Re: [PATCH] vdpa: regist vhost-vdpa dev class

From: Zhang Min <redacted>

Some applications like kata-containers need to acquire MAJOR/MINOR/DEVNAME
for devInfo [1], so regist vhost-vdpa dev class to expose uevent.

1. https://github.com/kata-containers/kata-containers/blob/main/src/runtime/virtcontainers/device/config/config.go

Signed-off-by: Zhang Min <redacted>
Signed-off-by: Yi Wang <redacted>
---
drivers/vhost/vdpa.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index fb41db3da611..90fbad93e7a2 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c

@@ -1012,6 +1012,7 @@ static void vhost_vdpa_release_dev(struct device *device)

	kfree(v);
}

+static struct class *vhost_vdpa_class;

static int vhost_vdpa_probe(struct vdpa_device *vdpa)
{
	const struct vdpa_config_ops *ops = vdpa->config;

@@ -1040,6 +1041,7 @@ static int vhost_vdpa_probe(struct vdpa_device *vdpa)

	v->dev.release = vhost_vdpa_release_dev;
	v->dev.parent = &vdpa->dev;
	v->dev.devt = MKDEV(MAJOR(vhost_vdpa_major), minor);
+	v->dev.class = vhost_vdpa_class;
	v->vqs = kmalloc_array(v->nvqs, sizeof(struct vhost_virtqueue),
			       GFP_KERNEL);
	if (!v->vqs) {

@@ -1097,6 +1099,14 @@ static int __init vhost_vdpa_init(void)

{
	int r;

+	vhost_vdpa_class = class_create(THIS_MODULE, "vhost-vdpa");
+	if (IS_ERR(vhost_vdpa_class)) {
+		r = PTR_ERR(vhost_vdpa_class);
+		pr_warn("vhost vdpa class create error %d,  maybe mod reinserted\n", r);

+		vhost_vdpa_class = NULL;
+		return r;
+	}
+
	r = alloc_chrdev_region(&vhost_vdpa_major, 0, VHOST_VDPA_DEV_MAX,
				"vhost-vdpa");
	if (r)

@@ -1111,6 +1121,7 @@ static int __init vhost_vdpa_init(void)

err_vdpa_register_driver:
	unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX);
err_alloc_chrdev:
+	class_destroy(vhost_vdpa_class);

	return r;
}
module_init(vhost_vdpa_init);

@@ -1118,6 +1129,7 @@ module_init(vhost_vdpa_init);

static void __exit vhost_vdpa_exit(void)
{
	vdpa_unregister_driver(&vhost_vdpa_driver);
+	class_destroy(vhost_vdpa_class);