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
netvsc_run_xdp(struct net_device * ndev,struct netvsc_channel * nvchan,struct xdp_buff * xdp)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->frame_sz = PAGE_SIZE;
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
netvsc_xdp_fraglen(unsigned int len)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
netvsc_xdp_get(struct netvsc_device * nvdev)89 struct bpf_prog *netvsc_xdp_get(struct netvsc_device *nvdev)
90 {
91 return rtnl_dereference(nvdev->chan_table[0].bpf_prog);
92 }
93
netvsc_xdp_set(struct net_device * dev,struct bpf_prog * prog,struct netlink_ext_ack * extack,struct netvsc_device * nvdev)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 - 1);
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
netvsc_vf_setxdp(struct net_device * vf_netdev,struct bpf_prog * prog)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 int ret;
140
141 ASSERT_RTNL();
142
143 if (!vf_netdev)
144 return 0;
145
146 ndo_bpf = vf_netdev->netdev_ops->ndo_bpf;
147 if (!ndo_bpf)
148 return 0;
149
150 memset(&xdp, 0, sizeof(xdp));
151
152 if (prog)
153 bpf_prog_inc(prog);
154
155 xdp.command = XDP_SETUP_PROG;
156 xdp.prog = prog;
157
158 ret = ndo_bpf(vf_netdev, &xdp);
159
160 if (ret && prog)
161 bpf_prog_put(prog);
162
163 return ret;
164 }
165
netvsc_bpf(struct net_device * dev,struct netdev_bpf * bpf)166 int netvsc_bpf(struct net_device *dev, struct netdev_bpf *bpf)
167 {
168 struct net_device_context *ndevctx = netdev_priv(dev);
169 struct netvsc_device *nvdev = rtnl_dereference(ndevctx->nvdev);
170 struct net_device *vf_netdev = rtnl_dereference(ndevctx->vf_netdev);
171 struct netlink_ext_ack *extack = bpf->extack;
172 int ret;
173
174 if (!nvdev || nvdev->destroy) {
175 return -ENODEV;
176 }
177
178 switch (bpf->command) {
179 case XDP_SETUP_PROG:
180 ret = netvsc_xdp_set(dev, bpf->prog, extack, nvdev);
181
182 if (ret)
183 return ret;
184
185 ret = netvsc_vf_setxdp(vf_netdev, bpf->prog);
186
187 if (ret) {
188 netdev_err(dev, "vf_setxdp failed:%d\n", ret);
189 NL_SET_ERR_MSG_MOD(extack, "vf_setxdp failed");
190
191 netvsc_xdp_set(dev, NULL, extack, nvdev);
192 }
193
194 return ret;
195
196 default:
197 return -EINVAL;
198 }
199 }
200
