[PATCH v4 3/8] net/nfb: add vdev as alternative device probe method

[spinler at cesnet.cz]

From: Martin Spinler <spinler at cesnet.cz>

VDEV are useful for NFB devices not represented by PCI device,
e.g. virtual or simulated devices.

Signed-off-by: Martin Spinler <spinler at cesnet.cz>
---
 drivers/net/nfb/meson.build |   1 +
 drivers/net/nfb/nfb_vdev.c  | 102 ++++++++++++++++++++++++++++++++++++
 2 files changed, 103 insertions(+)
 create mode 100644 drivers/net/nfb/nfb_vdev.c

diff --git a/drivers/net/nfb/meson.build b/drivers/net/nfb/meson.build
index d7a255c928..9e458dfb4a 100644
--- a/drivers/net/nfb/meson.build
+++ b/drivers/net/nfb/meson.build
@@ -16,6 +16,7 @@ ext_deps += dep
 
 sources = files(
         'nfb_ethdev.c',
+        'nfb_vdev.c',
         'nfb_rx.c',
         'nfb_rxmode.c',
         'nfb_stats.c',
diff --git a/drivers/net/nfb/nfb_vdev.c b/drivers/net/nfb/nfb_vdev.c
new file mode 100644
index 0000000000..c3629bd395
--- /dev/null
+++ b/drivers/net/nfb/nfb_vdev.c
@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2026 Cesnet
+ */
+
+#include <rte_kvargs.h>
+#include <ethdev_vdev.h>
+
+#include "nfb.h"
+
+#define VDEV_NFB_DRIVER net_vdev_nfb
+#define VDEV_NFB_ARG_DEV "dev"
+
+static int
+vdev_nfb_vdev_probe(struct rte_vdev_device *dev)
+{
+	unsigned int count;
+	int ret = 0;
+	size_t len, pos;
+
+	struct nfb_init_params params;
+
+	const char *vdev_name = rte_vdev_device_name(dev);
+	const char *vdev_args = rte_vdev_device_args(dev);
+	char *dev_params, *dev_params_mod;
+	struct rte_kvargs *kvargs;
+
+	kvargs = rte_kvargs_parse(vdev_args, NULL);
+	if (kvargs == NULL) {
+		NFB_LOG(ERR, "Failed to parse device arguments %s", vdev_args);
+		ret = -EINVAL;
+		goto err_parse_args;
+	}
+
+	dev_params = strdup(vdev_args);
+	if (dev_params == NULL) {
+		ret = -ENOMEM;
+		goto err_strdup_params;
+	}
+
+	params.args = dev_params;
+	params.path = nfb_default_dev_path();
+	params.nfb_id = 0;
+
+	len = strlen(dev_params) + 1;
+	pos = 0;
+	dev_params[pos] = '\0';
+
+	/* Parse parameters for virtual device */
+	for (count = 0; count != kvargs->count; ++count) {
+		const struct rte_kvargs_pair *pair = &kvargs->pairs[count];
+
+		if (!strcmp(pair->key, VDEV_NFB_ARG_DEV)) {
+			params.path = pair->value;
+		} else {
+			/* Clone non-vdev arguments, result is shorter or equal length */
+			dev_params_mod = dev_params + pos;
+			ret = snprintf(dev_params_mod, len, "%s%s=%s",
+					pos == 0 ? "" : ",", pair->key, pair->value);
+			if (ret < 0 || ret >= (signed int)len)
+				goto err_clone_args;
+			pos += ret;
+			len -= ret;
+		}
+	}
+
+	strlcpy(params.name, vdev_name, sizeof(params.name));
+
+	ret = nfb_eth_common_probe(&dev->device, NULL, NULL, &params, -1);
+	if (ret)
+		goto err_nfb_common_probe;
+
+	free(dev_params);
+	rte_kvargs_free(kvargs);
+
+	return ret;
+
+err_nfb_common_probe:
+err_clone_args:
+	free(dev_params);
+err_strdup_params:
+	rte_kvargs_free(kvargs);
+err_parse_args:
+	return ret;
+}
+
+static int
+vdev_nfb_vdev_remove(struct rte_vdev_device *dev)
+{
+	return nfb_eth_common_remove(&dev->device);
+}
+
+/** Virtual device descriptor. */
+static struct rte_vdev_driver vdev_nfb_vdev = {
+	.probe = vdev_nfb_vdev_probe,
+	.remove = vdev_nfb_vdev_remove,
+};
+
+RTE_PMD_REGISTER_VDEV(VDEV_NFB_DRIVER, vdev_nfb_vdev);
+RTE_PMD_REGISTER_ALIAS(VDEV_NFB_DRIVER, eth_vdev_nfb);
+RTE_PMD_REGISTER_PARAM_STRING(net_vdev_nfb,
+		VDEV_NFB_ARG_DEV "=<string>"
+		);
-- 
2.52.0