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=-3.8 required=3.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 8DAA2C433E0 for ; Fri, 7 Aug 2020 09:39:59 +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 5A8EC206B5 for ; Fri, 7 Aug 2020 09:39:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="JdXIRsWN" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5A8EC206B5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:41548 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k3yr0-0005Tq-MW for qemu-devel@archiver.kernel.org; Fri, 07 Aug 2020 05:39:58 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:34462) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k3yqQ-000534-9G for qemu-devel@nongnu.org; Fri, 07 Aug 2020 05:39:22 -0400 Received: from mail-pg1-x535.google.com ([2607:f8b0:4864:20::535]:43430) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1k3yqO-0003m2-Pc for qemu-devel@nongnu.org; Fri, 07 Aug 2020 05:39:22 -0400 Received: by mail-pg1-x535.google.com with SMTP id d19so631852pgl.10 for ; Fri, 07 Aug 2020 02:39:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=eTkztUbmivJRPCo+XsRK4Ev3J0cSbfzzlZVdWhD+bLw=; b=JdXIRsWN9VGNPXtJzUBJhESddTCYsX7CfwCVwynZC6Bs2bLcMjBiwX3KaZ5+44Qmrw H76nM31FwQwqUjWyH5yfgeTFRAerW5/kP7up6PxdxDSHpYdAuZ9RDlHfu5jZ1rH5t90r dTLZVySDXUXHuNqObUq86wVBLaQk4RnAkD/iVPplggJ0xROTigAFiIs7EJtB+rng56E6 tJTjnTxGVgDvebEhxc+2TEmCkr7Tj42wqWbeIFa7E+LBjCfaK4RuvYCQnTlzIldkUAfl xjfj8zinY3Hy8LffdO4Kjdt7Ys7vz8jq2AevUUDfCBY0AxUm3ftSZN/eMWoQQHwqsfE+ 9zOQ== 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=eTkztUbmivJRPCo+XsRK4Ev3J0cSbfzzlZVdWhD+bLw=; b=WBVORZlCt8bx0qvRoC6fmtP9CllAEA1wej7Btr98h0kwhdHmzrRuvKgSjgKVitZNK1 PdFOYI4rQvJQ+bmKH0B/tXXzwYGohfBkh2GGUCkhZ5jicDjhAPLsixneG4u0NkMdSPwX foF/72zMUzRCunJeMJ5mxP8L1qM/8qGB0Q1uwkbCEfhuNMf0k2woSfiRT0sRq4F1n47Z C4KxJv44OrHct2kLKIH+Wyv7QwXvIcP7ZDwni3tLo5RnEuDm93sUQu+aZUOE5x9tVjnw gC4Xc+xsjGBwkgTRSqc34XbjLkFTRR802cMHQ4PqqqpZniqFl1Zv6wDopBS6gS5r7gKL h2Pg== X-Gm-Message-State: AOAM530/0kliYuxcXBkwOuRkF7XL3kSmgvWk+kDHGlT/6bhrVPzDjDuG ofiVzKRZmU3IQaBkycFHjiDlBnMDHnEPAI+bgIM= X-Google-Smtp-Source: ABdhPJxVfhJinPsNOa1lWwv5ZIx5RQY09C/B/J+j63cjrA3QibcVyVBooHWBKEZpZ3eNS8THpw1E3w4Pkog7Jf+rw0k= X-Received: by 2002:a65:558b:: with SMTP id j11mr11449329pgs.61.1596793159091; Fri, 07 Aug 2020 02:39:19 -0700 (PDT) MIME-Version: 1.0 References: <20200806115148.7lz32dro645a3wv6@mhamilton> In-Reply-To: <20200806115148.7lz32dro645a3wv6@mhamilton> From: Stefan Hajnoczi Date: Fri, 7 Aug 2020 10:39:07 +0100 Message-ID: Subject: Re: Why QEMU should move from C to Rust (clickbait alert ;)) To: Sergio Lopez Content-Type: text/plain; charset="UTF-8" Received-SPF: pass client-ip=2607:f8b0:4864:20::535; envelope-from=stefanha@gmail.com; helo=mail-pg1-x535.google.com X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. 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, FREEMAIL_FROM=0.001, 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: Peter Maydell , Markus Armbruster , qemu-devel , Dave Gilbert , "Oleinik, Alexander" , Paolo Bonzini , =?UTF-8?B?QWxleCBCZW5uw6ll?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, Aug 6, 2020 at 12:51 PM Sergio Lopez wrote: > 1. Having a reference implementation for a simple device somewhere > close or inside the QEMU source tree. I'd say vhost-user-blk is a > clear candidate, given that a naive implementation for raw files > without any I/O optimization is quite easy to read and understand. Yes, it's important to have crates that make it easy to build device backends. The following common areas come to mind: 1. vhost-user protocol and vring APIs. 2. vhost-user conventions for command-line options. 3. Live migration support. 4. Sandboxing (seccomp, etc). 5. Management interface. They can all be separate crates and you can choose which ones to use. Rust-vmm and cloud-hypervisor have already started on some of these. It would be nice to work together. Stefan