On 12/10/24 12:35 PM, Ales Musil wrote:
> On Mon, Nov 11, 2024 at 11:43 AM Dumitru Ceara <[email protected]> wrote:
> 
>> The actions that retrieve the original tuple destination IPs and ports
>> were used in the following way in ovn-northd:
>>
>>   REG_ORIG_DIP_IPV4 " = ct_nw_dst()
>>   REG_ORIG_DIP_IPV6 " = ct_ip6_dst()
>>   REG_ORIG_TP_DPORT " = ct_tp_dst()
>>
>> Where:
>>   REG_ORIG_DIP_IPV4 is reg1
>>   REG_ORIG_DIP_IPV6 is xxreg1
>>   REG_ORIG_TP_DPORT is reg2[0..15]
>>
>> While the actions use a different intermediate register:
>>   ct_nw_dst()  was reg4<-0; reg4<-ct_nw_dst
>>   ct_ip6_dst() was xxreg0<-0; xxreg0<-ct_ip6_dst
>>   ct_tp_dst()  was reg8[0..15]<-0; reg8[0..15]<-ct_tp_dst
>>
>> We can reduce the set of registers we use in the OVN pipeline by
>> changing the action definition to use the same registers ovn-northd uses
>> as final destination for the ct_*_dst() values.  This will generate the
>> following openflow rules:
>>
>>   REG_ORIG_DIP_IPV4 " = ct_nw_dst()
>>     reg1<-0; reg1<-ct_nw_dst; reg1<-reg1
>>   REG_ORIG_DIP_IPV6 " = ct_ip6_dst()
>>     xxreg1<-0; xxreg1<-ct_ip6_dst; xxreg1<-xxreg1
>>   REG_ORIG_TP_DPORT " = ct_tp_dst()
>>     reg2[0..15]<-0; reg2[0..15]<-ct_tp_dst; reg2[0..15]<-reg2[0..15]
>>
>> As Ilya Maximets points out, overlapping source and destination are
>> well defined for move actions:
>>
>> https://opennetworking.org/wp-content/uploads/2014/10/openflow-switch-v1.5.0.noipr.pdf
>>
>>   This action must behaves properly when src_oxm_id overlaps with
>>   dst_oxm_id, that is, it behaves as if src_oxm_id were copied out
>>   to a temporary buffer, then the temporary buffer copied to
>>   dst_oxm_id, if this is not possible the switch must reject the
>>   Copy Field action with a Bad Set Type error message.
>>
>> OpenvSwitch doesn't reject such actions.
>>
>> Fixes: 0f806cf08c36 ("Fix load balanced hairpin traffic for fragmented
>> packets.")
>> Signed-off-by: Dumitru Ceara <[email protected]>
>> ---
>>  include/ovn/logical-fields.h | 7 ++++---
>>  tests/ovn.at                 | 8 ++++----
>>  2 files changed, 8 insertions(+), 7 deletions(-)
>>
>> diff --git a/include/ovn/logical-fields.h b/include/ovn/logical-fields.h
>> index d563e044cb..70c6b93c41 100644
>> --- a/include/ovn/logical-fields.h
>> +++ b/include/ovn/logical-fields.h
>> @@ -60,9 +60,10 @@ enum ovn_controller_event {
>>  #define MFF_LOG_LB_AFF_MATCH_LR_IP6_ADDR    MFF_XXREG1
>>  #define MFF_LOG_LB_AFF_MATCH_PORT           MFF_REG8
>>
>> -#define MFF_LOG_CT_ORIG_NW_DST_ADDR         MFF_REG4
>> -#define MFF_LOG_CT_ORIG_IP6_DST_ADDR        MFF_XXREG0
>> -#define MFF_LOG_CT_ORIG_TP_DST_PORT         MFF_REG8
>> +#define MFF_LOG_CT_ORIG_NW_DST_ADDR         MFF_REG1   /*
>> REG_ORIG_DIP_IPV4 */
>> +#define MFF_LOG_CT_ORIG_IP6_DST_ADDR        MFF_XXREG1 /*
>> REG_ORIG_DIP_IPV6 */
>> +#define MFF_LOG_CT_ORIG_TP_DST_PORT         MFF_REG2   /*
>> REG_ORIG_TP_DPORT
>> +                                                        * (bits 0..15). */
>>
>>  void ovn_init_symtab(struct shash *symtab);
>>
>> diff --git a/tests/ovn.at b/tests/ovn.at
>> index 15b78f4c37..03fd2090fc 100644
>> --- a/tests/ovn.at
>> +++ b/tests/ovn.at
>> @@ -2420,10 +2420,10 @@ mac_cache_use;
>>
>>  # ct_nw_dst()
>>  reg1 = ct_nw_dst();
>> -    encodes as
>> set_field:0->reg4,resubmit(,OFTABLE_CT_ORIG_NW_DST_LOAD),move:NXM_NX_REG4[[]]->NXM_NX_XXREG0[[64..95]]
>> +    encodes as
>> set_field:0->reg1,resubmit(,OFTABLE_CT_ORIG_NW_DST_LOAD),move:NXM_NX_REG1[[]]->NXM_NX_XXREG0[[64..95]]
>>
>>  xreg1[[3..34]] = ct_nw_dst();
>> -    encodes as
>> set_field:0->reg4,resubmit(,OFTABLE_CT_ORIG_NW_DST_LOAD),move:NXM_NX_REG4[[]]->NXM_NX_XXREG0[[3..34]]
>> +    encodes as
>> set_field:0->reg1,resubmit(,OFTABLE_CT_ORIG_NW_DST_LOAD),move:NXM_NX_REG1[[]]->NXM_NX_XXREG0[[3..34]]
>>
>>  reg1[[3..34]] = ct_nw_dst();
>>      Cannot select bits 3 to 34 of 32-bit field reg1.
>> @@ -2442,7 +2442,7 @@ ct_nw_dst();
>>
>>  # ct_ip6_dst()
>>  xxreg1 = ct_ip6_dst();
>> -    encodes as
>> set_field:0/0xffffffffffffffff->xxreg0,set_field:0/0xffffffffffffffff0000000000000000->xxreg0,resubmit(,OFTABLE_CT_ORIG_IP6_DST_LOAD),move:NXM_NX_XXREG0[[]]->NXM_NX_XXREG1[[]]
>> +    encodes as
>> set_field:0/0xffffffffffffffff->xxreg1,set_field:0/0xffffffffffffffff0000000000000000->xxreg1,resubmit(,OFTABLE_CT_ORIG_IP6_DST_LOAD),move:NXM_NX_XXREG1[[]]->NXM_NX_XXREG1[[]]
>>
>>  reg1 = ct_ip6_dst();
>>      Cannot use 32-bit field reg1[[0..31]] where 128-bit field is required.
>> @@ -2455,7 +2455,7 @@ ct_ip6_dst();
>>
>>  # ct_tp_dst()
>>  reg1[[0..15]] = ct_tp_dst();
>> -    encodes as
>> set_field:0/0xffff->reg8,resubmit(,OFTABLE_CT_ORIG_TP_DST_LOAD),move:NXM_NX_REG8[[0..15]]->NXM_NX_XXREG0[[64..79]]
>> +    encodes as
>> set_field:0/0xffff->reg2,resubmit(,OFTABLE_CT_ORIG_TP_DST_LOAD),move:NXM_NX_REG2[[0..15]]->NXM_NX_XXREG0[[64..79]]
>>
>>  reg1 = ct_tp_dst();
>>      Cannot use 32-bit field reg1[[0..31]] where 16-bit field is required.
>> --
>> 2.46.2
>>
>> _______________________________________________
>> dev mailing list
>> [email protected]
>> https://mail.openvswitch.org/mailman/listinfo/ovs-dev
>>
>>
> Looks good to me, thanks.
> 
> Acked-by: Ales Musil <[email protected]>
> 

Thanks, Ales!  Applied to main and backported to 24.09 and 24.03.

Regards,
Dumitru


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