Re: [Qemu-devel] [PATCH v3 4/5] 390x/css: introduce maximum data address checking

[Cornelia Huck <cohuck@redhat.com>]

On Tue, 19 Sep 2017 20:27:44 +0200
Halil Pasic <pasic@linux.vnet.ibm.com> wrote:

> The architecture mandates the addresses to be  accessed on the first
> indirection level (that is, the data addresses without IDA, and the
> (M)IDAW addresses with (M)IDA) to be checked against an CCW format
> dependent limit maximum address.  If a violation is detected, the storage
> access is not to be performed and a channel program check needs to be
> generated. As of today, we fail to do this check.
> 
> Let us stick even closer to the architecture specification.
> 
> Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
> ---
>  hw/s390x/css.c         | 10 ++++++++++
>  include/hw/s390x/css.h |  1 +
>  2 files changed, 11 insertions(+)
> 
> diff --git a/hw/s390x/css.c b/hw/s390x/css.c
> index 6b0cd8861b..2d37a9ddde 100644
> --- a/hw/s390x/css.c
> +++ b/hw/s390x/css.c
> @@ -795,6 +795,11 @@ static inline int cds_check_len(CcwDataStream *cds, int len)
>      return cds->flags & CDS_F_STREAM_BROKEN ? -EINVAL : len;
>  }
>  
> +static inline bool cds_ccw_addrs_ok(hwaddr addr, int len, bool ccw_fmt1)

cds_cda_limit_ok?

> +{
> +    return (addr + len) < (ccw_fmt1 ? (1UL << 31) : (1UL << 24));
> +}
> +
>  static int ccw_dstream_rw_noflags(CcwDataStream *cds, void *buff, int len,
>                                    CcwDataStreamOp op)
>  {

Looks good.