diff mbox series

vdpa: regist vhost-vdpa dev class

Message ID 20211223073145.35363-1-wang.yi59@zte.com.cn (mailing list archive)
State New, archived
Headers show
Series vdpa: regist vhost-vdpa dev class | expand

Commit Message

Yi Wang Dec. 23, 2021, 7:31 a.m. UTC 
From: Zhang Min <zhang.min9@zte.com.cn>

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 <zhang.min9@zte.com.cn>
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
---
 drivers/vhost/vdpa.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

Comments

Stefano Garzarella Dec. 23, 2021, 10:59 a.m. UTC | #1 
On Thu, Dec 23, 2021 at 03:31:45PM +0800, Yi Wang wrote:
>From: Zhang Min <zhang.min9@zte.com.cn>
>
>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 <zhang.min9@zte.com.cn>
>Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
>---
> 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;
   ^
Maybe is better to move this declaration on top, near `static dev_t 
vhost_vdpa_major;`

> 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);
                                                           ^
double space.

I'm not a native speaker, but I would rephrase the second part to "maybe 
the module is already loaded"

>+		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);

Should we set `vhost_vdpa_class` to NULL here?

If yes, maybe better to add a new label, and a goto in the 
`class_create` error handling.

> 	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);

I would move it after unregister_chrdev_region() to have the reverse 
order of initialization (as we already rightly do in the error path of 
vhost_vdpa_init()).

Thanks,
Stefano

> 	unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX);
> }
> module_exit(vhost_vdpa_exit);
>-- 
>2.27.0
>_______________________________________________
>Virtualization mailing list
>Virtualization@lists.linux-foundation.org
>https://lists.linuxfoundation.org/mailman/listinfo/virtualization
>
Michael S. Tsirkin Dec. 23, 2021, 1:58 p.m. UTC | #2 
typo in subject

On Thu, Dec 23, 2021 at 03:31:45PM +0800, Yi Wang wrote:
> From: Zhang Min <zhang.min9@zte.com.cn>
> 
> 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 <zhang.min9@zte.com.cn>
> Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
> ---
>  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);

what's mod reinserted? why warn not error?

> +		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);
>  	unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX);
>  }
>  module_exit(vhost_vdpa_exit);
> -- 
> 2.27.0
Longpeng(Mike) Dec. 23, 2021, 3:53 p.m. UTC | #3 
> -----Original Message-----
> From: Yi Wang [mailto:wang.yi59@zte.com.cn]
> Sent: Thursday, December 23, 2021 3:32 PM
> To: mst@redhat.com
> Cc: jasowang@redhat.com; kvm@vger.kernel.org;
> virtualization@lists.linux-foundation.org; netdev@vger.kernel.org;
> linux-kernel@vger.kernel.org; xue.zhihong@zte.com.cn; wang.yi59@zte.com.cn;
> wang.liang82@zte.com.cn; Zhang Min <zhang.min9@zte.com.cn>
> Subject: [PATCH] vdpa: regist vhost-vdpa dev class
> 
> From: Zhang Min <zhang.min9@zte.com.cn>
> 
> 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/vi
> rtcontainers/device/config/config.go
> 
> Signed-off-by: Zhang Min <zhang.min9@zte.com.cn>
> Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
> ---
>  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;

Unnecessary to reset?

> +		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);
>  	unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX);
>  }
>  module_exit(vhost_vdpa_exit);
> --
> 2.27.0
Yi Wang Dec. 24, 2021, 7:02 a.m. UTC | #4 
Hi Stefano,

Thanks for your quick reply and review, :)

> On Thu, Dec 23, 2021 at 03:31:45PM +0800, Yi Wang wrote:
> >From: Zhang Min <zhang.min9@zte.com.cn>
> >
> >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 <zhang.min9@zte.com.cn>
> >Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
> >---
> > 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

..

> >+    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);
>                                                            ^
> double space.
> 
> I'm not a native speaker, but I would rephrase the second part to "maybe 
> the module is already loaded"
> 
> >+        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);
> 
> Should we set `vhost_vdpa_class` to NULL here?
> 
> If yes, maybe better to add a new label, and a goto in the 
> `class_create` error handling.

Yes, reset to NULL is unnecessary, and pr_warn will not be reached when module
is already loaded, so it's no need too.
There will be a v2 patch which simply return PTR_ERR(vhost_vdpa_class);
Other suggestions are also accepted. 

> >     return r;
> > }
diff mbox series

Patch

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);
 	unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX);
 }
 module_exit(vhost_vdpa_exit);