Re: [RFC 2/3] vdpa: support exposing the count of vqs to userspace

Jason Wang
2022-01-18T03:14:17Z

在 2022/1/17 下午5:29, Longpeng(Mike) 写道:
> From: Longpeng <longpeng2@huawei.com>
>
> - GET_VQS_COUNT: the count of virtqueues that exposed
>
> Signed-off-by: Longpeng <longpeng2@huawei.com>
> ---
> drivers/vhost/vdpa.c | 13 +++++++++++++
> include/uapi/linux/vhost.h | 3 +++
> 2 files changed, 16 insertions(+)
>
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index 1eea14a4ea56..c1074278fc6b 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -369,6 +369,16 @@ 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;

While at it, I think it's better to change vdpa->nvqs to use u32?

Thanks

> +
> + 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 +519,9 @@ 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)
> diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
> index bc74e95a273a..5d99e7c242a2 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