From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57052) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dMrGf-00051N-TQ for qemu-devel@nongnu.org; Mon, 19 Jun 2017 03:38:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dMrGc-0002H1-Pu for qemu-devel@nongnu.org; Mon, 19 Jun 2017 03:38:37 -0400 Received: from mga02.intel.com ([134.134.136.20]:44667) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dMrGc-0002Er-FG for qemu-devel@nongnu.org; Mon, 19 Jun 2017 03:38:34 -0400 Message-ID: <59478003.6040709@intel.com> Date: Mon, 19 Jun 2017 15:40:51 +0800 From: Wei Wang MIME-Version: 1.0 References: <26250da7-b394-4964-8842-5c45bbe85e09@redhat.com> <6547dfcf-ea3a-f5f6-222d-40ff274654df@redhat.com> <20170614180459-mutt-send-email-mst@kernel.org> <59422E91.7080407@intel.com> <20170616061949-mutt-send-email-mst@kernel.org> <40a12829-6e84-e63e-ac47-6f09cc85c3cc@redhat.com> <5943AE93.7020502@intel.com> <20170616181040-mutt-send-email-mst@kernel.org> <5944EA2E.9030608@intel.com> <20170618224025-mutt-send-email-mst@kernel.org> In-Reply-To: <20170618224025-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [virtio-dev] Re: [virtio-dev] Re: [virtio-dev] Re: [PATCH v1] virtio-net: enable configurable tx queue size List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Jason Wang , "virtio-dev@lists.oasis-open.org" , "stefanha@gmail.com" , "qemu-devel@nongnu.org" , "jan.scheurich@ericsson.com" , "armbru@redhat.com" , "marcandre.lureau@gmail.com" , "pbonzini@redhat.com" On 06/19/2017 03:46 AM, Michael S. Tsirkin wrote: >>>> >>>> What do you have in mind about the protocol flag? >>> Merely this: older clients might be confused if they get >>> a s/g with 1024 entries. >> I don't disagree to add that. But the client (i.e. vhost-user >> slave) is a host userspace program, and it seems that users can >> easily patch their host side applications if there is any issue, >> maybe we also don't need to be too prudent about that, do we? > I won't insist on this but it might not be easy. For example, are there > clients that want to forward the packet to host kernel as a s/g? Not sure about all the client implementation, but it sounds like a strange and inefficient usage of vhost-user to pass packets to the host kernel, given vhost kernel backend is already there for the usage. Best, Wei