Re: tap device speed

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 10/4/23 09:42, Antonio Di Bacco wrote:
> Thank you for your info that are giving me the right heads up
> To experiment with VDUSE and share a virtual network interface (I
> don't have a physical NIC) between the Linux kernel and DPDK using
> VDUSE, I'm about to follow these steps:
> 
> Load Required Kernel Modules:
> modprobe vduse
> Create /dev/vdpa0 device with:
> vdpa -d /dev/vdpa0 -n my_vdpa_driver -q queue_count
> 
> I wonder which vdpa_driver should I use, I don't have a real NIC
> After having this vdpa0 interface up I can run my DPDK application:
> 
> ./my_dpdk_app --vdev "net_vdpa0,iface=/dev/vdpa0"

You will use the Vhost PMD in this case (alternative is to use the Vhost
API directly).

Maybe I missed to add steps with Vhost PMD in my doc repo, I'll improve
it but in the mean time you can refer to the steps provided in the DPDK
VDUSE series cover letter:
https://inbox.dpdk.org/dev/7f72500a-5317-c66d-3f36-2fd65c874b47@redhat.com/T/

Please read the vduse documentation on my gitlab repo anyways, it
provides pointers on the missing Kernel patches (being upstreamed).

Maxime


> Regards,
> Antonio.
> 
> On Wed, Oct 4, 2023 at 9:08 AM Maxime Coquelin
> <maxime.coquelin@redhat.com> wrote:
>>
>>
>>
>> On 10/4/23 08:17, David Marchand wrote:
>>> On Tue, Oct 3, 2023 at 6:01 PM Stephen Hemminger
>>> <stephen@networkplumber.org> wrote:
>>>>
>>>> On Tue, 3 Oct 2023 10:49:16 +0200
>>>> Antonio Di Bacco <a.dibacco.ks@gmail.com> wrote:
>>>>
>>>>> I understand, could we use another solution ? Like a memif  interface
>>>>> in DPDK and libmemif in Linux?
>>>>
>>>> The issue is accessing kernel networking devices. Both virtio user
>>>> and XDP are faster for that. Memif is for doing process to process networking.
>>>
>>> For dpdk <-> kernel, as you are mentioning virtio-user/vhost, let me
>>> add that there is some activity on this side, with VDUSE.
>>>
>>> Maxime is working on the VDUSE kernel and dpdk bits.
>>> He gave a talk about the current status during the summit and some
>>> performance numbers:
>>> https://dpdksummit2023.sched.com/event/1P9xA/vduse-performance-how-fast-is-it-maxime-coquelin-red-hat
>>>
>>>
>>
>> Thanks for sharing David.
>> I'd like just to add some more information on VDUSE if you want to
>> experiment with VDUSE, which is still under development:
>> https://gitlab.com/mcoquelin/vduse-doc
>>
>> Maxime
>>
>