From patchwork Tue Apr 25 07:36:02 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xuan Zhuo X-Patchwork-Id: 13222920 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 07D16C6FD18 for ; Tue, 25 Apr 2023 07:37:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231186AbjDYHhB (ORCPT ); Tue, 25 Apr 2023 03:37:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44946 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232430AbjDYHgZ (ORCPT ); Tue, 25 Apr 2023 03:36:25 -0400 Received: from out30-113.freemail.mail.aliyun.com (out30-113.freemail.mail.aliyun.com [115.124.30.113]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6E07FC168; Tue, 25 Apr 2023 00:36:17 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R561e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045168;MF=xuanzhuo@linux.alibaba.com;NM=1;PH=DS;RN=14;SR=0;TI=SMTPD_---0VgzCndC_1682408173; Received: from localhost(mailfrom:xuanzhuo@linux.alibaba.com fp:SMTPD_---0VgzCndC_1682408173) by smtp.aliyun-inc.com; Tue, 25 Apr 2023 15:36:14 +0800 From: Xuan Zhuo To: virtualization@lists.linux-foundation.org Cc: "Michael S. Tsirkin" , Jason Wang , Xuan Zhuo , Alexei Starovoitov , Daniel Borkmann , "David S. Miller" , Jesper Dangaard Brouer , John Fastabend , netdev@vger.kernel.org, bpf@vger.kernel.org, Christoph Hellwig , Jakub Kicinski , Alexander Lobakin Subject: [PATCH vhost v7 00/11] virtio core prepares for AF_XDP Date: Tue, 25 Apr 2023 15:36:02 +0800 Message-Id: <20230425073613.8839-1-xuanzhuo@linux.alibaba.com> X-Mailer: git-send-email 2.32.0.3.g01195cf9f MIME-Version: 1.0 X-Git-Hash: c518d34a1cf7 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org ## About DMA APIs Now, virtio may can not work with DMA APIs when virtio features do not have VIRTIO_F_ACCESS_PLATFORM. 1. I tried to let DMA APIs return phy address by virtio-device. But DMA APIs just work with the "real" devices. 2. I tried to let xsk support callballs to get phy address from virtio-net driver as the dma address. But the maintainers of xsk may want to use dma-buf to replace the DMA APIs. I think that may be a larger effort. We will wait too long. So rethinking this, firstly, we can support premapped-dma only for devices with VIRTIO_F_ACCESS_PLATFORM. In the case of af-xdp, if the users want to use it, they have to update the device to support VIRTIO_F_RING_RESET, and they can also enable the device's VIRTIO_F_ACCESS_PLATFORM feature by the way. Thanks for the help from Christoph. ================= XDP socket(AF_XDP) is an excellent bypass kernel network framework. The zero copy feature of xsk (XDP socket) needs to be supported by the driver. The performance of zero copy is very good. ENV: Qemu with vhost. vhost cpu | Guest APP CPU |Guest Softirq CPU | PPS -----------------------------|---------------|------------------|------------ xmit by sockperf: 90% | 100% | | 318967 xmit by xsk: 100% | 30% | 33% | 1192064 recv by sockperf: 100% | 68% | 100% | 692288 recv by xsk: 100% | 33% | 43% | 771670 Before achieving the function of Virtio-Net, we also have to let virtio core support these features: 1. virtio core support premapped 2. virtio core support reset per-queue 3. introduce DMA APIs to virtio core Please review. Thanks. v7: 1. virtqueue_dma_dev() return NULL when virtio is without DMA API. v6: 1. change the size of the flags to u32. v5: 1. fix for error handler 2. add flags to record internal dma mapping v4: 1. rename map_inter to dma_map_internal 2. fix: Excess function parameter 'vq' description in 'virtqueue_dma_dev' v3: 1. add map_inter to struct desc state to reocrd whether virtio core do dma map v2: 1. based on sgs[0]->dma_address to judgment is premapped 2. based on extra.addr to judgment to do unmap for no-indirect desc 3. based on indir_desc to judgment to do unmap for indirect desc 4. rename virtqueue_get_dma_dev to virtqueue_dma_dev v1: 1. expose dma device. NO introduce the api for dma and sync 2. split some commit for review. Xuan Zhuo (11): virtio_ring: split: separate dma codes virtio_ring: packed: separate dma codes virtio_ring: packed-indirect: separate dma codes virtio_ring: split: support premapped virtio_ring: packed: support premapped virtio_ring: packed-indirect: support premapped virtio_ring: update document for virtqueue_add_* virtio_ring: introduce virtqueue_dma_dev() virtio_ring: correct the expression of the description of virtqueue_resize() virtio_ring: separate the logic of reset/enable from virtqueue_resize virtio_ring: introduce virtqueue_reset() drivers/virtio/virtio_ring.c | 352 +++++++++++++++++++++++++---------- include/linux/virtio.h | 4 + 2 files changed, 259 insertions(+), 97 deletions(-) --- 2.32.0.3.g01195cf9f