Memif connect fails on arm setup

[nikhil-agarwal-git]

Description
Memif fails to initialize when testing on Arm arch setup.

How to reproduce
Bringup setup on Arm platform

Expected Behavior

Screenshots/Logs
"errors.errorString=initializeRegions: memfdCreate: memfd_create: function not implemented"

Environment (please complete the following information)

Info	Example	Value
OS/arch	linux/arm64
VPP version	v24.02-release
GoVPP version	v0.9.0

RCA: while creating memfd (memfdCreate()), syscall is called with trap 319 which is not valid when called from arm arch. 279 is a valid value to be used for arm setup.
To have a generic solution for all platforms, following call is more suitable which internally calls platform specific values instead of existing memfdCreate().

Proposed Fix:

• r.fd, err = unix.MemfdCreate("memif_region_0", mfd_allow_sealing)

[dwallacelf]

Is this reproducible with the latest VPP and goVPP releases?
Of note:

• VPP 24.02 is no longer supported by the VPP community
• goVPP 0.12.0 is in process and should be released in the next few days

[nikhil-agarwal-git]

Hi,

Yes, issue is with latest govpp as well.
I havn't tested with latest vpp + govpp versions, but I believe issue would be there as well since issue is local to govpp.

Attached is the proposed fix.

memif_fix.patch

[mohsinkazmi]

Hi @nikhil-agarwal-git Thanks for spotting the issue and suggesting a fix.
I am not sure if anyone has tried it on the ARM platform before.
Does everything work correctly on your end after applying the fix?

[nikhil-agarwal-git]

Hi @mohsinkazmi , after this memif connection is successful.
There is another issue because of which rx/tx is not happening. Issue seems to be at vpp memif plugin side since it is considering 128bit cacheline size for all memif data structures for arm platforms.
With the fix of both these issues, memif works fine. I am attaching patch of vpp memif-plugin as well here for reference.

vpp-memif-plugin-fix.patch .patch

[mohsinkazmi]

@nikhil-agarwal-git Thanks for reporting the second issue. The gomemif is computing the wrong cache-line size for memif on ARM based platforms. I will devise the fix which looks like something following:
https://github.com/FDio/vpp/blob/2c4a000e36a58276c62e63aa6a4147e4e43875cc/extras/libmemif/CMakeLists.txt#L68