From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Coquelin Subject: Re: [PATCH] net/virtio-user: add unsupported features mask Date: Wed, 27 Jun 2018 08:47:42 +0200 Message-ID: <6f409b78-f889-e3fb-2f63-d91940674dfc@redhat.com> References: <20180625131002.95629-1-yong.liu@intel.com> <86228AFD5BCD8E4EBFD2B90117B5E81E630CA896@SHSMSX103.ccr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: "Wang, Zhihong" , "dev@dpdk.org" To: "Liu, Yong" , "Bie, Tiwei" Return-path: Received: from mx1.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by dpdk.org (Postfix) with ESMTP id C02DC1BAB5 for ; Wed, 27 Jun 2018 08:47:46 +0200 (CEST) In-Reply-To: <86228AFD5BCD8E4EBFD2B90117B5E81E630CA896@SHSMSX103.ccr.corp.intel.com> Content-Language: en-US List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 06/26/2018 11:02 AM, Liu, Yong wrote: > > >> -----Original Message----- >> From: Maxime Coquelin [mailto:maxime.coquelin@redhat.com] >> Sent: Tuesday, June 26, 2018 4:08 PM >> To: Liu, Yong ; Bie, Tiwei >> Cc: Wang, Zhihong ; dev@dpdk.org >> Subject: Re: [PATCH] net/virtio-user: add unsupported features mask >> >> >> >> On 06/25/2018 03:10 PM, Marvin Liu wrote: >>> This patch introduces unsupported features mask for virtio-user device. >>> For virtio-user server mode, when reconnecting virtio-user will >>> retrieve vhost devcie features as base and then unmask unsupported >> s/devcie/device/ >>> features. >> >> I am not sure to understand why you are doing it like this. >> >> Shouldn't you just: >> 1. Don't advertise features you don't want to support >> 2. In server mode, save the negotiated features, and re-use it when >> reconnect happens? >> > Maxime, > I think our vhost reconnect design is following qemu vhost-user server mode. Virtio-user will try to support connected vhost device. > So device_features of virtio user just retrieve from vhost device. > And in server mode, we have recorded previous feature bits and used it for later negotiation. But virtio user device_features which may has changed by vdev parameters. This mask will guaranty device_features correct. Ok, get it now, thanks for the clarification. Please reword the variable name as I proposed, and pick this patch directly in your in_order series. With name change, feel free to add: Reviewed-by: Maxime Coquelin Thanks, Maxime > Thanks, > Marvin > >> Also, I find "unmask" a bit misleading, why not something like "unsupp" >> or "unsupported"? >> >> Thanks, >> Maxime