From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 4EB9EA0C41; Mon, 22 Nov 2021 03:52:53 +0100 (CET) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id B36234014E; Mon, 22 Nov 2021 03:52:52 +0100 (CET) Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by mails.dpdk.org (Postfix) with ESMTP id 0EA714003C for ; Mon, 22 Nov 2021 03:52:50 +0100 (CET) X-IronPort-AV: E=McAfee;i="6200,9189,10175"; a="232195042" X-IronPort-AV: E=Sophos;i="5.87,253,1631602800"; d="scan'208";a="232195042" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Nov 2021 18:52:49 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,253,1631602800"; d="scan'208";a="606261046" Received: from npgdpdkvirtiojiayuhu117.sh.intel.com ([10.67.119.202]) by orsmga004.jf.intel.com with ESMTP; 21 Nov 2021 18:52:45 -0800 From: Jiayu Hu To: dev@dpdk.org Cc: maxime.coquelin@redhat.com, i.maximets@ovn.org, chenbo.xia@intel.com, bruce.richardson@intel.com, harry.van.haaren@intel.com, john.mcnamara@intel.com, sunil.pai.g@intel.com, Jiayu Hu Subject: [RFC 0/1] integrate dmadev in vhost Date: Mon, 22 Nov 2021 05:54:36 -0500 Message-Id: <20211122105437.3534231-1-jiayu.hu@intel.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Since dmadev is introduced in 21.11, to avoid the overhead of vhost DMA abstraction layer and simplify application logics, this patch integrates dmadev in vhost. To enable the flexibility of using DMA devices in different function modules, not limited in vhost, vhost doesn't manage DMA devices. Applications, like OVS, need to manage and configure DMA devices and tell vhost what DMA device to use in every dataplane function call. In addition, vhost supports M:N mapping between vrings and DMA virtual channels. Specifically, one vring can use multiple different DMA channels and one DMA channel can be shared by multiple vrings at the same time. The reason of enabling one vring to use multiple DMA channels is that it's possible that more than one dataplane threads enqueue packets to the same vring with their own DMA virtual channels. Besides, the number of DMA devices is limited. For the purpose of scaling, it's necessary to support sharing DMA channels among vrings. As only enqueue path is enabled DMA acceleration, the new dataplane functions are like: 1). rte_vhost_submit_enqueue_burst(vid, queue_id, pkts, count, dma_id, dma_vchan): Get descriptors and submit copies to DMA virtual channel for the packets that need to be send to VM. 2). rte_vhost_poll_enqueue_completed(vid, queue_id, pkts, count, dma_id, dma_vchan): Check completed DMA copies from the given DMA virtual channel and write back corresponding descriptors to vring. OVS needs to call rte_vhost_poll_enqueue_completed to clean in-flight copies on previous call and it can be called inside rxq_recv function, so that it doesn't require big change in OVS datapath. For example: netdev_dpdk_vhost_rxq_recv() { ... qid = rxq->queue_id * VIRTIO_QNUM + VIRTIO_RXQ; rte_vhost_poll_enqueue_completed(vid, qid, ...); } Jiayu Hu (1): vhost: integrate dmadev in asynchronous datapath doc/guides/prog_guide/vhost_lib.rst | 63 ++++---- examples/vhost/ioat.c | 218 ---------------------------- examples/vhost/ioat.h | 63 -------- examples/vhost/main.c | 144 +++++++++++++++--- examples/vhost/main.h | 12 ++ examples/vhost/meson.build | 6 +- lib/vhost/meson.build | 3 +- lib/vhost/rte_vhost_async.h | 73 +++------- lib/vhost/vhost.c | 37 ++--- lib/vhost/vhost.h | 45 +++++- lib/vhost/virtio_net.c | 198 ++++++++++++++++++++----- 11 files changed, 410 insertions(+), 452 deletions(-) delete mode 100644 examples/vhost/ioat.c delete mode 100644 examples/vhost/ioat.h -- 2.25.1