[PATCH v5 12/13] s390: vfio-ap: implement VFIO_DEVICE_GET_INFO ioctl

Tony Krowiak
2018-05-07T15:11:51Z

Introduces ioctl access to the VFIO AP Matrix device driver
by implementing the VFIO_DEVICE_GET_INFO ioctl. This ioctl
provides the VFIO AP Matrix device driver information to the
guest machine.

Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: Tony Krowiak <akrowiak@linux.vnet.ibm.com>
---
drivers/s390/crypto/vfio_ap_ops.c | 43 +++++++++++++++++++++++++++++++++++++
1 files changed, 43 insertions(+), 0 deletions(-)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 8866b0e..01a036f 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -113,6 +113,48 @@ static void vfio_ap_mdev_release(struct mdev_device *mdev)
module_put(THIS_MODULE);
}

+static int vfio_ap_mdev_get_device_info(unsigned long arg)
+{
+ unsigned long minsz;
+ struct vfio_device_info info;
+
+ minsz = offsetofend(struct vfio_device_info, num_irqs);
+
+ if (copy_from_user(&info, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if (info.argsz < minsz) {
+ pr_err("%s: Argument size %u less than min size %li",
+ VFIO_AP_MODULE_NAME, info.argsz, minsz);
+ return -EINVAL;
+ }
+
+ info.flags = VFIO_DEVICE_FLAGS_AP;
+ info.num_regions = 0;
+ info.num_irqs = 0;
+
+ return copy_to_user((void __user *)arg, &info, minsz);
+}
+
+static ssize_t vfio_ap_mdev_ioctl(struct mdev_device *mdev,
+ unsigned int cmd, unsigned long arg)
+{
+ int ret;
+
+ switch (cmd) {
+ case VFIO_DEVICE_GET_INFO:
+ ret = vfio_ap_mdev_get_device_info(arg);
+ break;
+ default:
+ pr_err("%s: ioctl command %d is not a supported command",
+ VFIO_AP_MODULE_NAME, cmd);
+ ret = -EOPNOTSUPP;
+ break;
+ }
+
+ return ret;
+}
+
static ssize_t name_show(struct kobject *kobj, struct device *dev, char *buf)
{
return sprintf(buf, "%s\n", VFIO_AP_MDEV_NAME_HWVIRT);
@@ -841,6 +883,7 @@ static ssize_t matrix_show(struct device *dev, struct device_attribute *attr,
.remove = vfio_ap_mdev_remove,
.open = vfio_ap_mdev_open,
.release = vfio_ap_mdev_release,
+ .ioctl = vfio_ap_mdev_ioctl,
};

int vfio_ap_mdev_register(struct ap_matrix *ap_matrix)
--
1.7.1