On Wed, Feb 24, 2016 at 08:15:36AM +0000, Qiu, Michael wrote:

On 2/22/2016 10:35 PM, Yuanhan Liu wrote:

quoted

Broadcast RARP packet by injecting it to receiving mbuf array at
rte_vhost_dequeue_burst().

Commit 33226236a35e ("vhost: handle request to send RARP") iterates
all host interfaces and then broadcast it by all of them.  It did
notify the switches about the new location of the migrated VM, however,
the mac learning table in the target host is wrong (at least in my
test with OVS):

    $ ovs-appctl fdb/show ovsbr0
     port  VLAN  MAC                Age
        1     0  b6:3c:72:71:cd:4d   10
    LOCAL     0  b6:3c:72:71:cd:4e   10
    LOCAL     0  52:54:00:12:34:68    9
        1     0  56:f6:64:2c:bc:c0    1

Where 52:54:00:12:34:68 is the mac of the VM. As you can see from the
above, the port learned is "LOCAL", which is the "ovsbr0" port. That
is reasonable, since we indeed send the pkt by the "ovsbr0" interface.

The wrong mac table lead all the packets to the VM go to the "ovsbr0"
in the end, which ends up with all packets being lost, until the guest
send a ARP quest (or reply) to refresh the mac learning table.

Jianfeng then came up with a solution I have thought of firstly but NAKed

Is it suitable to mention someone in the commit log?

Why it's not? It's not a secret name or something like that after all :)

On the other hand, it's way of thanking Jianfeng's contribution to this
patch.

	--yliu