[v2] mbuf: move headers not fragmented check to checksum

Message ID 1553866934-21871-1-git-send-email-arybchenko@solarflare.com
State Accepted, archived
Delegated to: Thomas Monjalon
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Series
  • [v2] mbuf: move headers not fragmented check to checksum
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Checks

Context Check Description
ci/Intel-compilation success Compilation OK
ci/intel-Performance-Testing success Performance Testing PASS
ci/mellanox-Performance-Testing fail Performance Testing issues
ci/checkpatch success coding style OK

Commit Message

Andrew Rybchenko March 29, 2019, 1:42 p.m.
rte_validate_tx_offload() is used in Tx prepare callbacks
(RTE_LIBRTE_ETHDEV_DEBUG only) to check Tx offloads consistency.
Requirement that packet headers should not be fragmented is not
documented and unclear where it comes from except
rte_net_intel_cksum_prepare() functions which relies on it.

It could be NIC vendor specific driver or hardware limitation, but,
if so, it should be documented and checked in corresponding Tx
prepare callbacks.

Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
---
 lib/librte_mbuf/rte_mbuf.h | 12 ------------
 lib/librte_net/rte_net.h   | 21 +++++++++++++++++++++
 2 files changed, 21 insertions(+), 12 deletions(-)

Comments

Olivier Matz March 29, 2019, 2:18 p.m. | #1
On Fri, Mar 29, 2019 at 01:42:14PM +0000, Andrew Rybchenko wrote:
> rte_validate_tx_offload() is used in Tx prepare callbacks
> (RTE_LIBRTE_ETHDEV_DEBUG only) to check Tx offloads consistency.
> Requirement that packet headers should not be fragmented is not
> documented and unclear where it comes from except
> rte_net_intel_cksum_prepare() functions which relies on it.
> 
> It could be NIC vendor specific driver or hardware limitation, but,
> if so, it should be documented and checked in corresponding Tx
> prepare callbacks.
> 
> Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>

Acked-by: Olivier Matz <olivier.matz@6wind.com>

Thanks!
Thomas Monjalon April 2, 2019, 2:48 p.m. | #2
29/03/2019 15:18, Olivier Matz:
> On Fri, Mar 29, 2019 at 01:42:14PM +0000, Andrew Rybchenko wrote:
> > rte_validate_tx_offload() is used in Tx prepare callbacks
> > (RTE_LIBRTE_ETHDEV_DEBUG only) to check Tx offloads consistency.
> > Requirement that packet headers should not be fragmented is not
> > documented and unclear where it comes from except
> > rte_net_intel_cksum_prepare() functions which relies on it.
> > 
> > It could be NIC vendor specific driver or hardware limitation, but,
> > if so, it should be documented and checked in corresponding Tx
> > prepare callbacks.
> > 
> > Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
> 
> Acked-by: Olivier Matz <olivier.matz@6wind.com>
> 
> Thanks!

Applied with a more explicit title:
	mbuf: remove Intel offload checks from generic API

Patch

diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
index d961ccaf6..73daa8140 100644
--- a/lib/librte_mbuf/rte_mbuf.h
+++ b/lib/librte_mbuf/rte_mbuf.h
@@ -2257,23 +2257,11 @@  static inline int
 rte_validate_tx_offload(const struct rte_mbuf *m)
 {
 	uint64_t ol_flags = m->ol_flags;
-	uint64_t inner_l3_offset = m->l2_len;
 
 	/* Does packet set any of available offloads? */
 	if (!(ol_flags & PKT_TX_OFFLOAD_MASK))
 		return 0;
 
-	if (ol_flags & PKT_TX_OUTER_IP_CKSUM)
-		/* NB: elaborating the addition like this instead of using
-		 *     += gives the result uint64_t type instead of int,
-		 *     avoiding compiler warnings on gcc 8.1 at least */
-		inner_l3_offset = inner_l3_offset + m->outer_l2_len +
-				  m->outer_l3_len;
-
-	/* Headers are fragmented */
-	if (rte_pktmbuf_data_len(m) < inner_l3_offset + m->l3_len + m->l4_len)
-		return -ENOTSUP;
-
 	/* IP checksum can be counted only for IPv4 packet */
 	if ((ol_flags & PKT_TX_IP_CKSUM) && (ol_flags & PKT_TX_IPV6))
 		return -EINVAL;
diff --git a/lib/librte_net/rte_net.h b/lib/librte_net/rte_net.h
index e59760a0a..16970711b 100644
--- a/lib/librte_net/rte_net.h
+++ b/lib/librte_net/rte_net.h
@@ -118,10 +118,31 @@  rte_net_intel_cksum_flags_prepare(struct rte_mbuf *m, uint64_t ol_flags)
 	struct udp_hdr *udp_hdr;
 	uint64_t inner_l3_offset = m->l2_len;
 
+#ifdef RTE_LIBRTE_ETHDEV_DEBUG
+	/*
+	 * Does packet set any of available offloads?
+	 * Mainly it is required to avoid fragmented headers check if
+	 * no offloads are requested.
+	 */
+	if (!(ol_flags & PKT_TX_OFFLOAD_MASK))
+		return 0;
+#endif
+
 	if ((ol_flags & PKT_TX_OUTER_IP_CKSUM) ||
 		(ol_flags & PKT_TX_OUTER_IPV6))
 		inner_l3_offset += m->outer_l2_len + m->outer_l3_len;
 
+#ifdef RTE_LIBRTE_ETHDEV_DEBUG
+	/*
+	 * Check if headers are fragmented.
+	 * The check could be less strict depending on which offloads are
+	 * requested and headers to be used, but let's keep it simple.
+	 */
+	if (unlikely(rte_pktmbuf_data_len(m) <
+		     inner_l3_offset + m->l3_len + m->l4_len))
+		return -ENOTSUP;
+#endif
+
 	if (ol_flags & PKT_TX_IPV4) {
 		ipv4_hdr = rte_pktmbuf_mtod_offset(m, struct ipv4_hdr *,
 				inner_l3_offset);