Re: [dpdk-dev] [PATCH] net/nfp: add CPP bridge as service

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 1/11/2019 12:15 PM, Alejandro Lucero wrote:
> On Fri, Jan 11, 2019 at 11:48 AM Ferruh Yigit <ferruh.yigit@intel.com>
> wrote:
> 
>> On 1/10/2019 11:55 AM, Alejandro Lucero wrote:
>>>
>>>
>>> On Wed, Jan 9, 2019 at 4:15 PM Ferruh Yigit <ferruh.yigit@intel.com
>>> <mailto:ferruh.yigit@intel.com>> wrote:
>>>
>>>     On 1/9/2019 2:20 PM, Alejandro Lucero wrote:
>>>     >
>>>     >
>>>     > On Wed, Jan 9, 2019 at 10:54 AM Ferruh Yigit <
>> ferruh.yigit@intel.com
>>>     <mailto:ferruh.yigit@intel.com>
>>>     > <mailto:ferruh.yigit@intel.com <mailto:ferruh.yigit@intel.com>>>
>> wrote:
>>>     >
>>>     >     On 1/3/2019 8:56 AM, Alejandro Lucero wrote:
>>>     >     > The Netronome's Network Flow Processor chip is highly
>> programmable
>>>     >     > with the goal of processing packets at high speed.
>> Processing units
>>>     >     > and other chip components are available from the host
>> through the
>>>     >     > PCIe CPP(Command Push Pull bus) interface. The NFP PF PMD
>> configures
>>>     >     > a CPP handler for setting up and working with vNICs, perform
>> actions
>>>     >     > like link up or down, or accessing extended stats from the
>> MAC
>>>     component.
>>>     >     >
>>>     >     > There exist NFP host tools which access the NFP components
>> for
>>>     >     > programming and debugging but they require the CPP
>> interface. When the
>>>     >     > PMD is bound to the PF, the DPDK app owns the CPP interface,
>> so these
>>>     >     > host tools can not access the NFP through other means like
>> NFP kernel
>>>     >     > drivers.
>>>     >     >
>>>     >     > This patch adds a CPP bridge using the rte_service API which
>> can be
>>>     >     > enabled by a DPDK app. Interestingly, DPDK clients like OVS
>> will not
>>>     >     > enable specific service cores, but this can be performed
>> with a
>>>     >     > secondary process specifically enabling this CPP bridge
>> service and
>>>     >     > therefore giving access to the NFP to those host tools.
>>>     >
>>>     >     Hi Alejandro,
>>>     >
>>>     >
>>>     > Hi Ferruh,
>>>     >
>>>     >
>>>     >     Getting a few build errors, more details below.
>>>     >
>>>     >     >
>>>     >     > Signed-off-by: Alejandro Lucero <
>> alejandro.lucero@netronome.com
>>>     <mailto:alejandro.lucero@netronome.com>
>>>     >     <mailto:alejandro.lucero@netronome.com
>>>     <mailto:alejandro.lucero@netronome.com>>>
>>>     >     <...>
>>>     >
>>>     >     > +     /* Obtain target's CPP ID and offset in target */
>>>     >     > +     cpp_id = (offset >> 40) << 8;
>>>     >
>>>     >     With icc, i686 getting [1], it seems 'off_t' is 32bits long on
>> 32bit
>>>     build.
>>>     >
>>>     >     [1]
>>>     >     error #63: shift count is too large
>>>     >
>>>     >
>>>     > We do not support 32 bits. I thought our PMD was not built in that
>> case.
>>>
>>>     If PMD doesn't support 32 bits, above is OK, I will update my script
>>>     accordingly.
>>>
>>>     >
>>>     >
>>>     >     <...>
>>>     >
>>>     >     > +                     if (err != (int)len) {
>>>     >     > +                             printf("%s: error when
>> receiving, %d
>>>     of %lu\n",
>>>     >     > +                                     __func__, err, count);
>>>     >
>>>     >     Giving build error for 32bits [3], and can you please use
>> logging
>>>     macros instead
>>>     >     of printf?
>>>     >
>>>     >
>>>     > Sure.
>>>     >
>>>     >
>>>     >     [3]
>>>     >     error: format ‘%lu’ expects argument of type ‘long unsigned
>> int’, but
>>>     argument 4
>>>     >     has type ‘size_t’ {aka ‘unsigned int’} [-Werror=format=]
>>>     >
>>>     >     <...>
>>>     >
>>>     >     > +     /* Obtain target's CPP ID and offset in target */
>>>     >     > +     cpp_id = (offset >> 40) << 8;
>>>     >
>>>     >     Same as above [1].
>>>     >
>>>     >     <...>
>>>     >
>>>     >     > +                     if (err != (int)len) {
>>>     >     > +                             printf("%s: error when
>> sending: %d of
>>>     %lu\n",
>>>     >     > +                                     __func__, err, count);
>>>     >
>>>     >     Same build error with above [3].
>>>     >
>>>     >     <...>
>>>     >
>>>     >     > +nfp_cpp_bridge_serve_ioctl(int sockfd, struct nfp_cpp *cpp)
>>>     >     > +{
>>>     >     > +     int cmd, err;
>>>     >     > +     uint32_t ident_size, tmp;
>>>     >     > +
>>>     >     > +     /* Reading now the IOCTL command */
>>>     >     > +     err = recv(sockfd, &cmd, 4, 0);
>>>     >     > +     if (err != 4) {
>>>     >     > +             printf("%s: read error from socket\n",
>> __func__);
>>>     >     > +             return -EIO;
>>>     >     > +     }
>>>     >     > +
>>>     >     > +     /* Only supporting NFP_IOCTL_CPP_IDENTIFICATION */
>>>     >     > +     if (cmd != NFP_IOCTL_CPP_IDENTIFICATION) {
>>>     >
>>>     >     Giving build error with ppc_64-power8-linuxapp-gcc [2].
>>>     >
>>>     >
>>>     > We do not support power architecture.
>>>
>>>     Yes but issue seems not exactly ppc issue, more like signed -
>> unsigned
>>>     comparison. Can you please check if is there any valid issue here?
>>>
>>>
>>> This is a funny one. NFP_IOCTL_CPP_IDENTIFICATION is not zero, and cmd
>> could be
>>> anything.
>>> And it does work with other compilers!
>>>
>>> Talking with a compiler guy in the office, and it is hard to know why the
>>> compiler is triggering an error here. I suspect this is some sort of
>> endianness
>>> mess, and he thinks the compiler could be assuming the cmd variable
>> after recv
>>> call is always negative or positive, and the macro always being the
>> opposite in
>>> powerpc, so the comparison is always true, what is what the error
>> message says.
>>>
>>> Anyway, it is not clear how to fix this. Maybe defining cmd as uint32_t
>> could
>>> help. Any change we can test this before sending another patch version?
>>
>> I am using a cross compiler for ppc, it is freely available, you should be
>> able
>> to get and test with it, or I can test for you if you prefer.
>>
>>
> Ok. I got a cross compiler now. Any reference about how to use it with DPDK?

just providing CROSS= to makefile should be enough, rest is same.

I found following for arm, it applies to ppc too:
https://doc.dpdk.org/guides/linux_gsg/cross_build_dpdk_for_arm64.html

> 
> 
>>>
>>>
>>>
>>>     >
>>>     >
>>>     >     [2]
>>>     >     error: comparison is always true due to limited range of data
>> type
>>>     >     [-Werror=type-limits]
>>>     >
>>>
>>
>>