DPDK patches and discussions
 help / color / Atom feed
From: Tiwei Bie <tiwei.bie@intel.com>
To: Andrew Rybchenko <arybchenko@solarflare.com>
Cc: Maxime Coquelin <maxime.coquelin@redhat.com>,
	Zhihong Wang <zhihong.wang@intel.com>,
	dev@dpdk.org, Dilshod Urazov <Dilshod.Urazov@oktetlabs.ru>,
	stable@dpdk.org
Subject: Re: [dpdk-dev] [PATCH 3/3] net/virtio: reject unsupported Rx multi queue modes
Date: Wed, 9 Oct 2019 18:41:43 +0800
Message-ID: <20191009104143.GA14695@___> (raw)
In-Reply-To: <43e11493-65d6-fdf2-8086-106ed7b4eb25@solarflare.com>

On Wed, Oct 09, 2019 at 12:00:28PM +0300, Andrew Rybchenko wrote:
> On 10/9/19 11:43 AM, Tiwei Bie wrote:
> > On Wed, Oct 09, 2019 at 11:04:38AM +0300, Andrew Rybchenko wrote:
> > > On 10/8/19 8:46 AM, Tiwei Bie wrote:
> > > > On Tue, Oct 01, 2019 at 04:44:31PM +0100, Andrew Rybchenko wrote:
> > > > > From: Dilshod Urazov <Dilshod.Urazov@oktetlabs.ru>
> > > > > 
> > > > > This driver supports none of DCB, RSS or VMDQ modes,
> > > > > therefore must check and return error if configured incorrectly.
> > > > > 
> > > > > Fixes: c1f86306a026 ("virtio: add new driver")
> > > > > Cc: stable@dpdk.org
> > > > > 
> > > > > Signed-off-by: Dilshod Urazov <Dilshod.Urazov@oktetlabs.ru>
> > > > > Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
> > > > > ---
> > > > >    drivers/net/virtio/virtio_ethdev.c | 7 +++++++
> > > > >    1 file changed, 7 insertions(+)
> > > > > 
> > > > > diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
> > > > > index 7261109dd..0af4fc392 100644
> > > > > --- a/drivers/net/virtio/virtio_ethdev.c
> > > > > +++ b/drivers/net/virtio/virtio_ethdev.c
> > > > > @@ -2071,6 +2071,13 @@ virtio_dev_configure(struct rte_eth_dev *dev)
> > > > >    	PMD_INIT_LOG(DEBUG, "configure");
> > > > >    	req_features = VIRTIO_PMD_DEFAULT_GUEST_FEATURES;
> > > > > +	if (rxmode->mq_mode != ETH_MQ_RX_NONE) {
> > > > > +		PMD_DRV_LOG(ERR,
> > > > > +			"Unsupported Rx multi queue mode %d",
> > > > > +			rxmode->mq_mode);
> > > > > +		return -EINVAL;
> > > > > +	}
> > > > We need similar checks for Tx as well.
> > > OK, I'll add.
> > > 
> > > However, I'm not 100% sure about RSS. Yes, I know that virtio has
> > > no RSS configuration support, but it looks possible to have multi queue
> > > in vhost-net case.
> > Yeah, it's possible to have MQ in virtio.
> > The RSS support in virtio is still WIP.
> > https://github.com/oasis-tcs/virtio-spec/issues/48
> 
> Thanks for the link. So, may be ETH_MQ_RX_RSS should be accepted
> as well, but attempts to configure RSS rejected?
> Yes, it is a bit strange to accept RSS with empty rss_hf etc, but
> at least it is exactly what net/virtio can do.
> 
> And one more thought...
> It looks like if more than one Rx queue is configured, mq_mode must
> be ETH_MQ_RX_RSS and must not be ETH_MQ_RX_NONE.

Some apps in DPDK will set mq_mode to ETH_MQ_RX_NONE while
enabling multiple queue pairs, e.g.:

https://github.com/DPDK/dpdk/blob/5b5bb56532fd5dea5d6260c0a0e405c0e32da2a0/app/test/test_link_bonding.c#L137
https://github.com/DPDK/dpdk/blob/5b5bb56532fd5dea5d6260c0a0e405c0e32da2a0/app/test/test_link_bonding.c#L181-L182
https://github.com/DPDK/dpdk/blob/5b5bb56532fd5dea5d6260c0a0e405c0e32da2a0/app/test/test_link_bonding.c#L3938-L3948

Testpmd will also set mq_mode to ETH_MQ_RX_NONE when multiple
Rx queues are enabled but rss_hf is empty:

https://github.com/DPDK/dpdk/blob/5b5bb56532fd5dea5d6260c0a0e405c0e32da2a0/app/test-pmd/testpmd.c#L2935-L2938
https://github.com/DPDK/dpdk/blob/5b5bb56532fd5dea5d6260c0a0e405c0e32da2a0/app/test-pmd/testpmd.c#L2945-L2948
(the flow_type_rss_offloads reported by virtio-PMD is zero)

My understanding is that, setting mq_mode to ETH_MQ_RX_NONE means
no method is enforced on how to route packets to MQs.
It looks that ETH_MQ_RX_NONE is the best fit for virtio currently.


  reply index

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-01 15:44 [dpdk-dev] [PATCH 1/3] net/virtio: reject deferred start Rx queue setup Andrew Rybchenko
2019-10-01 15:44 ` [dpdk-dev] [PATCH 2/3] net/virtio: reject deferred start Tx " Andrew Rybchenko
2019-10-08  5:35   ` Tiwei Bie
2019-10-01 15:44 ` [dpdk-dev] [PATCH 3/3] net/virtio: reject unsupported Rx multi queue modes Andrew Rybchenko
2019-10-08  5:46   ` Tiwei Bie
2019-10-09  8:04     ` Andrew Rybchenko
2019-10-09  8:43       ` Tiwei Bie
2019-10-09  9:00         ` Andrew Rybchenko
2019-10-09 10:41           ` Tiwei Bie [this message]
2019-10-09 11:24             ` Andrew Rybchenko
2019-10-10  7:42               ` Thomas Monjalon
2019-10-10  8:13                 ` Andrew Rybchenko
2019-10-10  8:23                   ` David Marchand
2019-10-10  8:27                     ` Andrew Rybchenko
2019-10-10  9:10                       ` Tiwei Bie
2019-10-01 16:29 ` [dpdk-dev] [PATCH 1/3] net/virtio: reject deferred start Rx queue setup Kevin Traynor
2019-10-01 16:39   ` Andrew Rybchenko
2019-10-09 12:32 ` [dpdk-dev] [PATCH v2 1/4] " Andrew Rybchenko
2019-10-09 12:32   ` [dpdk-dev] [PATCH v2 2/4] net/virtio: reject deferred start Tx " Andrew Rybchenko
2019-10-24  9:44     ` Maxime Coquelin
2019-10-09 12:32   ` [dpdk-dev] [PATCH v2 3/4] net/virtio: reject unsupported Rx multi queue modes Andrew Rybchenko
2019-10-24  9:44     ` Maxime Coquelin
2019-10-09 12:32   ` [dpdk-dev] [PATCH v2 4/4] net/virtio: reject unsupported Tx " Andrew Rybchenko
2019-10-24  9:44     ` Maxime Coquelin
2019-10-24  9:44   ` [dpdk-dev] [PATCH v2 1/4] net/virtio: reject deferred start Rx queue setup Maxime Coquelin
2019-10-24 10:19     ` Maxime Coquelin

Reply instructions:

You may reply publically 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=20191009104143.GA14695@___ \
    --to=tiwei.bie@intel.com \
    --cc=Dilshod.Urazov@oktetlabs.ru \
    --cc=arybchenko@solarflare.com \
    --cc=dev@dpdk.org \
    --cc=maxime.coquelin@redhat.com \
    --cc=stable@dpdk.org \
    --cc=zhihong.wang@intel.com \
    /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 patches and discussions

Archives are clonable:
	git clone --mirror http://inbox.dpdk.org/dev/0 dev/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 dev dev/ http://inbox.dpdk.org/dev \
		dev@dpdk.org
	public-inbox-index dev


Newsgroup available over NNTP:
	nntp://inbox.dpdk.org/inbox.dpdk.dev


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