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 7283DEE6457 for ; Fri, 15 Sep 2023 12:03:24 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qh7XF-0001oT-2d; Fri, 15 Sep 2023 08:02:57 -0400 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 1qh7Wx-0001nT-B3 for qemu-devel@nongnu.org; Fri, 15 Sep 2023 08:02:39 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qh7Wv-0006uT-H3 for qemu-devel@nongnu.org; Fri, 15 Sep 2023 08:02:39 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1694779356; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=5ddIrqavdfmTLZ3xvfQjaukZtshD8d8bNOIyeMGt5wc=; b=TeD03l3CqO3PuGRSzmNJf1UG6OL6Gu2KOxD9ODg0bbCgDa7eLvQqy9IIFFJ1lBmnvyZLNw 5y6Ew00aJpdZSkYRj3bIjCo9UfZTY9cBYHWHZ2S25xk7qUmXRxrYQg2/L6il9fko0ScLB7 wR9A7Azb5jJbPoDscYLTN77ug7FTvvw= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-495-SB0Iw_DAP16wVXNBSftwUQ-1; Fri, 15 Sep 2023 08:02:35 -0400 X-MC-Unique: SB0Iw_DAP16wVXNBSftwUQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B90C6185A797; Fri, 15 Sep 2023 12:02:34 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.37]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D716B176C3; Fri, 15 Sep 2023 12:02:33 +0000 (UTC) Date: Fri, 15 Sep 2023 13:02:31 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Stefan Hajnoczi Cc: Tyler Fanelli , qemu-devel@nongnu.org, pbonzini@redhat.com, mtosatti@redhat.com, stefanha@redhat.com Subject: Re: [RFC PATCH 0/8] i386/sev: Use C API of Rust SEV library Message-ID: References: <20230914175835.382972-1-tfanelli@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/2.2.9 (2022-11-12) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.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, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= 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, Sep 15, 2023 at 07:33:32AM -0400, Stefan Hajnoczi wrote: > The library approach worked well for libblkio but the overhead of > creating a separate shared library and shipping it is significant. > When QEMU is the only user of some code, then it should definitely be > part of QEMU. Also, when QEMU needs early access to code that isn't > widely available yet, then bundling it inside QEMU until packages are > available also seems reasonable to me (I think we already do that for > libvfio-user and maybe other libraries). Yep, avoiding the public shared library significantly cuts down the maint burden, as you can freely adapt the exposed C FFI API to suit QEMU's needs and not worry about ABI compatibility. > I would prefer it if we minimize Rust wrappers for C APIs and instead > focus on using Rust to build new subsystems. Writing and maintaing two > sets of the same API is expensive and I hope we don't get bogged down > keeping C and Rust APIs in sync. That said, I think there's an > argument for wrapping core QEMU APIs needed for device emulation (e.g. > DeviceState, PCIDevice) because of the security benefits of writing > new device emulation code in Rust. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|