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=-8.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,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 57D3DC64E7A for ; Tue, 1 Dec 2020 06:26:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DCC5020857 for ; Tue, 1 Dec 2020 06:26:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="GurzyJYd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726396AbgLAG0m (ORCPT ); Tue, 1 Dec 2020 01:26:42 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:30355 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725859AbgLAG0m (ORCPT ); Tue, 1 Dec 2020 01:26:42 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1606803916; 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=KCHesexpjRFhWOcxGP78gptqdhCw6l2GCYqi5IE/c2M=; b=GurzyJYdaIbP7qEk7glfI4rJLLN636K9yE1TUOj48OgltwWmXfYJrU2RXVfhhSt4dEptds DUgRFiydI/ZoxJ9vMp7X/4qKB92uV9VkUA0NViLXfsC5AZg8ktI4N0NOLpH+LdHV+mxga+ Y1ZcVWaAMgnVP2YhAQM7uIGPMihOzhE= 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-180-h6Hs-gSMOVqrcs__jDRWng-1; Tue, 01 Dec 2020 01:25:12 -0500 X-MC-Unique: h6Hs-gSMOVqrcs__jDRWng-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7820F180E49D; Tue, 1 Dec 2020 06:25:11 +0000 (UTC) Received: from [10.72.13.167] (ovpn-13-167.pek2.redhat.com [10.72.13.167]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8F69860853; Tue, 1 Dec 2020 06:25:06 +0000 (UTC) Subject: Re: [External] Re: [PATCH 0/7] Introduce vdpa management tool To: Yongji Xie Cc: Parav Pandit , virtualization@lists.linux-foundation.org, "Michael S. Tsirkin" , elic@nvidia.com, netdev@vger.kernel.org References: <20201112064005.349268-1-parav@nvidia.com> <5b2235f6-513b-dbc9-3670-e4c9589b4d1f@redhat.com> <182708df-1082-0678-49b2-15d0199f20df@redhat.com> From: Jason Wang Message-ID: <7f80eeed-f5d3-8c6f-1b8c-87b7a449975c@redhat.com> Date: Tue, 1 Dec 2020 14:25:05 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2020/11/30 下午3:07, Yongji Xie wrote: >>> Thanks for adding me, Jason! >>> >>> Now I'm working on a v2 patchset for VDUSE (vDPA Device in Userspace) >>> [1]. This tool is very useful for the vduse device. So I'm considering >>> integrating this into my v2 patchset. But there is one problem： >>> >>> In this tool, vdpa device config action and enable action are combined >>> into one netlink msg: VDPA_CMD_DEV_NEW. But in vduse case, it needs to >>> be splitted because a chardev should be created and opened by a >>> userspace process before we enable the vdpa device (call >>> vdpa_register_device()). >>> >>> So I'd like to know whether it's possible (or have some plans) to add >>> two new netlink msgs something like: VDPA_CMD_DEV_ENABLE and >>> VDPA_CMD_DEV_DISABLE to make the config path more flexible. >>> >> Actually, we've discussed such intermediate step in some early >> discussion. It looks to me VDUSE could be one of the users of this. >> >> Or I wonder whether we can switch to use anonymous inode(fd) for VDUSE >> then fetching it via an VDUSE_GET_DEVICE_FD ioctl? >> > Yes, we can. Actually the current implementation in VDUSE is like > this. But seems like this is still a intermediate step. The fd should > be binded to a name or something else which need to be configured > before. The name could be specified via the netlink. It looks to me the real issue is that until the device is connected with a userspace, it can't be used. So we also need to fail the enabling if it doesn't opened. Thanks > > Thanks, > Yongji >