[dpdk-dev] [Patch v2] net/vdev_netvsc: prevent alarm loss on failed device probe

Long Li longli at linuxonhyperv.com
Thu Oct 22 10:11:34 CEST 2020


From: Long Li <longli at microsoft.com>

If a device probe fails, the alarm is canceled and will no longer work for
previously probed devices.

Fix this by checking if alarm is necessary at the end of each device probe.
Reset the alarm if there are vdev_netvsc_ctx created.

Change log:
v2: removed lock and flags, use counter to decide if alarm should be reset

Cc: stable at dpdk.org
Signed-off-by: Long Li <longli at microsoft.com>
---
 drivers/net/vdev_netvsc/vdev_netvsc.c | 27 +++++++++++++--------------
 1 file changed, 13 insertions(+), 14 deletions(-)

diff --git a/drivers/net/vdev_netvsc/vdev_netvsc.c b/drivers/net/vdev_netvsc/vdev_netvsc.c
index a865a82811..9ed8a4949d 100644
--- a/drivers/net/vdev_netvsc/vdev_netvsc.c
+++ b/drivers/net/vdev_netvsc/vdev_netvsc.c
@@ -684,6 +684,7 @@ vdev_netvsc_vdev_probe(struct rte_vdev_device *dev)
 	int ret;
 
 	DRV_LOG(DEBUG, "invoked as \"%s\", using arguments \"%s\"", name, args);
+	rte_eal_alarm_cancel(vdev_netvsc_alarm, NULL);
 	if (!kvargs) {
 		DRV_LOG(ERR, "cannot parse arguments list");
 		goto error;
@@ -699,17 +700,13 @@ vdev_netvsc_vdev_probe(struct rte_vdev_device *dev)
 			 !strcmp(pair->key, VDEV_NETVSC_ARG_MAC))
 			++specified;
 	}
-	if (ignore) {
-		if (kvargs)
-			rte_kvargs_free(kvargs);
-		return 0;
-	}
+	if (ignore)
+		goto ignore;
 	if (specified > 1) {
 		DRV_LOG(ERR, "More than one way used to specify the netvsc"
 			" device.");
 		goto error;
 	}
-	rte_eal_alarm_cancel(vdev_netvsc_alarm, NULL);
 	/* Gather interfaces. */
 	ret = vdev_netvsc_foreach_iface(vdev_netvsc_netvsc_probe, 1, name,
 					kvargs, specified, &matched);
@@ -730,17 +727,19 @@ vdev_netvsc_vdev_probe(struct rte_vdev_device *dev)
 		}
 		DRV_LOG(WARNING, "non-netvsc device was probed as netvsc");
 	}
-	ret = rte_eal_alarm_set(VDEV_NETVSC_PROBE_MS * 1000,
-				vdev_netvsc_alarm, NULL);
-	if (ret < 0) {
-		DRV_LOG(ERR, "unable to schedule alarm callback: %s",
-			rte_strerror(-ret));
-		goto error;
-	}
 error:
+	++vdev_netvsc_ctx_inst;
+ignore:
 	if (kvargs)
 		rte_kvargs_free(kvargs);
-	++vdev_netvsc_ctx_inst;
+	/* Reset alarm if there are device context created */
+	if (vdev_netvsc_ctx_count) {
+		ret = rte_eal_alarm_set(VDEV_NETVSC_PROBE_MS * 1000,
+					vdev_netvsc_alarm, NULL);
+		if (ret < 0)
+			DRV_LOG(ERR, "unable to schedule alarm callback: %s",
+				rte_strerror(-ret));
+	}
 	return 0;
 }
 
-- 
2.25.1



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