[PATCH v4 01/15] s390/vfio-ap: Provide function to get the number of queues assigned to mdev

[Anthony Krowiak <akrowiak@linux.ibm.com>]

Provides a function that returns the number of queues that are or will be
passed through to a guest when the mdev is attached to a guest.

Signed-off-by: Anthony Krowiak <akrowiak@linux.ibm.com>
---
 drivers/s390/crypto/vfio_ap_ops.c     | 14 ++++++++++++++
 drivers/s390/crypto/vfio_ap_private.h |  2 ++
 2 files changed, 16 insertions(+)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 44b3a1dcc1b3..71d3e2c2e07c 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -2098,6 +2098,20 @@ static void vfio_ap_mdev_request(struct vfio_device *vdev, unsigned int count)
 	release_update_locks_for_mdev(matrix_mdev);
 }
 
+int vfio_ap_mdev_get_num_queues(struct ap_matrix *ap_matrix)
+{
+	unsigned long apid, apqi;
+	int num_queues = 0;
+
+	lockdep_assert_held(&matrix_dev->mdevs_lock);
+
+	for_each_set_bit_inv(apid, ap_matrix->apm, AP_DEVICES)
+		for_each_set_bit_inv(apqi, ap_matrix->aqm, AP_DOMAINS)
+			num_queues++;
+
+	return num_queues;
+}
+
 static int vfio_ap_mdev_get_device_info(unsigned long arg)
 {
 	unsigned long minsz;
diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h
index 9bff666b0b35..9677e49554d7 100644
--- a/drivers/s390/crypto/vfio_ap_private.h
+++ b/drivers/s390/crypto/vfio_ap_private.h
@@ -152,6 +152,8 @@ struct vfio_ap_queue {
 	struct work_struct reset_work;
 };
 
+int vfio_ap_mdev_get_num_queues(struct ap_matrix *ap_matrix);
+
 int vfio_ap_mdev_register(void);
 void vfio_ap_mdev_unregister(void);
 
-- 
2.53.0