Re: [PATCH v1 16/16] vfio/ccw: remove old IDA format restrictions

[Matthew Rosato <mjrosato@linux.ibm.com>]

On 11/21/22 4:40 PM, Eric Farman wrote:
> By this point, all the pieces are in place to properly support
> a 2K Format-2 IDAL, and to convert a guest Format-1 IDAL to
> the 2K Format-2 variety. Let's remove the fence that prohibits
> them, and allow a guest to submit them if desired.
> 
> Signed-off-by: Eric Farman <farman@linux.ibm.com>
> ---
>  Documentation/s390/vfio-ccw.rst | 4 ++--
>  drivers/s390/cio/vfio_ccw_cp.c  | 8 --------
>  2 files changed, 2 insertions(+), 10 deletions(-)
> 
> diff --git a/Documentation/s390/vfio-ccw.rst b/Documentation/s390/vfio-ccw.rst
> index ea928a3806f4..53375dc86213 100644
> --- a/Documentation/s390/vfio-ccw.rst
> +++ b/Documentation/s390/vfio-ccw.rst
> @@ -219,8 +219,8 @@ values may occur:
>    The operation was successful.
>  
>  ``-EOPNOTSUPP``
> -  The orb specified transport mode or an unidentified IDAW format, or the
> -  scsw specified a function other than the start function.
> +  The ORB specified transport mode, or the

Nit:  Drop unnecessary comma

Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>

> +  SCSW specified a function other than the start function.
>  
>  ``-EIO``
>    A request was issued while the device was not in a state ready to accept
> diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c
> index 3829c346583c..60e972042979 100644
> --- a/drivers/s390/cio/vfio_ccw_cp.c
> +++ b/drivers/s390/cio/vfio_ccw_cp.c
> @@ -372,14 +372,6 @@ static int ccwchain_calc_length(u64 iova, struct channel_program *cp)
>  	do {
>  		cnt++;
>  
> -		/*
> -		 * As we don't want to fail direct addressing even if the
> -		 * orb specified one of the unsupported formats, we defer
> -		 * checking for IDAWs in unsupported formats to here.
> -		 */
> -		if ((!cp->orb.cmd.c64 || cp->orb.cmd.i2k) && ccw_is_idal(ccw))
> -			return -EOPNOTSUPP;
> -
>  		/*
>  		 * We want to keep counting if the current CCW has the
>  		 * command-chaining flag enabled, or if it is a TIC CCW