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kernel-aes67/drivers/net/vmxnet3/vmxnet3_xdp.h

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vmxnet3: Add XDP support. The patch adds native-mode XDP support: XDP DROP, PASS, TX, and REDIRECT. Background: The vmxnet3 rx consists of three rings: ring0, ring1, and dataring. For r0 and r1, buffers at r0 are allocated using alloc_skb APIs and dma mapped to the ring's descriptor. If LRO is enabled and packet size larger than 3K, VMXNET3_MAX_SKB_BUF_SIZE, then r1 is used to mapped the rest of the buffer larger than VMXNET3_MAX_SKB_BUF_SIZE. Each buffer in r1 is allocated using alloc_page. So for LRO packets, the payload will be in one buffer from r0 and multiple from r1, for non-LRO packets, only one descriptor in r0 is used for packet size less than 3k. When receiving a packet, the first descriptor will have the sop (start of packet) bit set, and the last descriptor will have the eop (end of packet) bit set. Non-LRO packets will have only one descriptor with both sop and eop set. Other than r0 and r1, vmxnet3 dataring is specifically designed for handling packets with small size, usually 128 bytes, defined in VMXNET3_DEF_RXDATA_DESC_SIZE, by simply copying the packet from the backend driver in ESXi to the ring's memory region at front-end vmxnet3 driver, in order to avoid memory mapping/unmapping overhead. In summary, packet size: A. < 128B: use dataring B. 128B - 3K: use ring0 (VMXNET3_RX_BUF_SKB) C. > 3K: use ring0 and ring1 (VMXNET3_RX_BUF_SKB + VMXNET3_RX_BUF_PAGE) As a result, the patch adds XDP support for packets using dataring and r0 (case A and B), not the large packet size when LRO is enabled. XDP Implementation: When user loads and XDP prog, vmxnet3 driver checks configurations, such as mtu, lro, and re-allocate the rx buffer size for reserving the extra headroom, XDP_PACKET_HEADROOM, for XDP frame. The XDP prog will then be associated with every rx queue of the device. Note that when using dataring for small packet size, vmxnet3 (front-end driver) doesn't control the buffer allocation, as a result we allocate a new page and copy packet from the dataring to XDP frame. The receive side of XDP is implemented for case A and B, by invoking the bpf program at vmxnet3_rq_rx_complete and handle its returned action. The vmxnet3_process_xdp(), vmxnet3_process_xdp_small() function handles the ring0 and dataring case separately, and decides the next journey of the packet afterward. For TX, vmxnet3 has split header design. Outgoing packets are parsed first and protocol headers (L2/L3/L4) are copied to the backend. The rest of the payload are dma mapped. Since XDP_TX does not parse the packet protocol, the entire XDP frame is dma mapped for transmission and transmitted in a batch. Later on, the frame is freed and recycled back to the memory pool. Performance: Tested using two VMs inside one ESXi vSphere 7.0 machine, using single core on each vmxnet3 device, sender using DPDK testpmd tx-mode attached to vmxnet3 device, sending 64B or 512B UDP packet. VM1 txgen: $ dpdk-testpmd -l 0-3 -n 1 -- -i --nb-cores=3 \ --forward-mode=txonly --eth-peer=0,<mac addr of vm2> option: add "--txonly-multi-flow" option: use --txpkts=512 or 64 byte VM2 running XDP: $ ./samples/bpf/xdp_rxq_info -d ens160 -a <options> --skb-mode $ ./samples/bpf/xdp_rxq_info -d ens160 -a <options> options: XDP_DROP, XDP_PASS, XDP_TX To test REDIRECT to cpu 0, use $ ./samples/bpf/xdp_redirect_cpu -d ens160 -c 0 -e drop Single core performance comparison with skb-mode. 64B: skb-mode -> native-mode XDP_DROP: 1.6Mpps -> 2.4Mpps XDP_PASS: 338Kpps -> 367Kpps XDP_TX: 1.1Mpps -> 2.3Mpps REDIRECT-drop: 1.3Mpps -> 2.3Mpps 512B: skb-mode -> native-mode XDP_DROP: 863Kpps -> 1.3Mpps XDP_PASS: 275Kpps -> 376Kpps XDP_TX: 554Kpps -> 1.2Mpps REDIRECT-drop: 659Kpps -> 1.2Mpps Demo: https://youtu.be/4lm1CSCi78Q Future work: - XDP frag support - use napi_consume_skb() instead of dev_kfree_skb_any at unmap - stats using u64_stats_t - using bitfield macro BIT() - optimization for DMA synchronization using actual frame length, instead of always max_len Signed-off-by: William Tu <u9012063@gmail.com> Reviewed-by: Alexander Duyck <alexanderduyck@fb.com> Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-10 00:13:04 -04:00
/* SPDX-License-Identifier: GPL-2.0-or-later
*
* Linux driver for VMware's vmxnet3 ethernet NIC.
* Copyright (C) 2008-2023, VMware, Inc. All Rights Reserved.
* Maintained by: pv-drivers@vmware.com
*
*/
#ifndef _VMXNET3_XDP_H
#define _VMXNET3_XDP_H
#include <linux/filter.h>
#include <linux/bpf_trace.h>
#include <linux/netlink.h>
#include "vmxnet3_int.h"
#define VMXNET3_XDP_HEADROOM (XDP_PACKET_HEADROOM + NET_IP_ALIGN)
#define VMXNET3_XDP_RX_TAILROOM SKB_DATA_ALIGN(sizeof(struct skb_shared_info))
#define VMXNET3_XDP_RX_OFFSET VMXNET3_XDP_HEADROOM
#define VMXNET3_XDP_MAX_FRSIZE (PAGE_SIZE - VMXNET3_XDP_HEADROOM - \
VMXNET3_XDP_RX_TAILROOM)
#define VMXNET3_XDP_MAX_MTU (VMXNET3_XDP_MAX_FRSIZE - ETH_HLEN - \
2 * VLAN_HLEN - ETH_FCS_LEN)
int vmxnet3_xdp(struct net_device *netdev, struct netdev_bpf *bpf);
int vmxnet3_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames,
u32 flags);
int vmxnet3_process_xdp(struct vmxnet3_adapter *adapter,
struct vmxnet3_rx_queue *rq,
struct Vmxnet3_RxCompDesc *rcd,
struct vmxnet3_rx_buf_info *rbi,
struct Vmxnet3_RxDesc *rxd,
struct sk_buff **skb_xdp_pass);
int vmxnet3_process_xdp_small(struct vmxnet3_adapter *adapter,
struct vmxnet3_rx_queue *rq,
void *data, int len,
struct sk_buff **skb_xdp_pass);
void *vmxnet3_pp_get_buff(struct page_pool *pp, dma_addr_t *dma_addr,
gfp_t gfp_mask);
static inline bool vmxnet3_xdp_enabled(struct vmxnet3_adapter *adapter)
{
return !!rcu_access_pointer(adapter->xdp_bpf_prog);
}
#endif