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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 9E348C4338F for ; Tue, 17 Aug 2021 13:34:46 +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 50EB060E09 for ; Tue, 17 Aug 2021 13:34:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 50EB060E09 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:33084 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mFzEr-0004L0-D3 for qemu-devel@archiver.kernel.org; Tue, 17 Aug 2021 09:34:45 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:35978) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mFzEF-0003gK-6L for qemu-devel@nongnu.org; Tue, 17 Aug 2021 09:34:07 -0400 Received: from mail-ed1-x536.google.com ([2a00:1450:4864:20::536]:38519) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1mFzED-0002Bd-M8 for qemu-devel@nongnu.org; Tue, 17 Aug 2021 09:34:06 -0400 Received: by mail-ed1-x536.google.com with SMTP id q3so27495938edt.5 for ; Tue, 17 Aug 2021 06:34:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=1MvMgBdv+UxvN+H9aPaZ2vBwax8OAsyUQzPcCcPXy+0=; b=YE0I7YNf5bwlKwpxasB370Ll1x+jZosz/NDQWz3HydToCwZ6cL5sbblVKtjmE+FSBk BJCa8P28nJadFG9GE2Xx76afWICK+Aw+j0QQnb4kSekjVCLfc7SLsgfbl1QygDmq90Pv skPo2+EDyame/sj7TTnRzUFTTRAq6nHnkFLtH2ShvuhR37M2hqNswCV7950aNY+5aiuw WIohe+TQihmj+H5dMQ5MLcN45u7X8G55Q33XsRycqq+ZrU4izLBB7Ymi+lA2JGmYLLAs yTroat7l9t1ZfCiLL7NoJkCu+SrPtYq2UCS6MQhEqdDfBRjEOwIoIo+nZzq8OTyiYerV ODug== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=1MvMgBdv+UxvN+H9aPaZ2vBwax8OAsyUQzPcCcPXy+0=; b=Tm8g06AOyaTetjmzz5QMZefyKIh4+87wGp8rMH0kC/7YXtRDl9PBdFhYtsu+sf3rvc JpSeNIVRujhxpTNPjiAJL5b0ERQnOcM0X2EXXFSI6kU0r+QiiWFvFyt/EsXRMRFssmLB VnM947qujvf2XMEWZvghz9X/LJhpzJfLfrXs4m81cXTeapmvQH72aHW98BEcZBA6KB9P /LI3uuEU/1u0tpRCaZwoT/v08dWdXjy64qqPNTgBNnG4ETD6uYyMmxNEaDX+wwb8Jn9m 9yoznLNebHEkusRVUPiirrk41C8p9lTriwLF7LTeshxRl/+Y763dc0Uc8val7rdhyK+o OHtg== X-Gm-Message-State: AOAM533fdbkjjZunREsrTj1TVW5BuszdiX+9MeAaM9JvgLxuKuo5M/f9 /2oDo5KPLASiE7TrNUO8lGJ0nKrU+az3HdMvFsVr2A== X-Google-Smtp-Source: ABdhPJwv2FqytEQef4HG3XpXAcTd3R4tET0lLhMBZuad5nEY4i5zwN1fSRRjgpFosmmNo1QlDdWfngP3zVUgZDSUVEo= X-Received: by 2002:a05:6402:220e:: with SMTP id cq14mr4194177edb.52.1629207244089; Tue, 17 Aug 2021 06:34:04 -0700 (PDT) MIME-Version: 1.0 References: <20210721195954.879535-1-richard.henderson@linaro.org> <20210721195954.879535-25-richard.henderson@linaro.org> In-Reply-To: <20210721195954.879535-25-richard.henderson@linaro.org> From: Peter Maydell Date: Tue, 17 Aug 2021 14:33:18 +0100 Message-ID: Subject: Re: [PULL 24/27] accel/tcg: Move breakpoint recognition outside translation To: Richard Henderson Content-Type: text/plain; charset="UTF-8" Received-SPF: pass client-ip=2a00:1450:4864:20::536; envelope-from=peter.maydell@linaro.org; helo=mail-ed1-x536.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, 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: =?UTF-8?B?QWxleCBCZW5uw6ll?= , Mark Cave-Ayland , QEMU Developers Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, 21 Jul 2021 at 21:00, Richard Henderson wrote: > > Trigger breakpoints before beginning translation of a TB > that would begin with a BP. Thus we never generate code > for the BP at all. I happened to notice in the Arm ARM today a corner case that this implementation approach I think gets wrong: the priority ordering of exceptions is supposed to be (among others) * (architectural) software step * instruction abort * (architectural) breakpoints I think that doing the bp check here means it is incorrectly hoisted up the priority order above both swstep and insn abort. We probably didn't do these in the right priority order before this series, though, and I dunno whether we get the insn-abort vs swstep ordering right either... -- PMM