Merge tag 'kvm-4.20-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Radim Krčmář:
 "ARM:
   - Improved guest IPA space support (32 to 52 bits)

   - RAS event delivery for 32bit

   - PMU fixes

   - Guest entry hardening

   - Various cleanups

   - Port of dirty_log_test selftest

  PPC:
   - Nested HV KVM support for radix guests on POWER9. The performance
     is much better than with PR KVM. Migration and arbitrary level of
     nesting is supported.

   - Disable nested HV-KVM on early POWER9 chips that need a particular
     hardware bug workaround

   - One VM per core mode to prevent potential data leaks

   - PCI pass-through optimization

   - merge ppc-kvm topic branch and kvm-ppc-fixes to get a better base

  s390:
   - Initial version of AP crypto virtualization via vfio-mdev

   - Improvement for vfio-ap

   - Set the host program identifier

   - Optimize page table locking

  x86:
   - Enable nested virtualization by default

   - Implement Hyper-V IPI hypercalls

   - Improve #PF and #DB handling

   - Allow guests to use Enlightened VMCS

   - Add migration selftests for VMCS and Enlightened VMCS

   - Allow coalesced PIO accesses

   - Add an option to perform nested VMCS host state consistency check
     through hardware

   - Automatic tuning of lapic_timer_advance_ns

   - Many fixes, minor improvements, and cleanups"

* tag 'kvm-4.20-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (204 commits)
  KVM/nVMX: Do not validate that posted_intr_desc_addr is page aligned
  Revert "kvm: x86: optimize dr6 restore"
  KVM: PPC: Optimize clearing TCEs for sparse tables
  x86/kvm/nVMX: tweak shadow fields
  selftests/kvm: add missing executables to .gitignore
  KVM: arm64: Safety check PSTATE when entering guest and handle IL
  KVM: PPC: Book3S HV: Don't use streamlined entry path on early POWER9 chips
  arm/arm64: KVM: Enable 32 bits kvm vcpu events support
  arm/arm64: KVM: Rename function kvm_arch_dev_ioctl_check_extension()
  KVM: arm64: Fix caching of host MDCR_EL2 value
  KVM: VMX: enable nested virtualization by default
  KVM/x86: Use 32bit xor to clear registers in svm.c
  kvm: x86: Introduce KVM_CAP_EXCEPTION_PAYLOAD
  kvm: vmx: Defer setting of DR6 until #DB delivery
  kvm: x86: Defer setting of CR2 until #PF delivery
  kvm: x86: Add payload operands to kvm_multiple_exception
  kvm: x86: Add exception payload fields to kvm_vcpu_events
  kvm: x86: Add has_payload and payload to kvm_queued_exception
  KVM: Documentation: Fix omission in struct kvm_vcpu_events
  KVM: selftests: add Enlightened VMCS test
  ...

4 files changed, 1188 insertions, 0 deletions

diff --git a/drivers/s390/crypto/Makefile b/drivers/s390/crypto/Makefile
index fd5e215c66b7..6ccd93d0b1cb 100644
--- a/drivers/s390/crypto/Makefile
+++ b/drivers/s390/crypto/Makefile
@@ -15,3 +15,7 @@ obj-$(CONFIG_ZCRYPT) += zcrypt_cex2c.o zcrypt_cex2a.o zcrypt_cex4.o
 # pkey kernel module
 pkey-objs := pkey_api.o
 obj-$(CONFIG_PKEY) += pkey.o
+
+# adjunct processor matrix
+vfio_ap-objs := vfio_ap_drv.o vfio_ap_ops.o
+obj-$(CONFIG_VFIO_AP) += vfio_ap.o
diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c
new file mode 100644
index 000000000000..7667b38728f0
--- /dev/null
+++ b/drivers/s390/crypto/vfio_ap_drv.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * VFIO based AP device driver
+ *
+ * Copyright IBM Corp. 2018
+ *
+ * Author(s): Tony Krowiak <akrowiak@linux.ibm.com>
+ */
+
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include "vfio_ap_private.h"
+
+#define VFIO_AP_ROOT_NAME "vfio_ap"
+#define VFIO_AP_DEV_TYPE_NAME "ap_matrix"
+#define VFIO_AP_DEV_NAME "matrix"
+
+MODULE_AUTHOR("IBM Corporation");
+MODULE_DESCRIPTION("VFIO AP device driver, Copyright IBM Corp. 2018");
+MODULE_LICENSE("GPL v2");
+
+static struct ap_driver vfio_ap_drv;
+
+static struct device_type vfio_ap_dev_type = {
+	.name = VFIO_AP_DEV_TYPE_NAME,
+};
+
+struct ap_matrix_dev *matrix_dev;
+
+/* Only type 10 adapters (CEX4 and later) are supported
+ * by the AP matrix device driver
+ */
+static struct ap_device_id ap_queue_ids[] = {
+	{ .dev_type = AP_DEVICE_TYPE_CEX4,
+	  .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
+	{ .dev_type = AP_DEVICE_TYPE_CEX5,
+	  .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
+	{ .dev_type = AP_DEVICE_TYPE_CEX6,
+	  .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
+	{ /* end of sibling */ },
+};
+
+MODULE_DEVICE_TABLE(vfio_ap, ap_queue_ids);
+
+static int vfio_ap_queue_dev_probe(struct ap_device *apdev)
+{
+	return 0;
+}
+
+static void vfio_ap_queue_dev_remove(struct ap_device *apdev)
+{
+	/* Nothing to do yet */
+}
+
+static void vfio_ap_matrix_dev_release(struct device *dev)
+{
+	struct ap_matrix_dev *matrix_dev = dev_get_drvdata(dev);
+
+	kfree(matrix_dev);
+}
+
+static int vfio_ap_matrix_dev_create(void)
+{
+	int ret;
+	struct device *root_device;
+
+	root_device = root_device_register(VFIO_AP_ROOT_NAME);
+	if (IS_ERR(root_device))
+		return PTR_ERR(root_device);
+
+	matrix_dev = kzalloc(sizeof(*matrix_dev), GFP_KERNEL);
+	if (!matrix_dev) {
+		ret = -ENOMEM;
+		goto matrix_alloc_err;
+	}
+
+	/* Fill in config info via PQAP(QCI), if available */
+	if (test_facility(12)) {
+		ret = ap_qci(&matrix_dev->info);
+		if (ret)
+			goto matrix_alloc_err;
+	}
+
+	mutex_init(&matrix_dev->lock);
+	INIT_LIST_HEAD(&matrix_dev->mdev_list);
+
+	matrix_dev->device.type = &vfio_ap_dev_type;
+	dev_set_name(&matrix_dev->device, "%s", VFIO_AP_DEV_NAME);
+	matrix_dev->device.parent = root_device;
+	matrix_dev->device.release = vfio_ap_matrix_dev_release;
+	matrix_dev->device.driver = &vfio_ap_drv.driver;
+
+	ret = device_register(&matrix_dev->device);
+	if (ret)
+		goto matrix_reg_err;
+
+	return 0;
+
+matrix_reg_err:
+	put_device(&matrix_dev->device);
+matrix_alloc_err:
+	root_device_unregister(root_device);
+
+	return ret;
+}
+
+static void vfio_ap_matrix_dev_destroy(void)
+{
+	device_unregister(&matrix_dev->device);
+	root_device_unregister(matrix_dev->device.parent);
+}
+
+static int __init vfio_ap_init(void)
+{
+	int ret;
+
+	/* If there are no AP instructions, there is nothing to pass through. */
+	if (!ap_instructions_available())
+		return -ENODEV;
+
+	ret = vfio_ap_matrix_dev_create();
+	if (ret)
+		return ret;
+
+	memset(&vfio_ap_drv, 0, sizeof(vfio_ap_drv));
+	vfio_ap_drv.probe = vfio_ap_queue_dev_probe;
+	vfio_ap_drv.remove = vfio_ap_queue_dev_remove;
+	vfio_ap_drv.ids = ap_queue_ids;
+
+	ret = ap_driver_register(&vfio_ap_drv, THIS_MODULE, VFIO_AP_DRV_NAME);
+	if (ret) {
+		vfio_ap_matrix_dev_destroy();
+		return ret;
+	}
+
+	ret = vfio_ap_mdev_register();
+	if (ret) {
+		ap_driver_unregister(&vfio_ap_drv);
+		vfio_ap_matrix_dev_destroy();
+
+		return ret;
+	}
+
+	return 0;
+}
+
+static void __exit vfio_ap_exit(void)
+{
+	vfio_ap_mdev_unregister();
+	ap_driver_unregister(&vfio_ap_drv);
+	vfio_ap_matrix_dev_destroy();
+}
+
+module_init(vfio_ap_init);
+module_exit(vfio_ap_exit);
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
new file mode 100644
index 000000000000..272ef427dcc0
--- /dev/null
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -0,0 +1,939 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Adjunct processor matrix VFIO device driver callbacks.
+ *
+ * Copyright IBM Corp. 2018
+ *
+ * Author(s): Tony Krowiak <akrowiak@linux.ibm.com>
+ *	      Halil Pasic <pasic@linux.ibm.com>
+ *	      Pierre Morel <pmorel@linux.ibm.com>
+ */
+#include <linux/string.h>
+#include <linux/vfio.h>
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/ctype.h>
+#include <linux/bitops.h>
+#include <linux/kvm_host.h>
+#include <linux/module.h>
+#include <asm/kvm.h>
+#include <asm/zcrypt.h>
+
+#include "vfio_ap_private.h"
+
+#define VFIO_AP_MDEV_TYPE_HWVIRT "passthrough"
+#define VFIO_AP_MDEV_NAME_HWVIRT "VFIO AP Passthrough Device"
+
+static void vfio_ap_matrix_init(struct ap_config_info *info,
+				struct ap_matrix *matrix)
+{
+	matrix->apm_max = info->apxa ? info->Na : 63;
+	matrix->aqm_max = info->apxa ? info->Nd : 15;
+	matrix->adm_max = info->apxa ? info->Nd : 15;
+}
+
+static int vfio_ap_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
+{
+	struct ap_matrix_mdev *matrix_mdev;
+
+	if ((atomic_dec_if_positive(&matrix_dev->available_instances) < 0))
+		return -EPERM;
+
+	matrix_mdev = kzalloc(sizeof(*matrix_mdev), GFP_KERNEL);
+	if (!matrix_mdev) {
+		atomic_inc(&matrix_dev->available_instances);
+		return -ENOMEM;
+	}
+
+	vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->matrix);
+	mdev_set_drvdata(mdev, matrix_mdev);
+	mutex_lock(&matrix_dev->lock);
+	list_add(&matrix_mdev->node, &matrix_dev->mdev_list);
+	mutex_unlock(&matrix_dev->lock);
+
+	return 0;
+}
+
+static int vfio_ap_mdev_remove(struct mdev_device *mdev)
+{
+	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+
+	if (matrix_mdev->kvm)
+		return -EBUSY;
+
+	mutex_lock(&matrix_dev->lock);
+	list_del(&matrix_mdev->node);
+	mutex_unlock(&matrix_dev->lock);
+
+	kfree(matrix_mdev);
+	mdev_set_drvdata(mdev, NULL);
+	atomic_inc(&matrix_dev->available_instances);
+
+	return 0;
+}
+
+static ssize_t name_show(struct kobject *kobj, struct device *dev, char *buf)
+{
+	return sprintf(buf, "%s\n", VFIO_AP_MDEV_NAME_HWVIRT);
+}
+
+static MDEV_TYPE_ATTR_RO(name);
+
+static ssize_t available_instances_show(struct kobject *kobj,
+					struct device *dev, char *buf)
+{
+	return sprintf(buf, "%d\n",
+		       atomic_read(&matrix_dev->available_instances));
+}
+
+static MDEV_TYPE_ATTR_RO(available_instances);
+
+static ssize_t device_api_show(struct kobject *kobj, struct device *dev,
+			       char *buf)
+{
+	return sprintf(buf, "%s\n", VFIO_DEVICE_API_AP_STRING);
+}
+
+static MDEV_TYPE_ATTR_RO(device_api);
+
+static struct attribute *vfio_ap_mdev_type_attrs[] = {
+	&mdev_type_attr_name.attr,
+	&mdev_type_attr_device_api.attr,
+	&mdev_type_attr_available_instances.attr,
+	NULL,
+};
+
+static struct attribute_group vfio_ap_mdev_hwvirt_type_group = {
+	.name = VFIO_AP_MDEV_TYPE_HWVIRT,
+	.attrs = vfio_ap_mdev_type_attrs,
+};
+
+static struct attribute_group *vfio_ap_mdev_type_groups[] = {
+	&vfio_ap_mdev_hwvirt_type_group,
+	NULL,
+};
+
+struct vfio_ap_queue_reserved {
+	unsigned long *apid;
+	unsigned long *apqi;
+	bool reserved;
+};
+
+/**
+ * vfio_ap_has_queue
+ *
+ * @dev: an AP queue device
+ * @data: a struct vfio_ap_queue_reserved reference
+ *
+ * Flags whether the AP queue device (@dev) has a queue ID containing the APQN,
+ * apid or apqi specified in @data:
+ *
+ * - If @data contains both an apid and apqi value, then @data will be flagged
+ *   as reserved if the APID and APQI fields for the AP queue device matches
+ *
+ * - If @data contains only an apid value, @data will be flagged as
+ *   reserved if the APID field in the AP queue device matches
+ *
+ * - If @data contains only an apqi value, @data will be flagged as
+ *   reserved if the APQI field in the AP queue device matches
+ *
+ * Returns 0 to indicate the input to function succeeded. Returns -EINVAL if
+ * @data does not contain either an apid or apqi.
+ */
+static int vfio_ap_has_queue(struct device *dev, void *data)
+{
+	struct vfio_ap_queue_reserved *qres = data;
+	struct ap_queue *ap_queue = to_ap_queue(dev);
+	ap_qid_t qid;
+	unsigned long id;
+
+	if (qres->apid && qres->apqi) {
+		qid = AP_MKQID(*qres->apid, *qres->apqi);
+		if (qid == ap_queue->qid)
+			qres->reserved = true;
+	} else if (qres->apid && !qres->apqi) {
+		id = AP_QID_CARD(ap_queue->qid);
+		if (id == *qres->apid)
+			qres->reserved = true;
+	} else if (!qres->apid && qres->apqi) {
+		id = AP_QID_QUEUE(ap_queue->qid);
+		if (id == *qres->apqi)
+			qres->reserved = true;
+	} else {
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * vfio_ap_verify_queue_reserved
+ *
+ * @matrix_dev: a mediated matrix device
+ * @apid: an AP adapter ID
+ * @apqi: an AP queue index
+ *
+ * Verifies that the AP queue with @apid/@apqi is reserved by the VFIO AP device
+ * driver according to the following rules:
+ *
+ * - If both @apid and @apqi are not NULL, then there must be an AP queue
+ *   device bound to the vfio_ap driver with the APQN identified by @apid and
+ *   @apqi
+ *
+ * - If only @apid is not NULL, then there must be an AP queue device bound
+ *   to the vfio_ap driver with an APQN containing @apid
+ *
+ * - If only @apqi is not NULL, then there must be an AP queue device bound
+ *   to the vfio_ap driver with an APQN containing @apqi
+ *
+ * Returns 0 if the AP queue is reserved; otherwise, returns -EADDRNOTAVAIL.
+ */
+static int vfio_ap_verify_queue_reserved(unsigned long *apid,
+					 unsigned long *apqi)
+{
+	int ret;
+	struct vfio_ap_queue_reserved qres;
+
+	qres.apid = apid;
+	qres.apqi = apqi;
+	qres.reserved = false;
+
+	ret = driver_for_each_device(matrix_dev->device.driver, NULL, &qres,
+				     vfio_ap_has_queue);
+	if (ret)
+		return ret;
+
+	if (qres.reserved)
+		return 0;
+
+	return -EADDRNOTAVAIL;
+}
+
+static int
+vfio_ap_mdev_verify_queues_reserved_for_apid(struct ap_matrix_mdev *matrix_mdev,
+					     unsigned long apid)
+{
+	int ret;
+	unsigned long apqi;
+	unsigned long nbits = matrix_mdev->matrix.aqm_max + 1;
+
+	if (find_first_bit_inv(matrix_mdev->matrix.aqm, nbits) >= nbits)
+		return vfio_ap_verify_queue_reserved(&apid, NULL);
+
+	for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm, nbits) {
+		ret = vfio_ap_verify_queue_reserved(&apid, &apqi);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * vfio_ap_mdev_verify_no_sharing
+ *
+ * Verifies that the APQNs derived from the cross product of the AP adapter IDs
+ * and AP queue indexes comprising the AP matrix are not configured for another
+ * mediated device. AP queue sharing is not allowed.
+ *
+ * @matrix_mdev: the mediated matrix device
+ *
+ * Returns 0 if the APQNs are not shared, otherwise; returns -EADDRINUSE.
+ */
+static int vfio_ap_mdev_verify_no_sharing(struct ap_matrix_mdev *matrix_mdev)
+{
+	struct ap_matrix_mdev *lstdev;
+	DECLARE_BITMAP(apm, AP_DEVICES);
+	DECLARE_BITMAP(aqm, AP_DOMAINS);
+
+	list_for_each_entry(lstdev, &matrix_dev->mdev_list, node) {
+		if (matrix_mdev == lstdev)
+			continue;
+
+		memset(apm, 0, sizeof(apm));
+		memset(aqm, 0, sizeof(aqm));
+
+		/*
+		 * We work on full longs, as we can only exclude the leftover
+		 * bits in non-inverse order. The leftover is all zeros.
+		 */
+		if (!bitmap_and(apm, matrix_mdev->matrix.apm,
+				lstdev->matrix.apm, AP_DEVICES))
+			continue;
+
+		if (!bitmap_and(aqm, matrix_mdev->matrix.aqm,
+				lstdev->matrix.aqm, AP_DOMAINS))
+			continue;
+
+		return -EADDRINUSE;
+	}
+
+	return 0;
+}
+
+/**
+ * assign_adapter_store
+ *
+ * @dev:	the matrix device
+ * @attr:	the mediated matrix device's assign_adapter attribute
+ * @buf:	a buffer containing the AP adapter number (APID) to
+ *		be assigned
+ * @count:	the number of bytes in @buf
+ *
+ * Parses the APID from @buf and sets the corresponding bit in the mediated
+ * matrix device's APM.
+ *
+ * Returns the number of bytes processed if the APID is valid; otherwise,
+ * returns one of the following errors:
+ *
+ *	1. -EINVAL
+ *	   The APID is not a valid number
+ *
+ *	2. -ENODEV
+ *	   The APID exceeds the maximum value configured for the system
+ *
+ *	3. -EADDRNOTAVAIL
+ *	   An APQN derived from the cross product of the APID being assigned
+ *	   and the APQIs previously assigned is not bound to the vfio_ap device
+ *	   driver; or, if no APQIs have yet been assigned, the APID is not
+ *	   contained in an APQN bound to the vfio_ap device driver.
+ *
+ *	4. -EADDRINUSE
+ *	   An APQN derived from the cross product of the APID being assigned
+ *	   and the APQIs previously assigned is being used by another mediated
+ *	   matrix device
+ */
+static ssize_t assign_adapter_store(struct device *dev,
+				    struct device_attribute *attr,
+				    const char *buf, size_t count)
+{
+	int ret;
+	unsigned long apid;
+	struct mdev_device *mdev = mdev_from_dev(dev);
+	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+
+	/* If the guest is running, disallow assignment of adapter */
+	if (matrix_mdev->kvm)
+		return -EBUSY;
+
+	ret = kstrtoul(buf, 0, &apid);
+	if (ret)
+		return ret;
+
+	if (apid > matrix_mdev->matrix.apm_max)
+		return -ENODEV;
+
+	/*
+	 * Set the bit in the AP mask (APM) corresponding to the AP adapter
+	 * number (APID). The bits in the mask, from most significant to least
+	 * significant bit, correspond to APIDs 0-255.
+	 */
+	mutex_lock(&matrix_dev->lock);
+
+	ret = vfio_ap_mdev_verify_queues_reserved_for_apid(matrix_mdev, apid);
+	if (ret)
+		goto done;
+
+	set_bit_inv(apid, matrix_mdev->matrix.apm);
+
+	ret = vfio_ap_mdev_verify_no_sharing(matrix_mdev);
+	if (ret)
+		goto share_err;
+
+	ret = count;
+	goto done;
+
+share_err:
+	clear_bit_inv(apid, matrix_mdev->matrix.apm);
+done:
+	mutex_unlock(&matrix_dev->lock);
+
+	return ret;
+}
+static DEVICE_ATTR_WO(assign_adapter);
+
+/**
+ * unassign_adapter_store
+ *
+ * @dev:	the matrix device
+ * @attr:	the mediated matrix device's unassign_adapter attribute
+ * @buf:	a buffer containing the adapter number (APID) to be unassigned
+ * @count:	the number of bytes in @buf
+ *
+ * Parses the APID from @buf and clears the corresponding bit in the mediated
+ * matrix device's APM.
+ *
+ * Returns the number of bytes processed if the APID is valid; otherwise,
+ * returns one of the following errors:
+ *	-EINVAL if the APID is not a number
+ *	-ENODEV if the APID it exceeds the maximum value configured for the
+ *		system
+ */
+static ssize_t unassign_adapter_store(struct device *dev,
+				      struct device_attribute *attr,
+				      const char *buf, size_t count)
+{
+	int ret;
+	unsigned long apid;
+	struct mdev_device *mdev = mdev_from_dev(dev);
+	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+
+	/* If the guest is running, disallow un-assignment of adapter */
+	if (matrix_mdev->kvm)
+		return -EBUSY;
+
+	ret = kstrtoul(buf, 0, &apid);
+	if (ret)
+		return ret;
+
+	if (apid > matrix_mdev->matrix.apm_max)
+		return -ENODEV;
+
+	mutex_lock(&matrix_dev->lock);
+	clear_bit_inv((unsigned long)apid, matrix_mdev->matrix.apm);
+	mutex_unlock(&matrix_dev->lock);
+
+	return count;
+}
+static DEVICE_ATTR_WO(unassign_adapter);
+
+static int
+vfio_ap_mdev_verify_queues_reserved_for_apqi(struct ap_matrix_mdev *matrix_mdev,
+					     unsigned long apqi)
+{
+	int ret;
+	unsigned long apid;
+	unsigned long nbits = matrix_mdev->matrix.apm_max + 1;
+
+	if (find_first_bit_inv(matrix_mdev->matrix.apm, nbits) >= nbits)
+		return vfio_ap_verify_queue_reserved(NULL, &apqi);
+
+	for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, nbits) {
+		ret = vfio_ap_verify_queue_reserved(&apid, &apqi);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * assign_domain_store
+ *
+ * @dev:	the matrix device
+ * @attr:	the mediated matrix device's assign_domain attribute
+ * @buf:	a buffer containing the AP queue index (APQI) of the domain to
+ *		be assigned
+ * @count:	the number of bytes in @buf
+ *
+ * Parses the APQI from @buf and sets the corresponding bit in the mediated
+ * matrix device's AQM.
+ *
+ * Returns the number of bytes processed if the APQI is valid; otherwise returns
+ * one of the following errors:
+ *
+ *	1. -EINVAL
+ *	   The APQI is not a valid number
+ *
+ *	2. -ENODEV
+ *	   The APQI exceeds the maximum value configured for the system
+ *
+ *	3. -EADDRNOTAVAIL
+ *	   An APQN derived from the cross product of the APQI being assigned
+ *	   and the APIDs previously assigned is not bound to the vfio_ap device
+ *	   driver; or, if no APIDs have yet been assigned, the APQI is not
+ *	   contained in an APQN bound to the vfio_ap device driver.
+ *
+ *	4. -EADDRINUSE
+ *	   An APQN derived from the cross product of the APQI being assigned
+ *	   and the APIDs previously assigned is being used by another mediated
+ *	   matrix device
+ */
+static ssize_t assign_domain_store(struct device *dev,
+				   struct device_attribute *attr,
+				   const char *buf, size_t count)
+{
+	int ret;
+	unsigned long apqi;
+	struct mdev_device *mdev = mdev_from_dev(dev);
+	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+	unsigned long max_apqi = matrix_mdev->matrix.aqm_max;
+
+	/* If the guest is running, disallow assignment of domain */
+	if (matrix_mdev->kvm)
+		return -EBUSY;
+
+	ret = kstrtoul(buf, 0, &apqi);
+	if (ret)
+		return ret;
+	if (apqi > max_apqi)
+		return -ENODEV;
+
+	mutex_lock(&matrix_dev->lock);
+
+	ret = vfio_ap_mdev_verify_queues_reserved_for_apqi(matrix_mdev, apqi);
+	if (ret)
+		goto done;
+
+	set_bit_inv(apqi, matrix_mdev->matrix.aqm);
+
+	ret = vfio_ap_mdev_verify_no_sharing(matrix_mdev);
+	if (ret)
+		goto share_err;
+
+	ret = count;
+	goto done;
+
+share_err:
+	clear_bit_inv(apqi, matrix_mdev->matrix.aqm);
+done:
+	mutex_unlock(&matrix_dev->lock);
+
+	return ret;
+}
+static DEVICE_ATTR_WO(assign_domain);
+
+
+/**
+ * unassign_domain_store
+ *
+ * @dev:	the matrix device
+ * @attr:	the mediated matrix device's unassign_domain attribute
+ * @buf:	a buffer containing the AP queue index (APQI) of the domain to
+ *		be unassigned
+ * @count:	the number of bytes in @buf
+ *
+ * Parses the APQI from @buf and clears the corresponding bit in the
+ * mediated matrix device's AQM.
+ *
+ * Returns the number of bytes processed if the APQI is valid; otherwise,
+ * returns one of the following errors:
+ *	-EINVAL if the APQI is not a number
+ *	-ENODEV if the APQI exceeds the maximum value configured for the system
+ */
+static ssize_t unassign_domain_store(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf, size_t count)
+{
+	int ret;
+	unsigned long apqi;
+	struct mdev_device *mdev = mdev_from_dev(dev);
+	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+
+	/* If the guest is running, disallow un-assignment of domain */
+	if (matrix_mdev->kvm)
+		return -EBUSY;
+
+	ret = kstrtoul(buf, 0, &apqi);
+	if (ret)
+		return ret;
+
+	if (apqi > matrix_mdev->matrix.aqm_max)
+		return -ENODEV;
+
+	mutex_lock(&matrix_dev->lock);
+	clear_bit_inv((unsigned long)apqi, matrix_mdev->matrix.aqm);
+	mutex_unlock(&matrix_dev->lock);
+
+	return count;
+}
+static DEVICE_ATTR_WO(unassign_domain);
+
+/**
+ * assign_control_domain_store
+ *
+ * @dev:	the matrix device
+ * @attr:	the mediated matrix device's assign_control_domain attribute
+ * @buf:	a buffer containing the domain ID to be assigned
+ * @count:	the number of bytes in @buf
+ *
+ * Parses the domain ID from @buf and sets the corresponding bit in the mediated
+ * matrix device's ADM.
+ *
+ * Returns the number of bytes processed if the domain ID is valid; otherwise,
+ * returns one of the following errors:
+ *	-EINVAL if the ID is not a number
+ *	-ENODEV if the ID exceeds the maximum value configured for the system
+ */
+static ssize_t assign_control_domain_store(struct device *dev,
+					   struct device_attribute *attr,
+					   const char *buf, size_t count)
+{
+	int ret;
+	unsigned long id;
+	struct mdev_device *mdev = mdev_from_dev(dev);
+	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+
+	/* If the guest is running, disallow assignment of control domain */
+	if (matrix_mdev->kvm)
+		return -EBUSY;
+
+	ret = kstrtoul(buf, 0, &id);
+	if (ret)
+		return ret;
+
+	if (id > matrix_mdev->matrix.adm_max)
+		return -ENODEV;
+
+	/* Set the bit in the ADM (bitmask) corresponding to the AP control
+	 * domain number (id). The bits in the mask, from most significant to
+	 * least significant, correspond to IDs 0 up to the one less than the
+	 * number of control domains that can be assigned.
+	 */
+	mutex_lock(&matrix_dev->lock);
+	set_bit_inv(id, matrix_mdev->matrix.adm);
+	mutex_unlock(&matrix_dev->lock);
+
+	return count;
+}
+static DEVICE_ATTR_WO(assign_control_domain);
+
+/**
+ * unassign_control_domain_store
+ *
+ * @dev:	the matrix device
+ * @attr:	the mediated matrix device's unassign_control_domain attribute
+ * @buf:	a buffer containing the domain ID to be unassigned
+ * @count:	the number of bytes in @buf
+ *
+ * Parses the domain ID from @buf and clears the corresponding bit in the
+ * mediated matrix device's ADM.
+ *
+ * Returns the number of bytes processed if the domain ID is valid; otherwise,
+ * returns one of the following errors:
+ *	-EINVAL if the ID is not a number
+ *	-ENODEV if the ID exceeds the maximum value configured for the system
+ */
+static ssize_t unassign_control_domain_store(struct device *dev,
+					     struct device_attribute *attr,
+					     const char *buf, size_t count)
+{
+	int ret;
+	unsigned long domid;
+	struct mdev_device *mdev = mdev_from_dev(dev);
+	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+	unsigned long max_domid =  matrix_mdev->matrix.adm_max;
+
+	/* If the guest is running, disallow un-assignment of control domain */
+	if (matrix_mdev->kvm)
+		return -EBUSY;
+
+	ret = kstrtoul(buf, 0, &domid);
+	if (ret)
+		return ret;
+	if (domid > max_domid)
+		return -ENODEV;
+
+	mutex_lock(&matrix_dev->lock);
+	clear_bit_inv(domid, matrix_mdev->matrix.adm);
+	mutex_unlock(&matrix_dev->lock);
+
+	return count;
+}
+static DEVICE_ATTR_WO(unassign_control_domain);
+
+static ssize_t control_domains_show(struct device *dev,
+				    struct device_attribute *dev_attr,
+				    char *buf)
+{
+	unsigned long id;
+	int nchars = 0;
+	int n;
+	char *bufpos = buf;
+	struct mdev_device *mdev = mdev_from_dev(dev);
+	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+	unsigned long max_domid = matrix_mdev->matrix.adm_max;
+
+	mutex_lock(&matrix_dev->lock);
+	for_each_set_bit_inv(id, matrix_mdev->matrix.adm, max_domid + 1) {
+		n = sprintf(bufpos, "%04lx\n", id);
+		bufpos += n;
+		nchars += n;
+	}
+	mutex_unlock(&matrix_dev->lock);
+
+	return nchars;
+}
+static DEVICE_ATTR_RO(control_domains);
+
+static ssize_t matrix_show(struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	struct mdev_device *mdev = mdev_from_dev(dev);
+	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+	char *bufpos = buf;
+	unsigned long apid;
+	unsigned long apqi;
+	unsigned long apid1;
+	unsigned long apqi1;
+	unsigned long napm_bits = matrix_mdev->matrix.apm_max + 1;
+	unsigned long naqm_bits = matrix_mdev->matrix.aqm_max + 1;
+	int nchars = 0;
+	int n;
+
+	apid1 = find_first_bit_inv(matrix_mdev->matrix.apm, napm_bits);
+	apqi1 = find_first_bit_inv(matrix_mdev->matrix.aqm, naqm_bits);
+
+	mutex_lock(&matrix_dev->lock);
+
+	if ((apid1 < napm_bits) && (apqi1 < naqm_bits)) {
+		for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, napm_bits) {
+			for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm,
+					     naqm_bits) {
+				n = sprintf(bufpos, "%02lx.%04lx\n", apid,
+					    apqi);
+				bufpos += n;
+				nchars += n;
+			}
+		}
+	} else if (apid1 < napm_bits) {
+		for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, napm_bits) {
+			n = sprintf(bufpos, "%02lx.\n", apid);
+			bufpos += n;
+			nchars += n;
+		}
+	} else if (apqi1 < naqm_bits) {
+		for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm, naqm_bits) {
+			n = sprintf(bufpos, ".%04lx\n", apqi);
+			bufpos += n;
+			nchars += n;
+		}
+	}
+
+	mutex_unlock(&matrix_dev->lock);
+
+	return nchars;
+}
+static DEVICE_ATTR_RO(matrix);
+
+static struct attribute *vfio_ap_mdev_attrs[] = {
+	&dev_attr_assign_adapter.attr,
+	&dev_attr_unassign_adapter.attr,
+	&dev_attr_assign_domain.attr,
+	&dev_attr_unassign_domain.attr,
+	&dev_attr_assign_control_domain.attr,
+	&dev_attr_unassign_control_domain.attr,
+	&dev_attr_control_domains.attr,
+	&dev_attr_matrix.attr,
+	NULL,
+};
+
+static struct attribute_group vfio_ap_mdev_attr_group = {
+	.attrs = vfio_ap_mdev_attrs
+};
+
+static const struct attribute_group *vfio_ap_mdev_attr_groups[] = {
+	&vfio_ap_mdev_attr_group,
+	NULL
+};
+
+/**
+ * vfio_ap_mdev_set_kvm
+ *
+ * @matrix_mdev: a mediated matrix device
+ * @kvm: reference to KVM instance
+ *
+ * Verifies no other mediated matrix device has @kvm and sets a reference to
+ * it in @matrix_mdev->kvm.
+ *
+ * Return 0 if no other mediated matrix device has a reference to @kvm;
+ * otherwise, returns an -EPERM.
+ */
+static int vfio_ap_mdev_set_kvm(struct ap_matrix_mdev *matrix_mdev,
+				struct kvm *kvm)
+{
+	struct ap_matrix_mdev *m;
+
+	mutex_lock(&matrix_dev->lock);
+
+	list_for_each_entry(m, &matrix_dev->mdev_list, node) {
+		if ((m != matrix_mdev) && (m->kvm == kvm)) {
+			mutex_unlock(&matrix_dev->lock);
+			return -EPERM;
+		}
+	}
+
+	matrix_mdev->kvm = kvm;
+	mutex_unlock(&matrix_dev->lock);
+
+	return 0;
+}
+
+static int vfio_ap_mdev_group_notifier(struct notifier_block *nb,
+				       unsigned long action, void *data)
+{
+	int ret;
+	struct ap_matrix_mdev *matrix_mdev;
+
+	if (action != VFIO_GROUP_NOTIFY_SET_KVM)
+		return NOTIFY_OK;
+
+	matrix_mdev = container_of(nb, struct ap_matrix_mdev, group_notifier);
+
+	if (!data) {
+		matrix_mdev->kvm = NULL;
+		return NOTIFY_OK;
+	}
+
+	ret = vfio_ap_mdev_set_kvm(matrix_mdev, data);
+	if (ret)
+		return NOTIFY_DONE;
+
+	/* If there is no CRYCB pointer, then we can't copy the masks */
+	if (!matrix_mdev->kvm->arch.crypto.crycbd)
+		return NOTIFY_DONE;
+
+	kvm_arch_crypto_set_masks(matrix_mdev->kvm, matrix_mdev->matrix.apm,
+				  matrix_mdev->matrix.aqm,
+				  matrix_mdev->matrix.adm);
+
+	return NOTIFY_OK;
+}
+
+static int vfio_ap_mdev_reset_queue(unsigned int apid, unsigned int apqi,
+				    unsigned int retry)
+{
+	struct ap_queue_status status;
+
+	do {
+		status = ap_zapq(AP_MKQID(apid, apqi));
+		switch (status.response_code) {
+		case AP_RESPONSE_NORMAL:
+			return 0;
+		case AP_RESPONSE_RESET_IN_PROGRESS:
+		case AP_RESPONSE_BUSY:
+			msleep(20);
+			break;
+		default:
+			/* things are really broken, give up */
+			return -EIO;
+		}
+	} while (retry--);
+
+	return -EBUSY;
+}
+
+static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev)
+{
+	int ret;
+	int rc = 0;
+	unsigned long apid, apqi;
+	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+
+	for_each_set_bit_inv(apid, matrix_mdev->matrix.apm,
+			     matrix_mdev->matrix.apm_max + 1) {
+		for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm,
+				     matrix_mdev->matrix.aqm_max + 1) {
+			ret = vfio_ap_mdev_reset_queue(apid, apqi, 1);
+			/*
+			 * Regardless whether a queue turns out to be busy, or
+			 * is not operational, we need to continue resetting
+			 * the remaining queues.
+			 */
+			if (ret)
+				rc = ret;
+		}
+	}
+
+	return rc;
+}
+
+static int vfio_ap_mdev_open(struct mdev_device *mdev)
+{
+	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+	unsigned long events;
+	int ret;
+
+
+	if (!try_module_get(THIS_MODULE))
+		return -ENODEV;
+
+	matrix_mdev->group_notifier.notifier_call = vfio_ap_mdev_group_notifier;
+	events = VFIO_GROUP_NOTIFY_SET_KVM;
+
+	ret = vfio_register_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY,
+				     &events, &matrix_mdev->group_notifier);
+	if (ret) {
+		module_put(THIS_MODULE);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void vfio_ap_mdev_release(struct mdev_device *mdev)
+{
+	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+
+	if (matrix_mdev->kvm)
+		kvm_arch_crypto_clear_masks(matrix_mdev->kvm);
+
+	vfio_ap_mdev_reset_queues(mdev);
+	vfio_unregister_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY,
+				 &matrix_mdev->group_notifier);
+	matrix_mdev->kvm = NULL;
+	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)
+		return -EINVAL;
+
+	info.flags = VFIO_DEVICE_FLAGS_AP | VFIO_DEVICE_FLAGS_RESET;
+	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;
+	case VFIO_DEVICE_RESET:
+		ret = vfio_ap_mdev_reset_queues(mdev);
+		break;
+	default:
+		ret = -EOPNOTSUPP;
+		break;
+	}
+
+	return ret;
+}
+
+static const struct mdev_parent_ops vfio_ap_matrix_ops = {
+	.owner			= THIS_MODULE,
+	.supported_type_groups	= vfio_ap_mdev_type_groups,
+	.mdev_attr_groups	= vfio_ap_mdev_attr_groups,
+	.create			= vfio_ap_mdev_create,
+	.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(void)
+{
+	atomic_set(&matrix_dev->available_instances, MAX_ZDEV_ENTRIES_EXT);
+
+	return mdev_register_device(&matrix_dev->device, &vfio_ap_matrix_ops);
+}
+
+void vfio_ap_mdev_unregister(void)
+{
+	mdev_unregister_device(&matrix_dev->device);
+}
diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h
new file mode 100644
index 000000000000..5675492233c7
--- /dev/null
+++ b/drivers/s390/crypto/vfio_ap_private.h
@@ -0,0 +1,88 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Private data and functions for adjunct processor VFIO matrix driver.
+ *
+ * Author(s): Tony Krowiak <akrowiak@linux.ibm.com>
+ *	      Halil Pasic <pasic@linux.ibm.com>
+ *
+ * Copyright IBM Corp. 2018
+ */
+
+#ifndef _VFIO_AP_PRIVATE_H_
+#define _VFIO_AP_PRIVATE_H_
+
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/mdev.h>
+#include <linux/delay.h>
+#include <linux/mutex.h>
+
+#include "ap_bus.h"
+
+#define VFIO_AP_MODULE_NAME "vfio_ap"
+#define VFIO_AP_DRV_NAME "vfio_ap"
+
+/**
+ * ap_matrix_dev - the AP matrix device structure
+ * @device:	generic device structure associated with the AP matrix device
+ * @available_instances: number of mediated matrix devices that can be created
+ * @info:	the struct containing the output from the PQAP(QCI) instruction
+ * mdev_list:	the list of mediated matrix devices created
+ * lock:	mutex for locking the AP matrix device. This lock will be
+ *		taken every time we fiddle with state managed by the vfio_ap
+ *		driver, be it using @mdev_list or writing the state of a
+ *		single ap_matrix_mdev device. It's quite coarse but we don't
+ *		expect much contention.
+ */
+struct ap_matrix_dev {
+	struct device device;
+	atomic_t available_instances;
+	struct ap_config_info info;
+	struct list_head mdev_list;
+	struct mutex lock;
+};
+
+extern struct ap_matrix_dev *matrix_dev;
+
+/**
+ * The AP matrix is comprised of three bit masks identifying the adapters,
+ * queues (domains) and control domains that belong to an AP matrix. The bits i
+ * each mask, from least significant to most significant bit, correspond to IDs
+ * 0 to 255. When a bit is set, the corresponding ID belongs to the matrix.
+ *
+ * @apm_max: max adapter number in @apm
+ * @apm identifies the AP adapters in the matrix
+ * @aqm_max: max domain number in @aqm
+ * @aqm identifies the AP queues (domains) in the matrix
+ * @adm_max: max domain number in @adm
+ * @adm identifies the AP control domains in the matrix
+ */
+struct ap_matrix {
+	unsigned long apm_max;
+	DECLARE_BITMAP(apm, 256);
+	unsigned long aqm_max;
+	DECLARE_BITMAP(aqm, 256);
+	unsigned long adm_max;
+	DECLARE_BITMAP(adm, 256);
+};
+
+/**
+ * struct ap_matrix_mdev - the mediated matrix device structure
+ * @list:	allows the ap_matrix_mdev struct to be added to a list
+ * @matrix:	the adapters, usage domains and control domains assigned to the
+ *		mediated matrix device.
+ * @group_notifier: notifier block used for specifying callback function for
+ *		    handling the VFIO_GROUP_NOTIFY_SET_KVM event
+ * @kvm:	the struct holding guest's state
+ */
+struct ap_matrix_mdev {
+	struct list_head node;
+	struct ap_matrix matrix;
+	struct notifier_block group_notifier;
+	struct kvm *kvm;
+};
+
+extern int vfio_ap_mdev_register(void);
+extern void vfio_ap_mdev_unregister(void);
+
+#endif /* _VFIO_AP_PRIVATE_H_ */