Re: [PATCH v2] s390/vfio_ccw: Fix target addresses of TIC CCWs

[Heiko Carstens <hca@linux.ibm.com>]

On Fri, Jun 28, 2024 at 06:37:38PM +0200, Eric Farman wrote:
> The processing of a Transfer-In-Channel (TIC) CCW requires locating
> the target of the CCW in the channel program, and updating the
> address to reflect what will actually be sent to hardware.
> 
> An error exists where the 64-bit virtual address is truncated to
> 32-bits (variable "cda") when performing this math. Since s390
> addresses of that size are 31-bits, this leaves that additional
> bit enabled such that the resulting I/O triggers a channel
> program check. This shows up occasionally when booting a KVM
> guest from a passthrough DASD device:
...
> Fixes: bd36cfbbb9e1 ("s390/vfio_ccw_cp: use new address translation helpers")
> Signed-off-by: Eric Farman <farman@linux.ibm.com>
> ---
> 
> Notes:
>     v2:
>      - [HC] Fix dma32/int warning on make C=1
>      - [HC] Rename cda variable to offset
>      - [HC] Fix similar bug in cp_update_scsw()
>     v1: https://lore.kernel.org/r/20240627200740.373192-1-farman@linux.ibm.com/
> 
>  drivers/s390/cio/vfio_ccw_cp.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>