From: Long Li
> If a device probe fails, the alarm is canceled and will no longer work for
> previously probed devices.
>
> Fix this by introducing a flag to track if alarm has been set. Because it's
> possible that an alarm is triggered while probing is in progress that may
> modify vdev_netvsc_ctx_list, introduce a lock to protect it.
>
> Cc: sta...@dpdk.org
> Signed-off-by: Long Li <lon...@microsoft.com>
> ---
> drivers/net/vdev_netvsc/vdev_netvsc.c | 41
> +++++++++++++++++++++++++----------
> 1 file changed, 30 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/net/vdev_netvsc/vdev_netvsc.c
> b/drivers/net/vdev_netvsc/vdev_netvsc.c
> index be8f19c..bd7e308 100644
> --- a/drivers/net/vdev_netvsc/vdev_netvsc.c
> +++ b/drivers/net/vdev_netvsc/vdev_netvsc.c
> @@ -76,6 +76,11 @@ struct vdev_netvsc_ctx {
> /** Context list is common to all driver instances. */ static LIST_HEAD(,
> vdev_netvsc_ctx) vdev_netvsc_ctx_list =
> LIST_HEAD_INITIALIZER(vdev_netvsc_ctx_list);
> +/* Lock to protect concurrent accesses to vdev_netvsc_ctx_list */
> +static rte_rwlock_t vdev_netvsc_ctx_list_lock;
> +
> +/* Flag to track if alarm has been set */ static int
> +vdev_netvsc_alarm_set;
>
> /** Number of entries in context list. */ static unsigned int
> vdev_netvsc_ctx_count; @@ -454,19 +459,26 @@ static LIST_HEAD(,
> vdev_netvsc_ctx) vdev_netvsc_ctx_list =
> struct vdev_netvsc_ctx *ctx;
> int ret;
>
> + rte_rwlock_write_lock(&vdev_netvsc_ctx_list_lock);
> LIST_FOREACH(ctx, &vdev_netvsc_ctx_list, entry) {
> ret = vdev_netvsc_foreach_iface(vdev_netvsc_device_probe, 0,
> ctx);
> if (ret < 0)
> break;
> }
> - if (!vdev_netvsc_ctx_count)
> + rte_rwlock_write_unlock(&vdev_netvsc_ctx_list_lock);
> +
> + if (!vdev_netvsc_ctx_count) {
> + vdev_netvsc_alarm_set = 0;
> return;
> + }
> +
> ret = rte_eal_alarm_set(VDEV_NETVSC_PROBE_MS * 1000,
> vdev_netvsc_alarm, NULL);
> if (ret < 0) {
> DRV_LOG(ERR, "unable to reschedule alarm callback: %s",
> rte_strerror(-ret));
> + vdev_netvsc_alarm_set = 0;
> }
> }
>
> @@ -698,34 +710,41 @@ static LIST_HEAD(, vdev_netvsc_ctx)
> vdev_netvsc_ctx_list =
> " device.");
> goto error;
> }
> - rte_eal_alarm_cancel(vdev_netvsc_alarm, NULL);
> +
> + rte_rwlock_write_lock(&vdev_netvsc_ctx_list_lock);
> /* Gather interfaces. */
> ret = vdev_netvsc_foreach_iface(vdev_netvsc_netvsc_probe, 1, name,
> kvargs, specified, &matched);
> if (ret < 0)
> - goto error;
> + goto error_unlock;
> if (specified && matched < specified) {
> if (!force) {
> DRV_LOG(ERR, "Cannot find the specified netvsc
> device");
> - goto error;
> + goto error_unlock;
> }
> /* Try to force probing on non-netvsc specified device. */
> if (vdev_netvsc_foreach_iface(vdev_netvsc_netvsc_probe, 0,
> name,
> kvargs, specified, &matched) <
> 0)
> - goto error;
> + goto error_unlock;
> if (matched < specified) {
> DRV_LOG(ERR, "Cannot find the specified device");
> - goto error;
> + goto error_unlock;
> }
> DRV_LOG(WARNING, "non-netvsc device was probed as netvsc");
> }
> - ret = rte_eal_alarm_set(VDEV_NETVSC_PROBE_MS * 1000,
> + if (!vdev_netvsc_alarm_set) {
> + 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;
> + if (ret < 0)
> + DRV_LOG(ERR, "unable to schedule alarm callback: %s",
> + rte_strerror(-ret));
> + else
> + vdev_netvsc_alarm_set = 1;
> }
> +
> +error_unlock:
> + rte_rwlock_write_unlock(&vdev_netvsc_ctx_list_lock);
> +
> error:
> if (kvargs)
> rte_kvargs_free(kvargs);
> --
Hi
Nice direction.
As I understand from your patch it looks like you want to add support for the
vdev_netvsc driver itself to be hot-plug aware - so it can be probed\removed in
run-time (even after EAL initialization).
So I think the title and commit log should be converted to this:
net/vdev_netvsc: support driver instance hot-plug
...
More things:
Look on convention of the file - blank line only after variables declarations
inside the blocks.
Need to adjust also vdev_netvsc_vdev_remove to the feature.
Matan
