On 2025/01/09 23:13, Willem de Bruijn wrote:
Akihiko Odaki wrote:
They are useful to implement VIRTIO_NET_F_RSS and VIRTIO_NET_F_HASH_REPORT.
Toeplitz potentially has users beyond virtio. I wonder if we should from the start implement this as net/core/rss.c.
Or in lib/toeplitz.c just as like lib/siphash.c. I just chose the easiest option to implement everything in include/linux/virtio_net.h.
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 02a9f4dc594d..3b25ca75710b 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);- }
+}
Have you verified that this algorithm matches a known toeplitz implementation. And computes the expected values for the test inputs in
https://learn.microsoft.com/en-us/windows-hardware/drivers/network/verifying...
Yes.
We have a toeplitz implementation in tools/testing/selftests/net/toeplitz.c that can also be used as reference.
+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 + 4;
Avoid magic constants. Please use sizeof or something else to signal what this 4 derives from.