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

Martin Schwidefsky
2017-10-16T09:13:58Z

On Fri, 13 Oct 2017 13:38:58 -0400
Tony Krowiak <akrowiak@linux.vnet.ibm.com> wrote:

> The AP control domain being assigned to the mediated
> matrix driver must be assigned to the LPAR.
>
> Signed-off-by: Tony Krowiak <akrowiak@linux.vnet.ibm.com>
> ---
> 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.