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=-3.1 required=3.0 tests=BAYES_00,HK_RANDOM_FROM, MAILING_LIST_MULTI,SPF_HELO_NONE 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 6D49EC4363C for ; Thu, 8 Oct 2020 13:27:59 +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 7EDEE20754 for ; Thu, 8 Oct 2020 13:27:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7EDEE20754 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bu.edu Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:35708 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kQVxc-00015A-Ad for qemu-devel@archiver.kernel.org; Thu, 08 Oct 2020 09:27:56 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:53434) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kQVwo-0000VN-RS for qemu-devel@nongnu.org; Thu, 08 Oct 2020 09:27:06 -0400 Received: from relay68.bu.edu ([128.197.228.73]:38266) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kQVwn-0006FT-5Y for qemu-devel@nongnu.org; Thu, 08 Oct 2020 09:27:06 -0400 X-Envelope-From: alxndr@bu.edu X-BU-AUTH: mozz.bu.edu [128.197.127.33] Received: from BU-AUTH (localhost.localdomain [127.0.0.1]) (authenticated bits=0) by relay68.bu.edu (8.14.3/8.14.3) with ESMTP id 098DQBmu028318 (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256 verify=NO); Thu, 8 Oct 2020 09:26:15 -0400 Date: Thu, 8 Oct 2020 09:26:11 -0400 From: Alexander Bulekov To: Paolo Bonzini Subject: Re: [PATCH v3 04/16] fuzz: Add DMA support to the generic-fuzzer Message-ID: <20201008132611.stxybcthnpwaclbc@mozz.bu.edu> References: <20200921022506.873303-1-alxndr@bu.edu> <20200921022506.873303-5-alxndr@bu.edu> <4fa19590-4b40-aedb-fa1d-44c844337ecf@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4fa19590-4b40-aedb-fa1d-44c844337ecf@redhat.com> Received-SPF: pass client-ip=128.197.228.73; envelope-from=alxndr@bu.edu; helo=relay68.bu.edu X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/08 09:27:03 X-ACL-Warn: Detected OS = Linux 2.6.x X-Spam_score_int: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, HK_RANDOM_ENVFROM=0.001, HK_RANDOM_FROM=0.903, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no 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: Laurent Vivier , Thomas Huth , qemu-devel@nongnu.org, darren.kenny@oracle.com, bsd@redhat.com, stefanha@redhat.com, philmd@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 201008 0943, Paolo Bonzini wrote: > On 21/09/20 04:24, Alexander Bulekov wrote: > > + if (qtest_log_enabled) { > > + /* > > + * With QTEST_LOG, use a normal, slow QTest memwrite. Prefix the log > > + * that will be written by qtest.c with a DMA tag, so we can reorder > > + * the resulting QTest trace so the DMA fills precede the last PIO/MMIO > > + * command. > > + */ > > + fprintf(stderr, "[DMA] "); > > + fflush(stderr); > > + qtest_memwrite(qts_global, ar.addr, buf, ar.size); > > + } else { > > + /* > > + * Populate the region using address_space_write_rom to avoid writing to > > + * any IO MemoryRegions > > + */ > > + address_space_write_rom(first_cpu->as, ar.addr, MEMTXATTRS_UNSPECIFIED, > > + buf, ar.size); > > + } > > I wonder if you should just copy address_space_write_rom to your own > code. This way you can log the write just like qtest_memwrite would, > while skipping memwrites that would access IO regions. > > Paolo I took a quick look, and I think this should be possible, though I might also need to carry over memory_access_size and invalidate_and_set_dirty. That would certainly make things better for building reproducers, since I have seen cases where bugs were not reproducible with QTEST_LOG=1, because we were not using address_space_write_rom. I'll give it a shot! Thanks