Re: [PATCH v2 2/2] vdpa: support exposing the count of vqs to userspace

[Jason Wang <jasowang@xxxxxxxxxx>]

在 2022/3/10 下午3:20, Longpeng(Mike) 写道:
> From: Longpeng <longpeng2@xxxxxxxxxx>
>
> - GET_VQS_COUNT: the count of virtqueues that exposed
>
> And change vdpa_device.nvqs and vhost_vdpa.nvqs to use u32.


Patch looks good, a nit is that we'd better use a separate patch for the 
u32 converting.

Thanks


> Signed-off-by: Longpeng <longpeng2@xxxxxxxxxx>
> ---
>   drivers/vdpa/vdpa.c        |  6 +++---
>   drivers/vhost/vdpa.c       | 23 +++++++++++++++++++----
>   include/linux/vdpa.h       |  6 +++---
>   include/uapi/linux/vhost.h |  3 +++
>   4 files changed, 28 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
> index 1ea5254..2b75c00 100644
> --- a/drivers/vdpa/vdpa.c
> +++ b/drivers/vdpa/vdpa.c
> @@ -232,7 +232,7 @@ static int vdpa_name_match(struct device *dev, const void *data)
>   	return (strcmp(dev_name(&vdev->dev), data) == 0);
>   }
>   
> -static int __vdpa_register_device(struct vdpa_device *vdev, int nvqs)
> +static int __vdpa_register_device(struct vdpa_device *vdev, u32 nvqs)
>   {
>   	struct device *dev;
>   
> @@ -257,7 +257,7 @@ static int __vdpa_register_device(struct vdpa_device *vdev, int nvqs)
>    *
>    * Return: Returns an error when fail to add device to vDPA bus
>    */
> -int _vdpa_register_device(struct vdpa_device *vdev, int nvqs)
> +int _vdpa_register_device(struct vdpa_device *vdev, u32 nvqs)
>   {
>   	if (!vdev->mdev)
>   		return -EINVAL;
> @@ -274,7 +274,7 @@ int _vdpa_register_device(struct vdpa_device *vdev, int nvqs)
>    *
>    * Return: Returns an error when fail to add to vDPA bus
>    */
> -int vdpa_register_device(struct vdpa_device *vdev, int nvqs)
> +int vdpa_register_device(struct vdpa_device *vdev, u32 nvqs)
>   {
>   	int err;
>   
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index 605c7ae..69b3f05 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -42,7 +42,7 @@ struct vhost_vdpa {
>   	struct device dev;
>   	struct cdev cdev;
>   	atomic_t opened;
> -	int nvqs;
> +	u32 nvqs;
>   	int virtio_id;
>   	int minor;
>   	struct eventfd_ctx *config_ctx;
> @@ -158,7 +158,8 @@ static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp)
>   	struct vdpa_device *vdpa = v->vdpa;
>   	const struct vdpa_config_ops *ops = vdpa->config;
>   	u8 status, status_old;
> -	int ret, nvqs = v->nvqs;
> +	u32 nvqs = v->nvqs;
> +	int ret;
>   	u16 i;
>   
>   	if (copy_from_user(&status, statusp, sizeof(status)))
> @@ -369,6 +370,16 @@ static long vhost_vdpa_get_config_size(struct vhost_vdpa *v, u32 __user *argp)
>   	return 0;
>   }
>   
> +static long vhost_vdpa_get_vqs_count(struct vhost_vdpa *v, u32 __user *argp)
> +{
> +	struct vdpa_device *vdpa = v->vdpa;
> +
> +	if (copy_to_user(argp, &vdpa->nvqs, sizeof(vdpa->nvqs)))
> +		return -EFAULT;
> +
> +	return 0;
> +}
> +
>   static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
>   				   void __user *argp)
>   {
> @@ -509,6 +520,9 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep,
>   	case VHOST_VDPA_GET_CONFIG_SIZE:
>   		r = vhost_vdpa_get_config_size(v, argp);
>   		break;
> +	case VHOST_VDPA_GET_VQS_COUNT:
> +		r = vhost_vdpa_get_vqs_count(v, argp);
> +		break;
>   	default:
>   		r = vhost_dev_ioctl(&v->vdev, cmd, argp);
>   		if (r == -ENOIOCTLCMD)
> @@ -965,7 +979,8 @@ static int vhost_vdpa_open(struct inode *inode, struct file *filep)
>   	struct vhost_vdpa *v;
>   	struct vhost_dev *dev;
>   	struct vhost_virtqueue **vqs;
> -	int nvqs, i, r, opened;
> +	int r, opened;
> +	u32 i, nvqs;
>   
>   	v = container_of(inode->i_cdev, struct vhost_vdpa, cdev);
>   
> @@ -1018,7 +1033,7 @@ static int vhost_vdpa_open(struct inode *inode, struct file *filep)
>   
>   static void vhost_vdpa_clean_irq(struct vhost_vdpa *v)
>   {
> -	int i;
> +	u32 i;
>   
>   	for (i = 0; i < v->nvqs; i++)
>   		vhost_vdpa_unsetup_vq_irq(v, i);
> diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
> index a526919..8943a20 100644
> --- a/include/linux/vdpa.h
> +++ b/include/linux/vdpa.h
> @@ -83,7 +83,7 @@ struct vdpa_device {
>   	unsigned int index;
>   	bool features_valid;
>   	bool use_va;
> -	int nvqs;
> +	u32 nvqs;
>   	struct vdpa_mgmt_dev *mdev;
>   };
>   
> @@ -338,10 +338,10 @@ struct vdpa_device *__vdpa_alloc_device(struct device *parent,
>   				       dev_struct, member)), name, use_va), \
>   				       dev_struct, member)
>   
> -int vdpa_register_device(struct vdpa_device *vdev, int nvqs);
> +int vdpa_register_device(struct vdpa_device *vdev, u32 nvqs);
>   void vdpa_unregister_device(struct vdpa_device *vdev);
>   
> -int _vdpa_register_device(struct vdpa_device *vdev, int nvqs);
> +int _vdpa_register_device(struct vdpa_device *vdev, u32 nvqs);
>   void _vdpa_unregister_device(struct vdpa_device *vdev);
>   
>   /**
> diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
> index bc74e95..5d99e7c 100644
> --- a/include/uapi/linux/vhost.h
> +++ b/include/uapi/linux/vhost.h
> @@ -154,4 +154,7 @@
>   /* Get the config size */
>   #define VHOST_VDPA_GET_CONFIG_SIZE	_IOR(VHOST_VIRTIO, 0x79, __u32)
>   
> +/* Get the count of all virtqueues */
> +#define VHOST_VDPA_GET_VQS_COUNT	_IOR(VHOST_VIRTIO, 0x80, __u32)
> +
>   #endif