From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by dpdk.org (Postfix) with ESMTP id 0C657FE5 for ; Fri, 31 Mar 2017 10:54:24 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=intel.com; i=@intel.com; q=dns/txt; s=intel; t=1490950465; x=1522486465; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=/snWmsYCHC05tez4CTirHx2Qyk3i+hLoN32WLfF07gw=; b=M2ioJ0dqJKEmTQI5kj3vn9/a+vVQy0uITm3RlkGY3dhIJ6l4PkzKUH4M prK6s42OC85DmmN3kFvVa/XnWQoJGA==; Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 31 Mar 2017 01:54:23 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.36,251,1486454400"; d="scan'208";a="83033943" Received: from yliu-dev.sh.intel.com (HELO yliu-dev) ([10.239.67.162]) by fmsmga006.fm.intel.com with ESMTP; 31 Mar 2017 01:54:22 -0700 Date: Fri, 31 Mar 2017 16:51:51 +0800 From: Yuanhan Liu To: Maxime Coquelin Cc: dev@dpdk.org, Harris James R , Liu Changpeng Message-ID: <20170331085151.GN18844@yliu-dev.sh.intel.com> References: <1490253059-28112-1-git-send-email-yuanhan.liu@linux.intel.com> <1490705142-893-1-git-send-email-yuanhan.liu@linux.intel.com> <1490705142-893-7-git-send-email-yuanhan.liu@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Subject: Re: [dpdk-dev] [PATCH v3 06/22] vhost: introduce API to fetch negotiated features X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 31 Mar 2017 08:54:25 -0000 On Fri, Mar 31, 2017 at 09:45:11AM +0200, Maxime Coquelin wrote: > >+uint64_t > >+rte_vhost_get_negotiated_features(int vid) > >+{ > >+ struct virtio_net *dev; > >+ > >+ dev = get_device(vid); > >+ if (!dev) > >+ return 0; > It's unlikely to happen with net devices, but as this series is about > generalizing the use of this lib, couldn't we have cases where the > negotiated features is 0? Yes, I think so. > If so, shouldn't be preferable the caller passes features pointer as > argument? I thought of that. The reason I did that is to keep the semantics with rte_vhost_driver_get_feature(path). But you are right, we don't have to follow that. More importantly, we may also need change the return value of rte_vhost_driver_get_features(path): which could also fail if 'path' is not found. --yliu