Re: [RFC 02/10] vhost: add 3 commands for vhost-vdpa

[Jason Wang]

On Wed, Jan 5, 2022 at 8:59 AM Longpeng(Mike) <longpeng2@huawei.com> wrote:
>
> From: Longpeng <longpeng2@huawei.com>
>
> To support generic vdpa deivce, we need add the following ioctls:
> - GET_VECTORS_NUM: the count of vectors that supported

Does this mean MSI vectors? If yes, it looks like a layer violation:
vhost is transport independent.  And it reveals device implementation
details which block (cross vendor) migration.

Thanks

> - GET_CONFIG_SIZE: the size of the virtio config space
> - GET_VQS_NUM: the count of virtqueues that exported
>
> Signed-off-by: Longpeng <longpeng2@huawei.com>
> ---
>  linux-headers/linux/vhost.h | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/linux-headers/linux/vhost.h b/linux-headers/linux/vhost.h
> index c998860d7b..c5edd75d15 100644
> --- a/linux-headers/linux/vhost.h
> +++ b/linux-headers/linux/vhost.h
> @@ -150,4 +150,14 @@
>  /* Get the valid iova range */
>  #define VHOST_VDPA_GET_IOVA_RANGE      _IOR(VHOST_VIRTIO, 0x78, \
>                                              struct vhost_vdpa_iova_range)
> +
> +/* Get the number of vectors */
> +#define VHOST_VDPA_GET_VECTORS_NUM     _IOR(VHOST_VIRTIO, 0x79, int)
> +
> +/* Get the virtio config size */
> +#define VHOST_VDPA_GET_CONFIG_SIZE     _IOR(VHOST_VIRTIO, 0x80, int)
> +
> +/* Get the number of virtqueues */
> +#define VHOST_VDPA_GET_VQS_NUM         _IOR(VHOST_VIRTIO, 0x81, int)
> +
>  #endif
> --
> 2.23.0
>