On 10/8/2018 12:55 PM, Jerin Jacob wrote: > -----Original Message----- >> Date: Mon, 8 Oct 2018 11:53:01 +0100 >> From: Ferruh Yigit <ferruh.yi...@intel.com> >> To: Jerin Jacob <jerin.ja...@caviumnetworks.com>, Thomas Monjalon >> <tho...@monjalon.net> >> CC: "Ananyev, Konstantin" <konstantin.anan...@intel.com>, Andrew Rybchenko >> <arybche...@solarflare.com>, "Lu, Wenzhuo" <wenzhuo...@intel.com>, "Wu, >> Jingjing" <jingjing...@intel.com>, "Iremonger, Bernard" >> <bernard.iremon...@intel.com>, "Mcnamara, John" <john.mcnam...@intel.com>, >> "Kovacevic, Marko" <marko.kovace...@intel.com>, Olivier Matz >> <olivier.m...@6wind.com>, "dev@dpdk.org" <dev@dpdk.org>, >> "shah...@mellanox.com" <shah...@mellanox.com>, "didier.pall...@6wind.com" >> <didier.pall...@6wind.com> >> Subject: Re: [dpdk-dev] [PATCH v2 1/4] ethdev: add Rx offload outer UDP >> checksum definition >> User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 >> Thunderbird/52.9.1 >> >> On 10/8/2018 10:37 AM, Jerin Jacob wrote: >>> -----Original Message----- >>>> Date: Mon, 08 Oct 2018 11:04:51 +0200 >>>> From: Thomas Monjalon <tho...@monjalon.net> >>>> To: Jerin Jacob <jerin.ja...@caviumnetworks.com>, Ferruh Yigit >>>> <ferruh.yi...@intel.com>, "Ananyev, Konstantin" >>>> <konstantin.anan...@intel.com> >>>> Cc: Andrew Rybchenko <arybche...@solarflare.com>, "Lu, Wenzhuo" >>>> <wenzhuo...@intel.com>, "Wu, Jingjing" <jingjing...@intel.com>, >>>> "Iremonger, Bernard" <bernard.iremon...@intel.com>, "Mcnamara, John" >>>> <john.mcnam...@intel.com>, "Kovacevic, Marko" <marko.kovace...@intel.com>, >>>> Olivier Matz <olivier.m...@6wind.com>, "dev@dpdk.org" <dev@dpdk.org>, >>>> "shah...@mellanox.com" <shah...@mellanox.com>, "didier.pall...@6wind.com" >>>> <didier.pall...@6wind.com> >>>> Subject: Re: [dpdk-dev] [PATCH v2 1/4] ethdev: add Rx offload outer UDP >>>> checksum definition >>>> >>>> 08/10/2018 10:24, Jerin Jacob: >>>>> From: Ferruh Yigit <ferruh.yi...@intel.com> >>>>>> On 10/6/2018 1:18 PM, Ananyev, Konstantin wrote: >>>>>>> From: Jerin Jacob [mailto:jerin.ja...@caviumnetworks.com] >>>>>>>> From: Thomas Monjalon <tho...@monjalon.net> >>>>>>>>> However, we should re-visit the flag PKT_RX_EIP_CKSUM_BAD. >>>>>>>> >>>>>>>> Do we need to block this patch due to the exiting PKT_RX_EIP_CKSUM_BAD >>>>>>>> definition? >>>>>>>> >>>>>>>> I already added the author of the PKT_RX_EIP_CKSUM_BAD flag and ethdev >>>>>>>> and mbuf >>>>>>>> maintainers in this list. So what else I need make forward progress >>>>>>>> on this patch? >>>>>>>> >>>>>>>> I think, the definition of PKT_RX_EIP_CKSUM_BAD based on HW >>>>>>>> capability. It >>>>>>>> is safe to assume that ALL HW can support CKSUM BAD if the feature is >>>>>>>> available and hence it is more portable. >>>>>>> >>>>>>> Yes, as I remember PKT_RX_EIP_CKSUM_BAD is based on >>>>>>> DEV_RX_OFFLOAD_OUTER_IPV4_CKSUM. >>>>>> >>>>>> Switching to two bit won't reduce the portability, HW supports only >>>>>> reporting >>>>>> CKSUM_BAD can set BAD || UNKNOWN. >>>>> >>>>> UNKNOWN is not a bit. It is represented as 0. It spec has 2 bit, then >>>>> driver need to report GOOD as well. >>>>> >>>>> Same applies for PKT_RX_EL4_CKSUM as well. >>>>> >>>>>> >>>>>> And I think patch is not blocked by PKT_RX_EIP_CKSUM_BAD, it can be >>>>>> changed >>>>>> separately, for this patch question is can we represent >>>>>> PKT_RX_EL4_CKSUM_* with >>>>>> two bits, to have BAD/GOOD/UNKNOWN? >>>> >>>> Yes, exact. >>>> >>>> PKT_RX_EIP_CKSUM_BAD must be left aside. >>>> We should just avoid taking it as a reference. >>>> And we can reconsider its definition later. >>> >>> OK. >>> >>> IMO, Using 2 bit scheme for tunneled checksum has following performance >>> issue from driver side. >>> >>> Driver need to mark the packet as GOOD. All the HW can support >>> detection of BAD. That not necessary mean GOOD in case of tunnel packet, >>> so driver has to detect the packet is tunneled and packet is not BAD >>> then mark GOOD. >> >> Yes UNKNOWN is not a bit, but a state, why don't use it? Why driver has to >> check >> it is GOOD? > > The application is going to check is it GOOD or not. Not the driver, > Right? My concern was, If application starts dropping the packet instead > checking the BAD, if > it checks == !GOOD.
Got it, but when 2 bits state introduced, app should check if check == BAD for drop decision, because it is not GOOD || BAD anymore. > >> >> 0x0 => UNKNOWN >> 0x1 => BAD >> 0x2 => GOOD >> 0x3 => ? (invalid perhaps) >> >> HW that supports detecting good packets can set BAD || GOOD state, HW can >> detect >> only BAD packet can set BAD || UNKNOWN state. >> >> If BAD is not set, there is an ambiguity of state, lets clarify it in lower >> level, if it is UNKNOWN, let application know it is UNKNOWN. > > OK. > > How about the following then? > > /** > * Mask of bits used to determine the status of outer RX L4 checksum. > * - PKT_RX_EL4_CKSUM_UNKNOWN: no information about the outer RX L4 checksum > * - PKT_RX_EL4_CKSUM_BAD: the outer L4 checksum in the packet is wrong > * - PKT_RX_EL4_CKSUM_GOOD: the outer L4 checksum in the packet is valid > * - PKT_RX_EL4_CKSUM_INVALID: invalid outer L4 checksum state. > * > * The detection of PKT_RX_EL4_CKSUM_GOOD shall be based on the given > * HW capability, At minimum, the PMD should support > * PKT_RX_EL4_CKSUM_UNKNOWN and PKT_RX_EL4_CKSUM_BAD states > * if the offload is available. > */ > #define PKT_RX_EL4_CKSUM_MASK ((1ULL << 21) | (1ULL << 22)) > > #define PKT_RX_IP_CKSUM_UNKNOWN 0 > #define PKT_RX_IP_CKSUM_BAD (1ULL << 21) > #define PKT_RX_IP_CKSUM_GOOD (1ULL << 22) > #define PKT_RX_IP_CKSUM_INVALID ((1ULL << 21) | (1ULL << 22)) Looks good to me. > > >
