[PATCH v1 10/24] s390/vfio-ap: Data structures for facilitating vfio device migration

[Anthony Krowiak]

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

Signed-off-by: Anthony Krowiak <akrowiak@xxxxxxxxxxxxx>
---
 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 514de4a73678..24db7d32e41c 100644
--- a/drivers/s390/crypto/vfio_ap_private.h
+++ b/drivers/s390/crypto/vfio_ap_private.h
@@ -116,6 +116,7 @@ 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;
@@ -134,6 +135,7 @@ 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