From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EA00417F9; Wed, 19 Jul 2023 04:04:28 +0000 (UTC) Received: from out30-98.freemail.mail.aliyun.com (out30-98.freemail.mail.aliyun.com [115.124.30.98]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 67F74127; Tue, 18 Jul 2023 21:04:26 -0700 (PDT) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R181e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046050;MF=xuanzhuo@linux.alibaba.com;NM=1;PH=DS;RN=15;SR=0;TI=SMTPD_---0Vnk1le9_1689739462; Received: from localhost(mailfrom:xuanzhuo@linux.alibaba.com fp:SMTPD_---0Vnk1le9_1689739462) by smtp.aliyun-inc.com; Wed, 19 Jul 2023 12:04:23 +0800 From: Xuan Zhuo To: virtualization@lists.linux-foundation.org Cc: "Michael S. Tsirkin" , Jason Wang , Xuan Zhuo , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , netdev@vger.kernel.org, bpf@vger.kernel.org, Christoph Hellwig Subject: [PATCH vhost v12 00/10] virtio core prepares for AF_XDP Date: Wed, 19 Jul 2023 12:04:12 +0800 Message-Id: <20230719040422.126357-1-xuanzhuo@linux.alibaba.com> X-Mailer: git-send-email 2.32.0.3.g01195cf9f Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Git-Hash: fc7afa711e97 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-9.9 required=5.0 tests=BAYES_00, ENV_AND_HDR_SPF_MATCH,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS, T_SCC_BODY_TEXT_LINE,UNPARSEABLE_RELAY,USER_IN_DEF_SPF_WL autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net ## 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. Thanks for the help from Christoph. ## For AF_XDP 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 ## VirtioNET rx dma merge After introducing premapping, I added an example to virtio-net. virtio-net can merge dma mappings through this feature. @Jason kernel command line: intel_iommu=on iommu.passthrough=0 | strict=0 | strict=1 Before | 775496pps | 428614pps After | 1109316pps | 742853pps Please review. Thanks. v12: 1. Alloc dma info from the alloc frag. Avoid alloc array to store the dma info. 2. rename virtqueue_set_premapped() to virtqueue_set_dma_premapped() v11 1. virtio-net merges dma operates based on the feature premapped 2. A better way to handle the map error with the premapped v10: 1. support to set vq to premapped mode, then the vq just handles the premapped request. 2. virtio-net support to do dma mapping in advance v9: 1. use flag to distinguish the premapped operations. no do judgment by sg. v8: 1. vring_sg_address: check by sg_page(sg) not dma_address. Because 0 is a valid dma address 2. remove unused code from vring_map_one_sg() 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 (10): virtio_ring: check use_dma_api before unmap desc for indirect virtio_ring: put mapping error check in vring_map_one_sg virtio_ring: introduce virtqueue_set_dma_premapped() virtio_ring: support add premapped buf virtio_ring: introduce virtqueue_dma_dev() virtio_ring: skip unmap for premapped 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() virtio_net: merge dma operations when filling mergeable buffers drivers/net/virtio_net.c | 225 +++++++++++++++++++++++++---- drivers/virtio/virtio_ring.c | 265 ++++++++++++++++++++++++++++------- include/linux/virtio.h | 6 + 3 files changed, 418 insertions(+), 78 deletions(-) -- 2.32.0.3.g01195cf9f