[PATCH v2 03/16] s390/vfio-ap: Data structures for facilitating vfio device migration

Anthony Krowiak
2026-04-07T20:51:14Z

Creates the data structures used to facilitate state transitions during
vfio device migration.

Signed-off-by: Anthony Krowiak <akrowiak@linux.ibm.com>
---
drivers/s390/crypto/Makefile | 2 +-
drivers/s390/crypto/vfio_ap_migration.c | 68 +++++++++++++++++++++++++
drivers/s390/crypto/vfio_ap_private.h | 2 +
3 files changed, 71 insertions(+), 1 deletion(-)
create mode 100644 drivers/s390/crypto/vfio_ap_migration.c

diff --git a/drivers/s390/crypto/Makefile b/drivers/s390/crypto/Makefile
index e83c6603c858..20f29184825a 100644
--- a/drivers/s390/crypto/Makefile
+++ b/drivers/s390/crypto/Makefile
@@ -34,5 +34,5 @@ pkey-uv-objs := pkey_uv.o
obj-$(CONFIG_PKEY_UV) += pkey-uv.o

# adjunct processor matrix
-vfio_ap-objs := vfio_ap_drv.o vfio_ap_ops.o
+vfio_ap-objs := vfio_ap_drv.o vfio_ap_ops.o vfio_ap_migration.o
obj-$(CONFIG_VFIO_AP) += vfio_ap.o
diff --git a/drivers/s390/crypto/vfio_ap_migration.c b/drivers/s390/crypto/vfio_ap_migration.c
new file mode 100644
index 000000000000..2c5978dde61d
--- /dev/null
+++ b/drivers/s390/crypto/vfio_ap_migration.c
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Drives vfio_ap mdev migration.
+ *
+ * Copyright IBM Corp. 2025
+ */
+#include "uapi/linux/vfio_ap.h"
+
+#include "vfio_ap_private.h"
+
+/**
+ * vfio_ap_migration_data - the data needed to migrate a guest with pass-through
+ * access to AP devices
+ *
+ * @mig_state: the current migration state
+ * @resuming_migf: the object used to resume the target guest
+ * @saving_migf: the object used to save the state of the source guest
+ */
+struct vfio_ap_migration_data {
+ enum vfio_device_mig_state mig_state;
+ struct vfio_ap_migration_file *resuming_migf;
+ struct vfio_ap_migration_file *saving_migf;
+};
+
+/**
+ * vfio_ap_queue_info - the information for an AP queue
+ *
+ * @data: contains the queue information returned in GR2 from the PQAP(TAPQ)
+ * command
+ * @apqn: the APQN of the queue
+ */
+struct vfio_ap_queue_info {
+ u64 data;
+ u16 apqn;
+};
+
+/**
+ * vfio_ap_config - the guest's AP configuration
+ *
+ * @num_queues: the number of queues passed through to the guest
+ * @qinfo: an array of vfio_ap_queue_info objects, each specifying the
+ * queue information for a queue passed through to the guest
+ */
+struct vfio_ap_config {
+ unsigned int num_queues;
+ struct vfio_ap_queue_info qinfo[];
+};
+
+/**
+ * vfio_ap_migration_file - object used to facilitate migration of a guest with
+ * pass-through access to AP devices
+ *
+ * @matrix_mdev: the mediated device attached to the guest being migrated
+ * @filp: the file used to facilitate communication between userspace
+ * and the vfio_ap device driver during a particular phase of
+ * the migration
+ * @disabled: boolean value indicating whether this object is disabled (true)
+ * or not (false)
+ * @ap_config: the information for each queue passed through to a guest
+ * @config_sz: the size of @ap_config when filled with queue information
+ */
+struct vfio_ap_migration_file {
+ struct ap_matrix_mdev *matrix_mdev;
+ struct file *filp;
+ bool disabled;
+ struct vfio_ap_config *ap_config;
+ size_t config_sz;
+};
diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h
index d66586825ef4..a1bc50a59633 100644
--- a/drivers/s390/crypto/vfio_ap_private.h
+++ b/drivers/s390/crypto/vfio_ap_private.h
@@ -110,6 +110,7 @@ struct ap_queue_table {
* @aqm_add: bitmap of APQIs added to the host's AP configuration
* @adm_add: bitmap of control domain numbers added to the host's AP
* configuration
+ * @mig_data: vfio device migration data
*/
struct ap_matrix_mdev {
struct vfio_device vdev;
@@ -125,6 +126,7 @@ struct ap_matrix_mdev {
DECLARE_BITMAP(apm_add, AP_DEVICES);
DECLARE_BITMAP(aqm_add, AP_DOMAINS);
DECLARE_BITMAP(adm_add, AP_DOMAINS);
+ void *mig_data;
};

/**
--
2.52.0