On Tue, Jan 26, 2021 at 6:01 AM Ferruh Yigit [off-list ref] wrote:

On 1/26/2021 3:45 AM, Lance Richardson wrote:

quoted

On Mon, Jan 25, 2021 at 7:44 PM Ferruh Yigit [off-list ref] wrote:

quoted

quoted

quoted

+       if (rx_offloads != port->dev_conf.rxmode.offloads) {
+               uint16_t qid;
+
+               port->dev_conf.rxmode.offloads = rx_offloads;
+
+               /* Apply JUMBO_FRAME offload configuration to Rx queue(s) */
+               for (qid = 0; qid < port->dev_info.nb_rx_queues; qid++) {
+                       if (on)
+                               port->rx_conf[qid].offloads |= DEV_RX_OFFLOAD_JUMBO_FRAME;
+                       else
+                               port->rx_conf[qid].offloads &= ~DEV_RX_OFFLOAD_JUMBO_FRAME;
+               }

Is it correct to set per-queue offloads that aren't advertised by the PMD
as supported in rx_queue_offload_capa?

'port->rx_conf[]' is testpmd struct, and 'port->dev_conf.rxmode.offloads' values
are reflected to 'port->rx_conf[].offloads' for all queues.

We should set the offload in 'port->rx_conf[].offloads' if it is set in
'port->dev_conf.rxmode.offloads'.

If a port has capability for 'JUMBO_FRAME', 'port->rx_conf[].offloads' can have
it. And the port level capability is already checked above.

I'm still not 100% clear about the per-queue offload question.

With this patch, and jumbo max packet size configured (on the command
line in this case), I see:

testpmd> show port 0 rx_offload configuration
Rx Offloading Configuration of port 0 :
   Port : JUMBO_FRAME
   Queue[ 0] : JUMBO_FRAME

testpmd> show port 0 rx_offload capabilities
Rx Offloading Capabilities of port 0 :
   Per Queue :
   Per Port  : VLAN_STRIP IPV4_CKSUM UDP_CKSUM TCP_CKSUM TCP_LRO
OUTER_IPV4_CKSUM VLAN_FILTER VLAN_EXTEND JUMBO_FRAME SCATTER TIMESTAMP
KEEP_CRC OUTER_UDP_CKSUM RSS_HASH

The port level offload is applied to all queues on the port, testpmd config
structure reflects this logic in implementation.
If Rx offload X is set for a port, it is set for all Rx queue offloads, this is
not new behavior and not related to this patch.

OK, is this purely for display purposes within testpmd? I ask because
it appears that all PMDs supporting per-queue offload configuration already
take care of combining port-level and per-queue offloads within their
tx_queue_setup()/rx_queue_setup() functions and then track the combined
set of offloads within a per-queue field, e.g. this line is common to
e1000/i40e/ionic/ixgbe/octeontx2/thunderx/txgbe rx_queue_setup()
implementations:
    offloads = rx_conf->offloads | dev->data->dev_conf.rxmode.offloads;

And rte_ethdev.h says:
   No need to repeat any bit in rx_conf->offloads which has already been
   enabled in rte_eth_dev_configure() at port level. An offloading enabled
  at port level can't be disabled at queue level.

Which I suppose confirms that if testpmd is combining per-port and per-
queue offloads, it's just for the purposes of testpmd.

Apologies for worrying at this even more, I just wanted to be sure that
I understand what the PMD is expected to do.

Regards,
    Lance