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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 482ABC64EC4 for ; Fri, 10 Mar 2023 12:45:34 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pac7g-0001Av-QH; Fri, 10 Mar 2023 07:45:24 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pac7c-0001AP-Pu for qemu-devel@nongnu.org; Fri, 10 Mar 2023 07:45:20 -0500 Received: from mail-pj1-x102a.google.com ([2607:f8b0:4864:20::102a]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1pac7b-0004EU-3L for qemu-devel@nongnu.org; Fri, 10 Mar 2023 07:45:20 -0500 Received: by mail-pj1-x102a.google.com with SMTP id h17-20020a17090aea9100b0023739b10792so5059826pjz.1 for ; Fri, 10 Mar 2023 04:45:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1678452317; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=RpuYiEAKbm4Qfr2AKsSAnd879Dy4ZTeAB8TgLuhER/c=; b=Kl2BezlzW7es/06NzB30kxas1opljwlWmMi5ZVFb5rMVNCYC+lr9Bwc8gjCtZCSA85 ZGfQGwJqUm9FBsn8AuWQxxU+X2dTEZT/oPkUopKRTJ2loddyJ7dt/YFVLTPKitE2TfaA XXOtMB/A6g+L4/9oJ64vlaTrW3rd6SXnMuuj/NE1qFbHyfEcO/oGbb7uE1jHWWexVBSj uObyltnoZNcnNbeiYP4e6iSnhZnkRXQa5E5nE3hFczY8Z/p2dF+RJ1YjgNiZJUjDuqpc gmm2SZ4R13se1CO8SMKByqXNcJC3t8yIUN3PD85b8Xrp/CYynKCKnSmBQ5DbjKtwMo5O r8Kw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678452317; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=RpuYiEAKbm4Qfr2AKsSAnd879Dy4ZTeAB8TgLuhER/c=; b=A7TeKNDfDnlhTaktWJfpR/Kv/bNm8c+p8emd9Kc48ZWFyiUsZ9/my5zHtK2QH+I8Tt K31hWd70SMuBxST88MtXJbyO5BwGq0HbFboOIyC6jxxQyvGFs3uGv3fiVYIyd25R/vzj qKQEf39cp7EiUF3DRTHT/Nt6YJn/98sj1kMS4uXwjIAH1EolvoBKtuLy0vtxdoVrpU3+ fw1R3fHP5rgmNBEkxZUXUMwkNdzIMwBuIBUTUzxBi/kSmOxxaRp7n2CvfzsJtjjbNWCH 4XeWA6n2mGBmpt8p/8bTXyTyhVvrjy+s0pBVRp3GaUclNaCmu5gk1BIkEm8t4OnoXYGQ yWrA== X-Gm-Message-State: AO0yUKXqHnFmdlNsPGFDKw+Q8TsWLWWqEZUrCJUrjw7iHfN5PpIZC66i /jtN6JxZ0u+tWUaAhqf68ZqcqVVASiU/qcWdxK2f6w== X-Google-Smtp-Source: AK7set8Q3ym1GXmnDqhCCSpmZnUx60vtG9pBjafalSnocKOF0obpg88yYKi8c8ebgh8kAZ62nVs7nfc5dEi2XztD75g= X-Received: by 2002:a17:90b:f12:b0:237:5834:2808 with SMTP id br18-20020a17090b0f1200b0023758342808mr9517485pjb.0.1678452317328; Fri, 10 Mar 2023 04:45:17 -0800 (PST) MIME-Version: 1.0 References: <20230205040737.3567731-1-alxndr@bu.edu> <20230205040737.3567731-2-alxndr@bu.edu> <9cfa0cc8-01c7-cf79-72ef-3224d1276e16@proxmox.com> <20230310122347.hghmijad7wajiqne@mozz.bu.edu> <20230310123117.d2uxze7zqtigmg44@mozz.bu.edu> In-Reply-To: <20230310123117.d2uxze7zqtigmg44@mozz.bu.edu> From: Peter Maydell Date: Fri, 10 Mar 2023 12:45:05 +0000 Message-ID: Subject: Re: [PATCH v6 1/4] memory: prevent dma-reentracy issues To: Alexander Bulekov Cc: Fiona Ebner , qemu-devel@nongnu.org, Stefan Hajnoczi , =?UTF-8?Q?Philippe_Mathieu=2DDaud=C3=A9?= , Mauro Matteo Cascella , Peter Xu , Jason Wang , David Hildenbrand , Gerd Hoffmann , Thomas Huth , Laurent Vivier , Bandan Das , "Edgar E . Iglesias" , Darren Kenny , Bin Meng , Paolo Bonzini , "Michael S . Tsirkin" , Marcel Apfelbaum , =?UTF-8?Q?Daniel_P_=2E_Berrang=C3=A9?= , Eduardo Habkost , Jon Maloy , Siqi Chen , Fam Zheng Content-Type: text/plain; charset="UTF-8" Received-SPF: pass client-ip=2607:f8b0:4864:20::102a; envelope-from=peter.maydell@linaro.org; helo=mail-pj1-x102a.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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Fri, 10 Mar 2023 at 12:32, Alexander Bulekov wrote: > This MR seems to be "lsi-ram". > > From hw/scsi/lsi53c895a.c: > > memory_region_init_io(&s->ram_io, OBJECT(s), &lsi_ram_ops, s, > "lsi-ram", 0x2000); > > So the LSI device is reading an LSI "Script" from its own IO region.. In > this particular case, I think there was no reason to use > memory_region_init_io rather than memory_region_init_ram, but this makes > me worried that there are other devices that use something like this. This particular device predates the entire MemoryRegion set of abstractions, so it might have seemed easier at the time. The endianness handling of the current code is also a bit confusing and might make it tricky to convert to a RAM MR. thanks -- PMM