[PATCH] net/gve: add reset path

["Jasper Tran O'Leary" <jtranoleary@google.com>]

Currently, the driver does not include any reset functionality and hence
cannot be reset by the application. This patch introduces a driver
callback for the `rte_eth_dev_reset` function which will reset the
device.

Also, as a precaution, null out device pointers to rx and tx queue
arrays when we release the queues during a reset.

Signed-off-by: Jasper Tran O'Leary <jtranoleary@google.com>
Reviewed-by: Joshua Washington <joshwash@google.com>
---
 drivers/net/gve/gve_ethdev.c | 40 ++++++++++++++++++++++++++++++++++++++++
 drivers/net/gve/gve_rx.c     |  2 ++
 drivers/net/gve/gve_rx_dqo.c |  2 ++
 drivers/net/gve/gve_tx.c     |  2 ++
 drivers/net/gve/gve_tx_dqo.c |  2 ++
 5 files changed, 48 insertions(+)

diff --git a/drivers/net/gve/gve_ethdev.c b/drivers/net/gve/gve_ethdev.c
index 6341d89..d62f74b 100644
--- a/drivers/net/gve/gve_ethdev.c
+++ b/drivers/net/gve/gve_ethdev.c
@@ -12,6 +12,8 @@
 #include "gve_rss.h"
 #include <ethdev_driver.h>
 
+static int gve_init_priv(struct gve_priv *priv, bool skip_describe_device);
+
 static void
 gve_write_version(uint8_t *driver_version_register)
 {
@@ -550,6 +552,42 @@ gve_dev_close(struct rte_eth_dev *dev)
 	return err;
 }
 
+static int
+gve_dev_reset(struct rte_eth_dev *dev)
+{
+	struct gve_priv *priv = dev->data->dev_private;
+	int err = 0;
+
+	if (rte_eal_process_type() != RTE_PROC_PRIMARY) {
+		PMD_DRV_LOG(ERR,
+			"Device reset on port %u not supported in secondary processes.",
+			dev->data->port_id);
+		return -EPERM;
+	}
+
+	if (dev->data->dev_started) {
+		PMD_DRV_LOG(ERR,
+			"Must stop device on port %u before reset.",
+			dev->data->port_id);
+		return -EBUSY;
+	}
+
+	/* Tear down all device resources before re-initializing. */
+	gve_free_queues(dev);
+	gve_teardown_device_resources(priv);
+	gve_adminq_free(priv);
+
+	err = gve_init_priv(priv, true);
+	if (err != 0) {
+		PMD_DRV_LOG(ERR,
+			"Failed to re-init device on port %u after reset.",
+			dev->data->port_id);
+		return err;
+	}
+
+	return 0;
+}
+
 static int
 gve_verify_driver_compatibility(struct gve_priv *priv)
 {
@@ -1068,6 +1106,7 @@ static const struct eth_dev_ops gve_eth_dev_ops = {
 	.dev_start            = gve_dev_start,
 	.dev_stop             = gve_dev_stop,
 	.dev_close            = gve_dev_close,
+	.dev_reset            = gve_dev_reset,
 	.dev_infos_get        = gve_dev_info_get,
 	.rx_queue_setup       = gve_rx_queue_setup,
 	.tx_queue_setup       = gve_tx_queue_setup,
@@ -1094,6 +1133,7 @@ static const struct eth_dev_ops gve_eth_dev_ops_dqo = {
 	.dev_start            = gve_dev_start,
 	.dev_stop             = gve_dev_stop,
 	.dev_close            = gve_dev_close,
+	.dev_reset            = gve_dev_reset,
 	.dev_infos_get        = gve_dev_info_get,
 	.rx_queue_setup       = gve_rx_queue_setup_dqo,
 	.tx_queue_setup       = gve_tx_queue_setup_dqo,
diff --git a/drivers/net/gve/gve_rx.c b/drivers/net/gve/gve_rx.c
index 7a91c31..625649c 100644
--- a/drivers/net/gve/gve_rx.c
+++ b/drivers/net/gve/gve_rx.c
@@ -290,6 +290,8 @@ gve_rx_queue_release(struct rte_eth_dev *dev, uint16_t qid)
 	rte_memzone_free(q->qres_mz);
 	q->qres = NULL;
 	rte_free(q);
+
+	dev->data->rx_queues[qid] = NULL;
 }
 
 int
diff --git a/drivers/net/gve/gve_rx_dqo.c b/drivers/net/gve/gve_rx_dqo.c
index a0ef21b..3aa82b3 100644
--- a/drivers/net/gve/gve_rx_dqo.c
+++ b/drivers/net/gve/gve_rx_dqo.c
@@ -252,6 +252,8 @@ gve_rx_queue_release_dqo(struct rte_eth_dev *dev, uint16_t qid)
 	rte_memzone_free(q->qres_mz);
 	q->qres = NULL;
 	rte_free(q);
+
+	dev->data->rx_queues[qid] = NULL;
 }
 
 static void
diff --git a/drivers/net/gve/gve_tx.c b/drivers/net/gve/gve_tx.c
index 015ea96..5c73c21 100644
--- a/drivers/net/gve/gve_tx.c
+++ b/drivers/net/gve/gve_tx.c
@@ -547,6 +547,8 @@ gve_tx_queue_release(struct rte_eth_dev *dev, uint16_t qid)
 	rte_memzone_free(q->qres_mz);
 	q->qres = NULL;
 	rte_free(q);
+
+	dev->data->tx_queues[qid] = NULL;
 }
 
 int
diff --git a/drivers/net/gve/gve_tx_dqo.c b/drivers/net/gve/gve_tx_dqo.c
index 64141ac..4c632d7 100644
--- a/drivers/net/gve/gve_tx_dqo.c
+++ b/drivers/net/gve/gve_tx_dqo.c
@@ -379,6 +379,8 @@ gve_tx_queue_release_dqo(struct rte_eth_dev *dev, uint16_t qid)
 	rte_memzone_free(q->qres_mz);
 	q->qres = NULL;
 	rte_free(q);
+
+	dev->data->tx_queues[qid] = NULL;
 }
 
 static int
-- 
2.52.0.351.gbe84eed79e-goog