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 2CE8DECAAA1 for ; Thu, 27 Oct 2022 10:55:58 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oo0VN-0008HA-3w; Thu, 27 Oct 2022 06:52:57 -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 1oo0VK-0007v0-Kh for qemu-devel@nongnu.org; Thu, 27 Oct 2022 06:52:55 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oo0V3-0003pC-7g for qemu-devel@nongnu.org; Thu, 27 Oct 2022 06:52:54 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1666867955; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=SUhhYy63RNNp85bOHEX4Eg7UuagOhwfgnJD00ygKVMQ=; b=Ahvxq5RhfQKD7ZRePXmdtGp1ZwFZo6NpXNOfiKi7qmKlBXiPjhB7L/AUBteH87r5Kki8UY oEk8Si2wuvWtKKSIdDyV3utJU3x3bA7FZ0eP8fn6U8u8BtTkCThuw/imskT7S7vl16614x EqNmN0VTtwl2CVmq30cW7v0cAmqOzSE= 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-482-YwdV7GCXNDuiI_jcAjiVOQ-1; Thu, 27 Oct 2022 06:52:34 -0400 X-MC-Unique: YwdV7GCXNDuiI_jcAjiVOQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 5D2B487B2A0; Thu, 27 Oct 2022 10:52:34 +0000 (UTC) Received: from redhat.com (unknown [10.33.36.167]) by smtp.corp.redhat.com (Postfix) with ESMTPS id EDE5640C6EC3; Thu, 27 Oct 2022 10:52:32 +0000 (UTC) Date: Thu, 27 Oct 2022 11:52:30 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: qemu-devel@nongnu.org Cc: =?utf-8?Q?Marc-Andr=C3=A9?= Lureau , Christian Schoenebeck , Thomas Huth , Jason Wang Subject: Re: [PATCH] net: improve error message for missing netdev backend Message-ID: References: <20221003100612.596845-1-berrange@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20221003100612.596845-1-berrange@redhat.com> User-Agent: Mutt/2.2.7 (2022-08-07) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -25 X-Spam_score: -2.6 X-Spam_bar: -- X-Spam_report: (-2.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.515, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, 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?= Sender: "Qemu-devel" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org ping: Jason, are you willing to queue this since it has two positive reviews. On Mon, Oct 03, 2022 at 11:06:12AM +0100, Daniel P. Berrangé wrote: > The current message when using '-net user...' with SLIRP disabled at > compile time is: > > qemu-system-x86_64: -net user: Parameter 'type' expects a net backend type (maybe it is not compiled into this binary) > > An observation is that we're using the 'netdev->type' field here which > is an enum value, produced after QAPI has converted from its string > form. > > IOW, at this point in the code, we know that the user's specified > type name was a valid network backend. The only possible scenario that > can make the backend init function be NULL, is if support for that > backend was disabled at build time. Given this, we don't need to caveat > our error message with a 'maybe' hint, we can be totally explicit. > > The use of QERR_INVALID_PARAMETER_VALUE doesn't really lend itself to > user friendly error message text. Since this is not used to set a > specific QAPI error class, we can simply stop using this pre-formatted > error text and provide something better. > > Thus the new message is: > > qemu-system-x86_64: -net user: network backend 'user' is not compiled into this binary > > The case of passing 'hubport' for -net is also given a message reminding > people they should have used -netdev/-nic instead, as this backend type > is only valid for the modern syntax. > > Signed-off-by: Daniel P. Berrangé > --- > > NB, this does not make any difference to people who were relying on the > QEMU built-in default hub that was created if you don't list any -net / > -netdev / -nic argument, only those using explicit args. > > net/net.c | 18 +++++++++++------- > 1 file changed, 11 insertions(+), 7 deletions(-) > > diff --git a/net/net.c b/net/net.c > index 2db160e063..8ddafacf13 100644 > --- a/net/net.c > +++ b/net/net.c > @@ -1036,19 +1036,23 @@ static int net_client_init1(const Netdev *netdev, bool is_netdev, Error **errp) > if (is_netdev) { > if (netdev->type == NET_CLIENT_DRIVER_NIC || > !net_client_init_fun[netdev->type]) { > - error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type", > - "a netdev backend type"); > + error_setg(errp, "network backend '%s' is not compiled into this binary", > + NetClientDriver_str(netdev->type)); > return -1; > } > } else { > if (netdev->type == NET_CLIENT_DRIVER_NONE) { > return 0; /* nothing to do */ > } > - if (netdev->type == NET_CLIENT_DRIVER_HUBPORT || > - !net_client_init_fun[netdev->type]) { > - error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type", > - "a net backend type (maybe it is not compiled " > - "into this binary)"); > + if (netdev->type == NET_CLIENT_DRIVER_HUBPORT) { > + error_setg(errp, "network backend '%s' is only supported with -netdev/-nic", > + NetClientDriver_str(netdev->type)); > + return -1; > + } > + > + if (!net_client_init_fun[netdev->type]) { > + error_setg(errp, "network backend '%s' is not compiled into this binary", > + NetClientDriver_str(netdev->type)); > return -1; > } > > -- > 2.37.3 > 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 :|