Re: [PATCH -next] vdpa: mlx5: select VHOST to fix build errors

[Saeed Mahameed <saeed@kernel.org>]

On Thu, 2020-09-17 at 11:58 -0700, Randy Dunlap wrote:
> From: Randy Dunlap <rdunlap@infradead.org>
> 
> drivers/vdpa/mlx5/ uses vhost_iotlb*() interfaces, so select
> VHOST to eliminate build errors.
> 
> ld: drivers/vdpa/mlx5/core/mr.o: in function `add_direct_chain':
> mr.c:(.text+0x106): undefined reference to `vhost_iotlb_itree_first'
> ld: mr.c:(.text+0x1cf): undefined reference to
> `vhost_iotlb_itree_next'
> ld: mr.c:(.text+0x30d): undefined reference to
> `vhost_iotlb_itree_first'
> ld: mr.c:(.text+0x3e8): undefined reference to
> `vhost_iotlb_itree_next'
> ld: drivers/vdpa/mlx5/core/mr.o: in function `_mlx5_vdpa_create_mr':
> mr.c:(.text+0x908): undefined reference to `vhost_iotlb_itree_first'
> ld: mr.c:(.text+0x9e6): undefined reference to
> `vhost_iotlb_itree_next'
> ld: drivers/vdpa/mlx5/core/mr.o: in function
> `mlx5_vdpa_handle_set_map':
> mr.c:(.text+0xf1d): undefined reference to `vhost_iotlb_itree_first'
> 
> Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>
> Cc: virtualization@lists.linux-foundation.org
> Cc: Saeed Mahameed <saeedm@nvidia.com>
> Cc: Leon Romanovsky <leonro@nvidia.com>
> Cc: netdev@vger.kernel.org
> ---
> Note: This patch may not be the right thing, but it fixes the build
> errors.
> 
>  drivers/vdpa/Kconfig |    1 +
>  1 file changed, 1 insertion(+)
> 
> --- linux-next-20200917.orig/drivers/vdpa/Kconfig
> +++ linux-next-20200917/drivers/vdpa/Kconfig
> @@ -32,6 +32,7 @@ config IFCVF
>  config MLX5_VDPA
>  	bool "MLX5 VDPA support library for ConnectX devices"
>  	depends on MLX5_CORE
> +	select VHOST

select keyword usually complicates things.
It is better if you add a dependency rather than forcing VHOST.
Just do:
depends on VHOST & MLX5_CORE

>  	default n
>  	help
>  	  Support library for Mellanox VDPA drivers. Provides code that
> is
>