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dpif-netdev: fix vlan and ipv4 parsing in avx512
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This commit fixes the minimum packet size for the vlan/ipv4/tcp
traffic profile, which was previously incorrectly set.

This commit also disallows any fragmented IPv4 packets from being
matched in the optimized miniflow-extract, avoiding complexity of
handling fragmented packets and using scalar fallback instead.
The DF (don't fragment) bit is now ignored, and stripped from the
resulting miniflow.

Fixes: aa85a25 ("dpif-netdev/mfex: Add more AVX512 traffic profiles.")
Signed-off-by: Harry van Haaren <[email protected]>
Tested-by: Kumar Amber <[email protected]>
Acked-by: Eelco Chaudron <[email protected]>
Signed-off-by: Ian Stokes <[email protected]>
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@harry-van-haaren @istokes
harry-van-haaren authored and istokes committed Feb 8, 2022
1 parent d545300 commit 4f810de
Showing 1 changed file with 31 additions and 5 deletions.
36 changes: 31 additions & 5 deletions lib/dpif-netdev-extract-avx512.c
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Original file line number Diff line number Diff line change
Expand Up @@ -157,7 +157,7 @@ _mm512_maskz_permutexvar_epi8_wrap(__mmask64 kmask, __m512i idx, __m512i a)
0, 0, 0, 0, /* Src IP */ \
0, 0, 0, 0, /* Dst IP */

#define PATTERN_IPV4_MASK PATTERN_IPV4_GEN(0xFF, 0xFE, 0xFF, 0xFF)
#define PATTERN_IPV4_MASK PATTERN_IPV4_GEN(0xFF, 0xBF, 0xFF, 0xFF)
#define PATTERN_IPV4_UDP PATTERN_IPV4_GEN(0x45, 0, 0, 0x11)
#define PATTERN_IPV4_TCP PATTERN_IPV4_GEN(0x45, 0, 0, 0x06)

Expand Down Expand Up @@ -226,6 +226,25 @@ _mm512_maskz_permutexvar_epi8_wrap(__mmask64 kmask, __m512i idx, __m512i a)
#define PATTERN_DT1Q_IPV4_TCP_KMASK \
(KMASK_ETHER | (KMASK_DT1Q << 16) | (KMASK_IPV4 << 24) | (KMASK_TCP << 40))

/* Miniflow Strip post-processing masks.
* This allows unsetting specific bits from the resulting miniflow. It is used
* for e.g. IPv4 where the "DF" bit is never pushed to the miniflow itself.
* The NC define is for "No Change", allowing the bits to pass through.
*/
#define NC 0xFF

#define PATTERN_STRIP_IPV4_MASK \
NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, \
NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, 0xBF, NC, NC, NC, \
NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, \
NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC

#define PATTERN_STRIP_DOT1Q_IPV4_MASK \
NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, \
NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, \
NC, NC, NC, NC, 0xBF, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, \
NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC

/* This union allows initializing static data as u8, but easily loading it
* into AVX512 registers too. The union ensures proper alignment for the zmm.
*/
Expand All @@ -250,8 +269,9 @@ struct mfex_profile {
union mfex_data probe_mask;
union mfex_data probe_data;

/* Required for reshaping packet into miniflow. */
/* Required for reshaping packet into miniflow and post-processing it. */
union mfex_data store_shuf;
union mfex_data strip_mask;
__mmask64 store_kmsk;

/* Constant data to set in mf.bits and dp_packet data on hit. */
Expand Down Expand Up @@ -319,6 +339,7 @@ static const struct mfex_profile mfex_profiles[PROFILE_COUNT] =
.probe_data.u8_data = { PATTERN_ETHERTYPE_IPV4 PATTERN_IPV4_UDP},

.store_shuf.u8_data = { PATTERN_IPV4_UDP_SHUFFLE },
.strip_mask.u8_data = { PATTERN_STRIP_IPV4_MASK },
.store_kmsk = PATTERN_IPV4_UDP_KMASK,

.mf_bits = { 0x18a0000000000000, 0x0000000000040401},
Expand All @@ -341,6 +362,7 @@ static const struct mfex_profile mfex_profiles[PROFILE_COUNT] =
},

.store_shuf.u8_data = { PATTERN_IPV4_TCP_SHUFFLE },
.strip_mask.u8_data = { PATTERN_STRIP_IPV4_MASK },
.store_kmsk = PATTERN_IPV4_TCP_KMASK,

.mf_bits = { 0x18a0000000000000, 0x0000000000044401},
Expand All @@ -359,6 +381,7 @@ static const struct mfex_profile mfex_profiles[PROFILE_COUNT] =
},

.store_shuf.u8_data = { PATTERN_DT1Q_IPV4_UDP_SHUFFLE },
.strip_mask.u8_data = { PATTERN_STRIP_DOT1Q_IPV4_MASK },
.store_kmsk = PATTERN_DT1Q_IPV4_UDP_KMASK,

.mf_bits = { 0x38a0000000000000, 0x0000000000040401},
Expand All @@ -383,13 +406,14 @@ static const struct mfex_profile mfex_profiles[PROFILE_COUNT] =
},

.store_shuf.u8_data = { PATTERN_DT1Q_IPV4_TCP_SHUFFLE },
.strip_mask.u8_data = { PATTERN_STRIP_DOT1Q_IPV4_MASK },
.store_kmsk = PATTERN_DT1Q_IPV4_TCP_KMASK,

.mf_bits = { 0x38a0000000000000, 0x0000000000044401},
.dp_pkt_offs = {
14, UINT16_MAX, 18, 38,
},
.dp_pkt_min_size = 46,
.dp_pkt_min_size = 58,
},
};

Expand Down Expand Up @@ -471,6 +495,7 @@ mfex_avx512_process(struct dp_packet_batch *packets,
__m512i v_vals = _mm512_loadu_si512(&profile->probe_data);
__m512i v_mask = _mm512_loadu_si512(&profile->probe_mask);
__m512i v_shuf = _mm512_loadu_si512(&profile->store_shuf);
__m512i v_strp = _mm512_loadu_si512(&profile->strip_mask);

__mmask64 k_shuf = profile->store_kmsk;
__m128i v_bits = _mm_loadu_si128((void *) &profile->mf_bits);
Expand Down Expand Up @@ -498,7 +523,7 @@ mfex_avx512_process(struct dp_packet_batch *packets,

__m512i v_pkt0_masked = _mm512_and_si512(v_pkt0, v_mask);
__mmask64 k_cmp = _mm512_cmpeq_epi8_mask(v_pkt0_masked, v_vals);
if (k_cmp != UINT64_MAX) {
if (OVS_UNLIKELY(k_cmp != UINT64_MAX)) {
continue;
}

Expand Down Expand Up @@ -526,8 +551,9 @@ mfex_avx512_process(struct dp_packet_batch *packets,
v_blk0 = _mm512_maskz_permutex2var_epi8_skx(k_shuf, v_pkt0,
v_shuf, v512_zeros);
}
_mm512_storeu_si512(&blocks[2], v_blk0);

__m512i v_blk0_strip = _mm512_and_si512(v_blk0, v_strp);
_mm512_storeu_si512(&blocks[2], v_blk0_strip);

/* Perform "post-processing" per profile, handling details not easily
* handled in the above generic AVX512 code. Examples include TCP flag
Expand Down

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