On Fri, May 30, 2025 at 12:50 PM Akihiko Odaki akihiko.odaki@daynix.com wrote:
They are useful to implement VIRTIO_NET_F_RSS and VIRTIO_NET_F_HASH_REPORT.
Signed-off-by: Akihiko Odaki akihiko.odaki@daynix.com Tested-by: Lei Yang leiyang@redhat.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 02a9f4dc594d..426f33b4b824 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;
So I still think we need a comment here to explain why this is not an issue if the device can report HASH_XXX_EX. Or we need to add the support, since this is the code from the driver side, I don't think we need to worry about the device implementation issues.
For the issue of the number of options, does the spec forbid fallback to VIRTIO_NET_HASH_REPORT_NONE? If not, we can do that.
Thanks
}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) {
-- 2.49.0