netdev - Re: [Intel-wired-lan] [PATCH net-next] i40e: allow VMDQs to be used with AF_XDP zero-copy

Open Source and information security mailing list archives

Date:   Fri, 11 Sep 2020 11:04:49 -0700
From:   "Samudrala, Sridhar" <sridhar.samudrala@...el.com>
To:     Maciej Fijalkowski <maciej.fijalkowski@...el.com>,
        Magnus Karlsson <magnus.karlsson@...il.com>
Cc:     Maciej Fijalkowski <maciejromanfijalkowski@...il.com>,
        Network Development <netdev@...r.kernel.org>,
        intel-wired-lan <intel-wired-lan@...ts.osuosl.org>,
        Björn Töpel <bjorn.topel@...el.com>,
        "Karlsson, Magnus" <magnus.karlsson@...el.com>,
        "Nambiar, Amritha" <amritha.nambiar@...el.com>
Subject: Re: [Intel-wired-lan] [PATCH net-next] i40e: allow VMDQs to be used
 with AF_XDP zero-copy

On 9/11/2020 6:10 AM, Maciej Fijalkowski wrote:
> On Fri, Sep 11, 2020 at 02:29:50PM +0200, Magnus Karlsson wrote:
>> On Fri, Sep 11, 2020 at 2:11 PM Maciej Fijalkowski
>> <maciej.fijalkowski@...el.com> wrote:
>>>
>>> On Fri, Sep 11, 2020 at 02:08:26PM +0200, Magnus Karlsson wrote:
>>>> From: Magnus Karlsson <magnus.karlsson@...el.com>
>>>>
>>>> Allow VMDQs to be used with AF_XDP sockets in zero-copy mode. For some
>>>> reason, we only allowed main VSIs to be used with zero-copy, but
>>>> there is now reason to not allow VMDQs also.
>>>
>>> You meant 'to allow' I suppose. And what reason? :)
>>
>> Yes, sorry. Should be "not to allow". I was too trigger happy ;-).
>>
>> I have gotten requests from users that they want to use VMDQs in
>> conjunction with containers. Basically small slices of the i40e
>> portioned out as netdevs. Do you see any problems with using a VMDQ
>> iwth zero-copy?

Today VMDQ VSIs are used when a macvlan interface is created on top of a 
i40e PF with l2-fwd-offload on. But i don't think we can create an 
AF_XDP zerocopy socket on top of a macvlan netdev as it doesn't support 
ndo_bpf or ndo_xdp_xxx apis or expose hw queues directly.

We need to expose VMDQ VSI as a native netdev that can expose its own 
queues and support ndo_ ops in order to enable AF_XDP zerocopy on a 
VMDQ. We talked about this approach at the recent netdev conference to 
expose VMDQ VSI as a subdevice with its own netdev.

https://netdevconf.info/0x14/session.html?talk-hardware-acceleration-of-container-networking-interfaces

> 
> No, I only meant to provide the actual reason (what you wrote above) in
> the commit message.
> 
>>
>> /Magnus
>>
>>>>
>>>> Signed-off-by: Magnus Karlsson <magnus.karlsson@...el.com>
>>>> ---
>>>>   drivers/net/ethernet/intel/i40e/i40e_xsk.c | 2 +-
>>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
>>>> index 2a1153d..ebe15ca 100644
>>>> --- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
>>>> +++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
>>>> @@ -45,7 +45,7 @@ static int i40e_xsk_pool_enable(struct i40e_vsi *vsi,
>>>>        bool if_running;
>>>>        int err;
>>>>
>>>> -     if (vsi->type != I40E_VSI_MAIN)
>>>> +     if (!(vsi->type == I40E_VSI_MAIN || vsi->type == I40E_VSI_VMDQ2))
>>>>                return -EINVAL;
>>>>
>>>>        if (qid >= vsi->num_queue_pairs)
>>>> --
>>>> 2.7.4
>>>>
> _______________________________________________
> Intel-wired-lan mailing list
> Intel-wired-lan@...osl.org
> https://lists.osuosl.org/mailman/listinfo/intel-wired-lan
> 

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives