LXR qemu/ebpf/ebpf

   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
  26void ebpf_rss_init(struct EBPFRSSContext *ctx)
  27{
  28    if (ctx != NULL) {
  29        ctx->obj = NULL;
  30    }
  31}
  32
  33bool ebpf_rss_is_loaded(struct EBPFRSSContext *ctx)
  34{
  35    return ctx != NULL && ctx->obj != NULL;
  36}
  37
  38bool 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;
  70error:
  71    rss_bpf__destroy(rss_bpf_ctx);
  72    ctx->obj = NULL;
  73
  74    return false;
  75}
  76
  77static 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
  92static 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
 112static 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
 133bool 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
 157void 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}
 166