From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-comment-return-946-cohuck=redhat.com@lists.oasis-open.org Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 48D3C985CAF for ; Mon, 25 Nov 2019 08:30:34 +0000 (UTC) Date: Mon, 25 Nov 2019 03:30:26 -0500 From: "Michael S. Tsirkin" Message-ID: <20191125032811-mutt-send-email-mst@kernel.org> References: <20191111092046-mutt-send-email-mst@kernel.org> <20191120081531-mutt-send-email-mst@kernel.org> <20191124100825-mutt-send-email-mst@kernel.org> <20191125022719-mutt-send-email-mst@kernel.org> <5730ce35-19fc-e707-1113-30fe24caaeaa@redhat.com> <20191125031208-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 In-Reply-To: Subject: Re: [virtio-comment] Re: [EXT] Re: [virtio-comment] Re: [PATCH] virtio-net: Add equal-sized receive buffers feature Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline To: Jason Wang Cc: Vitaly Mireyno , "virtio-comment@lists.oasis-open.org" List-ID: On Mon, Nov 25, 2019 at 04:22:47PM +0800, Jason Wang wrote: >=20 > On 2019/11/25 =E4=B8=8B=E5=8D=884:18, Michael S. Tsirkin wrote: > > > > > > Again I can see how we might want to disallow crazy setups with= e.g. 1 > > > > > > byte per buffer. That's just abuse, no guest does that anyway. = So asking > > > > > > e.g. for a minimal buffer size sounds very reasonable. > > > > > One question here is that, the minimal buffer size should depends= on various > > > > > factors. E.g the ring size. Consider a 256 entries ring, the mini= mal size > > > > > should be 64K/256=3D256 ... > > > > I guess you are right. We can make this driver programmable I guess= ? > > > > Basically pass min_buf_len to the device. > > > Then it still have the chance to program the min_buf_len to 1? > > If it wants to - yes - presumably device won't work as well, > > fetching all kind of extra data e.g. unnecessary descriptors. > >=20 >=20 > Technically, device should still work for small packet and drop large > packet. I am not sure I agree. How is this different from just not being sufficient space in the RX ring? We certainly do not want to drop packets just because there's not enough buffers - it's a temporary condition. > Vhost has a bug that will stall RX in the case. I think we want to spec this first then. > Will post a fix. >=20 > Thanks This publicly archived list offers a means to provide input to the=0D OASIS Virtual I/O Device (VIRTIO) TC.=0D =0D In order to verify user consent to the Feedback License terms and=0D to minimize spam in the list archive, subscription is required=0D before posting.=0D =0D Subscribe: virtio-comment-subscribe@lists.oasis-open.org=0D Unsubscribe: virtio-comment-unsubscribe@lists.oasis-open.org=0D List help: virtio-comment-help@lists.oasis-open.org=0D List archive: https://lists.oasis-open.org/archives/virtio-comment/=0D Feedback License: https://www.oasis-open.org/who/ipr/feedback_license.pdf= =0D List Guidelines: https://www.oasis-open.org/policies-guidelines/mailing-lis= ts=0D Committee: https://www.oasis-open.org/committees/virtio/=0D Join OASIS: https://www.oasis-open.org/join/