It's not clear to me why only the frontend has been tristate. Switch the
backend to be, too.

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -214,7 +214,7 @@ config XEN_PVCALLS_FRONTEND
 	  implements them.
 
 config XEN_PVCALLS_BACKEND
-	bool "XEN PV Calls backend driver"
+	tristate "XEN PV Calls backend driver"
 	depends on INET && XEN && XEN_BACKEND
 	help
 	  Experimental backend for the Xen PV Calls protocol

On Tue, 7 Sep 2021, Jan Beulich wrote:
> It's not clear to me why only the frontend has been tristate. Switch the
> backend to be, too.
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Actually although the frontend is a tristate, it cannot really work as a
module. Specifically see pvcalls_stream_ops in the enabling patch (still
not upstream):

https://github.com/lf-edge/runx/blob/master/kernel/patches/0001-patch-pvcalls_enable.patch


So I had to change tristate to bool for XEN_PVCALLS_FRONTEND in our
internal kernel tree.

That said, the PVCalls backend could very well be a module and
technically I don't see any reasons why not. So:


Acked-by: Stefano Stabellini <sstabellini@kernel.org>



> --- a/drivers/xen/Kconfig
> +++ b/drivers/xen/Kconfig
> @@ -214,7 +214,7 @@ config XEN_PVCALLS_FRONTEND
>  	  implements them.
>  
>  config XEN_PVCALLS_BACKEND
> -	bool "XEN PV Calls backend driver"
> +	tristate "XEN PV Calls backend driver"
>  	depends on INET && XEN && XEN_BACKEND
>  	help
>  	  Experimental backend for the Xen PV Calls protocol
> 

On 07.09.21 14:17, Jan Beulich wrote:
> It's not clear to me why only the frontend has been tristate. Switch the
> backend to be, too.
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Pushed to xen/tip.git for-linus-5.15


Juergen