patch 'net/tap: fix to populate FDs in secondary process' has been queued to stable release 21.11.1

[Kevin Traynor]

Hi,

FYI, your patch has been queued to stable release 21.11.1

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 02/26/22. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/kevintraynor/dpdk-stable

This queued commit can be viewed at:
https://github.com/kevintraynor/dpdk-stable/commit/ac180f4d2662503ecd18a2e94689a229104d3d61

Thanks.

Kevin

---
>From ac180f4d2662503ecd18a2e94689a229104d3d61 Mon Sep 17 00:00:00 2001
From: Kumara Parameshwaran <kparameshwar at vmware.com>
Date: Mon, 31 Jan 2022 20:02:34 +0530
Subject: [PATCH] net/tap: fix to populate FDs in secondary process

[ upstream commit c36ce7099c2187926cd62cff7ebd479823554929 ]

When a tap device is hotplugged to primary process which in turn
adds the device to all secondary process, the secondary process
does a tap_mp_attach_queues, but the fds are not populated in
the primary during the probe they are populated during the queue_setup,
added a fix to sync the queues during rte_eth_dev_start

Fixes: 4852aa8f6e21 ("drivers/net: enable hotplug on secondary process")

Signed-off-by: Kumara Parameshwaran <kparameshwar at vmware.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit at intel.com>
---
 drivers/net/tap/rte_eth_tap.c | 80 +++++++++++++++++++++++++++++++++++
 1 file changed, 80 insertions(+)

diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
index 5bb472f1a6..b0c09956de 100644
--- a/drivers/net/tap/rte_eth_tap.c
+++ b/drivers/net/tap/rte_eth_tap.c
@@ -68,4 +68,5 @@
 /* IPC key for queue fds sync */
 #define TAP_MP_KEY "tap_mp_sync_queues"
+#define TAP_MP_REQ_START_RXTX "tap_mp_req_start_rxtx"
 
 #define TAP_IOV_DEFAULT_MAX 1024
@@ -881,4 +882,39 @@ tap_link_set_up(struct rte_eth_dev *dev)
 }
 
+static int
+tap_mp_req_on_rxtx(struct rte_eth_dev *dev)
+{
+	struct rte_mp_msg msg;
+	struct ipc_queues *request_param = (struct ipc_queues *)msg.param;
+	int err;
+	int fd_iterator = 0;
+	struct pmd_process_private *process_private = dev->process_private;
+	int i;
+
+	memset(&msg, 0, sizeof(msg));
+	strlcpy(msg.name, TAP_MP_REQ_START_RXTX, sizeof(msg.name));
+	strlcpy(request_param->port_name, dev->data->name, sizeof(request_param->port_name));
+	msg.len_param = sizeof(*request_param);
+	for (i = 0; i < dev->data->nb_tx_queues; i++) {
+		msg.fds[fd_iterator++] = process_private->txq_fds[i];
+		msg.num_fds++;
+		request_param->txq_count++;
+	}
+	for (i = 0; i < dev->data->nb_rx_queues; i++) {
+		msg.fds[fd_iterator++] = process_private->rxq_fds[i];
+		msg.num_fds++;
+		request_param->rxq_count++;
+	}
+
+	err = rte_mp_sendmsg(&msg);
+	if (err < 0) {
+		TAP_LOG(ERR, "Failed to send start req to secondary %d",
+			rte_errno);
+		return -1;
+	}
+
+	return 0;
+}
+
 static int
 tap_dev_start(struct rte_eth_dev *dev)
@@ -886,4 +922,7 @@ tap_dev_start(struct rte_eth_dev *dev)
 	int err, i;
 
+	if (rte_eal_process_type() == RTE_PROC_PRIMARY)
+		tap_mp_req_on_rxtx(dev);
+
 	err = tap_intr_handle_set(dev, 1);
 	if (err)
@@ -902,4 +941,32 @@ tap_dev_start(struct rte_eth_dev *dev)
 }
 
+static int
+tap_mp_req_start_rxtx(const struct rte_mp_msg *request, __rte_unused const void *peer)
+{
+	struct rte_eth_dev *dev;
+	const struct ipc_queues *request_param =
+		(const struct ipc_queues *)request->param;
+	int fd_iterator;
+	int queue;
+	struct pmd_process_private *process_private;
+
+	dev = rte_eth_dev_get_by_name(request_param->port_name);
+	if (!dev) {
+		TAP_LOG(ERR, "Failed to get dev for %s",
+			request_param->port_name);
+		return -1;
+	}
+	process_private = dev->process_private;
+	fd_iterator = 0;
+	TAP_LOG(DEBUG, "tap_attach rx_q:%d tx_q:%d\n", request_param->rxq_count,
+		request_param->txq_count);
+	for (queue = 0; queue < request_param->txq_count; queue++)
+		process_private->txq_fds[queue] = request->fds[fd_iterator++];
+	for (queue = 0; queue < request_param->rxq_count; queue++)
+		process_private->rxq_fds[queue] = request->fds[fd_iterator++];
+
+	return 0;
+}
+
 /* This function gets called when the current port gets stopped.
  */
@@ -1085,4 +1152,7 @@ tap_dev_close(struct rte_eth_dev *dev)
 	if (rte_eal_process_type() != RTE_PROC_PRIMARY) {
 		rte_free(dev->process_private);
+		if (tap_devices_count == 1)
+			rte_mp_action_unregister(TAP_MP_REQ_START_RXTX);
+		tap_devices_count--;
 		return 0;
 	}
@@ -2446,4 +2516,14 @@ rte_pmd_tap_probe(struct rte_vdev_device *dev)
 		if (ret != 0)
 			return -1;
+
+		if (!tap_devices_count) {
+			ret = rte_mp_action_register(TAP_MP_REQ_START_RXTX, tap_mp_req_start_rxtx);
+			if (ret < 0 && rte_errno != ENOTSUP) {
+				TAP_LOG(ERR, "tap: Failed to register IPC callback: %s",
+					strerror(rte_errno));
+				return -1;
+			}
+		}
+		tap_devices_count++;
 		rte_eth_dev_probing_finish(eth_dev);
 		return 0;
-- 
2.34.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2022-02-21 15:22:47.635759931 +0000
+++ 0140-net-tap-fix-to-populate-FDs-in-secondary-process.patch	2022-02-21 15:22:44.295704585 +0000
@@ -1 +1 @@
-From c36ce7099c2187926cd62cff7ebd479823554929 Mon Sep 17 00:00:00 2001
+From ac180f4d2662503ecd18a2e94689a229104d3d61 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit c36ce7099c2187926cd62cff7ebd479823554929 ]
+
@@ -13 +14,0 @@
-Cc: stable at dpdk.org
@@ -22 +23 @@
-index 02eb311e09..111037de65 100644
+index 5bb472f1a6..b0c09956de 100644
@@ -112 +113 @@
-@@ -1093,4 +1160,7 @@ tap_dev_close(struct rte_eth_dev *dev)
+@@ -1085,4 +1152,7 @@ tap_dev_close(struct rte_eth_dev *dev)
@@ -120 +121 @@
-@@ -2454,4 +2524,14 @@ rte_pmd_tap_probe(struct rte_vdev_device *dev)
+@@ -2446,4 +2516,14 @@ rte_pmd_tap_probe(struct rte_vdev_device *dev)