stgit@pasha-ThinkPad-X280> From: Pavel Dovgalyuk Message-ID: Date: Tue, 25 May 2021 09:40:24 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <162072430303.827403.7379783546934958566.stgit@pasha-ThinkPad-X280> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit 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, NICE_REPLY_A=-0.001, 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: pbonzini@redhat.com, alex.bennee@linaro.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" ping On 11.05.2021 12:11, Pavel Dovgalyuk wrote: > This patch enables reverse debugging with watchpoints. > Reverse continue scans the execution to find the breakpoints > and watchpoints that should fire. It uses helper function > replay_breakpoint() for that. But this function needs to access > icount, which can't be correct in the middle of TB. > Therefore, in case of watchpoint, we have to retranslate the block > to allow this access. > > Signed-off-by: Pavel Dovgalyuk > --- > softmmu/physmem.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/softmmu/physmem.c b/softmmu/physmem.c > index 5232696571..2826d60cef 100644 > --- a/softmmu/physmem.c > +++ b/softmmu/physmem.c > @@ -904,6 +904,16 @@ void cpu_check_watchpoint(CPUState *cpu, vaddr addr, vaddr len, > if (watchpoint_address_matches(wp, addr, len) > && (wp->flags & flags)) { > if (replay_running_debug()) { > + /* > + * replay_breakpoint reads icount. > + * Force recompile to succeed, because icount may > + * be read only at the end of the block. > + */ > + if (!cpu->can_do_io) { > + /* Force execution of one insn next time. */ > + cpu->cflags_next_tb = 1 | CF_LAST_IO | curr_cflags(cpu); > + cpu_loop_exit_restore(cpu, ra); > + } > /* > * Don't process the watchpoints when we are > * in a reverse debugging operation. >