They are useful to implement VIRTIO_NET_F_RSS and VIRTIO_NET_F_HASH_REPORT.
Signed-off-by: Akihiko Odaki akihiko.odaki@daynix.com --- include/linux/virtio_net.h | 188 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 188 insertions(+)
diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h index 02a9f4dc594d02372a6c1850cd600eff9d000d8d..426f33b4b82440d61b2af9fdc4c0b0d4c571b2c5 100644 --- a/include/linux/virtio_net.h +++ b/include/linux/virtio_net.h @@ -9,6 +9,194 @@ #include <uapi/linux/tcp.h> #include <uapi/linux/virtio_net.h>
+struct virtio_net_hash { + u32 value; + u16 report; +}; + +struct virtio_net_toeplitz_state { + u32 hash; + const u32 *key; +}; + +#define VIRTIO_NET_SUPPORTED_HASH_TYPES (VIRTIO_NET_RSS_HASH_TYPE_IPv4 | \ + VIRTIO_NET_RSS_HASH_TYPE_TCPv4 | \ + VIRTIO_NET_RSS_HASH_TYPE_UDPv4 | \ + VIRTIO_NET_RSS_HASH_TYPE_IPv6 | \ + VIRTIO_NET_RSS_HASH_TYPE_TCPv6 | \ + VIRTIO_NET_RSS_HASH_TYPE_UDPv6) + +#define VIRTIO_NET_RSS_MAX_KEY_SIZE 40 + +static inline void virtio_net_toeplitz_convert_key(u32 *input, size_t len) +{ + while (len >= sizeof(*input)) { + *input = be32_to_cpu((__force __be32)*input); + input++; + len -= sizeof(*input); + } +} + +static inline void virtio_net_toeplitz_calc(struct virtio_net_toeplitz_state *state, + const __be32 *input, size_t len) +{ + while (len >= sizeof(*input)) { + for (u32 map = be32_to_cpu(*input); map; map &= (map - 1)) { + u32 i = ffs(map); + + state->hash ^= state->key[0] << (32 - i) | + (u32)((u64)state->key[1] >> i); + } + + state->key++; + input++; + len -= sizeof(*input); + } +} + +static inline u8 virtio_net_hash_key_length(u32 types) +{ + size_t len = 0; + + if (types & VIRTIO_NET_HASH_REPORT_IPv4) + len = max(len, + sizeof(struct flow_dissector_key_ipv4_addrs)); + + if (types & + (VIRTIO_NET_HASH_REPORT_TCPv4 | VIRTIO_NET_HASH_REPORT_UDPv4)) + len = max(len, + sizeof(struct flow_dissector_key_ipv4_addrs) + + sizeof(struct flow_dissector_key_ports)); + + if (types & VIRTIO_NET_HASH_REPORT_IPv6) + len = max(len, + sizeof(struct flow_dissector_key_ipv6_addrs)); + + if (types & + (VIRTIO_NET_HASH_REPORT_TCPv6 | VIRTIO_NET_HASH_REPORT_UDPv6)) + len = max(len, + sizeof(struct flow_dissector_key_ipv6_addrs) + + sizeof(struct flow_dissector_key_ports)); + + return len + sizeof(u32); +} + +static inline u32 virtio_net_hash_report(u32 types, + const struct flow_keys_basic *keys) +{ + switch (keys->basic.n_proto) { + case cpu_to_be16(ETH_P_IP): + if (!(keys->control.flags & FLOW_DIS_IS_FRAGMENT)) { + if (keys->basic.ip_proto == IPPROTO_TCP && + (types & VIRTIO_NET_RSS_HASH_TYPE_TCPv4)) + return VIRTIO_NET_HASH_REPORT_TCPv4; + + if (keys->basic.ip_proto == IPPROTO_UDP && + (types & VIRTIO_NET_RSS_HASH_TYPE_UDPv4)) + return VIRTIO_NET_HASH_REPORT_UDPv4; + } + + if (types & VIRTIO_NET_RSS_HASH_TYPE_IPv4) + return VIRTIO_NET_HASH_REPORT_IPv4; + + return VIRTIO_NET_HASH_REPORT_NONE; + + case cpu_to_be16(ETH_P_IPV6): + if (!(keys->control.flags & FLOW_DIS_IS_FRAGMENT)) { + if (keys->basic.ip_proto == IPPROTO_TCP && + (types & VIRTIO_NET_RSS_HASH_TYPE_TCPv6)) + return VIRTIO_NET_HASH_REPORT_TCPv6; + + if (keys->basic.ip_proto == IPPROTO_UDP && + (types & VIRTIO_NET_RSS_HASH_TYPE_UDPv6)) + return VIRTIO_NET_HASH_REPORT_UDPv6; + } + + if (types & VIRTIO_NET_RSS_HASH_TYPE_IPv6) + return VIRTIO_NET_HASH_REPORT_IPv6; + + return VIRTIO_NET_HASH_REPORT_NONE; + + default: + return VIRTIO_NET_HASH_REPORT_NONE; + } +} + +static inline void virtio_net_hash_rss(const struct sk_buff *skb, + u32 types, const u32 *key, + struct virtio_net_hash *hash) +{ + struct virtio_net_toeplitz_state toeplitz_state = { .key = key }; + struct flow_keys flow; + struct flow_keys_basic flow_basic; + u16 report; + + if (!skb_flow_dissect_flow_keys(skb, &flow, 0)) { + hash->report = VIRTIO_NET_HASH_REPORT_NONE; + return; + } + + flow_basic = (struct flow_keys_basic) { + .control = flow.control, + .basic = flow.basic + }; + + report = virtio_net_hash_report(types, &flow_basic); + + switch (report) { + case VIRTIO_NET_HASH_REPORT_IPv4: + virtio_net_toeplitz_calc(&toeplitz_state, + (__be32 *)&flow.addrs.v4addrs, + sizeof(flow.addrs.v4addrs)); + break; + + case VIRTIO_NET_HASH_REPORT_TCPv4: + virtio_net_toeplitz_calc(&toeplitz_state, + (__be32 *)&flow.addrs.v4addrs, + sizeof(flow.addrs.v4addrs)); + virtio_net_toeplitz_calc(&toeplitz_state, &flow.ports.ports, + sizeof(flow.ports.ports)); + break; + + case VIRTIO_NET_HASH_REPORT_UDPv4: + virtio_net_toeplitz_calc(&toeplitz_state, + (__be32 *)&flow.addrs.v4addrs, + sizeof(flow.addrs.v4addrs)); + virtio_net_toeplitz_calc(&toeplitz_state, &flow.ports.ports, + sizeof(flow.ports.ports)); + break; + + case VIRTIO_NET_HASH_REPORT_IPv6: + virtio_net_toeplitz_calc(&toeplitz_state, + (__be32 *)&flow.addrs.v6addrs, + sizeof(flow.addrs.v6addrs)); + break; + + case VIRTIO_NET_HASH_REPORT_TCPv6: + virtio_net_toeplitz_calc(&toeplitz_state, + (__be32 *)&flow.addrs.v6addrs, + sizeof(flow.addrs.v6addrs)); + virtio_net_toeplitz_calc(&toeplitz_state, &flow.ports.ports, + sizeof(flow.ports.ports)); + break; + + case VIRTIO_NET_HASH_REPORT_UDPv6: + virtio_net_toeplitz_calc(&toeplitz_state, + (__be32 *)&flow.addrs.v6addrs, + sizeof(flow.addrs.v6addrs)); + virtio_net_toeplitz_calc(&toeplitz_state, &flow.ports.ports, + sizeof(flow.ports.ports)); + break; + + default: + hash->report = VIRTIO_NET_HASH_REPORT_NONE; + return; + } + + hash->value = toeplitz_state.hash; + hash->report = report; +} + static inline bool virtio_net_hdr_match_proto(__be16 protocol, __u8 gso_type) { switch (gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {