This commit adds support for the AVX512 implementation of the ipv4_set_addrs action as well as an AVX512 implementation of updating the checksums.
Signed-off-by: Emma Finn <[email protected]> Acked-by: Sunil Pai G <[email protected]> --- lib/odp-execute-avx512.c | 206 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 206 insertions(+) diff --git a/lib/odp-execute-avx512.c b/lib/odp-execute-avx512.c index f38c44152..6c7713251 100644 --- a/lib/odp-execute-avx512.c +++ b/lib/odp-execute-avx512.c @@ -21,6 +21,7 @@ #include <config.h> #include <errno.h> +#include "csum.h" #include "dp-packet.h" #include "immintrin.h" #include "odp-execute.h" @@ -58,6 +59,22 @@ BUILD_ASSERT_DECL(offsetof(struct ovs_key_ethernet, eth_src) + MEMBER_SIZEOF(struct ovs_key_ethernet, eth_src) == offsetof(struct ovs_key_ethernet, eth_dst)); +BUILD_ASSERT_DECL(offsetof(struct ovs_key_ipv4, ipv4_src) + + MEMBER_SIZEOF(struct ovs_key_ipv4, ipv4_src) == + offsetof(struct ovs_key_ipv4, ipv4_dst)); + +BUILD_ASSERT_DECL(offsetof(struct ovs_key_ipv4, ipv4_dst) + + MEMBER_SIZEOF(struct ovs_key_ipv4, ipv4_dst) == + offsetof(struct ovs_key_ipv4, ipv4_proto)); + +BUILD_ASSERT_DECL(offsetof(struct ovs_key_ipv4, ipv4_proto) + + MEMBER_SIZEOF(struct ovs_key_ipv4, ipv4_proto) == + offsetof(struct ovs_key_ipv4, ipv4_tos)); + +BUILD_ASSERT_DECL(offsetof(struct ovs_key_ipv4, ipv4_tos) + + MEMBER_SIZEOF(struct ovs_key_ipv4, ipv4_tos) == + offsetof(struct ovs_key_ipv4, ipv4_ttl)); + /* Array of callback functions, one for each masked operation. */ odp_execute_action_cb impl_set_masked_funcs[__OVS_KEY_ATTR_MAX]; @@ -278,6 +295,194 @@ action_avx512_eth_set_addrs(struct dp_packet_batch *batch, } } +static inline uint16_t ALWAYS_INLINE +avx512_get_delta(__m256i old_header, __m256i new_header) +{ + __m256i v_zeros = _mm256_setzero_si256(); + + /* These two shuffle masks, v_swap16a and v_swap16b, are to shuffle the + * old and new header to add padding after each 16-bit value for the + * following carry over addition. */ + __m256i v_swap16a = _mm256_setr_epi16(0x0100, 0xFFFF, 0x0302, 0xFFFF, + 0x0504, 0xFFFF, 0x0706, 0xFFFF, + 0x0100, 0xFFFF, 0x0302, 0xFFFF, + 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF); + __m256i v_swap16b = _mm256_setr_epi16(0x0908, 0xFFFF, 0x0B0A, 0xFFFF, + 0x0D0C, 0xFFFF, 0x0F0E, 0xFFFF, + 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, + 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF); + __m256i v_shuf_old1 = _mm256_shuffle_epi8(old_header, v_swap16a); + __m256i v_shuf_old2 = _mm256_shuffle_epi8(old_header, v_swap16b); + __m256i v_shuf_new1 = _mm256_shuffle_epi8(new_header, v_swap16a); + __m256i v_shuf_new2 = _mm256_shuffle_epi8(new_header, v_swap16b); + + /* Add each part of the old and new headers together. */ + __m256i v_delta1 = _mm256_add_epi32(v_shuf_old1, v_shuf_new1); + __m256i v_delta2 = _mm256_add_epi32(v_shuf_old2, v_shuf_new2); + + /* Add old and new header. */ + __m256i v_delta = _mm256_add_epi32(v_delta1, v_delta2); + + /* Perform horizontal add to go from 8x32-bits to 2x32-bits. */ + v_delta = _mm256_hadd_epi32(v_delta, v_zeros); + v_delta = _mm256_hadd_epi32(v_delta, v_zeros); + + /* Shuffle 32-bit value from 3rd lane into first lane for final + * horizontal add. */ + __m256i v_swap32a = _mm256_setr_epi32(0x0, 0x4, 0xF, 0xF, + 0xF, 0xF, 0xF, 0xF); + v_delta = _mm256_permutexvar_epi32(v_swap32a, v_delta); + + v_delta = _mm256_hadd_epi32(v_delta, v_zeros); + v_delta = _mm256_hadd_epi16(v_delta, v_zeros); + + /* Extract delta value. */ + return _mm256_extract_epi16(v_delta, 0); +} + +/* This function will calculate the csum delta for the IPv4 addresses in the + * new_header and old_header, assuming the csum field on the new_header was + * updated. */ +static inline uint16_t ALWAYS_INLINE +avx512_ipv4_addr_csum_delta(__m256i old_header, __m256i new_header) +{ + __m256i v_zeros = _mm256_setzero_si256(); + + /* Set the v_ones register to all one's. */ + __m256i v_ones = _mm256_cmpeq_epi16(v_zeros, v_zeros); + + /* Combine the old and new header, i.e. adding in the new IP addresses + * in the old header (oh). This is done by using the 0x03C 16-bit mask, + * picking 16-bit word 7 till 10. */ + __m256i v_blend_new = _mm256_mask_blend_epi16(0x03C0, old_header, + new_header); + + /* Invert the old_header register. */ + old_header =_mm256_andnot_si256(old_header, v_ones); + + /* Calculate the delta between the old and new header. */ + return avx512_get_delta(old_header, v_blend_new); +} + +/* This function will calculate the csum delta between the new_header and + * old_header, assuming the csum field on the new_header was not yet updated + * or reset. It also assumes headers contain the first 20-bytes of the IPv4 + * header data, and the rest is zeroed out. */ +static inline uint16_t ALWAYS_INLINE +avx512_ipv4_hdr_csum_delta(__m256i old_header, __m256i new_header) +{ + __m256i v_zeros = _mm256_setzero_si256(); + + /* Set the v_ones register to all one's. */ + __m256i v_ones = _mm256_cmpeq_epi16(v_zeros, v_zeros); + + /* Invert the old_header register. */ + old_header =_mm256_andnot_si256(old_header, v_ones); + + /* Calculate the delta between the old and new header. */ + return avx512_get_delta(old_header, new_header); +} + +/* This function performs the same operation on each packet in the batch as + * the scalar odp_set_ipv4() function. */ +static void +action_avx512_ipv4_set_addrs(struct dp_packet_batch *batch, + const struct nlattr *a) +{ + const struct ovs_key_ipv4 *key, *mask; + struct dp_packet *packet; + a = nl_attr_get(a); + key = nl_attr_get(a); + mask = odp_get_key_mask(a, struct ovs_key_ipv4); + + /* Read the content of the key(src) and mask in the respective registers. + * We only load the size of the actual structure, which is only 96-bits. */ + __m256i v_key = _mm256_maskz_loadu_epi32(0x7, (void *) key); + __m256i v_mask = _mm256_maskz_loadu_epi32(0x7, (void *) mask); + + /* This two shuffle masks, v_shuf32, v_shuffle, are to shuffle key and + * mask to match the ip_header structure layout. */ + static const uint8_t ip_shuffle_mask[32] = { + 0xFF, 0x05, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, + 0x06, 0xFF, 0xFF, 0xFF, 0x00, 0x01, 0x02, 0x03, + 0x00, 0x01, 0x02, 0x03, 0xFF, 0xFF, 0xFF, 0xFF, + 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}; + + __m256i v_shuf32 = _mm256_setr_epi32(0x0, 0x2, 0xF, 0xF, + 0x1, 0xF, 0xF, 0xF); + + __m256i v_shuffle = _mm256_loadu_si256((void *) ip_shuffle_mask); + + /* Two shuffles are required for key and mask to match the layout of + * the ip_header struct. The _shuffle_epi8 only works within 128-bit + * lanes, so a permute is required to move src and dst into the correct + * lanes. And then a shuffle is used to move the fields into the right + * order. */ + __m256i v_key_shuf = _mm256_permutexvar_epi32(v_shuf32, v_key); + v_key_shuf = _mm256_shuffle_epi8(v_key_shuf, v_shuffle); + + __m256i v_mask_shuf = _mm256_permutexvar_epi32(v_shuf32, v_mask); + v_mask_shuf = _mm256_shuffle_epi8(v_mask_shuf, v_shuffle); + + DP_PACKET_BATCH_FOR_EACH (i, packet, batch) { + struct ip_header *nh = dp_packet_l3(packet); + ovs_be16 old_csum = ~nh->ip_csum; + + /* Load the 20 bytes of the IPv4 header. Without options, which is the + * most common case it's 20 bytes, but can be up to 60 bytes. */ + __m256i v_packet = _mm256_maskz_loadu_epi32(0x1F, (void *) nh); + + /* AND the v_pkt_mask to the packet data (v_packet). */ + __m256i v_pkt_masked = _mm256_andnot_si256(v_mask_shuf, v_packet); + + /* OR the new addresses (v_key_shuf) with the masked packet addresses + * (v_pkt_masked). */ + __m256i v_new_hdr = _mm256_or_si256(v_key_shuf, v_pkt_masked); + + /* Update the IP checksum based on updated IP values. */ + uint16_t delta = avx512_ipv4_hdr_csum_delta(v_packet, v_new_hdr); + uint32_t new_csum = old_csum + delta; + delta = csum_finish(new_csum); + + /* Insert new checksum. */ + v_new_hdr = _mm256_insert_epi16(v_new_hdr, delta, 5); + + /* If ip_src or ip_dst has been modified, L4 checksum needs to + * be updated too. */ + if (mask->ipv4_src || mask->ipv4_dst) { + + uint16_t delta_checksum = avx512_ipv4_addr_csum_delta(v_packet, + v_new_hdr); + + if (nh->ip_proto == IPPROTO_UDP) { + /* New UDP checksum. */ + struct udp_header *uh = dp_packet_l4(packet); + if (uh->udp_csum) { + uint16_t old_udp_checksum = ~uh->udp_csum; + uint32_t udp_checksum = old_udp_checksum + delta_checksum; + udp_checksum = csum_finish(udp_checksum); + + if (!udp_checksum) { + udp_checksum = htons(0xffff); + } + /* Insert new udp checksum. */ + uh->udp_csum = udp_checksum; + } + } else if (nh->ip_proto == IPPROTO_TCP) { + /* New TCP checksum. */ + struct tcp_header *th = dp_packet_l4(packet); + uint16_t old_tcp_checksum = ~th->tcp_csum; + uint32_t tcp_checksum = old_tcp_checksum + delta_checksum; + tcp_checksum = csum_finish(tcp_checksum); + + th->tcp_csum = tcp_checksum; + } + } + /* Write back the modified IPv4 addresses. */ + _mm256_mask_storeu_epi32((void *) nh, 0x1F, v_new_hdr); + } +} + static void action_avx512_set_masked(struct dp_packet_batch *batch, const struct nlattr *a) { @@ -307,6 +512,7 @@ action_avx512_init(struct odp_execute_action_impl *self OVS_UNUSED) /* Set function pointers for the individual operations supported by the * SET_MASKED action. */ impl_set_masked_funcs[OVS_KEY_ATTR_ETHERNET] = action_avx512_eth_set_addrs; + impl_set_masked_funcs[OVS_KEY_ATTR_IPV4] = action_avx512_ipv4_set_addrs; return 0; } -- 2.32.0 _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
