[dpdk-dev] [PATCH v2] Add toeplitz hash algorithm used by RSS

[Chilikin, Andrey]

Hi Vladimir,

Why limit Toeplitz hash calculation to predefined tuples and length? Should it be more general, something like
rte_softrss_be(void *input, uint32_t input_len, const uint8_t *rss_key) to enable hash calculation for an input of any size? It would be useful for distributing packets using some non-standard tuples, like hashing on QinQ or adding IP protocol to hash calculation to separate UDP and TCP flows or even some other fields from a packet, for example, tunnel ID from VXLAN headers. By the way, i40e already supports RSS for SCTP in addition to TCP and UDP and includes Verification Tag as well as SCTP source and destination ports for RSS hash.

Regards,
Andrey

> -----Original Message-----
> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Vladimir
> Medvedkin
> Sent: Tuesday, May 5, 2015 2:20 PM
> To: dev at dpdk.org
> Subject: [dpdk-dev] [PATCH v2] Add toeplitz hash algorithm used by RSS
> 
> Software implementation of the Toeplitz hash function used by RSS.
> Can be used either for packet distribution on single queue NIC or for
> simulating of RSS computation on specific NIC (for example after GRE header
> decapsulating).
> 
> v2 changes
> - Add ipv6 support
> - Various style fixes
> 
> Signed-off-by: Vladimir Medvedkin <medvedkinv at gmail.com>
> ---
>  lib/librte_hash/Makefile    |   1 +
>  lib/librte_hash/rte_thash.h | 209
> ++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 210 insertions(+)
>  create mode 100644 lib/librte_hash/rte_thash.h
> 
> diff --git a/lib/librte_hash/Makefile b/lib/librte_hash/Makefile index
> 3696cb1..981230b 100644
> --- a/lib/librte_hash/Makefile
> +++ b/lib/librte_hash/Makefile
> @@ -49,6 +49,7 @@ SRCS-$(CONFIG_RTE_LIBRTE_HASH) += rte_fbk_hash.c
> SYMLINK-$(CONFIG_RTE_LIBRTE_HASH)-include := rte_hash.h  SYMLINK-
> $(CONFIG_RTE_LIBRTE_HASH)-include += rte_hash_crc.h  SYMLINK-
> $(CONFIG_RTE_LIBRTE_HASH)-include += rte_jhash.h
> +SYMLINK-$(CONFIG_RTE_LIBRTE_HASH)-include += rte_thash.h
>  SYMLINK-$(CONFIG_RTE_LIBRTE_HASH)-include += rte_fbk_hash.h
> 
>  # this lib needs eal
> diff --git a/lib/librte_hash/rte_thash.h b/lib/librte_hash/rte_thash.h new file
> mode 100644 index 0000000..42c7bf6
> --- /dev/null
> +++ b/lib/librte_hash/rte_thash.h
> @@ -0,0 +1,209 @@
> +/*-
> + *   BSD LICENSE
> + *
> + *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
> + *   All rights reserved.
> + *
> + *   Redistribution and use in source and binary forms, with or without
> + *   modification, are permitted provided that the following conditions
> + *   are met:
> + *
> + *     * Redistributions of source code must retain the above copyright
> + *       notice, this list of conditions and the following disclaimer.
> + *     * Redistributions in binary form must reproduce the above copyright
> + *       notice, this list of conditions and the following disclaimer in
> + *       the documentation and/or other materials provided with the
> + *       distribution.
> + *     * Neither the name of Intel Corporation nor the names of its
> + *       contributors may be used to endorse or promote products derived
> + *       from this software without specific prior written permission.
> + *
> + *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
> CONTRIBUTORS
> + *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT
> NOT
> + *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
> FITNESS FOR
> + *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
> COPYRIGHT
> + *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
> INCIDENTAL,
> + *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
> NOT
> + *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
> OF USE,
> + *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
> AND ON ANY
> + *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
> TORT
> + *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
> THE USE
> + *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
> DAMAGE.
> + */
> +
> +#ifndef _RTE_THASH_H
> +#define _RTE_THASH_H
> +
> +/**
> + * @file
> + *
> + * toeplitz hash functions.
> + */
> +
> +#ifdef __cplusplus
> +extern "C" {
> +#endif
> +
> +/**
> + * Software implementation of the Toeplitz hash function used by RSS.
> + * Can be used either for packet distribution on single queue NIC
> + * or for simulating of RSS computation on specific NIC (for example
> + * after GRE header decapsulating)
> + */
> +
> +#include <stdint.h>
> +#include <rte_byteorder.h>
> +#include <rte_vect.h>
> +
> +#ifdef __SSE3__
> +static const __m128i bswap_mask = {0x0405060700010203,
> +0x0C0D0E0F08090A0B}; #endif
> +
> +enum rte_thash_len {
> +	RTE_THASH_V4_L3	= 2,	/*calculate hash of ipv4 header
> only*/
> +	RTE_THASH_V4_L4	= 3,	/*calculate hash of ipv4 + transport
> headers*/
> +	RTE_THASH_V6_L3	= 8,	/*calculate hash of ipv6 header only
> */
> +	RTE_THASH_V6_L4	= 9,	/*calculate hash of ipv6 + transport
> headers */
> +};
> +
> +/**
> + * IPv4 tuple
> + * addreses and ports have to be CPU byte order  */ struct
> +rte_ipv4_tuple {
> +	uint32_t	src_addr;
> +	uint32_t	dst_addr;
> +	uint16_t	dport;
> +	uint16_t	sport;
> +};
> +
> +/**
> + * IPv6 tuple
> + * Addresses have to be filled by rte_thash_load_v6_addr()
> + * ports have to be CPU byte order
> + */
> +struct rte_ipv6_tuple {
> +	uint8_t		src_addr[16];
> +	uint8_t		dst_addr[16];
> +	uint16_t	dport;
> +	uint16_t	sport;
> +};
> +
> +union rte_thash_tuple {
> +	struct rte_ipv4_tuple	v4;
> +	struct rte_ipv6_tuple	v6;
> +} __attribute__((aligned(16)));
> +
> +/**
> + * Prepare special converted key to use with rte_softrss_be()
> + * @param orig
> + *   pointer to original RSS key
> + * @param targ
> + *   pointer to target RSS key
> + * @param len
> + *   RSS key length
> + */
> +static inline void
> +rte_convert_rss_key(const uint32_t *orig, uint32_t *targ, int len) {
> +	int i;
> +
> +	for (i = 0; i < (len >> 2); i++) {
> +		targ[i] = rte_be_to_cpu_32(orig[i]);
> +	}
> +}
> +
> +/**
> + * Prepare and load IPv6 address
> + * @param orig
> + *   Pointer to ipv6 address inside ipv6_hdr
> + * @param targ
> + *   Pointer to ipv6 address inside rte_ipv6_tuple
> + */
> +static inline void
> +rte_thash_load_v6_addr(const uint8_t *orig, uint8_t *targ) { #ifdef
> +__SSE3__
> +	__m128i ipv6 = _mm_loadu_si128((const __m128i *)orig);
> +	*(__m128i *)targ = _mm_shuffle_epi8(ipv6, bswap_mask); #else
> +	int i;
> +
> +	for (i = 0; i < 4; i++) {
> +		*((uint32_t *)targ + i) =
> +			rte_be_to_cpu_32(*((const uint32_t *)orig + i));
> +	}
> +#endif
> +}
> +
> +/**
> + * Generic implementation. Can be used with original rss_key
> + * @param input_tuple
> + *   Pointer to rte_thash_tuple union
> + * @param input_len
> + *   Length of input_tuple in 4-bytes chunks
> + *   RTE_THASH_V4_L3:	calculate hash of IPv4 src address and IPv4 dst
> address
> + *   RTE_THASH_V4_L4	calculate hash of IPv4 adresses and TCP|UDP
> ports
> + *   RTE_THASH_V6_L3:	calculate hash of IPv6 src address and IPv4 dst
> address
> + *   RTE_THASH_V6_L4	calculate hash of IPv6 adresses and TCP|UDP
> ports
> + * @param rss_key
> + *   Pointer to RSS hash key.
> + * @return
> + *   Calculated hash value.
> + */
> +static inline uint32_t
> +rte_softrss(union rte_thash_tuple *input_tuple, enum rte_thash_len
> input_len,
> +		const uint8_t *rss_key)
> +{
> +	uint32_t i, j, ret = 0;
> +
> +	for (j = 0; j < input_len; j++) {
> +		for (i = 0; i < 32; i++) {
> +			if (((uint32_t *)input_tuple)[j] & (1 << (31 - i))) {
> +				ret ^= rte_cpu_to_be_32(((const uint32_t
> *)rss_key)[j]) << i |
> +
> 	(uint32_t)((uint64_t)(rte_cpu_to_be_32(((const uint32_t
> *)rss_key)[j + 1])) >> (32 - i));
> +			}
> +		}
> +	}
> +	return ret;
> +}
> +
> +/**
> + * Optimized implementation.
> + * If you want the calculated hash value matches NIC RSS value
> + * you have to use special converted key.
> + * @param input_tuple
> + *   Pointer to rte_thash_tuple union
> + * @param input_len
> + *   Length of input_tuple in 4-bytes chunks
> + *   RTE_THASH_V4_L3:	calculate hash of IPv4 src address and IPv4 dst
> address
> + *   RTE_THASH_V4_L4	calculate hash of IPv4 adresses and TCP|UDP
> ports
> + *   RTE_THASH_V6_L3:	calculate hash of IPv6 src address and IPv4 dst
> address
> + *   RTE_THASH_V6_L4	calculate hash of IPv6 adresses and TCP|UDP
> ports
> + * @param *rss_key
> + *   Pointer to RSS hash key.
> + * @return
> + *   Calculated hash value.
> + */
> +static inline uint32_t
> +rte_softrss_be(union rte_thash_tuple *input_tuple, enum rte_thash_len
> input_len,
> +		const uint8_t *rss_key)
> +{
> +	uint32_t i, j, ret = 0;
> +
> +	for (j = 0; j < input_len; j++) {
> +		for (i = 0; i < 32; i++) {
> +			if (((uint32_t *)input_tuple)[j] & (1 << (31 - i))) {
> +				ret ^= ((const uint32_t *)rss_key)[j] << i |
> +					(uint32_t)((uint64_t)(((const uint32_t
> *)rss_key)[j + 1]) >> (32 - i));
> +			}
> +		}
> +	}
> +	return ret;
> +}
> +
> +#ifdef __cplusplus
> +}
> +#endif
> +
> +#endif /* _RTE_THASH_H */
> --
> 1.8.3.2