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=-5.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS autolearn=ham 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 0B640C33CAD for ; Mon, 13 Jan 2020 13:45:14 +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 CA7E421556 for ; Mon, 13 Jan 2020 13:45:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="XbR8qUZ6" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CA7E421556 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:50624 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ir01o-0007Ei-Qz for qemu-devel@archiver.kernel.org; Mon, 13 Jan 2020 08:45:12 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:52279) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ir00v-0006U0-9v for qemu-devel@nongnu.org; Mon, 13 Jan 2020 08:44:18 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ir00t-0005Gp-5C for qemu-devel@nongnu.org; Mon, 13 Jan 2020 08:44:16 -0500 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:59152 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ir00t-0005EP-1K for qemu-devel@nongnu.org; Mon, 13 Jan 2020 08:44:15 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1578923054; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2dN/yPyoFMeDL81OcuZj8le7+MM3kYXIME8a+Apfxzw=; b=XbR8qUZ6mx5w4K2GOdlHea2eb9RfW+iqg2zO3Hafn482aMvQNK/qCpNgBYRT9Y5Rpwcv4V XZPg5CMX4GKh6VW/y1TEEbdZvTfxgszOekoF93RZJBV+XLb1uraB7xuysXPbFQeGZctJPL BMi7VINlpcd0/KuazfO0pcl4GexNOI0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-113-UN7SW-qCPP2ZzZOmaR1P1A-1; Mon, 13 Jan 2020 08:44:10 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 76993107B288; Mon, 13 Jan 2020 13:44:09 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-116-131.ams2.redhat.com [10.36.116.131]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 0F51419C6A; Mon, 13 Jan 2020 13:44:02 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 925691138600; Mon, 13 Jan 2020 14:44:00 +0100 (CET) From: Markus Armbruster To: "Dr. David Alan Gilbert" Subject: Re: Making QEMU easier for management tools and applications References: <87h81unja8.fsf@dusky.pond.sub.org> <20200102150501.GA2973@work-vm> Date: Mon, 13 Jan 2020 14:44:00 +0100 In-Reply-To: <20200102150501.GA2973@work-vm> (David Alan Gilbert's message of "Thu, 2 Jan 2020 15:05:01 +0000") Message-ID: <87blr7zd27.fsf@dusky.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-MC-Unique: UN7SW-qCPP2ZzZOmaR1P1A-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.81 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: Kevin Wolf , Peter Maydell , "Daniel P. Berrange" , "Denis V. Lunev" , Cleber Rosa , Stefan Hajnoczi , qemu-devel , Eduardo Habkost , Paolo Bonzini , =?utf-8?Q?Marc-Andr=C3=A9?= Lureau , John Snow , Dominik Csapak Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" "Dr. David Alan Gilbert" writes: > * Markus Armbruster (armbru@redhat.com) wrote: >> Stefan Hajnoczi writes: >> > 4. Go and Rust bindings would also be useful. There is >> > https://github.com/intel/govmm but I think it makes sense to keep it >> > in qemu.git and provide an interface similar to our Python modules. >>=20 >> Mapping QAPI/QMP commands and events to function signatures isn't hard >> (the QAPI code generator does). Two problems (at least): >>=20 >> 1. Leads to some pretty ridiculous functions. Here's one: >>=20 >> void qmp_blockdev_mirror(bool has_job_id, const char *job_id, >> const char *device, >> const char *target, >> bool has_replaces, const char *replaces, >> MirrorSyncMode sync, >> bool has_speed, int64_t speed, >> bool has_granularity, uint32_t granularity, >> bool has_buf_size, int64_t buf_size, >> bool has_on_source_error, >> BlockdevOnError on_source_error, >> bool has_on_target_error, BlockdevOnError o= n_target_error, >> bool has_filter_node_name, const char *filt= er_node_name, >> bool has_copy_mode, MirrorCopyMode copy_mod= e,=20 >> bool has_auto_finalize, bool auto_finalize, >> bool has_auto_dismiss, bool auto_dismiss, >> Error **errp); > > Those might not be as bad when mapped to other languages, all the > bool/value pairs would become Option<...> so that removes that doubling. > The Error ** mechanism should somehow map onto functions returning a > normal Rust Result<> type. Fifteen parameters even with the has_FOO and the errp dropped. Still ridiculous enough for me.