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

[Tony Krowiak]

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);
 
-- 
1.7.1