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=-8.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 08E58C433E2 for ; Wed, 16 Sep 2020 16:08:51 +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 544B5224D4 for ; Wed, 16 Sep 2020 16:08:50 +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="XlJ6Xluu" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 544B5224D4 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]:39954 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kIZzF-0005iQ-Bm for qemu-devel@archiver.kernel.org; Wed, 16 Sep 2020 12:08:49 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:46550) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kIZvN-0002Te-6i for qemu-devel@nongnu.org; Wed, 16 Sep 2020 12:04:50 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:45478) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kIZvF-0005Tb-H3 for qemu-devel@nongnu.org; Wed, 16 Sep 2020 12:04:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1600272279; 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=SLa5bw1GcCI7RE2LQpwcOYLfofLwOTikWmuG3Qk2KAI=; b=XlJ6Xluu+yVzgPGLEi8lXFPcLCa2aW2GSgZShFw4CvmjkhbHT51YlMWhL6ybT4zgTXgvly GGGzY4pj1SaoS0Z/fBYGPDRF6BZiaUqke6YFgN5SJa3HTbjaz9vUBJoX4GzP4YEPRfYPY9 y2lPAfiXFZNQl3noycgIYZyspOl6+7w= 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-12-8ebWZnfkOb-1I2Y_YOFGQg-1; Wed, 16 Sep 2020 12:04:36 -0400 X-MC-Unique: 8ebWZnfkOb-1I2Y_YOFGQg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7A28FAD6B7 for ; Wed, 16 Sep 2020 16:04:18 +0000 (UTC) Received: from [10.3.113.91] (ovpn-113-91.phx2.redhat.com [10.3.113.91]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1821B75141; Wed, 16 Sep 2020 16:04:18 +0000 (UTC) Subject: Re: [PATCH 9/9] vhost-vdpa: allow pre-opend file descriptor To: Cindy Lu , Jason Wang References: <20200831082737.10983-1-jasowang@redhat.com> <20200831082737.10983-10-jasowang@redhat.com> From: Eric Blake Organization: Red Hat, Inc. Message-ID: <29454777-87fa-c42c-122b-bef4fd708464@redhat.com> Date: Wed, 16 Sep 2020 11:04:17 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eblake@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Received-SPF: pass client-ip=63.128.21.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/16 02:35:56 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -51 X-Spam_score: -5.2 X-Spam_bar: ----- X-Spam_report: (-5.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-2.999, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.062, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Markus Armbruster , QEMU Developers , Michael Tsirkin Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 8/31/20 6:16 AM, Cindy Lu wrote: > On Mon, 31 Aug 2020 at 16:30, Jason Wang wrote: >> >> This patch allows to initialize vhost-vdpa network backend with pre >> opened vhost-vdpa file descriptor. This is useful for running >> unprivileged qemu through libvirt. >> >> Cc: Eric Blake >> Cc: Markus Armbruster >> Signed-off-by: Jason Wang >> --- >> +++ b/qapi/net.json >> @@ -442,12 +442,15 @@ >> # @queues: number of queues to be created for multiqueue vhost-vdpa >> # (default: 1) >> # >> +# @fd: file descriptor of an already opened vhost-vdpa (since 5.2) >> +# >> # Since: 5.1 >> ## >> { 'struct': 'NetdevVhostVDPAOptions', >> 'data': { >> '*vhostdev': 'str', >> - '*queues': 'int' } } >> + '*queues': 'int', >> + '*fd': 'str' } } >> >> ## >> # @NetClientDriver: >> -- >> 2.20.1 >> > I think the latest code supported this part. > you can pass a pre open file descriptor to it via the add-fd QMP > command to /dev/fdset/NNN, and then pass the string > "/dev/fdset/NNN" as vhostdev. so we don't need a special fd parameter here. Correct - the 'vhostdev' parameter + magic filename is all the more that is needed to access a pre-opened fd, so no 'fd' parameter should be added. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org