Re: [PATCH net-next 0/2] GCPS Spec Compliance Patch Set

[Hari Kalavakunta]

On 4/8/2025 4:23 PM, Hari Kalavakunta wrote:
> On 4/8/2025 3:35 PM, Paul Fertser wrote:
> > On Tue, Apr 08, 2025 at 03:02:14PM -0700, Hari Kalavakunta wrote:
> > > On 4/8/2025 12:19 PM, Paul Fertser wrote:
> > >
> > > > In other words, you're testing your code only with simulated data so
> > > > there's no way to guarantee it's going to work on any real life
> > > > hardware (as we know hardware doesn't always exactly match the specs)?
> > > > That's unsettling. Please do mention it in the commit log, it's an
> > > > essential point. Better yet, consider going a bit off-centre after the
> > > > regular verification and do a control run on real hardware.
> > > >
> > > > After all, that's what the code is for so if it all possible it's
> > > > better to know if it does the actual job before merging (to avoid
> > > > noise from follow-up patches like yours which fix something that never
> > > > worked because it was never tested).
> > >
> > > I would like to request a week's time to integrate a real hardware
> > > interface, which will enable me to test and demonstrate end-to-end 
> > > results.
> > > This will also allow me to identify and address any additional issues 
> > > that
> > > may arise during the testing process. Thank you for the feedback.
> >
> > Thank you for doing the right thing! Looking forward to your updated
> > patch (please do not forget to consider __be64 for the fields).
>
> I had not previously considered using __be64 for the struct 
> ncsi_rsp_gcps_pkt, as it is an interface structure. I would like to seek 
> your input on whether it is a good idea to use __be64 for interface 
> messages. In my experience, I haven't come across implementations that 
> utilize __be64. I am unsure about the portability of this approach, 
> particularly with regards to the Management Controller (MC).

Here are the results from a real hardware test, which validates the patch.


a. Initiate GCPS command to the NIC-2
root@bmc:~# ./ncsi-cmd -i 3 -p 0 -c 0 raw 0x18
<7> Command: type 0x18, payload 0 bytes:
<7> Send Command, CHANNEL : 0x0 , PACKAGE : 0x0, INTERFACE: 0x008cd598
<7> Response 228 bytes: 00 01 00 3b 98 00 00 cc 00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 2b e5 fc e0 c0 00 00 00 00 
65 70 d5 54 00 00 00 00 09 50 66 56 00 00 00 00 03 08 a8 79 00 00 00 00 
00 3d 5c 44 00 00 00 00 00 79 38 23 00 00 00 00 00 02 fe 06 00 00 00 00 
00 00 02 be 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 00 00 00 00 b8 21 5f 03 8f da af 00 d8 6d 36 
00 73 a3 e7 00 17 20 70 00 00 00 00 00 00 d8 8a 00 00 0e 9c 00 56 4f 83 
00 10 17 e2 00 01 5b 76 00 13 6e a3 00 00 f8 cd 00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 2c 20 55 f5

b. tcpdump capture of the GCPS
GCPS Command Capture:
        0x0000:  0001 003b 1800 0000 0000 0000 0000 0000
        0x0010:  ffff e7c4 0000 0000 0000 0000 0000 0000
        0x0020:  0000 0000 0000 0000 0000 0000 0000

GCPS Response
        0x0000:  0001 003b 9800 00cc 0000 0000 0000 0000
        0x0010:  0000 0000 0000 0000 0000 0000 0000 002b
        0x0020:  e5fc e0c0 0000 0000 6570 d554 0000 0000
        0x0030:  0950 6656 0000 0000 0308 a879 0000 0000
        0x0040:  003d 5c44 0000 0000 0079 3823 0000 0000
        0x0050:  0002 fe06 0000 0000 0000 02be 0000 0000
        0x0060:  0000 0000 0000 0000 0000 0000 0000 0000
        0x0070:  0000 0000 0000 0000 0000 0000 0000 0000
        0x0080:  0000 0000 0000 0000 0000 0000 0000 0000
        0x0090:  0000 0000 00b8 215f 038f daaf 00d8 6d36
        0x00a0:  0073 a3e7 0017 2070 0000 0000 0000 d88a
        0x00b0:  0000 0e9c 0056 4f83 0010 17e2 0001 5b76
        0x00c0:  0013 6ea3 0000 f8cd 0000 0000 0000 0000
        0x00d0:  0000 0000 0000 0000 0000 0000 0000 0000
        0x00e0:  2c20 55f5

c. dmesg log (Debug purpose only) to demonstrate correct value read.
[ 1350.369741] ncsi_rsp_handler_gcps ENTRY
[ 1350.369768] ncs->hnc_rx_bytes = 188542148800 (0x2be5fce0c0)


Let us examine the "Total Bytes Received" statistic. Specifically, we'll 
look at offset 28..35 (0x1c..0x24), bytes read - '0000 002b e5fc e0c0'. 
NCSI now correctly collects this value into it's internal structure.


I just noticed a warning regarding line length in the patch submission, 
I will address this issue in version 2 of the patch. Let me know if we 
need additional information.