net/virtio: fix crash on querying xstats

Trying to access xstats_names after "if (xstats_names == NULL)" is
obviously wrong, which would result to a crash while running "show
port xstats 0" in testpmd with virtio PMD.

The fix is straightforward; just reverse the check.

Fixes: baf91c395b18 ("net/virtio: fetch extended statistics with integer ids")

Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>

diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
index 19d5d8a..12fa640 100644 (file)
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -776,7 +776,7 @@ static int virtio_dev_xstats_get_names(struct rte_eth_dev *dev,
        unsigned nstats = dev->data->nb_tx_queues * VIRTIO_NB_TXQ_XSTATS +
                dev->data->nb_rx_queues * VIRTIO_NB_RXQ_XSTATS;
 
-       if (xstats_names == NULL) {
+       if (xstats_names != NULL) {
                /* Note: limit checked in rte_eth_xstats_names() */
 
                for (i = 0; i < dev->data->nb_rx_queues; i++) {