The table is sent through an out of band message with a specific head to the 
synthetic NIC. The driver on the guest side understands it and treats it as a 
update of send table.

Do you mean the host OS put the tx queue selection directly on the receive 
packet descriptor? It is a very good idea. The driver doesn't need to calculate 
the hash -- it already has the tx queue number saved. The host side make the 
rebalance decision anyway, why just tell the guest directly?  For those packets 
that don't have tx queen number it still can use the send table or default 
queue. 

Wei


-----Original Message-----
From: adrian.ch...@gmail.com [mailto:adrian.ch...@gmail.com] On Behalf Of 
Adrian Chadd
Sent: Wednesday, August 13, 2014 2:54 PM
To: Wei Hu
Cc: d...@delphij.net; freebsd-net@freebsd.org
Subject: Re: vRSS support on FreeBSD

On 12 August 2014 23:27, Wei Hu <w...@microsoft.com> wrote:
> Unfortunately I am not aware of any official spec.

Damn!

Ok, so when they send the update for the redirect table, what's that look like? 
How do they send it?

> The driver for Linux guest OS does the similar thing for the tx path -- 
> receive the send table update from host, calculate the hash value for each tx 
> packet and use it to find the tx queue from the send table.
>
> I think the Windows guests do the same.

I wonder if there's any possibility for getting that added to the receive 
packet descriptor if the underlying hardware supports it - or well, if the OS 
has done it already.




-a
_______________________________________________
freebsd-net@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-net
To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"

Reply via email to