From 82d71ca917b2631bcf31848d39b589ed432d5b35 Mon Sep 17 00:00:00 2001 From: Sepherosa Ziehau Date: Mon, 31 Oct 2016 05:05:12 +0000 Subject: [PATCH] hyperv/hn: Reset do_lro, if the hash types are not TCP related. Mainly because the host side only set TCPCS and IPCS even for UDP datagrams. MFC after: 1 week Sponsored by: Microsoft Differential Revision: https://reviews.freebsd.org/D8369 --- sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c b/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c index 318fcb4eb70e..88f1834a5e15 100644 --- a/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c +++ b/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c @@ -1754,6 +1754,13 @@ hn_rxpkt(struct hn_rx_ring *rxr, const void *data, int dlen, rxr->hn_csum_udp++; } + /* + * XXX + * As of this write (Oct 28th, 2016), host side will turn + * on only TCPCS_OK and IPCS_OK even for UDP datagrams, so + * the do_lro setting here is actually _not_ accurate. We + * depend on the RSS hash type check to reset do_lro. + */ if ((info->csum_info & (NDIS_RXCSUM_INFO_TCPCS_OK | NDIS_RXCSUM_INFO_IPCS_OK)) == (NDIS_RXCSUM_INFO_TCPCS_OK | NDIS_RXCSUM_INFO_IPCS_OK)) @@ -1828,9 +1835,16 @@ skip: NDIS_HASH_FUNCTION_TOEPLITZ) { uint32_t type = (info->hash_info & NDIS_HASH_TYPE_MASK); + /* + * NOTE: + * do_lro is resetted, if the hash types are not TCP + * related. See the comment in the above csum_flags + * setup section. + */ switch (type) { case NDIS_HASH_IPV4: hash_type = M_HASHTYPE_RSS_IPV4; + do_lro = 0; break; case NDIS_HASH_TCP_IPV4: @@ -1839,10 +1853,12 @@ skip: case NDIS_HASH_IPV6: hash_type = M_HASHTYPE_RSS_IPV6; + do_lro = 0; break; case NDIS_HASH_IPV6_EX: hash_type = M_HASHTYPE_RSS_IPV6_EX; + do_lro = 0; break; case NDIS_HASH_TCP_IPV6: