[dpdk-dev] [PATCH v1] net/vhost: support queue update

[Matan Azrad]

The commit below changed the readiness condition of vhost device to fix
multi-queues issues showed with QEMU versions.

Now, the vhost device is ready when the first queue-pair is ready.
When more queues are being ready, the queue state callback will be
triggered to notify the vhost manager.

In case of Rx interrupt configuration, the vhost driver set the
kickfd queue file descriptor in order to be notified on Rx traffic.

So, when queue becomes ready, the kickfd may be changed and should be
updated in the Rx interrupt structure.

Update kickfd when the queue state callback is invoked.

Fixes: d0fcc38f5fa4 ("vhost: improve device readiness notifications")

Signed-off-by: Matan Azrad <matan at mellanox.com>
---
 drivers/net/vhost/rte_eth_vhost.c | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/drivers/net/vhost/rte_eth_vhost.c b/drivers/net/vhost/rte_eth_vhost.c
index 9fbf39f..805d75e 100644
--- a/drivers/net/vhost/rte_eth_vhost.c
+++ b/drivers/net/vhost/rte_eth_vhost.c
@@ -831,6 +831,39 @@ struct vhost_xstats_name_off {
 }
 
 static int
+vring_conf_update(int vid, struct rte_eth_dev *eth_dev, uint16_t vring_id)
+{
+	struct rte_eth_conf *dev_conf = &eth_dev->data->dev_conf;
+	struct pmd_internal *internal = eth_dev->data->dev_private;
+	struct rte_vhost_vring vring;
+	int rx_idx = vring_id % 2 ? (vring_id - 1) >> 1 : -1;
+	int ret = 0;
+
+	/*
+	 * The vring kickfd may be changed after the new device notification.
+	 * Update it when the vring state is updated.
+	 */
+	if (rx_idx >= 0 && rx_idx < eth_dev->data->nb_rx_queues &&
+	    rte_atomic32_read(&internal->dev_attached) &&
+	    rte_atomic32_read(&internal->started) &&
+	    dev_conf->intr_conf.rxq) {
+		ret = rte_vhost_get_vhost_vring(vid, vring_id, &vring);
+		if (!ret) {
+			if (vring.kickfd !=
+			    eth_dev->intr_handle->efds[rx_idx]) {
+				VHOST_LOG(INFO,
+					  "kickfd for rxq-%d was changed.\n",
+					  rx_idx);
+				eth_dev->intr_handle->efds[rx_idx] =
+								   vring.kickfd;
+			}
+		}
+	}
+
+	return ret;
+}
+
+static int
 vring_state_changed(int vid, uint16_t vring, int enable)
 {
 	struct rte_vhost_vring_state *state;
@@ -848,6 +881,11 @@ struct vhost_xstats_name_off {
 	eth_dev = list->eth_dev;
 	/* won't be NULL */
 	state = vring_states[eth_dev->data->port_id];
+
+	if (vring_conf_update(vid, eth_dev, vring))
+		VHOST_LOG(INFO, "Failed to update vring-%d configuration.\n",
+			  (int)vring);
+
 	rte_spinlock_lock(&state->lock);
 	if (state->cur[vring] == enable) {
 		rte_spinlock_unlock(&state->lock);
-- 
1.8.3.1