Re: [qemu-s390x] [RFC 13/19] s390/zcrypt: validate control domain assignment

[Martin Schwidefsky]

On Fri, 13 Oct 2017 13:38:58 -0400
Tony Krowiak <address@hidden> wrote:

> The AP control domain being assigned to the mediated
> matrix driver must be assigned to the LPAR.
> 
> Signed-off-by: Tony Krowiak <address@hidden>
> ---
>  drivers/s390/crypto/vfio_ap_matrix_ops.c |   33 
> ++++++++++++++++++++++++++++++
>  1 files changed, 33 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/s390/crypto/vfio_ap_matrix_ops.c 
> b/drivers/s390/crypto/vfio_ap_matrix_ops.c
> index 2387916..10a006c 100644
> --- a/drivers/s390/crypto/vfio_ap_matrix_ops.c
> +++ b/drivers/s390/crypto/vfio_ap_matrix_ops.c
> @@ -469,12 +469,41 @@ static ssize_t ap_matrix_domains_show(struct device 
> *dev,
>  static DEVICE_ATTR(domains, 0644, ap_matrix_domains_show,
>                  NULL);
> 
> +static int
> +ap_matrix_validate_control_domains(struct ap_matrix_mdev *matrix_mdev,
> +                                unsigned long id)
> +{
> +     int ret;
> +     struct ap_config_info config;
> +
> +     memset(&config, 0, sizeof(config));
> +
> +     ret = ap_query_configuration(&config);
> +     if (ret == -EOPNOTSUPP)
> +             return 0;
> +
> +     if (ret) {
> +             pr_err("%s: query AP configuration failed with rc %d",
> +                    VFIO_AP_MATRIX_MODULE_NAME, ret);
> +             return ret;
> +     }
> +
> +     if (!test_bit_inv(id, (unsigned long *)config.adm)) {
> +             pr_err("%s: control domain %04lx is not installed on the lpar",
> +                    VFIO_AP_MATRIX_MODULE_NAME, id);
> +             return -ENODEV;
> +     }
> +
> +     return 0;
> +}
> +
>  static ssize_t ap_matrix_control_domain_assign(struct device *dev,
>                                              struct device_attribute *attr,
>                                              const char *buf, size_t count)
>  {
>       int ret;
>       unsigned int id;
> +
>       struct mdev_device *mdev = mdev_from_dev(dev);
>       struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
> 
> @@ -482,6 +511,10 @@ static ssize_t ap_matrix_control_domain_assign(struct 
> device *dev,
>       if (ret)
>               return ret;
> 
> +     ret = ap_matrix_validate_control_domains(matrix_mdev, id);
> +     if (ret)
> +             return ret;
> +
>       set_bit_inv((unsigned long)id,
>                   (unsigned long *)matrix_mdev->masks.adm);
> 

Is there a specific reason why patch #13 is separate from patch #12 that
introduces the domain assignment? The assignment code does not make much
sense with the check if the domain is assigned to the LPAR, no?

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.