From 3eab064e3fadaf2a6a128f167ad04ca0319b4e17 Mon Sep 17 00:00:00 2001 From: Anton Ivanov Date: Tue, 3 Oct 2017 10:08:05 +0100 Subject: VPP-1001 - update AF Packet Driver to for modern kernels 1. Add VNET headers support for checksumming - required to operate correctly on any recent Linux 2. Bypass QDISC on transmit - improves performance by ~ 5%. Enabled only if the macro is detected - apparently not present on archaic distributions. This still does not solve all issues with TSO - it can be fixed only by going to tpacket v3 and dynamic rx ring as well as significant changes in the TX (sendmmsg?). Change-Id: Iea14ade12586c0a8da49e6dd1012108a08bc85b3 Signed-off-by: Anton Ivanov --- src/vnet/devices/af_packet/node.c | 66 ++++++++++++++++++++++++++++++++++----- 1 file changed, 59 insertions(+), 7 deletions(-) (limited to 'src/vnet/devices/af_packet/node.c') diff --git a/src/vnet/devices/af_packet/node.c b/src/vnet/devices/af_packet/node.c index 99c91f38805..5301ad299f2 100644 --- a/src/vnet/devices/af_packet/node.c +++ b/src/vnet/devices/af_packet/node.c @@ -1,5 +1,4 @@ -/* - *------------------------------------------------------------------ +/*------------------------------------------------------------------ * af_packet.c - linux kernel packet interface * * Copyright (c) 2016 Cisco and/or its affiliates. @@ -18,6 +17,7 @@ */ #include +#include #include #include @@ -155,9 +155,18 @@ af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node, while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs) && n_left_to_next) { + + struct virtio_net_hdr *vh = + (struct virtio_net_hdr *) (((u8 *) tph) + tph->tp_mac - + sizeof (struct virtio_net_hdr)); u32 data_len = tph->tp_snaplen; u32 offset = 0; u32 bi0 = 0, first_bi0 = 0, prev_bi0; + u32 vlan_len = 0; + ip_csum_t wsum = 0; + u16 *wsum_addr = NULL; + u32 do_vnet = apm->flags & AF_PACKET_USES_VNET_HEADERS; + u32 do_csum = tph->tp_status & TP_STATUS_CSUMNOTREADY; while (data_len) { @@ -173,7 +182,6 @@ af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node, /* copy data */ u32 bytes_to_copy = data_len > n_buffer_bytes ? n_buffer_bytes : data_len; - u32 vlan_len = 0; u32 bytes_copied = 0; b0->current_data = 0; /* Kernel removes VLAN headers, so reconstruct VLAN */ @@ -195,10 +203,50 @@ af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node, bytes_copied = sizeof (ethernet_header_t); } } - clib_memcpy (((u8 *) vlib_buffer_get_current (b0)) + - bytes_copied + vlan_len, - (u8 *) tph + tph->tp_mac + offset + bytes_copied, - (bytes_to_copy - bytes_copied)); + /* Check if the incoming skb is marked as CSUM_PARTIAL, + * If VNET Headers are enabled TP_STATUS_CSUMNOTREADY is + * equivalent to the vnet csum flag. + **/ + if (PREDICT_TRUE ((do_vnet != 0) && (do_csum != 0))) + { + wsum_addr = (u16 *) (((u8 *) vlib_buffer_get_current (b0)) + + vlan_len + vh->csum_start + + vh->csum_offset); + if (bytes_copied <= vh->csum_start) + { + clib_memcpy (((u8 *) vlib_buffer_get_current (b0)) + + bytes_copied + vlan_len, + (u8 *) tph + tph->tp_mac + offset + + bytes_copied, + (vh->csum_start - bytes_copied)); + wsum = + ip_csum_and_memcpy (wsum, + ((u8 *) + vlib_buffer_get_current (b0)) + + vh->csum_start + vlan_len, + (u8 *) tph + tph->tp_mac + + offset + vh->csum_start, + (bytes_to_copy - vh->csum_start)); + } + else + { + wsum = + ip_csum_and_memcpy (wsum, + ((u8 *) + vlib_buffer_get_current (b0)) + + bytes_copied + vlan_len, + (u8 *) tph + tph->tp_mac + + offset + bytes_copied, + (bytes_to_copy - bytes_copied)); + } + } + else + { + clib_memcpy (((u8 *) vlib_buffer_get_current (b0)) + + bytes_copied + vlan_len, + (u8 *) tph + tph->tp_mac + offset + + bytes_copied, (bytes_to_copy - bytes_copied)); + } /* fill buffer header */ b0->current_length = bytes_to_copy + vlan_len; @@ -218,6 +266,10 @@ af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node, offset += bytes_to_copy; data_len -= bytes_to_copy; } + if (PREDICT_TRUE ((do_vnet != 0) && (do_csum != 0))) + { + *wsum_addr = ~ip_csum_fold (wsum); + } n_rx_packets++; n_rx_bytes += tph->tp_snaplen; to_next[0] = first_bi0; -- cgit 1.2.3-korg