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[ovs-dev,v2] odp-execute: Add ISA implementation of set_masked IPv6 action

Message ID 20220920131759.1072627-1-emma.finn@intel.com
State Superseded
Headers show
Series [ovs-dev,v2] odp-execute: Add ISA implementation of set_masked IPv6 action | expand

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Commit Message

Finn, Emma Sept. 20, 2022, 1:17 p.m. UTC
This commit adds support for the AVX512 implementation of the
ipv6_set_addrs action as well as an AVX512 implementation of
updating the L4 checksums.

Signed-off-by: Emma Finn <emma.finn@intel.com>

---
v2:
  - Added check for availbility of s6_addr32 field of struct in6_addr.
  - Fixed network headers for freebsd builds.
---
---
 lib/odp-execute-avx512.c | 172 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 172 insertions(+)

Comments

David Marchand Sept. 21, 2022, 10:25 a.m. UTC | #1
On Tue, Sep 20, 2022 at 3:19 PM Emma Finn <emma.finn@intel.com> wrote:
>
> This commit adds support for the AVX512 implementation of the
> ipv6_set_addrs action as well as an AVX512 implementation of
> updating the L4 checksums.
>
> Signed-off-by: Emma Finn <emma.finn@intel.com>
>
> ---
> v2:
>   - Added check for availbility of s6_addr32 field of struct in6_addr.
>   - Fixed network headers for freebsd builds.
> ---
> ---
>  lib/odp-execute-avx512.c | 172 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 172 insertions(+)
>
> diff --git a/lib/odp-execute-avx512.c b/lib/odp-execute-avx512.c
> index 6c7713251..58d1746c9 100644
> --- a/lib/odp-execute-avx512.c
> +++ b/lib/odp-execute-avx512.c
> @@ -20,6 +20,9 @@
>
>  #include <config.h>
>  #include <errno.h>
> +#include <sys/types.h>
> +#include <netinet/in.h>
> +#include <netinet/ip6.h>
>
>  #include "csum.h"
>  #include "dp-packet.h"
> @@ -483,6 +486,172 @@ action_avx512_ipv4_set_addrs(struct dp_packet_batch *batch,
>      }
>  }
>
> +#if HAVE_AVX512VBMI
> +static inline uint16_t ALWAYS_INLINE
> +__attribute__((__target__("avx512vbmi")))
> +avx512_ipv6_get_delta(__m512i ip6_header)
> +{
> +    __m256i v_zeros = _mm256_setzero_si256();
> +    __m512i v_shuf_src_dst = _mm512_setr_epi64(0x01, 0x02, 0x03, 0x04,
> +                                               0xFF, 0xFF, 0xFF, 0xFF);
> +
> +    __m512i v_header = _mm512_permutexvar_epi64(v_shuf_src_dst, ip6_header);
> +    __m256i v_ip6_src_dst =  _mm512_extracti64x4_epi64(v_header, 0);
> +    /* These two shuffle masks, v_swap16a and v_swap16b, are to shuffle the
> +     * src and dst fields and 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,
> +                                          0x0504, 0xFFFF, 0x0706, 0xFFFF);
> +    __m256i v_swap16b = _mm256_setr_epi16(0x0908, 0xFFFF, 0x0B0A, 0xFFFF,
> +                                          0x0D0C, 0xFFFF, 0x0F0E, 0xFFFF,
> +                                          0x0908, 0xFFFF, 0x0B0A, 0xFFFF,
> +                                          0x0D0C, 0xFFFF, 0x0F0E, 0xFFFF);
> +    __m256i v_shuf_old1 = _mm256_shuffle_epi8(v_ip6_src_dst, v_swap16a);
> +    __m256i v_shuf_old2 = _mm256_shuffle_epi8(v_ip6_src_dst, v_swap16b);
> +
> +    /* Add each part of the old and new headers together. */
> +    __m256i v_delta = _mm256_add_epi32(v_shuf_old1, v_shuf_old2);
> +
> +    /* 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);
> +}
> +
> +static inline uint16_t ALWAYS_INLINE
> +__attribute__((__target__("avx512vbmi")))
> +avx512_ipv6_addr_csum_delta(__m512i old_header, __m512i new_header)
> +{
> +    uint16_t delta;
> +    uint16_t old_delta = avx512_ipv6_get_delta(old_header);
> +    uint16_t new_delta = avx512_ipv6_get_delta(new_header);
> +    old_delta = ~old_delta;
> +    uint32_t csum_delta = old_delta + new_delta;
> +    delta = csum_finish(csum_delta);
> +
> +    return ~delta;
> +}
> +
> +/* This function performs the same operation on each packet in the batch as
> + * the scalar odp_set_ipv6() function. */
> +static void
> +__attribute__((__target__("avx512vbmi")))
> +action_avx512_ipv6_set_addrs(struct dp_packet_batch *batch,
> +                             const struct nlattr *a)
> +{
> +    const struct ovs_key_ipv6 *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_ipv6);
> +
> +    /* Read the content of the key and mask in the respective registers. We
> +     * only load the size of the actual structure, which is only 40 bytes. */
> +    __m512i v_key = _mm512_maskz_loadu_epi64(0x1F, (void *) key);
> +    __m512i v_mask = _mm512_maskz_loadu_epi64(0x1F, (void *) mask);
> +
> +    /* This shuffle mask v_shuffle, is to shuffle key and mask to match the
> +     * ip6_hdr structure layout. */
> +    static const uint8_t ip_shuffle_mask[64] = {
> +            0x20, 0x21, 0x22, 0x23, 0xFF, 0xFF, 0x24, 0x26,
> +            0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
> +            0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
> +            0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
> +            0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F,
> +            0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0XFF, 0xFF, 0xFF,
> +            0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
> +            0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0XFF, 0xFF
> +    };
> +
> +    __m512i v_shuffle = _mm512_loadu_si512((void *) ip_shuffle_mask);
> +
> +    /* This shuffle is required for key and mask to match the layout of the
> +     * ip6_hdr struct. */
> +    __m512i v_key_shuf = _mm512_permutexvar_epi8(v_shuffle, v_key);
> +    __m512i v_mask_shuf = _mm512_permutexvar_epi8(v_shuffle, v_mask);
> +
> +    DP_PACKET_BATCH_FOR_EACH (i, packet, batch) {
> +        struct ovs_16aligned_ip6_hdr *nh = dp_packet_l3(packet);
> +
> +        /* Load the 40 bytes of the IPv6 header. */
> +        __m512i v_packet = _mm512_maskz_loadu_epi64(0x1F, (void *) nh);
> +
> +        /* AND the v_pkt_mask to the packet data (v_packet). */
> +        __m512i v_pkt_masked = _mm512_andnot_si512(v_mask_shuf, v_packet);
> +
> +        /* OR the new addresses (v_key_shuf) with the masked packet addresses
> +         * (v_pkt_masked). */
> +        __m512i v_new_hdr = _mm512_or_si512(v_key_shuf, v_pkt_masked);
> +
> +        /* If ip6_src or ip6_dst has been modified, L4 checksum needs to
> +         * be updated. */
> +        bool do_checksum = false;
> +#ifdef s6_addr32
> +        for (int j = 0; j < 4; j++) {
> +            if (mask->ipv6_dst.s6_addr32[j] || mask->ipv6_src.s6_addr32[j]) {
> +                do_checksum = true;
> +            }
> +        }
> +#else
> +        for (int j = 0; j < 16; j++) {
> +             if (mask->ipv6_dst.s6_addr[j] || mask->ipv6_src.s6_addr[j]) {
> +                do_checksum = true;
> +            }
> +        }
> +#endif
> +        if (do_checksum) {
> +            uint8_t proto = nh->ip6_nxt;
> +            uint16_t delta_checksum = avx512_ipv6_addr_csum_delta(v_packet,
> +                                                                  v_new_hdr);
> +
> +            if (proto == IPPROTO_UDP) {
> +                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);
> +                    }
> +
> +                    uh->udp_csum = udp_checksum;
> +                }
> +            } else if (proto == IPPROTO_TCP) {
> +                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;
> +            } else if (proto == IPPROTO_ICMPV6) {
> +                struct icmp6_header *icmp = dp_packet_l4(packet);
> +                uint16_t old_icmp_checksum = ~icmp->icmp6_cksum;
> +                uint32_t icmp6_checksum = old_icmp_checksum + delta_checksum;
> +                icmp6_checksum = csum_finish(icmp6_checksum);
> +
> +                icmp->icmp6_cksum = icmp6_checksum;
> +            }
> +        }
> +        /* Write back the modified IPv6 addresses. */
> +         _mm512_mask_storeu_epi64((void *) nh, 0x1F, v_new_hdr);
> +    }
> +}
> +#endif
> +
>  static void
>  action_avx512_set_masked(struct dp_packet_batch *batch, const struct nlattr *a)
>  {
> @@ -513,6 +682,9 @@ action_avx512_init(struct odp_execute_action_impl *self OVS_UNUSED)
>       * 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;
> +#if HAVE_AVX512VBMI
> +    impl_set_masked_funcs[OVS_KEY_ATTR_IPV6] = action_avx512_ipv6_set_addrs;
> +#endif
>

I did not review the AVX512 stuff, neither test the patch.
One comment though.

All I see are build checks on vbmi availability.
Don't we need a runtime check for AVX512 platforms that don't have vbmi?
Finn, Emma Sept. 23, 2022, 3:30 p.m. UTC | #2
> -----Original Message-----
> From: David Marchand <david.marchand@redhat.com>
> Sent: Wednesday 21 September 2022 11:26
> To: Finn, Emma <emma.finn@intel.com>
> Cc: dev@openvswitch.org; i.maximets@ovn.org
> Subject: Re: [ovs-dev] [v2] odp-execute: Add ISA implementation of
> set_masked IPv6 action
> 
> On Tue, Sep 20, 2022 at 3:19 PM Emma Finn <emma.finn@intel.com> wrote:
> >
> > This commit adds support for the AVX512 implementation of the
> > ipv6_set_addrs action as well as an AVX512 implementation of updating
> > the L4 checksums.
> >
> > Signed-off-by: Emma Finn <emma.finn@intel.com>
> >
> > ---
> > v2:
> >   - Added check for availbility of s6_addr32 field of struct in6_addr.
> >   - Fixed network headers for freebsd builds.
> > ---
> > ---
> >  lib/odp-execute-avx512.c | 172
> > +++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 172 insertions(+)
> >
> > diff --git a/lib/odp-execute-avx512.c b/lib/odp-execute-avx512.c index
> > 6c7713251..58d1746c9 100644
> > --- a/lib/odp-execute-avx512.c
> > +++ b/lib/odp-execute-avx512.c
> > @@ -20,6 +20,9 @@
> >
> >  #include <config.h>
> >  #include <errno.h>
> > +#include <sys/types.h>
> > +#include <netinet/in.h>
> > +#include <netinet/ip6.h>
> >
> >  #include "csum.h"
> >  #include "dp-packet.h"
> > @@ -483,6 +486,172 @@ action_avx512_ipv4_set_addrs(struct
> dp_packet_batch *batch,
> >      }
> >  }
> >
> > +#if HAVE_AVX512VBMI
> > +static inline uint16_t ALWAYS_INLINE
> > +__attribute__((__target__("avx512vbmi")))
> > +avx512_ipv6_get_delta(__m512i ip6_header) {
> > +    __m256i v_zeros = _mm256_setzero_si256();
> > +    __m512i v_shuf_src_dst = _mm512_setr_epi64(0x01, 0x02, 0x03, 0x04,
> > +                                               0xFF, 0xFF, 0xFF,
> > +0xFF);
> > +
> > +    __m512i v_header = _mm512_permutexvar_epi64(v_shuf_src_dst,
> ip6_header);
> > +    __m256i v_ip6_src_dst =  _mm512_extracti64x4_epi64(v_header, 0);
> > +    /* These two shuffle masks, v_swap16a and v_swap16b, are to shuffle
> the
> > +     * src and dst fields and 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,
> > +                                          0x0504, 0xFFFF, 0x0706, 0xFFFF);
> > +    __m256i v_swap16b = _mm256_setr_epi16(0x0908, 0xFFFF, 0x0B0A,
> 0xFFFF,
> > +                                          0x0D0C, 0xFFFF, 0x0F0E, 0xFFFF,
> > +                                          0x0908, 0xFFFF, 0x0B0A, 0xFFFF,
> > +                                          0x0D0C, 0xFFFF, 0x0F0E, 0xFFFF);
> > +    __m256i v_shuf_old1 = _mm256_shuffle_epi8(v_ip6_src_dst,
> v_swap16a);
> > +    __m256i v_shuf_old2 = _mm256_shuffle_epi8(v_ip6_src_dst,
> > + v_swap16b);
> > +
> > +    /* Add each part of the old and new headers together. */
> > +    __m256i v_delta = _mm256_add_epi32(v_shuf_old1, v_shuf_old2);
> > +
> > +    /* 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); }
> > +
> > +static inline uint16_t ALWAYS_INLINE
> > +__attribute__((__target__("avx512vbmi")))
> > +avx512_ipv6_addr_csum_delta(__m512i old_header, __m512i
> new_header) {
> > +    uint16_t delta;
> > +    uint16_t old_delta = avx512_ipv6_get_delta(old_header);
> > +    uint16_t new_delta = avx512_ipv6_get_delta(new_header);
> > +    old_delta = ~old_delta;
> > +    uint32_t csum_delta = old_delta + new_delta;
> > +    delta = csum_finish(csum_delta);
> > +
> > +    return ~delta;
> > +}
> > +
> > +/* This function performs the same operation on each packet in the
> > +batch as
> > + * the scalar odp_set_ipv6() function. */ static void
> > +__attribute__((__target__("avx512vbmi")))
> > +action_avx512_ipv6_set_addrs(struct dp_packet_batch *batch,
> > +                             const struct nlattr *a) {
> > +    const struct ovs_key_ipv6 *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_ipv6);
> > +
> > +    /* Read the content of the key and mask in the respective registers. We
> > +     * only load the size of the actual structure, which is only 40 bytes. */
> > +    __m512i v_key = _mm512_maskz_loadu_epi64(0x1F, (void *) key);
> > +    __m512i v_mask = _mm512_maskz_loadu_epi64(0x1F, (void *) mask);
> > +
> > +    /* This shuffle mask v_shuffle, is to shuffle key and mask to match the
> > +     * ip6_hdr structure layout. */
> > +    static const uint8_t ip_shuffle_mask[64] = {
> > +            0x20, 0x21, 0x22, 0x23, 0xFF, 0xFF, 0x24, 0x26,
> > +            0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
> > +            0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
> > +            0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
> > +            0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F,
> > +            0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0XFF, 0xFF, 0xFF,
> > +            0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
> > +            0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0XFF, 0xFF
> > +    };
> > +
> > +    __m512i v_shuffle = _mm512_loadu_si512((void *) ip_shuffle_mask);
> > +
> > +    /* This shuffle is required for key and mask to match the layout of the
> > +     * ip6_hdr struct. */
> > +    __m512i v_key_shuf = _mm512_permutexvar_epi8(v_shuffle, v_key);
> > +    __m512i v_mask_shuf = _mm512_permutexvar_epi8(v_shuffle,
> v_mask);
> > +
> > +    DP_PACKET_BATCH_FOR_EACH (i, packet, batch) {
> > +        struct ovs_16aligned_ip6_hdr *nh = dp_packet_l3(packet);
> > +
> > +        /* Load the 40 bytes of the IPv6 header. */
> > +        __m512i v_packet = _mm512_maskz_loadu_epi64(0x1F, (void *)
> > + nh);
> > +
> > +        /* AND the v_pkt_mask to the packet data (v_packet). */
> > +        __m512i v_pkt_masked = _mm512_andnot_si512(v_mask_shuf,
> > + v_packet);
> > +
> > +        /* OR the new addresses (v_key_shuf) with the masked packet
> addresses
> > +         * (v_pkt_masked). */
> > +        __m512i v_new_hdr = _mm512_or_si512(v_key_shuf,
> > + v_pkt_masked);
> > +
> > +        /* If ip6_src or ip6_dst has been modified, L4 checksum needs to
> > +         * be updated. */
> > +        bool do_checksum = false;
> > +#ifdef s6_addr32
> > +        for (int j = 0; j < 4; j++) {
> > +            if (mask->ipv6_dst.s6_addr32[j] || mask->ipv6_src.s6_addr32[j]) {
> > +                do_checksum = true;
> > +            }
> > +        }
> > +#else
> > +        for (int j = 0; j < 16; j++) {
> > +             if (mask->ipv6_dst.s6_addr[j] || mask->ipv6_src.s6_addr[j]) {
> > +                do_checksum = true;
> > +            }
> > +        }
> > +#endif
> > +        if (do_checksum) {
> > +            uint8_t proto = nh->ip6_nxt;
> > +            uint16_t delta_checksum =
> avx512_ipv6_addr_csum_delta(v_packet,
> > +
> > +v_new_hdr);
> > +
> > +            if (proto == IPPROTO_UDP) {
> > +                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);
> > +                    }
> > +
> > +                    uh->udp_csum = udp_checksum;
> > +                }
> > +            } else if (proto == IPPROTO_TCP) {
> > +                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;
> > +            } else if (proto == IPPROTO_ICMPV6) {
> > +                struct icmp6_header *icmp = dp_packet_l4(packet);
> > +                uint16_t old_icmp_checksum = ~icmp->icmp6_cksum;
> > +                uint32_t icmp6_checksum = old_icmp_checksum +
> delta_checksum;
> > +                icmp6_checksum = csum_finish(icmp6_checksum);
> > +
> > +                icmp->icmp6_cksum = icmp6_checksum;
> > +            }
> > +        }
> > +        /* Write back the modified IPv6 addresses. */
> > +         _mm512_mask_storeu_epi64((void *) nh, 0x1F, v_new_hdr);
> > +    }
> > +}
> > +#endif
> > +
> >  static void
> >  action_avx512_set_masked(struct dp_packet_batch *batch, const struct
> > nlattr *a)  { @@ -513,6 +682,9 @@ action_avx512_init(struct
> > odp_execute_action_impl *self OVS_UNUSED)
> >       * 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;
> > +#if HAVE_AVX512VBMI
> > +    impl_set_masked_funcs[OVS_KEY_ATTR_IPV6] =
> > +action_avx512_ipv6_set_addrs; #endif
> >
> 
> I did not review the AVX512 stuff, neither test the patch.
> One comment though.
> 
> All I see are build checks on vbmi availability.
> Don't we need a runtime check for AVX512 platforms that don't have vbmi?
> 
> 
Thanks for looking at this, good catch.
I will add runtime checks for vmbi in the next revision.

Thanks, 
Emma

> --
> David Marchand
diff mbox series

Patch

diff --git a/lib/odp-execute-avx512.c b/lib/odp-execute-avx512.c
index 6c7713251..58d1746c9 100644
--- a/lib/odp-execute-avx512.c
+++ b/lib/odp-execute-avx512.c
@@ -20,6 +20,9 @@ 
 
 #include <config.h>
 #include <errno.h>
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <netinet/ip6.h>
 
 #include "csum.h"
 #include "dp-packet.h"
@@ -483,6 +486,172 @@  action_avx512_ipv4_set_addrs(struct dp_packet_batch *batch,
     }
 }
 
+#if HAVE_AVX512VBMI
+static inline uint16_t ALWAYS_INLINE
+__attribute__((__target__("avx512vbmi")))
+avx512_ipv6_get_delta(__m512i ip6_header)
+{
+    __m256i v_zeros = _mm256_setzero_si256();
+    __m512i v_shuf_src_dst = _mm512_setr_epi64(0x01, 0x02, 0x03, 0x04,
+                                               0xFF, 0xFF, 0xFF, 0xFF);
+
+    __m512i v_header = _mm512_permutexvar_epi64(v_shuf_src_dst, ip6_header);
+    __m256i v_ip6_src_dst =  _mm512_extracti64x4_epi64(v_header, 0);
+    /* These two shuffle masks, v_swap16a and v_swap16b, are to shuffle the
+     * src and dst fields and 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,
+                                          0x0504, 0xFFFF, 0x0706, 0xFFFF);
+    __m256i v_swap16b = _mm256_setr_epi16(0x0908, 0xFFFF, 0x0B0A, 0xFFFF,
+                                          0x0D0C, 0xFFFF, 0x0F0E, 0xFFFF,
+                                          0x0908, 0xFFFF, 0x0B0A, 0xFFFF,
+                                          0x0D0C, 0xFFFF, 0x0F0E, 0xFFFF);
+    __m256i v_shuf_old1 = _mm256_shuffle_epi8(v_ip6_src_dst, v_swap16a);
+    __m256i v_shuf_old2 = _mm256_shuffle_epi8(v_ip6_src_dst, v_swap16b);
+
+    /* Add each part of the old and new headers together. */
+    __m256i v_delta = _mm256_add_epi32(v_shuf_old1, v_shuf_old2);
+
+    /* 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);
+}
+
+static inline uint16_t ALWAYS_INLINE
+__attribute__((__target__("avx512vbmi")))
+avx512_ipv6_addr_csum_delta(__m512i old_header, __m512i new_header)
+{
+    uint16_t delta;
+    uint16_t old_delta = avx512_ipv6_get_delta(old_header);
+    uint16_t new_delta = avx512_ipv6_get_delta(new_header);
+    old_delta = ~old_delta;
+    uint32_t csum_delta = old_delta + new_delta;
+    delta = csum_finish(csum_delta);
+
+    return ~delta;
+}
+
+/* This function performs the same operation on each packet in the batch as
+ * the scalar odp_set_ipv6() function. */
+static void
+__attribute__((__target__("avx512vbmi")))
+action_avx512_ipv6_set_addrs(struct dp_packet_batch *batch,
+                             const struct nlattr *a)
+{
+    const struct ovs_key_ipv6 *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_ipv6);
+
+    /* Read the content of the key and mask in the respective registers. We
+     * only load the size of the actual structure, which is only 40 bytes. */
+    __m512i v_key = _mm512_maskz_loadu_epi64(0x1F, (void *) key);
+    __m512i v_mask = _mm512_maskz_loadu_epi64(0x1F, (void *) mask);
+
+    /* This shuffle mask v_shuffle, is to shuffle key and mask to match the
+     * ip6_hdr structure layout. */
+    static const uint8_t ip_shuffle_mask[64] = {
+            0x20, 0x21, 0x22, 0x23, 0xFF, 0xFF, 0x24, 0x26,
+            0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+            0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
+            0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+            0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F,
+            0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0XFF, 0xFF, 0xFF,
+            0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+            0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0XFF, 0xFF
+    };
+
+    __m512i v_shuffle = _mm512_loadu_si512((void *) ip_shuffle_mask);
+
+    /* This shuffle is required for key and mask to match the layout of the
+     * ip6_hdr struct. */
+    __m512i v_key_shuf = _mm512_permutexvar_epi8(v_shuffle, v_key);
+    __m512i v_mask_shuf = _mm512_permutexvar_epi8(v_shuffle, v_mask);
+
+    DP_PACKET_BATCH_FOR_EACH (i, packet, batch) {
+        struct ovs_16aligned_ip6_hdr *nh = dp_packet_l3(packet);
+
+        /* Load the 40 bytes of the IPv6 header. */
+        __m512i v_packet = _mm512_maskz_loadu_epi64(0x1F, (void *) nh);
+
+        /* AND the v_pkt_mask to the packet data (v_packet). */
+        __m512i v_pkt_masked = _mm512_andnot_si512(v_mask_shuf, v_packet);
+
+        /* OR the new addresses (v_key_shuf) with the masked packet addresses
+         * (v_pkt_masked). */
+        __m512i v_new_hdr = _mm512_or_si512(v_key_shuf, v_pkt_masked);
+
+        /* If ip6_src or ip6_dst has been modified, L4 checksum needs to
+         * be updated. */
+        bool do_checksum = false;
+#ifdef s6_addr32
+        for (int j = 0; j < 4; j++) {
+            if (mask->ipv6_dst.s6_addr32[j] || mask->ipv6_src.s6_addr32[j]) {
+                do_checksum = true;
+            }
+        }
+#else
+        for (int j = 0; j < 16; j++) {
+             if (mask->ipv6_dst.s6_addr[j] || mask->ipv6_src.s6_addr[j]) {
+                do_checksum = true;
+            }
+        }
+#endif
+        if (do_checksum) {
+            uint8_t proto = nh->ip6_nxt;
+            uint16_t delta_checksum = avx512_ipv6_addr_csum_delta(v_packet,
+                                                                  v_new_hdr);
+
+            if (proto == IPPROTO_UDP) {
+                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);
+                    }
+
+                    uh->udp_csum = udp_checksum;
+                }
+            } else if (proto == IPPROTO_TCP) {
+                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;
+            } else if (proto == IPPROTO_ICMPV6) {
+                struct icmp6_header *icmp = dp_packet_l4(packet);
+                uint16_t old_icmp_checksum = ~icmp->icmp6_cksum;
+                uint32_t icmp6_checksum = old_icmp_checksum + delta_checksum;
+                icmp6_checksum = csum_finish(icmp6_checksum);
+
+                icmp->icmp6_cksum = icmp6_checksum;
+            }
+        }
+        /* Write back the modified IPv6 addresses. */
+         _mm512_mask_storeu_epi64((void *) nh, 0x1F, v_new_hdr);
+    }
+}
+#endif
+
 static void
 action_avx512_set_masked(struct dp_packet_batch *batch, const struct nlattr *a)
 {
@@ -513,6 +682,9 @@  action_avx512_init(struct odp_execute_action_impl *self OVS_UNUSED)
      * 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;
+#if HAVE_AVX512VBMI
+    impl_set_masked_funcs[OVS_KEY_ATTR_IPV6] = action_avx512_ipv6_set_addrs;
+#endif
 
     return 0;
 }