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

Message ID 1548751746-16030-1-git-send-email-arybchenko@solarflare.com
State Superseded, archived
Delegated to: Thomas Monjalon
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  • [RFC] mbuf: move headers not fragmented check to checksum
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Context Check Description
ci/Intel-compilation success Compilation OK
ci/checkpatch success coding style OK

Commit Message

Andrew Rybchenko Jan. 29, 2019, 8:49 a.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>
---
May be the check should be done in rte_net_intel_cksum_prepare()
under RTE_LIBRTE_ETHDEV_DEBUG only. Mainly I'd like to get feedback
on where the limitation comes from and idea to remove it from
rte_validate_tx_offload().

 lib/librte_mbuf/rte_mbuf.h | 12 ------------
 lib/librte_net/rte_net.h   | 17 +++++++++++++++++
 2 files changed, 17 insertions(+), 12 deletions(-)

Comments

Andrew Rybchenko Feb. 13, 2019, 9:50 a.m. | #1
Ping.

Do 2 weeks without reply mean that it looks good and I should send 
non-RCF version?

Andrew.

On 1/29/19 11:49 AM, 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>
> ---
> May be the check should be done in rte_net_intel_cksum_prepare()
> under RTE_LIBRTE_ETHDEV_DEBUG only. Mainly I'd like to get feedback
> on where the limitation comes from and idea to remove it from
> rte_validate_tx_offload().
>
>   lib/librte_mbuf/rte_mbuf.h | 12 ------------
>   lib/librte_net/rte_net.h   | 17 +++++++++++++++++
>   2 files changed, 17 insertions(+), 12 deletions(-)
>
> diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
> index a7f67023a..14a3b472b 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..bd75aea8e 100644
> --- a/lib/librte_net/rte_net.h
> +++ b/lib/librte_net/rte_net.h
> @@ -118,10 +118,27 @@ 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;
>   
> +	/*
> +	 * 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;
> +
>   	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;
>   
> +	/*
> +	 * 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;
> +
>   	if (ol_flags & PKT_TX_IPV4) {
>   		ipv4_hdr = rte_pktmbuf_mtod_offset(m, struct ipv4_hdr *,
>   				inner_l3_offset);
Wiles, Keith Feb. 13, 2019, 2:48 p.m. | #2
> On Feb 13, 2019, at 3:50 AM, Andrew Rybchenko <arybchenko@solarflare.com> wrote:
> 
> Ping.
> 
> Do 2 weeks without reply mean that it looks good and I should send non-RCF version?

Just send the non-RFC patch as it seems most do not even look at the RFC’s anyway.
> 
> Andrew.
> 
> On 1/29/19 11:49 AM, 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>
>> ---
>> May be the check should be done in rte_net_intel_cksum_prepare()
>> under RTE_LIBRTE_ETHDEV_DEBUG only. Mainly I'd like to get feedback
>> on where the limitation comes from and idea to remove it from
>> rte_validate_tx_offload().
>> 
>>  lib/librte_mbuf/rte_mbuf.h | 12 ------------
>>  lib/librte_net/rte_net.h   | 17 +++++++++++++++++
>>  2 files changed, 17 insertions(+), 12 deletions(-)
>> 
>> diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
>> index a7f67023a..14a3b472b 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..bd75aea8e 100644
>> --- a/lib/librte_net/rte_net.h
>> +++ b/lib/librte_net/rte_net.h
>> @@ -118,10 +118,27 @@ 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;
>>  +	/*
>> +	 * 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;
>> +
>>  	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;
>>  +	/*
>> +	 * 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;
>> +
>>  	if (ol_flags & PKT_TX_IPV4) {
>>  		ipv4_hdr = rte_pktmbuf_mtod_offset(m, struct ipv4_hdr *,
>>  				inner_l3_offset);
> 

Regards,
Keith
Ananyev, Konstantin Feb. 13, 2019, 11:27 p.m. | #3
Hi Andrew,
 
> 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>
> ---
> May be the check should be done in rte_net_intel_cksum_prepare()
> under RTE_LIBRTE_ETHDEV_DEBUG only. Mainly I'd like to get feedback
> on where the limitation comes from and idea to remove it from
> rte_validate_tx_offload().
> 
>  lib/librte_mbuf/rte_mbuf.h | 12 ------------
>  lib/librte_net/rte_net.h   | 17 +++++++++++++++++
>  2 files changed, 17 insertions(+), 12 deletions(-)
> 
> diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
> index a7f67023a..14a3b472b 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..bd75aea8e 100644
> --- a/lib/librte_net/rte_net.h
> +++ b/lib/librte_net/rte_net.h
> @@ -118,10 +118,27 @@ 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;
> 
> +	/*
> +	 * 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;
> +
>  	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;
> 
> +	/*
> +	 * 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;
> +
>  	if (ol_flags & PKT_TX_IPV4) {
>  		ipv4_hdr = rte_pktmbuf_mtod_offset(m, struct ipv4_hdr *,
>  				inner_l3_offset);
> --

Looks good to me, though extra-testing would be needed.
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>

> 2.17.1

Patch

diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
index a7f67023a..14a3b472b 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..bd75aea8e 100644
--- a/lib/librte_net/rte_net.h
+++ b/lib/librte_net/rte_net.h
@@ -118,10 +118,27 @@  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;
 
+	/*
+	 * 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;
+
 	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;
 
+	/*
+	 * 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;
+
 	if (ol_flags & PKT_TX_IPV4) {
 		ipv4_hdr = rte_pktmbuf_mtod_offset(m, struct ipv4_hdr *,
 				inner_l3_offset);