vhost: fix maximum of queues

Currently, the maximum value of rx/tx queues are kept by EAL. But,
the value is used like below with different meanings in vhost PMD.
 - The maximum value of current enabled queues.
 - The maximum value of current supported queues.

This wrong double meaning will cause an issue like below steps.

* Invoke application with below option.
  --vdev 'eth_vhost0,iface=<socket path>,queues=4'
* Configure queues like below.
  rte_eth_dev_configure(portid, 2, 2, ...);
* Configure queues again like below.
  rte_eth_dev_configure(portid, 4, 4, ...);

The second rte_eth_dev_configure() will fail because both
the maximum value of current enabled queues and supported queues
will be '2' after calling first rte_eth_dev_configure().

To fix the issue, the patch adds another variable to keep the maximum
number of supported queues in vhost PMD.

Fixes: 23981fb0d78b ("vhost: Add vhost PMD")

Signed-off-by: Tetsuya Mukawa <mukawa@igel.co.jp>
Acked-by: Ciara Loftus <ciara.loftus@intel.com>

diff --git a/drivers/net/vhost/rte_eth_vhost.c b/drivers/net/vhost/rte_eth_vhost.c
index 4ee10c1..ec19c22 100644 (file)
--- a/drivers/net/vhost/rte_eth_vhost.c
+++ b/drivers/net/vhost/rte_eth_vhost.c
@@ -88,6 +88,7 @@ struct vhost_queue {
 struct pmd_internal {
        char *dev_name;
        char *iface_name;
+       uint16_t max_queues;
 
        volatile uint16_t once;
 };
@@ -554,11 +555,19 @@ static void
 eth_dev_info(struct rte_eth_dev *dev,
             struct rte_eth_dev_info *dev_info)
 {
+       struct pmd_internal *internal;
+
+       internal = dev->data->dev_private;
+       if (internal == NULL) {
+               RTE_LOG(ERR, PMD, "Invalid device specified\n");
+               return;
+       }
+
        dev_info->driver_name = drivername;
        dev_info->max_mac_addrs = 1;
        dev_info->max_rx_pktlen = (uint32_t)-1;
-       dev_info->max_rx_queues = dev->data->nb_rx_queues;
-       dev_info->max_tx_queues = dev->data->nb_tx_queues;
+       dev_info->max_rx_queues = internal->max_queues;
+       dev_info->max_tx_queues = internal->max_queues;
        dev_info->min_rx_bufsize = 0;
 }
 
@@ -750,6 +759,7 @@ eth_dev_vhost_create(const char *name, char *iface_name, int16_t queues,
        memmove(data->name, eth_dev->data->name, sizeof(data->name));
        data->nb_rx_queues = queues;
        data->nb_tx_queues = queues;
+       internal->max_queues = queues;
        data->dev_link = pmd_link;
        data->mac_addrs = eth_addr;