summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--doc/guides/nics/enic.rst53
-rw-r--r--drivers/net/enic/enic_main.c14
2 files changed, 57 insertions, 10 deletions
diff --git a/doc/guides/nics/enic.rst b/doc/guides/nics/enic.rst
index 8170286..bff5c77 100644
--- a/doc/guides/nics/enic.rst
+++ b/doc/guides/nics/enic.rst
@@ -59,11 +59,31 @@ Configuration information
- **Number of Queues**
- The maximum number of receive and transmit queues are configurable on a per
- vNIC basis through the Cisco UCS Manager (CIMC or UCSM). These values
- should be configured to be greater than or equal to the nb_rx_q and nb_tx_q
- parameters expected to used in the call to the rte_eth_dev_configure()
- function.
+ The maximum number of receive queues (RQs), work queues (WQs) and
+ completion queues (CQs) are configurable on a per vNIC basis
+ through the Cisco UCS Manager (CIMC or UCSM).
+
+ These values should be configured as follows:
+
+ - The number of WQs should be greater or equal to the value of the
+ expected nb_tx_q parameter in the call to the
+ rte_eth_dev_configure()
+
+ - The number of RQs configured in the vNIC should be greater or
+ equal to *twice* the value of the expected nb_rx_q parameter in
+ the call to rte_eth_dev_configure(). With the addition of rx
+ scatter, a pair of RQs on the vnic is needed for each receive
+ queue used by DPDK, even if rx scatter is not being used.
+ Having a vNIC with only 1 RQ is not a valid configuration, and
+ will fail with an error message.
+
+ - The number of CQs should set so that there is one CQ for each
+ WQ, and one CQ for each pair of RQs.
+
+ For example: If the application requires 3 Rx queues, and 3 Tx
+ queues, the vNIC should be configured to have at least 3 WQs, 6
+ RQs (3 pairs), and 6 CQs (3 for use by WQs + 3 for use by the 3
+ pairs of RQs).
- **Size of Queues**
@@ -71,6 +91,29 @@ Configuration information
a per vNIC bases via the UCS Manager and should be greater than or equal to
the nb_rx_desc and nb_tx_desc parameters expected to be used in the calls
to rte_eth_rx_queue_setup() and rte_eth_tx_queue_setup() respectively.
+ An application requesting more than the set size will be limited to that
+ size.
+
+ Unless there is a lack of resources due to creating many vNICs, it
+ is recommended that the WQ and RQ sizes be set to the maximum. This
+ gives the application the greatest amount of flexibility in its
+ queue configuration.
+
+ - *Note*: Since the introduction of rx scatter, for performance
+ reasons, this PMD uses two RQs on the vNIC per receive queue in
+ DPDK. One RQ holds descriptors for the start of a packet the
+ second RQ holds the descriptors for the rest of the fragments of
+ a packet. This means that the nb_rx_desc parameter to
+ rte_eth_rx_queue_setup() can be a greater than 4096. The exact
+ amount will depend on the size of the mbufs being used for
+ receives, and the MTU size.
+
+ For example: If the mbuf size is 2048, and the MTU is 9000, then
+ receiving a full size packet will take 5 descriptors, 1 from the
+ start of packet queue, and 4 from the second queue. Assuming
+ that the RQ size was set to the maximum of 4096, then the
+ application can specify up to 1024 + 4096 as the nb_rx_desc
+ parameter to rte_eth_rx_queue_setup().
- **Interrupts**
diff --git a/drivers/net/enic/enic_main.c b/drivers/net/enic/enic_main.c
index 15a05b4..e3e58fb 100644
--- a/drivers/net/enic/enic_main.c
+++ b/drivers/net/enic/enic_main.c
@@ -1284,6 +1284,15 @@ static int enic_dev_init(struct enic *enic)
return err;
}
+ /* Get available resource counts */
+ enic_get_res_counts(enic);
+ if (enic->conf_rq_count == 1) {
+ dev_err(enic, "Running with only 1 RQ configured in the vNIC is not supported.\n");
+ dev_err(enic, "Please configure 2 RQs in the vNIC for each Rx queue used by DPDK.\n");
+ dev_err(enic, "See the ENIC PMD guide for more information.\n");
+ return -EINVAL;
+ }
+
eth_dev->data->mac_addrs = rte_zmalloc("enic_mac_addr", ETH_ALEN, 0);
if (!eth_dev->data->mac_addrs) {
dev_err(enic, "mac addr storage alloc failed, aborting.\n");
@@ -1292,11 +1301,6 @@ static int enic_dev_init(struct enic *enic)
ether_addr_copy((struct ether_addr *) enic->mac_addr,
&eth_dev->data->mac_addrs[0]);
-
- /* Get available resource counts
- */
- enic_get_res_counts(enic);
-
vnic_dev_set_reset_flag(enic->vdev, 0);
/* set up link status checking */