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 2A05BC38A02 for ; Fri, 28 Oct 2022 05:53:19 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ooIFF-0007JF-N1; Fri, 28 Oct 2022 01:49:29 -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 1ooIEq-00073K-B1 for qemu-devel@nongnu.org; Fri, 28 Oct 2022 01:49:07 -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 1ooIEo-0007LY-NG for qemu-devel@nongnu.org; Fri, 28 Oct 2022 01:49:04 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1666936142; 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=9rVv9D1CHccCIYnMskVo+qTgBNeSRSnMfEyAnX8wGE8=; b=gRIBOdwykV6EDMDsWOP5/m3wAXJITv477M04Idx75ETKR7iNQgLA22kCBy0av6qaXT3PaM ZdOHEVFzpkOnxnbxAQwUHaLmPJZVgXkHOwgxEMyRvqZE6ByZRbHyCu+CcJ+JdWYdZqL6zX 4kPy9kb6aEVKnav/GJkiF+BtpBkbm2c= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-365-vl5NDE2zNgSJsMokt95_6g-1; Fri, 28 Oct 2022 01:49:00 -0400 X-MC-Unique: vl5NDE2zNgSJsMokt95_6g-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A0DE13802B89 for ; Fri, 28 Oct 2022 05:48:59 +0000 (UTC) Received: from localhost.localdomain (ovpn-13-50.pek2.redhat.com [10.72.13.50]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0AE5DC15BA8; Fri, 28 Oct 2022 05:48:56 +0000 (UTC) From: Jason Wang To: stefanha@redhat.com, qemu-devel@nongnu.org Cc: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , Thomas Huth , Jason Wang Subject: [PULL 06/26] net: improve error message for missing netdev backend Date: Fri, 28 Oct 2022 13:48:15 +0800 Message-Id: <20221028054835.29674-7-jasowang@redhat.com> In-Reply-To: <20221028054835.29674-1-jasowang@redhat.com> References: <20221028054835.29674-1-jasowang@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Received-SPF: pass client-ip=170.10.129.124; envelope-from=jasowang@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, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-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: , Sender: "Qemu-devel" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Daniel P. Berrangé 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. Reviewed-by: Marc-André Lureau Reviewed-by: Thomas Huth Signed-off-by: Daniel P. Berrangé Signed-off-by: Jason Wang --- net/net.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/net/net.c b/net/net.c index 2db160e..8ddafac 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; } -- 2.7.4