[PATCH] net/sfc: invalidate switch port entry on representor unplug

[Ivan Malov]

Once allocated, a switch port list entry always stays there,
even after unplugging the ethdev that created it. Currently,
the entry's ethdev ID is not cleared on unplug. Referencing
the ethdev ID of a detached representor from a flow rule is
going to succeed, which is a bug. Also, if the user unplugs
endpoint "A" representor and plugs one for "B" instead, the
latter will pick the same ethdev ID as the gone representor,
but it will have a new port list entry added for it. If the
user tries to reference the ethdev ID from a flow rule, the
code will fetch the wrong entry ("A" rather than "B") since
it sits closer to the list head. That is a serious bug, too.

Make the driver invalidate ethdev ID field on ethdev unplug.

Fixes: 1fb65e4dae8a ("net/sfc: support flow action port ID in transfer rules")
Fixes: a62ec90522a6 ("net/sfc: add port representors infrastructure")
Cc: sta...@dpdk.org

Signed-off-by: Ivan Malov <ivan.ma...@arknetworks.am>
Reviewed-by: Andy Moreton <amore...@xilinx.com>
---
 drivers/net/sfc/sfc_repr.c   |  2 ++
 drivers/net/sfc/sfc_switch.c | 12 ++++++++++++
 2 files changed, 14 insertions(+)

diff --git a/drivers/net/sfc/sfc_repr.c b/drivers/net/sfc/sfc_repr.c
index 291860ec56..b3a41167fb 100644
--- a/drivers/net/sfc/sfc_repr.c
+++ b/drivers/net/sfc/sfc_repr.c
@@ -837,6 +837,8 @@ sfc_repr_dev_close(struct rte_eth_dev *dev)
 
        (void)sfc_repr_proxy_del_port(srs->pf_port_id, srs->repr_id);
 
+       sfc_mae_clear_switch_port(srs->switch_domain_id, srs->switch_port_id);
+
        dev->rx_pkt_burst = NULL;
        dev->tx_pkt_burst = NULL;
        dev->dev_ops = NULL;
diff --git a/drivers/net/sfc/sfc_switch.c b/drivers/net/sfc/sfc_switch.c
index 5c10e8fc74..8f1ee97fa8 100644
--- a/drivers/net/sfc/sfc_switch.c
+++ b/drivers/net/sfc/sfc_switch.c
@@ -489,6 +489,7 @@ sfc_mae_clear_switch_port(uint16_t switch_domain_id,
                          uint16_t switch_port_id)
 {
        struct sfc_mae_switch_domain *domain;
+       struct sfc_mae_switch_port *port;
 
        rte_spinlock_lock(&sfc_mae_switch.lock);
 
@@ -504,6 +505,17 @@ sfc_mae_clear_switch_port(uint16_t switch_domain_id,
                domain->mae_admin_port = NULL;
        }
 
+       TAILQ_FOREACH(port, &domain->ports, switch_domain_ports) {
+               if (port->id == switch_port_id) {
+                       /*
+                        * Invalidate the field to prevent wrong
+                        * look-ups from flow rule handling path.
+                        */
+                       port->ethdev_port_id = RTE_MAX_ETHPORTS;
+                       break;
+               }
+       }
+
        rte_spinlock_unlock(&sfc_mae_switch.lock);
        return 0;
 }
-- 
2.17.1