Hi Long,
I could not get to this in the past month. I have resumed netvsc work today. I shall get back to you as soon as possible.
Regards,
Nandini

On Wed, Oct 16, 2024 at 12:26 PM Long Li <longli@microsoft.com> wrote:

Hi Nandini,

 

Do you have any luck with UDP traffic?

 

Thanks,

Long

 

From: Nandini Rangaswamy <nandini.rangaswamy@broadcom.com>
Sent: Thursday, September 19, 2024 9:46 AM
To: Long Li <longli@microsoft.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>; users@dpdk.org
Subject: Re: Netvsc vs Failsafe Performance

 

Hi Long Li,

I shall test with UDP traffic and get back to you.

Regards,

Nandini

 

On Tue, Sep 17, 2024 at 2:57PM Long Li <longli@microsoft.com> wrote:

Thank you!

 

Are you seeing problems with UDP traffic on the receive side? If everything works fine for you, I’m sending a patch.

 

Long

 

From: Nandini Rangaswamy <nandini.rangaswamy@broadcom.com>
Sent: Monday, September 16, 2024 3:58 PM
To: Long Li <longli@microsoft.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>; users@dpdk.org
Subject: Re: Netvsc vs Failsafe Performance

 

Hi Long,

I tested this patch and it works as expected. The UDP IPv6 RSS offload bit is set and my dpdk app is able to successfully configure the netvsc port.

Regards,

Nandini

 

On Fri, Sep 13, 2024 at 2:29PM Nandini Rangaswamy <nandini.rangaswamy@broadcom.com> wrote:

Thanks Long Li.

I shall try this patch and get back to you.

 

On Fri, Sep 13, 2024 at 2:27PM Long Li <longli@microsoft.com> wrote:

It’s a bug in netvsc for not reporting RTE_ETH_RSS_NONFRAG_IPV6_UDP. It is implied as in the case in IPV4.

 

Can you try the following patch?

 

diff --git a/drivers/net/netvsc/hn_rndis.c b/drivers/net/netvsc/hn_rndis.c

index 1ba75ee804..fe1f04d8d9 100644

--- a/drivers/net/netvsc/hn_rndis.c

+++ b/drivers/net/netvsc/hn_rndis.c

@@ -717,6 +717,7 @@ hn_rndis_query_rsscaps(struct hn_data *hv,

        if (caps.ndis_caps & NDIS_RSS_CAP_IPV6)

                hv->rss_offloads |= RTE_ETH_RSS_IPV6

                        | RTE_ETH_RSS_NONFRAG_IPV6_TCP;

+                       | RTE_ETH_RSS_NONFRAG_IPV6_UDP;

        if (caps.ndis_caps & NDIS_RSS_CAP_IPV6_EX)

                hv->rss_offloads |= RTE_ETH_RSS_IPV6_EX

                        | RTE_ETH_RSS_IPV6_TCP_EX;

 

 

From: Nandini Rangaswamy <nandini.rangaswamy@broadcom.com>
Sent: Friday, September 13, 2024 10:56 AM
To: Stephen Hemminger <stephen@networkplumber.org>
Cc: Long Li <longli@microsoft.com>; users@dpdk.org
Subject: Re: Netvsc vs Failsafe Performance

 

Thanks for clarifying the question regarding Txd size Stephen.

I tested out the RSS for TCP UDP.

As suggested , I set the TCP flags alone in RSS conf and configured the netvsc port.

 

struct rte_eth_conf conf = {

.intr_conf = {

.lsc = !dpdk.lsc_intr_disable && !dpdk_if->lsc_intr_disable &&

!!(dev->data->dev_flags & RTE_ETH_DEV_INTR_LSC),

},

.rxmode = {

.mq_mode = RTE_ETH_MQ_RX_RSS,

.offloads = RTE_ETH_RX_OFFLOAD_VLAN_STRIP | RTE_ETH_RX_OFFLOAD_IPV4_CKSUM |

RTE_ETH_RX_OFFLOAD_RSS_HASH | RTE_ETH_RX_OFFLOAD_UDP_CKSUM,

},

.rx_adv_conf.rss_conf = {

.rss_hf = RTE_ETH_RSS_NONFRAG_IPV4_TCP | RTE_ETH_RSS_NONFRAG_IPV6_TCP,

.rss_key = conf_rss_key,

.rss_key_len = rss_key_len,

},

.txmode = {

.offloads = RTE_ETH_TX_OFFLOAD_UDP_CKSUM | RTE_ETH_TX_OFFLOAD_IPV4_CKSUM,

},

};

rte_eth_dev_configure(<netvsc port>, num_rxq,num_txq, &conf);

uint8_t rss_key_temp[64];

struct rte_eth_rss_conf rss_conf = {

.rss_key = rss_key_temp,

.rss_key_len = sizeof(rss_key_temp),

};

ret = rte_eth_dev_rss_hash_conf_get(<VF port>, &rss_conf);

 

 

Now the VF port RSS offloads show only TCP flags set and not UDP. I assumed that even the UDP flags might be set. Is this expected ?

 

Regards,

Nandini 

 

 

On Thu, Sep 12, 2024 at 4:09PM Stephen Hemminger <stephen@networkplumber.org> wrote:

On Thu, 12 Sep 2024 13:47:37 -0700
Nandini Rangaswamy <nandini.rangaswamy@broadcom.com> wrote:

> Thanks for your response Long Li.
> I see with netvsc the maximum number of Tx descriptors is restricted to
> 4096 whereas the number of Rx descriptors is restricted to 8192.
> But, for failsafe PMD , we see that both the number of Txd and Rxd is
> restricted to 8192.
> How is netvsc PMD giving the same performance as failsafe PMD ?
>
> Regards

I think the limits there were somewhat arbitrary chose with netvsc.
Don't remember a hard reason that would block larger sizes.


Having really big rings won't help performance (i.e BufferBloat) and
could a lot of memory consumption. When all heavy data traffic goes through
the VF and that ring is different. Only DoS attacks should be impacted
by rx/tx descriptor limits in the netvsc device. The linux driver actually
has much smaller buffer.


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