[RFC 14/19] KVM: s390: Connect the AP mediated matrix device to KVM

Tony Krowiak
2017-10-13T17:38:59Z

Registers a group notifier during the open of the mediated
device to get information on KVM presence through the
VFIO_GROUP_NOTIFY_SET_KVM event.

When notified, save the pointer to KVM inside mediated matrix device
structure.

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

diff --git a/drivers/s390/crypto/vfio_ap_matrix_ops.c b/drivers/s390/crypto/vfio_ap_matrix_ops.c
index 10a006c..fd36074 100644
--- a/drivers/s390/crypto/vfio_ap_matrix_ops.c
+++ b/drivers/s390/crypto/vfio_ap_matrix_ops.c
@@ -12,6 +12,9 @@
#include <linux/device.h>
#include <linux/list.h>
#include <linux/ctype.h>
+#include <linux/kvm_host.h>
+#include <linux/eventfd.h>
+#include <linux/notifier.h>

#include "vfio_ap_matrix_private.h"

@@ -24,6 +27,8 @@ struct ap_matrix_mdev {
struct mdev_device *mdev;
struct list_head node;
struct ap_config_masks masks;
+ struct notifier_block group_notifier;
+ struct kvm *kvm;
};

struct ap_matrix *matrix;
@@ -97,6 +102,41 @@ static int ap_matrix_mdev_remove(struct mdev_device *mdev)
return 0;
}

+static int ap_matrix_mdev_group_notifier(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct ap_matrix_mdev *matrix_mdev;
+
+ matrix_mdev = container_of(nb, struct ap_matrix_mdev, group_notifier);
+
+ if (action == VFIO_GROUP_NOTIFY_SET_KVM)
+ matrix_mdev->kvm = data;
+
+ return NOTIFY_OK;
+}
+
+static int ap_matrix_mdev_open(struct mdev_device *mdev)
+{
+ struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+ unsigned long events;
+ int ret;
+
+ matrix_mdev->group_notifier.notifier_call =
+ ap_matrix_mdev_group_notifier;
+ events = VFIO_GROUP_NOTIFY_SET_KVM;
+ ret = vfio_register_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY,
+ &events, &matrix_mdev->group_notifier);
+ return ret;
+}
+
+static void ap_matrix_mdev_release(struct mdev_device *mdev)
+{
+ struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+
+ vfio_unregister_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY,
+ &matrix_mdev->group_notifier);
+}
+
static ssize_t name_show(struct kobject *kobj, struct device *dev, char *buf)
{
return sprintf(buf, "%s\n", AP_MATRIX_MDEV_NAME_HWVIRT);
@@ -609,6 +649,9 @@ static DEVICE_ATTR(control_domains, 0644, ap_matrix_control_domains_show,
.mdev_attr_groups = ap_matrix_mdev_attr_groups,
.create = ap_matrix_mdev_create,
.remove = ap_matrix_mdev_remove,
+ .open = ap_matrix_mdev_open,
+ .release = ap_matrix_mdev_release,
+
};

int ap_matrix_mdev_register(struct ap_matrix *ap_matrix)
--
1.7.1