Re: [dpdk-dev] [PATCH v4] ethdev: add IPv4 and L4 checksum RSS offload types

["Zhang, AlvinX" <alvinx.zhang@intel.com>]

> -----Original Message-----
> From: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
> Sent: Tuesday, July 13, 2021 3:55 PM
> To: Zhang, AlvinX <alvinx.zhang@intel.com>; Zhang, Qi Z
> <qi.z.zhang@intel.com>; ajit.khaparde@broadcom.com
> Cc: dev@dpdk.org; Singh, Aman Deep <aman.deep.singh@intel.com>
> Subject: Re: [PATCH v4] ethdev: add IPv4 and L4 checksum RSS offload types
> 
> On 7/13/21 4:13 AM, Alvin Zhang wrote:
> > This patch defines new RSS offload types for IPv4 and
> > L4(TCP/UDP/SCTP) checksum, which are required when users want to
> > distribute packets based on the IPv4 or L4 checksum field.
> >
> > For example "flow create 0 ingress pattern eth / ipv4 / end actions
> > rss types ipv4-chksum end queues end / end", this flow causes all
> > matching packets to be distributed to queues on basis of IPv4
> > checksum.
> >
> > Signed-off-by: Alvin Zhang <alvinx.zhang@intel.com>
> > Reviewed-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
> 
> I've failed to find mail where I've added the tag. I've replied with "LGTM" for v2
> which has IPv4 checksum only and many comments on L4 checksum added in v3.
> So, I think it is incorrect to inherit "LGTM" as Reviewed-by.
> 
 
I'll correct it at next version.         
    
> > Acked-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
> > Acked-by: Aman Deep Singh <aman.deep.singh@intel.com>
> > ---
> >
> > v3: Add L4 checksum RSS offload type
> > v4: Add doc and help string, update commit log
> > ---
> >  app/test-pmd/cmdline.c  | 12 +++++++++---
> >  app/test-pmd/config.c   |  2 ++
> >  lib/ethdev/rte_ethdev.h |  2 ++
> >  3 files changed, 13 insertions(+), 3 deletions(-)
> >
> > diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c index
> > 0268b18..93543d8 100644
> > --- a/app/test-pmd/cmdline.c
> > +++ b/app/test-pmd/cmdline.c
> > @@ -2254,6 +2254,10 @@ struct cmd_config_rss {
> >  		rss_conf.rss_hf = ETH_RSS_ECPRI;
> >  	else if (!strcmp(res->value, "mpls"))
> >  		rss_conf.rss_hf = ETH_RSS_MPLS;
> > +	else if (!strcmp(res->value, "ipv4-chksum"))
> > +		rss_conf.rss_hf = ETH_RSS_IPV4_CHKSUM;
> > +	else if (!strcmp(res->value, "l4-chksum"))
> > +		rss_conf.rss_hf = ETH_RSS_L4_CHKSUM;
> >  	else if (!strcmp(res->value, "none"))
> >  		rss_conf.rss_hf = 0;
> >  	else if (!strcmp(res->value, "level-default")) { @@ -2325,7 +2329,7
> > @@ struct cmd_config_rss {
> >  	.help_str = "port config all rss "
> >  		"all|default|eth|vlan|ip|tcp|udp|sctp|ether|port|vxlan|geneve|"
> >
> 	"nvgre|vxlan-gpe|l2tpv3|esp|ah|pfcp|ecpri|mpls|none|level-default|"
> > -		"level-outer|level-inner|<flowtype_id>",
> > +		"level-outer|level-inner|ipv4-chksum|l4-chksum|<flowtype_id>",
> >  	.tokens = {
> >  		(void *)&cmd_config_rss_port,
> >  		(void *)&cmd_config_rss_keyword,
> > @@ -2438,7 +2442,8 @@ struct cmd_config_rss_hash_key {
> >  				 "ipv6-tcp-ex#ipv6-udp-ex#"
> >  				 "l3-src-only#l3-dst-only#l4-src-only#l4-dst-only#"
> >  				 "l2-src-only#l2-dst-only#s-vlan#c-vlan#"
> > -				 "l2tpv3#esp#ah#pfcp#pppoe#gtpu#ecpri#mpls");
> > +				 "l2tpv3#esp#ah#pfcp#pppoe#gtpu#ecpri#mpls#"
> > +				 "ipv4-chksum#l4-chksum");
> >  cmdline_parse_token_string_t cmd_config_rss_hash_key_value =
> >  	TOKEN_STRING_INITIALIZER(struct cmd_config_rss_hash_key, key, NULL);
> >
> > @@ -2451,7 +2456,8 @@ struct cmd_config_rss_hash_key {
> >  		"l2-payload|ipv6-ex|ipv6-tcp-ex|ipv6-udp-ex|"
> >  		"l3-src-only|l3-dst-only|l4-src-only|l4-dst-only|"
> >  		"l2-src-only|l2-dst-only|s-vlan|c-vlan|"
> > -		"l2tpv3|esp|ah|pfcp|pppoe|gtpu|ecpri|mpls "
> > +		"l2tpv3|esp|ah|pfcp|pppoe|gtpu|ecpri|mpls|"
> > +		"ipv4-chksum|l4-chksum "
> >  		"<string of hex digits (variable length, NIC dependent)>",
> >  	.tokens = {
> >  		(void *)&cmd_config_rss_hash_key_port, diff --git
> > a/app/test-pmd/config.c b/app/test-pmd/config.c index 43c79b5..14968bf
> > 100644
> > --- a/app/test-pmd/config.c
> > +++ b/app/test-pmd/config.c
> > @@ -140,6 +140,8 @@
> >  	{ "gtpu", ETH_RSS_GTPU },
> >  	{ "ecpri", ETH_RSS_ECPRI },
> >  	{ "mpls", ETH_RSS_MPLS },
> > +	{ "ipv4-chksum", ETH_RSS_IPV4_CHKSUM },
> > +	{ "l4-chksum", ETH_RSS_L4_CHKSUM },
> >  	{ NULL, 0 },
> >  };
> >
> > diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h index
> > faf3bd9..63b0321 100644
> > --- a/lib/ethdev/rte_ethdev.h
> > +++ b/lib/ethdev/rte_ethdev.h
> > @@ -537,6 +537,8 @@ struct rte_eth_rss_conf {
> >  #define ETH_RSS_PPPOE		   (1ULL << 31)
> >  #define ETH_RSS_ECPRI		   (1ULL << 32)
> >  #define ETH_RSS_MPLS		   (1ULL << 33)
> > +#define ETH_RSS_IPV4_CHKSUM	   (1ULL << 34)
> > +#define ETH_RSS_L4_CHKSUM	   (1ULL << 35)	/* TCP/UDP/SCTP */
> 
> It does not reply on my questions at all.
  
You have said:       
> >> I don't think so. IMHO, it should report all RSS capabilities      
> >> regardless generic vs flow API RSS action.       
> >      
> May be it is OK to report subset in      
> dev_info->flow_type_rss_offloads, but I'm very uncomfortable with the       
> approach. Superset sounds more logical to me, but has drawbacks as        
> well.         

Here I have another question:              
There are flow type definition and RSS offload type definition,         
#define RTE_ETH_FLOW_RAW                 1       
#define RTE_ETH_FLOW_IPV4                2     
#define RTE_ETH_FLOW_FRAG_IPV4           3       
#define RTE_ETH_FLOW_NONFRAG_IPV4_TCP    4        

#define ETH_RSS_IPV4               (1ULL << 2)      
#define ETH_RSS_FRAG_IPV4          (1ULL << 3)         
#define ETH_RSS_NONFRAG_IPV4_TCP   (1ULL << 4)        
  
are they the different expressions of the same concept?             

If yes, why they have been decoupled by the commit: fce6b66893.   
Then what the flow type of ETH_RSS_PORT, it's UDP, TCP, or SCTP?      

If not, the PMDs can report supported RSS flow type by dev_info->flow_type_rss_offloads,   
but have no way to report supported RSS offload types.          

Thanks Alvin

> 
> Nack