Re: [RFC PATCH 0/2] make mac programming for virtio net more robust
From: John Fastabend <hidden>
Date: 2013-01-11 14:52:51
Also in:
kvm, qemu-devel, virtualization
On 1/10/2013 11:46 PM, Michael S. Tsirkin wrote:
On Fri, Jan 11, 2013 at 12:53:07PM +1030, Rusty Russell wrote:quoted
"Michael S. Tsirkin" [off-list ref] writes:quoted
On Thu, Jan 10, 2013 at 10:45:39PM +0800, akong@redhat.com wrote:quoted
From: Amos Kong <redacted> Currenly mac is programmed byte by byte. This means that we have an intermediate step where mac is wrong. Second patch introduced a new vq control command to set mac address in one time.As you mention we could alternatively do it without new commands, simply add a feature bit that says that MACs are in the mac table. This would be a much bigger patch, and I'm fine with either way. Rusty what do you think?Hmm, mac filtering and "my mac address" are not quite the same thing. I don't know if it matters for anyone: does it? The mac address is abused for things like identifying machines, etc.I don't know either. I think net core differentiates between mac and uc_list because linux has to know which mac to use when building up packets, so at some level, I agree it might be useful to identify the machine. BTW netdev/davem should have been copied on this, Amos I think it's a good idea to remember to do it next time you post.quoted
If we keep it as a separate concept, Amos' patch seems to make sense.Yes. It also keeps the patch small, I just thought I'd mention the option.quoted
Cheers, Rusty.
Don't have the entire context here but if you implement the ndo_fdb_dump() probably hooking it up to ndo_dflt_fdb_dump() you could use the 'bridge' tool dump the uc_list. Then use ndo_fdb_add() and ndo_fdb_del() to add and remove entries from the uc_list. We do this today in macvlan and the ixgbe driver when it is in SR-IOV mode and the embedded switch needs to be programmed. fdb is "forwarding database" its a bit different then mac filtering in that its telling the "switch" how to forward mac addresses, in ixgbe and macvlan at least we have been overloading it a bit to also stop filtering the mac address. I think this makes sense if you setup forwarding to a port it doesn't make much sense to then drop them. Maybe its not entirely applicable here just thought I would mention it. Thanks, John