From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Coquelin Subject: Re: [PATCH v2 09/12] virtio: add Rx checksum offload support Date: Wed, 5 Oct 2016 15:27:47 +0200 Message-ID: References: <1469088510-7552-1-git-send-email-olivier.matz@6wind.com> <1475485223-30566-1-git-send-email-olivier.matz@6wind.com> <1475485223-30566-10-git-send-email-olivier.matz@6wind.com> <1da0b2c2-931b-3164-d211-4ceee7fd6864@redhat.com> <98db7fbb-42bd-512f-1d40-a1f3304a895e@6wind.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: konstantin.ananyev@intel.com, sugesh.chandran@intel.com, bruce.richardson@intel.com, jianfeng.tan@intel.com, helin.zhang@intel.com, adrien.mazarguil@6wind.com, stephen@networkplumber.org, dprovan@bivio.net, xiao.w.wang@intel.com To: Olivier Matz , dev@dpdk.org, yuanhan.liu@linux.intel.com Return-path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id 99B8328F3 for ; Wed, 5 Oct 2016 15:27:53 +0200 (CEST) In-Reply-To: <98db7fbb-42bd-512f-1d40-a1f3304a895e@6wind.com> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Hi Olivier, On 10/05/2016 01:56 PM, Olivier Matz wrote: > Hi Maxime, > > On 10/03/2016 02:51 PM, Maxime Coquelin wrote: >>> --- a/drivers/net/virtio/virtio_rxtx.c >>> +++ b/drivers/net/virtio/virtio_rxtx.c >>> @@ -50,6 +50,7 @@ >>> #include >>> #include >>> #include >>> +#include >>> >>> #include "virtio_logs.h" >>> #include "virtio_ethdev.h" >>> @@ -627,6 +628,56 @@ virtio_update_packet_stats(struct virtnet_stats >>> *stats, struct rte_mbuf *mbuf) >>> } >>> } >>> >>> +/* Optionally fill offload information in structure */ >>> +static int >>> +virtio_rx_offload(struct rte_mbuf *m, struct virtio_net_hdr *hdr) >>> +{ >>> + struct rte_net_hdr_lens hdr_lens; >>> + uint32_t hdrlen, ptype; >>> + int l4_supported = 0; >>> + >>> + /* nothing to do */ >>> + if (hdr->flags == 0 && hdr->gso_type == VIRTIO_NET_HDR_GSO_NONE) >>> + return 0; >> Maybe we could first check whether offload features were negotiated? >> Doing this, we could return before accessing the header and so avoid a >> cache miss. > > Yes, doing this would avoid reading the virtio header when the rx > function is virtio_recv_pkts(). When using virtio_recv_mergeable_pkts(), > it won't have a big impact since we already need to read hdr->num_buffers. Right, it matters only for the non-mergeable buffers case. > > > I plan to do something like this in both recv functions: > > @@ -854,6 +854,7 @@ virtio_recv_pkts(void *rx_queue, struct rte_mbuf > **rx_pkts, uint16_t nb_pkts) > int error; > uint32_t i, nb_enqueued; > uint32_t hdr_size; > + uint64_t features; > struct virtio_net_hdr *hdr; > > nb_used = VIRTQUEUE_NUSED(vq); > @@ -872,6 +873,7 @@ virtio_recv_pkts(void *rx_queue, struct rte_mbuf > **rx_pkts, uint16_t nb_pkts) > nb_rx = 0; > nb_enqueued = 0; > hdr_size = hw->vtnet_hdr_size; > + features = hw->guest_features; > > for (i = 0; i < num ; i++) { > rxm = rcv_pkts[i]; > @@ -903,7 +905,8 @@ virtio_recv_pkts(void *rx_queue, struct rte_mbuf > **rx_pkts, uint16_t nb_pkts) > rte_vlan_strip(rxm); > > /* Update offload features */ > - if (virtio_rx_offload(rxm, hdr) < 0) { > + if ((features & VIRTIO_NET_F_GUEST_CSUM) && s/VIRTIO_NET_F_GUEST_CSUM/(1u << VIRTIO_NET_F_GUEST_CSUM)/ And don't forget to update the test for LRO patch. Except this, it sounds good. Thanks, Maxime > + virtio_rx_offload(rxm, hdr) < 0) { > virtio_discard_rxbuf(vq, rxm); > rxvq->stats.errors++; > continue; > > Thank you for the feedback. > Olivier >