[PATCH v3] app/testpmd: fail on shared rxq switch mismatch

[a.schollmeyer@syseleven.de]

From: Adrian Schollmeyer <a.schollmeyer@syseleven.de>

Shared Rx queues do not work with every combination of ports. Besides
requiring the corresponding device capability, shared Rx queues also
require all ports of one share group and queue ID have the same switch
domain and Rx domain. When these fields do not match, shared Rx queues
are not properly set up and queue sharing may fail silently. This can
happen even in some less intuitive cases like multiple VFs of one
physical NIC and may cause packets not to be read by the application,
depending on how the data path is implemented.

To help with debugging issues with shared Rx queue configuration when
using testpmd, this commit introduces simple checks and error messages
for members of a share_group and share_qid to fail whenever there is a
mismatch in the switch and Rx domain.

Signed-off-by: Adrian Schollmeyer <a.schollmeyer@syseleven.de>
---
v3 changes:

  * make switch/rx domain mismatch an error with shared Rx queues
  * shorten error message
  * move error message outside of the loops
  * update commit message to reflect warning -> failure

v2 changes:

  * remove unnecessary casts
  * refactor message printing logic to remove duplicate fprintf()

 app/test-pmd/testpmd.c | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
index 1fe41d852a..6464a97b9b 100644
--- a/app/test-pmd/testpmd.c
+++ b/app/test-pmd/testpmd.c
@@ -2675,6 +2675,47 @@ rx_queue_setup(uint16_t port_id, uint16_t rx_queue_id,
 	uint32_t prev_hdrs = 0;
 	int ret;
 
+	if (rx_conf->share_group > 0) {
+		/* Check required switch info for Rx queue sharing */
+
+		const uint16_t dom_id = ports[port_id].dev_info.switch_info.domain_id;
+		const uint16_t rx_dom = ports[port_id].dev_info.switch_info.rx_domain;
+
+		uint16_t pid;
+		const char *mismatch = NULL;
+		uint16_t mismatch_pid = (uint16_t)RTE_PORT_ALL;
+		RTE_ETH_FOREACH_DEV(pid) {
+			struct rte_port *o_port = &ports[pid];
+			const uint16_t o_dom_id = o_port->dev_info.switch_info.domain_id;
+			const uint16_t o_rx_dom = o_port->dev_info.switch_info.rx_domain;
+
+			for (uint16_t q = 0; q < nb_rxq; ++q) {
+				struct port_rxqueue *rxq = &o_port->rxq[q];
+				if (rxq->conf.share_group != rx_conf->share_group ||
+						rxq->conf.share_qid != rx_conf->share_qid)
+					continue;
+				if (o_dom_id == dom_id && o_rx_dom == rx_dom)
+					continue;
+
+				if (o_dom_id != dom_id)
+					mismatch = "switch domain";
+				else if (o_rx_dom != rx_dom)
+					mismatch = "rx domain";
+
+				mismatch_pid = pid;
+				break;
+			}
+		}
+
+		if (mismatch) {
+			fprintf(stderr,
+				"Invalid shared rxq config: %s mismatch between ports %u and %u\n",
+				mismatch,
+				port_id,
+				mismatch_pid);
+			return -EINVAL;
+		}
+	}
 
 	if ((rx_pkt_nb_segs > 1) &&
 	    (rx_conf->offloads & RTE_ETH_RX_OFFLOAD_BUFFER_SPLIT)) {
-- 
2.34.1