1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Copyright (c) 2019, Microsoft Corporation. 3 * 4 * Author: 5 * Haiyang Zhang <haiyangz@microsoft.com> 6 */ 7 8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 9 10 #include <linux/netdevice.h> 11 #include <linux/etherdevice.h> 12 #include <linux/ethtool.h> 13 #include <linux/bpf.h> 14 #include <linux/bpf_trace.h> 15 #include <linux/kernel.h> 16 #include <net/xdp.h> 17 18 #include <linux/mutex.h> 19 #include <linux/rtnetlink.h> 20 21 #include "hyperv_net.h" 22 23 u32 netvsc_run_xdp(struct net_device *ndev, struct netvsc_channel *nvchan, 24 struct xdp_buff *xdp) 25 { 26 void *data = nvchan->rsc.data[0]; 27 u32 len = nvchan->rsc.len[0]; 28 struct page *page = NULL; 29 struct bpf_prog *prog; 30 u32 act = XDP_PASS; 31 32 xdp->data_hard_start = NULL; 33 34 rcu_read_lock(); 35 prog = rcu_dereference(nvchan->bpf_prog); 36 37 if (!prog) 38 goto out; 39 40 /* allocate page buffer for data */ 41 page = alloc_page(GFP_ATOMIC); 42 if (!page) { 43 act = XDP_DROP; 44 goto out; 45 } 46 47 xdp->data_hard_start = page_address(page); 48 xdp->data = xdp->data_hard_start + NETVSC_XDP_HDRM; 49 xdp_set_data_meta_invalid(xdp); 50 xdp->data_end = xdp->data + len; 51 xdp->rxq = &nvchan->xdp_rxq; 52 xdp->handle = 0; 53 54 memcpy(xdp->data, data, len); 55 56 act = bpf_prog_run_xdp(prog, xdp); 57 58 switch (act) { 59 case XDP_PASS: 60 case XDP_TX: 61 case XDP_DROP: 62 break; 63 64 case XDP_ABORTED: 65 trace_xdp_exception(ndev, prog, act); 66 break; 67 68 default: 69 bpf_warn_invalid_xdp_action(act); 70 } 71 72 out: 73 rcu_read_unlock(); 74 75 if (page && act != XDP_PASS && act != XDP_TX) { 76 __free_page(page); 77 xdp->data_hard_start = NULL; 78 } 79 80 return act; 81 } 82 83 unsigned int netvsc_xdp_fraglen(unsigned int len) 84 { 85 return SKB_DATA_ALIGN(len) + 86 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); 87 } 88 89 struct bpf_prog *netvsc_xdp_get(struct netvsc_device *nvdev) 90 { 91 return rtnl_dereference(nvdev->chan_table[0].bpf_prog); 92 } 93 94 int netvsc_xdp_set(struct net_device *dev, struct bpf_prog *prog, 95 struct netlink_ext_ack *extack, 96 struct netvsc_device *nvdev) 97 { 98 struct bpf_prog *old_prog; 99 int buf_max, i; 100 101 old_prog = netvsc_xdp_get(nvdev); 102 103 if (!old_prog && !prog) 104 return 0; 105 106 buf_max = NETVSC_XDP_HDRM + netvsc_xdp_fraglen(dev->mtu + ETH_HLEN); 107 if (prog && buf_max > PAGE_SIZE) { 108 netdev_err(dev, "XDP: mtu:%u too large, buf_max:%u\n", 109 dev->mtu, buf_max); 110 NL_SET_ERR_MSG_MOD(extack, "XDP: mtu too large"); 111 112 return -EOPNOTSUPP; 113 } 114 115 if (prog && (dev->features & NETIF_F_LRO)) { 116 netdev_err(dev, "XDP: not support LRO\n"); 117 NL_SET_ERR_MSG_MOD(extack, "XDP: not support LRO"); 118 119 return -EOPNOTSUPP; 120 } 121 122 if (prog) 123 bpf_prog_add(prog, nvdev->num_chn); 124 125 for (i = 0; i < nvdev->num_chn; i++) 126 rcu_assign_pointer(nvdev->chan_table[i].bpf_prog, prog); 127 128 if (old_prog) 129 for (i = 0; i < nvdev->num_chn; i++) 130 bpf_prog_put(old_prog); 131 132 return 0; 133 } 134 135 int netvsc_vf_setxdp(struct net_device *vf_netdev, struct bpf_prog *prog) 136 { 137 struct netdev_bpf xdp; 138 bpf_op_t ndo_bpf; 139 140 ASSERT_RTNL(); 141 142 if (!vf_netdev) 143 return 0; 144 145 ndo_bpf = vf_netdev->netdev_ops->ndo_bpf; 146 if (!ndo_bpf) 147 return 0; 148 149 memset(&xdp, 0, sizeof(xdp)); 150 151 xdp.command = XDP_SETUP_PROG; 152 xdp.prog = prog; 153 154 return ndo_bpf(vf_netdev, &xdp); 155 } 156 157 static u32 netvsc_xdp_query(struct netvsc_device *nvdev) 158 { 159 struct bpf_prog *prog = netvsc_xdp_get(nvdev); 160 161 if (prog) 162 return prog->aux->id; 163 164 return 0; 165 } 166 167 int netvsc_bpf(struct net_device *dev, struct netdev_bpf *bpf) 168 { 169 struct net_device_context *ndevctx = netdev_priv(dev); 170 struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev); 171 struct net_device *vf_netdev = rtnl_dereference(ndevctx->vf_netdev); 172 struct netlink_ext_ack *extack = bpf->extack; 173 int ret; 174 175 if (!nvdev || nvdev->destroy) { 176 if (bpf->command == XDP_QUERY_PROG) { 177 bpf->prog_id = 0; 178 return 0; /* Query must always succeed */ 179 } else { 180 return -ENODEV; 181 } 182 } 183 184 switch (bpf->command) { 185 case XDP_SETUP_PROG: 186 ret = netvsc_xdp_set(dev, bpf->prog, extack, nvdev); 187 188 if (ret) 189 return ret; 190 191 ret = netvsc_vf_setxdp(vf_netdev, bpf->prog); 192 193 if (ret) { 194 netdev_err(dev, "vf_setxdp failed:%d\n", ret); 195 NL_SET_ERR_MSG_MOD(extack, "vf_setxdp failed"); 196 197 netvsc_xdp_set(dev, NULL, extack, nvdev); 198 } 199 200 return ret; 201 202 case XDP_QUERY_PROG: 203 bpf->prog_id = netvsc_xdp_query(nvdev); 204 return 0; 205 206 default: 207 return -EINVAL; 208 } 209 } 210