Re: [Qemu-devel] [PATCH 2/2] virtio-ccw: assure be accesses for set-revision

[Thomas Huth <thuth@linux.vnet.ibm.com>]

On Wed, 11 Mar 2015 10:57:51 +0100
Cornelia Huck <cornelia.huck@de.ibm.com> wrote:

> All fields in structures transmitted by ccws are big endian; assure
> we handle them as such for the set-revision ccw as well.
> 
> Should be merged into "s390x/virtio-ccw: add virtio set-revision call".
> 
> CC: Thomas Huth <thuth@linux.vnet.ibm.com>
> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
> ---
>  hw/s390x/virtio-ccw.c | 15 +++++++++++++--
>  1 file changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
> index 60f8a14..a64f116 100644
> --- a/hw/s390x/virtio-ccw.c
> +++ b/hw/s390x/virtio-ccw.c
> @@ -687,7 +687,7 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
>          break;
>      case CCW_CMD_SET_VIRTIO_REV:
>          len = sizeof(revinfo);
> -        if (ccw.count < len || (check_len && ccw.count > len)) {
> +        if (ccw.count < sizeof(revinfo)) {
>              ret = -EINVAL;
>              break;
>          }
> @@ -695,7 +695,18 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
>              ret = -EFAULT;
>              break;
>          }
> -        cpu_physical_memory_read(ccw.cda, &revinfo, len);
> +        revinfo.revision = lduw_be_phys(&address_space_memory, ccw.cda);
> +        revinfo.length = lduw_be_phys(&address_space_memory,
> +                                   ccw.cda + sizeof(revinfo.revision));
> +        if (ccw.count < len + revinfo.length ||
> +            (check_len && ccw.count > len + revinfo.length)) {
> +            ret = -EINVAL;
> +            break;
> +        }
> +        /*
> +         * Once we start to support revisions with additional data, we'll
> +         * need to fetch it here. Nothing to do for now, though.
> +         */
>          if (dev->revision >= 0 ||
>              revinfo.revision > virtio_ccw_rev_max(dev)) {
>              ret = -ENOSYS;

Looks fine to me.

Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>