[Coin] mtpsa and P4

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For a host, such as a user using a cloud, the cloud operator just provides a
VM per user or multiple VMs to a user.  This is why, for a host, a MTPSA
wasn't necessary.  With a network virtual switch, of course, MTPSA would
help.  However, in the same cloud, if a virtual switch is used, why not just
provide a virtual switch per user and the switch uses a few ports? This way
MTPSA is avoided.  Use a router to isolate virtual switch traffic.  If I
really want to separate user traffic, I could also use a virtual router per
user and don't use MTPSA - of course, a router has multiple interfaces to
supports connections to different VMs for a user.

 

Around May 2017, the first P4 compiler (p4c) came out as p4lang/p4c.
Hardware asic vendors have taken this p4c and developed their p4c backends.
It takes few years to develop a compiler backend.  I suspect, this is why
P4's focus could not get to MTPSA.  In the past few months, a P4 to DPDK p4c
backend was added to p4lang/p4c.   Now that server machines are running P4
to DPDK, I think, more virtual switch R&D will take place. In the past there
has been a P4 to OVS (Open Virtual Switch) but I don't know if this effort
looked into MTPSA.  

 

Also, the source code for the P4 bmv2 software switch is obtuse and hard to
change causing more delays.

 

Best wishes,

 

Hemant