DPDK usage discussions
 help / color / mirror / Atom feed
From: Stephen Hemminger <stephen@networkplumber.org>
To: Yang Luan <luan.penny@gmail.com>
Cc: users@dpdk.org
Subject: Re: running DPDK application on Azure
Date: Wed, 13 Apr 2022 16:36:19 -0700
Message-ID: <20220413163619.546655de@hermes.local> (raw)
In-Reply-To: <CAPHT=bYVN1+sKCsZ6tbbRwAtcGNbKoEX75t56dFr=BSQO-pi1w@mail.gmail.com>

On Wed, 13 Apr 2022 11:41:30 -0700
Yang Luan <luan.penny@gmail.com> wrote:

> Thanks Stephen.
> 
> Is the Netvsc PMD selected by default or I'll need to specify it somewhere?
> 
> Since I'm running a proprietary UDP protocol, 3rd parties (e.g. Azure)
> won't know how a flow is established. I'm curious how exactly Azure selects
> which NIC to receive a given packet?
> 
> Yang
> 
> On Wed, Apr 13, 2022 at 8:58 AM Stephen Hemminger <
> stephen@networkplumber.org> wrote:  
> 
> > On Tue, 12 Apr 2022 13:09:51 -0700
> > Yang Luan <luan.penny@gmail.com> wrote:
> >  
> > > Hi,
> > >
> > > We have an application using DPDK on AWS and would like to port it to
> > > Azure. What would be recommended PMD to use? If I understand correctly,  
> > we  
> > > can either use the Netvsc PMD or the vdev_Netvsc PMD. It seems the Netvsc
> > > PMD is newer.  
> >
> > Short answer:
> >
> > Netvsc PMD is faster and can handle events better.
> > vdev_netvsc/failsafe/tap is slower but can emulate some types of rte_flow.
> >  
> > >
> > > An alternative is to use the mlx4 PMD by only attaching to the mlx NIC's
> > > PCI address. As I understand it, the concern is the mlx nic may not  
> > receive  
> > > all the packets. We run a proprietary UDP based protocol on top of DPDK.
> > > Are all UDP packets guaranteed to be received by the mlx NIC?  
> >
> > That won't work. the MLX device only sees established flows.
> >  

The choice is made based on whether vmbus is unbound from kernel or not.
If vmbus is left bound to kernel, then hv_netvsc will look at all the network
devices, and those without any routes it will setup.  The setup makes the
TAP/failsafe sub devices.

If vmbus device is unbound from network device and instead bound to hv_uio_generic,
then the DPDK startup code will see it and should setup from there.

The documentation is there in many places.

      reply	other threads:[~2022-04-13 23:36 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-12 20:09 Yang Luan
2022-04-13 15:58 ` Stephen Hemminger
2022-04-13 18:41   ` Yang Luan
2022-04-13 23:36     ` Stephen Hemminger [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20220413163619.546655de@hermes.local \
    --to=stephen@networkplumber.org \
    --cc=luan.penny@gmail.com \
    --cc=users@dpdk.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

DPDK usage discussions

This inbox may be cloned and mirrored by anyone:

	git clone --mirror http://inbox.dpdk.org/users/0 users/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 users users/ http://inbox.dpdk.org/users \
		users@dpdk.org
	public-inbox-index users

Example config snippet for mirrors.
Newsgroup available over NNTP:
	nntp://inbox.dpdk.org/inbox.dpdk.users


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git