ebpf/ebpf_rss.c

   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
  17 #include <bpf/libbpf.h>
  18 #include <bpf/bpf.h>
  19
  20 #include "hw/virtio/virtio-net.h" /* VIRTIO_NET_RSS_MAX_TABLE_LEN */
  21
  22 #include "ebpf/ebpf_rss.h"
  23 #include "ebpf/rss.bpf.skeleton.h"
  24 #include "trace.h"
  25
  26 void ebpf_rss_init(struct EBPFRSSContext *ctx)
  27 {
  28     if (ctx != NULL) {
  29         ctx->obj = NULL;
  30     }
  31 }
  32
  33 bool ebpf_rss_is_loaded(struct EBPFRSSContext *ctx)
  34 {
  35     return ctx != NULL && ctx->obj != NULL;
  36 }
  37
  38 bool ebpf_rss_load(struct EBPFRSSContext *ctx)
  39 {
  40     struct rss_bpf *rss_bpf_ctx;
  41
  42     if (ctx == NULL) {
  43         return false;
  44     }
  45
  46     rss_bpf_ctx = rss_bpf__open();
  47     if (rss_bpf_ctx == NULL) {
  48         trace_ebpf_error("eBPF RSS", "can not open eBPF RSS object");
  49         goto error;
  50     }
  51
  52     bpf_program__set_socket_filter(rss_bpf_ctx->progs.tun_rss_steering_prog);
  53
  54     if (rss_bpf__load(rss_bpf_ctx)) {
  55         trace_ebpf_error("eBPF RSS", "can not load RSS program");
  56         goto error;
  57     }
  58
  59     ctx->obj = rss_bpf_ctx;
  60     ctx->program_fd = bpf_program__fd(
  61             rss_bpf_ctx->progs.tun_rss_steering_prog);
  62     ctx->map_configuration = bpf_map__fd(
  63             rss_bpf_ctx->maps.tap_rss_map_configurations);
  64     ctx->map_indirections_table = bpf_map__fd(
  65             rss_bpf_ctx->maps.tap_rss_map_indirection_table);
  66     ctx->map_toeplitz_key = bpf_map__fd(
  67             rss_bpf_ctx->maps.tap_rss_map_toeplitz_key);
  68
  69     return true;
  70 error:
  71     rss_bpf__destroy(rss_bpf_ctx);
  72     ctx->obj = NULL;
  73
  74     return false;
  75 }
  76
  77 static bool ebpf_rss_set_config(struct EBPFRSSContext *ctx,
  78                                 struct EBPFRSSConfig *config)
  79 {
  80     uint32_t map_key = 0;
  81
  82     if (!ebpf_rss_is_loaded(ctx)) {
  83         return false;
  84     }
  85     if (bpf_map_update_elem(ctx->map_configuration,
  86                             &map_key, config, 0) < 0) {
  87         return false;
  88     }
  89     return true;
  90 }
  91
  92 static bool ebpf_rss_set_indirections_table(struct EBPFRSSContext *ctx,
  93                                             uint16_t *indirections_table,
  94                                             size_t len)
  95 {
  96     uint32_t i = 0;
  97
  98     if (!ebpf_rss_is_loaded(ctx) || indirections_table == NULL ||
  99        len > VIRTIO_NET_RSS_MAX_TABLE_LEN) {
 100         return false;
 101     }
 102
 103     for (; i < len; ++i) {
 104         if (bpf_map_update_elem(ctx->map_indirections_table, &i,
 105                                 indirections_table + i, 0) < 0) {
 106             return false;
 107         }
 108     }
 109     return true;
 110 }
 111
 112 static bool ebpf_rss_set_toepliz_key(struct EBPFRSSContext *ctx,
 113                                      uint8_t *toeplitz_key)
 114 {
 115     uint32_t map_key = 0;
 116
 117     /* prepare toeplitz key */
 118     uint8_t toe[VIRTIO_NET_RSS_MAX_KEY_SIZE] = {};
 119
 120     if (!ebpf_rss_is_loaded(ctx) || toeplitz_key == NULL) {
 121         return false;
 122     }
 123     memcpy(toe, toeplitz_key, VIRTIO_NET_RSS_MAX_KEY_SIZE);
 124     *(uint32_t *)toe = ntohl(*(uint32_t *)toe);
 125
 126     if (bpf_map_update_elem(ctx->map_toeplitz_key, &map_key, toe,
 127                             0) < 0) {
 128         return false;
 129     }
 130     return true;
 131 }
 132
 133 bool ebpf_rss_set_all(struct EBPFRSSContext *ctx, struct EBPFRSSConfig *config,
 134                       uint16_t *indirections_table, uint8_t *toeplitz_key)
 135 {
 136     if (!ebpf_rss_is_loaded(ctx) || config == NULL ||
 137         indirections_table == NULL || toeplitz_key == NULL) {
 138         return false;
 139     }
 140
 141     if (!ebpf_rss_set_config(ctx, config)) {
 142         return false;
 143     }
 144
 145     if (!ebpf_rss_set_indirections_table(ctx, indirections_table,
 146                                       config->indirections_len)) {
 147         return false;
 148     }
 149
 150     if (!ebpf_rss_set_toepliz_key(ctx, toeplitz_key)) {
 151         return false;
 152     }
 153
 154     return true;
 155 }
 156
 157 void ebpf_rss_unload(struct EBPFRSSContext *ctx)
 158 {
 159     if (!ebpf_rss_is_loaded(ctx)) {
 160         return;
 161     }
 162
 163     rss_bpf__destroy(ctx->obj);
 164     ctx->obj = NULL;
 165 }