Linux Virtualization - Sep 2020 - [PATCH v2 -next] vdpa: mlx5: change Kconfig depends to fix build errors

From: Randy Dunlap <rdunlap at infradead.org>

drivers/vdpa/mlx5/ uses vhost_iotlb*() interfaces, so add a dependency
on 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 at infradead.org>
Cc: "Michael S. Tsirkin" <mst at redhat.com>
Cc: Jason Wang <jasowang at redhat.com>
Cc: virtualization at lists.linux-foundation.org
Cc: Saeed Mahameed <saeedm at nvidia.com>
Cc: Leon Romanovsky <leonro at nvidia.com>
Cc: netdev at vger.kernel.org
---
v2: change from select to depends (Saeed)

 drivers/vdpa/Kconfig |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- linux-next-20200917.orig/drivers/vdpa/Kconfig
+++ linux-next-20200917/drivers/vdpa/Kconfig
@@ -31,7 +31,7 @@ config IFCVF
 
 config MLX5_VDPA
 	bool "MLX5 VDPA support library for ConnectX devices"
-	depends on MLX5_CORE
+	depends on VHOST && MLX5_CORE
 	default n
 	help
 	  Support library for Mellanox VDPA drivers. Provides code that is

On 2020/9/18 ??3:45, Randy Dunlap wrote:
> From: Randy Dunlap <rdunlap at infradead.org>
>
> drivers/vdpa/mlx5/ uses vhost_iotlb*() interfaces, so add a dependency
> on 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 at infradead.org>
> Cc: "Michael S. Tsirkin" <mst at redhat.com>
> Cc: Jason Wang <jasowang at redhat.com>
> Cc: virtualization at lists.linux-foundation.org
> Cc: Saeed Mahameed <saeedm at nvidia.com>
> Cc: Leon Romanovsky <leonro at nvidia.com>
> Cc: netdev at vger.kernel.org
> ---
> v2: change from select to depends (Saeed)
>
>   drivers/vdpa/Kconfig |    2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- linux-next-20200917.orig/drivers/vdpa/Kconfig
> +++ linux-next-20200917/drivers/vdpa/Kconfig
> @@ -31,7 +31,7 @@ config IFCVF
>   
>   config MLX5_VDPA
>   	bool "MLX5 VDPA support library for ConnectX devices"
> -	depends on MLX5_CORE
> +	depends on VHOST && MLX5_CORE

It looks to me that depending on VHOST is too heavyweight.

I guess what it really needs is VHOST_IOTLB. So we can use select 
VHOST_IOTLB here.

Thanks

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