From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yuanhan Liu Subject: Re: [PATCH v4 1/2] vhost: Add callback and private data for vhost PMD Date: Thu, 19 Nov 2015 10:18:50 +0800 Message-ID: <20151119021850.GF2326@yliu-dev.sh.intel.com> References: <1447046221-20811-3-git-send-email-mukawa@igel.co.jp> <1447392031-24970-1-git-send-email-mukawa@igel.co.jp> <1447392031-24970-2-git-send-email-mukawa@igel.co.jp> <20151117132933.GV2326@yliu-dev.sh.intel.com> <564D2E06.7060608@igel.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: dev@dpdk.org, ann.zhuangyanying@huawei.com To: Tetsuya Mukawa Return-path: Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by dpdk.org (Postfix) with ESMTP id 606B72E8D for ; Thu, 19 Nov 2015 03:17:46 +0100 (CET) Content-Disposition: inline In-Reply-To: <564D2E06.7060608@igel.co.jp> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Thu, Nov 19, 2015 at 11:03:50AM +0900, Tetsuya Mukawa wrote: > On 2015/11/17 22:29, Yuanhan Liu wrote: > > On Fri, Nov 13, 2015 at 02:20:30PM +0900, Tetsuya Mukawa wrote: > >> These variables are needed to be able to manage one of virtio devices > >> using both vhost library APIs and vhost PMD. > >> For example, if vhost PMD uses current callback handler and private data > >> provided by vhost library, A DPDK application that links vhost library > >> cannot use some of vhost library APIs. > > Can you be more specific about this? > > > > --yliu > > How about like below? > > commit log: > Currently, when virtio device is created and destroyed, vhost library > will call one of callback handlers. > The vhost PMD need to use this pair of callback handlers to know which > virtio devices are connected actually. > Because we can register only one pair of callbacks to vhost library, if > the PMD use it, DPDK applications > cannot have a way to know the events. Will (and why) the two co-exist at same time? --yliu > This may break legacy DPDK > applications that uses vhost library. > To prevent it, this patch adds one more pair of callbacks to vhost > library especially for the vhost PMD. > With the patch, legacy applications can use the vhost PMD even if they > need additional specific handling > for virtio device creation and destruction. > For example, legacy application can call > rte_vhost_enable_guest_notification() in callbacks to change setting. > > Tetsuya