xref: /qemu/ebpf/ebpf_rss.c (revision 4a1babe5) 
1 /*
2  * eBPF RSS loader
3  *
4  * Developed by Daynix Computing LTD (http://www.daynix.com)
5  *
6  * Authors:
7  *  Andrew Melnychenko <andrew@daynix.com>
8  *  Yuri Benditovich <yuri.benditovich@daynix.com>
9  *
10  * This work is licensed under the terms of the GNU GPL, version 2.  See
11  * the COPYING file in the top-level directory.
12  */
13 
14 #include "qemu/osdep.h"
15 #include "qemu/error-report.h"
16 #include "qapi/qapi-types-misc.h"
17 #include "qapi/qapi-commands-ebpf.h"
18 
19 #include <bpf/libbpf.h>
20 #include <bpf/bpf.h>
21 
22 #include "hw/virtio/virtio-net.h" /* VIRTIO_NET_RSS_MAX_TABLE_LEN */
23 
24 #include "ebpf/ebpf_rss.h"
25 #include "ebpf/rss.bpf.skeleton.h"
26 #include "ebpf/ebpf.h"
27 
28 void ebpf_rss_init(struct EBPFRSSContext *ctx)
29 {
30     if (ctx != NULL) {
31         ctx->obj = NULL;
32         ctx->program_fd = -1;
33         ctx->map_configuration = -1;
34         ctx->map_toeplitz_key = -1;
35         ctx->map_indirections_table = -1;
36 
37         ctx->mmap_configuration = NULL;
38         ctx->mmap_toeplitz_key = NULL;
39         ctx->mmap_indirections_table = NULL;
40     }
41 }
42 
43 bool ebpf_rss_is_loaded(struct EBPFRSSContext *ctx)
44 {
45     return ctx != NULL && (ctx->obj != NULL || ctx->program_fd != -1);
46 }
47 
48 static bool ebpf_rss_mmap(struct EBPFRSSContext *ctx)
49 {
50     if (!ebpf_rss_is_loaded(ctx)) {
51         return false;
52     }
53 
54     ctx->mmap_configuration = mmap(NULL, qemu_real_host_page_size(),
55                                    PROT_READ | PROT_WRITE, MAP_SHARED,
56                                    ctx->map_configuration, 0);
57     if (ctx->mmap_configuration == MAP_FAILED) {
58         return false;
59     }
60     ctx->mmap_toeplitz_key = mmap(NULL, qemu_real_host_page_size(),
61                                    PROT_READ | PROT_WRITE, MAP_SHARED,
62                                    ctx->map_toeplitz_key, 0);
63     if (ctx->mmap_toeplitz_key == MAP_FAILED) {
64         goto toeplitz_fail;
65     }
66     ctx->mmap_indirections_table = mmap(NULL, qemu_real_host_page_size(),
67                                    PROT_READ | PROT_WRITE, MAP_SHARED,
68                                    ctx->map_indirections_table, 0);
69     if (ctx->mmap_indirections_table == MAP_FAILED) {
70         goto indirection_fail;
71     }
72 
73     return true;
74 
75 indirection_fail:
76     munmap(ctx->mmap_toeplitz_key, qemu_real_host_page_size());
77     ctx->mmap_toeplitz_key = NULL;
78 toeplitz_fail:
79     munmap(ctx->mmap_configuration, qemu_real_host_page_size());
80     ctx->mmap_configuration = NULL;
81 
82     ctx->mmap_indirections_table = NULL;
83     return false;
84 }
85 
86 static void ebpf_rss_munmap(struct EBPFRSSContext *ctx)
87 {
88     if (!ebpf_rss_is_loaded(ctx)) {
89         return;
90     }
91 
92     munmap(ctx->mmap_indirections_table, qemu_real_host_page_size());
93     munmap(ctx->mmap_toeplitz_key, qemu_real_host_page_size());
94     munmap(ctx->mmap_configuration, qemu_real_host_page_size());
95 
96     ctx->mmap_configuration = NULL;
97     ctx->mmap_toeplitz_key = NULL;
98     ctx->mmap_indirections_table = NULL;
99 }
100 
101 bool ebpf_rss_load(struct EBPFRSSContext *ctx)
102 {
103     struct rss_bpf *rss_bpf_ctx;
104 
105     if (ebpf_rss_is_loaded(ctx)) {
106         return false;
107     }
108 
109     rss_bpf_ctx = rss_bpf__open();
110     if (rss_bpf_ctx == NULL) {
111         goto error;
112     }
113 
114     bpf_program__set_type(rss_bpf_ctx->progs.tun_rss_steering_prog, BPF_PROG_TYPE_SOCKET_FILTER);
115 
116     if (rss_bpf__load(rss_bpf_ctx)) {
117         goto error;
118     }
119 
120     ctx->obj = rss_bpf_ctx;
121     ctx->program_fd = bpf_program__fd(
122             rss_bpf_ctx->progs.tun_rss_steering_prog);
123     ctx->map_configuration = bpf_map__fd(
124             rss_bpf_ctx->maps.tap_rss_map_configurations);
125     ctx->map_indirections_table = bpf_map__fd(
126             rss_bpf_ctx->maps.tap_rss_map_indirection_table);
127     ctx->map_toeplitz_key = bpf_map__fd(
128             rss_bpf_ctx->maps.tap_rss_map_toeplitz_key);
129 
130     if (!ebpf_rss_mmap(ctx)) {
131         goto error;
132     }
133 
134     return true;
135 error:
136     rss_bpf__destroy(rss_bpf_ctx);
137     ctx->obj = NULL;
138     ctx->program_fd = -1;
139     ctx->map_configuration = -1;
140     ctx->map_toeplitz_key = -1;
141     ctx->map_indirections_table = -1;
142 
143     return false;
144 }
145 
146 bool ebpf_rss_load_fds(struct EBPFRSSContext *ctx, int program_fd,
147                        int config_fd, int toeplitz_fd, int table_fd)
148 {
149     if (ebpf_rss_is_loaded(ctx)) {
150         return false;
151     }
152 
153     if (program_fd < 0 || config_fd < 0 || toeplitz_fd < 0 || table_fd < 0) {
154         return false;
155     }
156 
157     ctx->program_fd = program_fd;
158     ctx->map_configuration = config_fd;
159     ctx->map_toeplitz_key = toeplitz_fd;
160     ctx->map_indirections_table = table_fd;
161 
162     if (!ebpf_rss_mmap(ctx)) {
163         ctx->program_fd = -1;
164         ctx->map_configuration = -1;
165         ctx->map_toeplitz_key = -1;
166         ctx->map_indirections_table = -1;
167         return false;
168     }
169 
170     return true;
171 }
172 
173 static bool ebpf_rss_set_config(struct EBPFRSSContext *ctx,
174                                 struct EBPFRSSConfig *config)
175 {
176     if (!ebpf_rss_is_loaded(ctx)) {
177         return false;
178     }
179 
180     memcpy(ctx->mmap_configuration, config, sizeof(*config));
181     return true;
182 }
183 
184 static bool ebpf_rss_set_indirections_table(struct EBPFRSSContext *ctx,
185                                             uint16_t *indirections_table,
186                                             size_t len)
187 {
188     if (!ebpf_rss_is_loaded(ctx) || indirections_table == NULL ||
189        len > VIRTIO_NET_RSS_MAX_TABLE_LEN) {
190         return false;
191     }
192 
193     memcpy(ctx->mmap_indirections_table, indirections_table,
194             sizeof(*indirections_table) * len);
195     return true;
196 }
197 
198 static bool ebpf_rss_set_toepliz_key(struct EBPFRSSContext *ctx,
199                                      uint8_t *toeplitz_key)
200 {
201     /* prepare toeplitz key */
202     uint8_t toe[VIRTIO_NET_RSS_MAX_KEY_SIZE] = {};
203 
204     if (!ebpf_rss_is_loaded(ctx) || toeplitz_key == NULL) {
205         return false;
206     }
207     memcpy(toe, toeplitz_key, VIRTIO_NET_RSS_MAX_KEY_SIZE);
208     *(uint32_t *)toe = ntohl(*(uint32_t *)toe);
209 
210     memcpy(ctx->mmap_toeplitz_key, toe, VIRTIO_NET_RSS_MAX_KEY_SIZE);
211     return true;
212 }
213 
214 bool ebpf_rss_set_all(struct EBPFRSSContext *ctx, struct EBPFRSSConfig *config,
215                       uint16_t *indirections_table, uint8_t *toeplitz_key)
216 {
217     if (!ebpf_rss_is_loaded(ctx) || config == NULL ||
218         indirections_table == NULL || toeplitz_key == NULL) {
219         return false;
220     }
221 
222     if (!ebpf_rss_set_config(ctx, config)) {
223         return false;
224     }
225 
226     if (!ebpf_rss_set_indirections_table(ctx, indirections_table,
227                                       config->indirections_len)) {
228         return false;
229     }
230 
231     if (!ebpf_rss_set_toepliz_key(ctx, toeplitz_key)) {
232         return false;
233     }
234 
235     return true;
236 }
237 
238 void ebpf_rss_unload(struct EBPFRSSContext *ctx)
239 {
240     if (!ebpf_rss_is_loaded(ctx)) {
241         return;
242     }
243 
244     ebpf_rss_munmap(ctx);
245 
246     if (ctx->obj) {
247         rss_bpf__destroy(ctx->obj);
248     } else {
249         close(ctx->program_fd);
250         close(ctx->map_configuration);
251         close(ctx->map_toeplitz_key);
252         close(ctx->map_indirections_table);
253     }
254 
255     ctx->obj = NULL;
256     ctx->program_fd = -1;
257     ctx->map_configuration = -1;
258     ctx->map_toeplitz_key = -1;
259     ctx->map_indirections_table = -1;
260 }
261 
262 ebpf_binary_init(EBPF_PROGRAMID_RSS, rss_bpf__elf_bytes)
263