Chalk this one up to yet another crazy idea.
At NFS testing events, we'd like to test NFS/RDMA over the event's
private network. We can do that with iWARP using siw from guests.
If the guest itself is on the VPN, that means siw's slave device
is a tun device. Such devices have no MAC address. That breaks the
RDMA core's ability to find the correct egress device for siw when
given a source IP address.
We've worked around this in the past with various software hacks,
but we'd rather see full support for this capability in stock
kernels.
A direct and perhaps naïve way to do that is to give loopback and
tun devices their own artificial MAC addresses for this purpose.
---
Chuck Lever (3):
net/tun: Ensure tun devices have a MAC address
net/lo: Ensure lo devices have a MAC address
RDMA/siw: Require non-zero 6-byte MACs for soft iWARP
drivers/infiniband/sw/siw/siw_main.c | 22 +++++++---------------
drivers/net/loopback.c | 2 ++
drivers/net/tun.c | 6 +++---
3 files changed, 12 insertions(+), 18 deletions(-)
--
Chuck Lever
