From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-5414-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 56AF7985D23 for ; Tue, 12 Feb 2019 18:58:29 +0000 (UTC) Date: Tue, 12 Feb 2019 13:58:26 -0500 From: "Michael S. Tsirkin" Message-ID: <20190212135541-mutt-send-email-mst@kernel.org> References: <501110004.11631.1549031044295@oodm23.prod.google.com> <20190204053628.GD29758@stefanha-x1.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190204053628.GD29758@stefanha-x1.localdomain> Subject: Re: [virtio-dev] RFC: Doorbell suppression, packed-ring mode and hardware offload To: Stefan Hajnoczi Cc: Rob Miller , David Riddoch , Virtio-Dev List-ID: On Mon, Feb 04, 2019 at 01:36:28PM +0800, Stefan Hajnoczi wrote: > On Fri, Feb 01, 2019 at 09:43:02AM -0800, Rob Miller wrote: > > Agreed that this is needed. > > > > I would also like to suggest splitting the F_IN_ORDER into > > F_RX_IN_ORDER and F_TX_IN_ORDER to support hw LRO implementations, > > which can be more of a scatter/gather than tx. This would allow > > batchmode for tx at least in packed rings. > > > > Finally, i would suggest a means to specify a given rings ring mode > > and packed leans more towards TX, whilst split can be either really > > depending upon LRO, jumbo, rx buff size, ect.. just like F_IN_ORDER, > > we can have RX & TX, split out. > > Device types beside virtio-net might also want per-virtqueue F_IN_ORDER > and other features, Do you know that they will? Now that we already have implementations, how about a prototype patch showing the performance gains? > so let's find a way to make it independent of > virtio-net concepts like rx/tx. Add another field along with VQ PA. It's not rocket science. > The per-virtqueue in-order flag could live in struct > pvirtq_event_suppress (VIRTIO 1.1 2.7.14 Event Suppression Structure > Format). That's for dynamic things though. > Or a new structure could be used for per-virtqueue configuration. Doing > this is a little tricky if you want to select split vs packed ring > layout on a per-virtqueue basis, since this structure is part of the > split/packed ring layout. It would probably be necessary to add vring > mode selection to the transport (PCI, MMIO, CCW) instead. > > Stefan Yes. -- MST --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org