Merge branch 'apv11' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kernelorgnext
diff --git a/Documentation/s390/vfio-ap.txt b/Documentation/s390/vfio-ap.txt
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+Introduction:
+============
+The Adjunct Processor (AP) facility is an IBM Z cryptographic facility comprised
+of three AP instructions and from 1 up to 256 PCIe cryptographic adapter cards.
+The AP devices provide cryptographic functions to all CPUs assigned to a
+linux system running in an IBM Z system LPAR.
+
+The AP adapter cards are exposed via the AP bus. The motivation for vfio-ap
+is to make AP cards available to KVM guests using the VFIO mediated device
+framework. This implementation relies considerably on the s390 virtualization
+facilities which do most of the hard work of providing direct access to AP
+devices.
+
+AP Architectural Overview:
+=========================
+To facilitate the comprehension of the design, let's start with some
+definitions:
+
+* AP adapter
+
+  An AP adapter is an IBM Z adapter card that can perform cryptographic
+  functions. There can be from 0 to 256 adapters assigned to an LPAR. Adapters
+  assigned to the LPAR in which a linux host is running will be available to
+  the linux host. Each adapter is identified by a number from 0 to 255; however,
+  the maximum adapter number is determined by machine model and/or adapter type.
+  When installed, an AP adapter is accessed by AP instructions executed by any
+  CPU.
+
+  The AP adapter cards are assigned to a given LPAR via the system's Activation
+  Profile which can be edited via the HMC. When the linux host system is IPL'd
+  in the LPAR, the AP bus detects the AP adapter cards assigned to the LPAR and
+  creates a sysfs device for each assigned adapter. For example, if AP adapters
+  4 and 10 (0x0a) are assigned to the LPAR, the AP bus will create the following
+  sysfs device entries:
+
+    /sys/devices/ap/card04
+    /sys/devices/ap/card0a
+
+  Symbolic links to these devices will also be created in the AP bus devices
+  sub-directory:
+
+    /sys/bus/ap/devices/[card04]
+    /sys/bus/ap/devices/[card04]
+
+* AP domain
+
+  An adapter is partitioned into domains. An adapter can hold up to 256 domains
+  depending upon the adapter type and hardware configuration. A domain is
+  identified by a number from 0 to 255; however, the maximum domain number is
+  determined by machine model and/or adapter type.. A domain can be thought of
+  as a set of hardware registers and memory used for processing AP commands. A
+  domain can be configured with a secure private key used for clear key
+  encryption. A domain is classified in one of two ways depending upon how it
+  may be accessed:
+
+    * Usage domains are domains that are targeted by an AP instruction to
+      process an AP command.
+
+    * Control domains are domains that are changed by an AP command sent to a
+      usage domain; for example, to set the secure private key for the control
+      domain.
+
+  The AP usage and control domains are assigned to a given LPAR via the system's
+  Activation Profile which can be edited via the HMC. When a linux host system
+  is IPL'd in the LPAR, the AP bus module detects the AP usage and control
+  domains assigned to the LPAR. The domain number of each usage domain and
+  adapter number of each AP adapter are combined to create AP queue devices
+  (see AP Queue section below). The domain number of each control domain will be
+  represented in a bitmask and stored in a sysfs file
+  /sys/bus/ap/ap_control_domain_mask. The bits in the mask, from most to least
+  significant bit, correspond to domains 0-255.
+
+* AP Queue
+
+  An AP queue is the means by which an AP command is sent to a usage domain
+  inside a specific adapter. An AP queue is identified by a tuple
+  comprised of an AP adapter ID (APID) and an AP queue index (APQI). The
+  APQI corresponds to a given usage domain number within the adapter. This tuple
+  forms an AP Queue Number (APQN) uniquely identifying an AP queue. AP
+  instructions include a field containing the APQN to identify the AP queue to
+  which the AP command is to be sent for processing.
+
+  The AP bus will create a sysfs device for each APQN that can be derived from
+  the cross product of the AP adapter and usage domain numbers detected when the
+  AP bus module is loaded. For example, if adapters 4 and 10 (0x0a) and usage
+  domains 6 and 71 (0x47) are assigned to the LPAR, the AP bus will create the
+  following sysfs entries:
+
+    /sys/devices/ap/card04/04.0006
+    /sys/devices/ap/card04/04.0047
+    /sys/devices/ap/card0a/0a.0006
+    /sys/devices/ap/card0a/0a.0047
+
+  The following symbolic links to these devices will be created in the AP bus
+  devices subdirectory:
+
+    /sys/bus/ap/devices/[04.0006]
+    /sys/bus/ap/devices/[04.0047]
+    /sys/bus/ap/devices/[0a.0006]
+    /sys/bus/ap/devices/[0a.0047]
+
+* AP Instructions:
+
+  There are three AP instructions:
+
+  * NQAP: to enqueue an AP command-request message to a queue
+  * DQAP: to dequeue an AP command-reply message from a queue
+  * PQAP: to administer the queues
+
+  AP instructions identify the domain that is targeted to process the AP
+  command; this must be one of the usage domains. An AP command may modify a
+  domain that is not one of the usage domains, but the modified domain
+  must be one of the control domains.
+
+AP and SIE:
+==========
+Let's now take a look at how AP instructions executed on a guest are interpreted
+by the hardware.
+
+A satellite control block called the Crypto Control Block (CRYCB) is attached to
+our main hardware virtualization control block. The CRYCB contains three fields
+to identify the adapters, usage domains and control domains assigned to the KVM
+guest:
+
+* The AP Mask (APM) field is a bit mask that identifies the AP adapters assigned
+  to the KVM guest. Each bit in the mask, from left to right (i.e. from most
+  significant to least significant bit in big endian order), corresponds to
+  an APID from 0-255. If a bit is set, the corresponding adapter is valid for
+  use by the KVM guest.
+
+* The AP Queue Mask (AQM) field is a bit mask identifying the AP usage domains
+  assigned to the KVM guest. Each bit in the mask, from left to right (i.e. from
+  most significant to least significant bit in big endian order), corresponds to
+  an AP queue index (APQI) from 0-255. If a bit is set, the corresponding queue
+  is valid for use by the KVM guest.
+
+* The AP Domain Mask field is a bit mask that identifies the AP control domains
+  assigned to the KVM guest. The ADM bit mask controls which domains can be
+  changed by an AP command-request message sent to a usage domain from the
+  guest. Each bit in the mask, from left to right (i.e. from most significant to
+  least significant bit in big endian order), corresponds to a domain from
+  0-255. If a bit is set, the corresponding domain can be modified by an AP
+  command-request message sent to a usage domain.
+
+If you recall from the description of an AP Queue, AP instructions include
+an APQN to identify the AP queue to which an AP command-request message is to be
+sent (NQAP and PQAP instructions), or from which a command-reply message is to
+be received (DQAP instruction). The validity of an APQN is defined by the matrix
+calculated from the APM and AQM; it is the cross product of all assigned adapter
+numbers (APM) with all assigned queue indexes (AQM). For example, if adapters 1
+and 2 and usage domains 5 and 6 are assigned to a guest, the APQNs (1,5), (1,6),
+(2,5) and (2,6) will be valid for the guest.
+
+The APQNs can provide secure key functionality - i.e., a private key is stored
+on the adapter card for each of its domains - so each APQN must be assigned to
+at most one guest or to the linux host.
+
+   Example 1: Valid configuration:
+   ------------------------------
+   Guest1: adapters 1,2  domains 5,6
+   Guest2: adapter  1,2  domain 7
+
+   This is valid because both guests have a unique set of APQNs:
+      Guest1 has APQNs (1,5), (1,6), (2,5), (2,6);
+      Guest2 has APQNs (1,7), (2,7)
+
+   Example 2: Valid configuration:
+   ------------------------------
+   Guest1: adapters 1,2 domains 5,6
+   Guest2: adapters 3,4 domains 5,6
+
+   This is also valid because both guests have a unique set of APQNs:
+      Guest1 has APQNs (1,5), (1,6), (2,5), (2,6);
+      Guest2 has APQNs (3,5), (3,6), (4,5), (4,6)
+
+   Example 3: Invalid configuration:
+   --------------------------------
+   Guest1: adapters 1,2  domains 5,6
+   Guest2: adapter  1    domains 6,7
+
+   This is an invalid configuration because both guests have access to
+   APQN (1,6).
+
+The Design:
+===========
+The design introduces three new objects:
+
+1. AP matrix device
+2. VFIO AP device driver (vfio_ap.ko)
+3. VFIO AP mediated matrix pass-through device
+
+The VFIO AP device driver
+-------------------------
+The VFIO AP (vfio_ap) device driver serves the following purposes:
+
+1. Provides the interfaces to secure APQNs for exclusive use of KVM guests.
+
+2. Sets up the VFIO mediated device interfaces to manage a mediated matrix
+   device and creates the sysfs interfaces for assigning adapters, usage
+   domains, and control domains comprising the matrix for a KVM guest.
+
+3. Configures the APM, AQM and ADM in the CRYCB referenced by a KVM guest's
+   SIE state description to grant the guest access to a matrix of AP devices
+
+Reserve APQNs for exclusive use of KVM guests
+---------------------------------------------
+The following block diagram illustrates the mechanism by which APQNs are
+reserved:
+
+                              +------------------+
+               7 remove       |                  |
+         +--------------------> cex4queue driver |
+         |                    |                  |
+         |                    +------------------+
+         |
+         |
+         |                    +------------------+          +-----------------+
+         |  5 register driver |                  | 3 create |                 |
+         |   +---------------->   Device core    +---------->  matrix device  |
+         |   |                |                  |          |                 |
+         |   |                +--------^---------+          +-----------------+
+         |   |                         |
+         |   |                         +-------------------+
+         |   | +-----------------------------------+       |
+         |   | |      4 register AP driver         |       | 2 register device
+         |   | |                                   |       |
++--------+---+-v---+                      +--------+-------+-+
+|                  |                      |                  |
+|      ap_bus      +--------------------- >  vfio_ap driver  |
+|                  |       8 probe        |                  |
++--------^---------+                      +--^--^------------+
+6 edit   |                                   |  |
+  apmask |     +-----------------------------+  | 9 mdev create
+  aqmask |     |           1 modprobe           |
++--------+-----+---+           +----------------+-+         +------------------+
+|                  |           |                  |8 create |     mediated     |
+|      admin       |           | VFIO device core |--------->     matrix       |
+|                  +           |                  |         |     device       |
++------+-+---------+           +--------^---------+         +--------^---------+
+       | |                              |                            |
+       | | 9 create vfio_ap-passthrough |                            |
+       | +------------------------------+                            |
+       +-------------------------------------------------------------+
+                   10  assign adapter/domain/control domain
+
+The process for reserving an AP queue for use by a KVM guest is:
+
+1. The administrator loads the vfio_ap device driver
+2. The vfio-ap driver during its initialization will register a single 'matrix'
+   device with the device core. This will serve as the parent device for
+   all mediated matrix devices used to configure an AP matrix for a guest.
+3. The /sys/devices/vfio_ap/matrix device is created by the device core
+4  The vfio_ap device driver will register with the AP bus for AP queue devices
+   of type 10 and higher (CEX4 and newer). The driver will provide the vfio_ap
+   driver's probe and remove callback interfaces. Devices older than CEX4 queues
+   are not supported to simplify the implementation by not needlessly
+   complicating the design by supporting older devices that will go out of
+   service in the relatively near future, and for which there are few older
+   systems around on which to test.
+5. The AP bus registers the vfio_ap device driver with the device core
+6. The administrator edits the AP adapter and queue masks to reserve AP queues
+   for use by the vfio_ap device driver.
+7. The AP bus removes the AP queues reserved for the vfio_ap driver from the
+   default zcrypt cex4queue driver.
+8. The AP bus probes the vfio_ap device driver to bind the queues reserved for
+   it.
+9. The administrator creates a passthrough type mediated matrix device to be
+   used by a guest
+10 The administrator assigns the adapters, usage domains and control domains
+   to be exclusively used by a guest.
+
+Set up the VFIO mediated device interfaces
+------------------------------------------
+The VFIO AP device driver utilizes the common interface of the VFIO mediated
+device core driver to:
+* Register an AP mediated bus driver to add a mediated matrix device to and
+  remove it from a VFIO group.
+* Create and destroy a mediated matrix device
+* Add a mediated matrix device to and remove it from the AP mediated bus driver
+* Add a mediated matrix device to and remove it from an IOMMU group
+
+The following high-level block diagram shows the main components and interfaces
+of the VFIO AP mediated matrix device driver:
+
+ +-------------+
+ |             |
+ | +---------+ | mdev_register_driver() +--------------+
+ | |  Mdev   | +<-----------------------+              |
+ | |  bus    | |                        | vfio_mdev.ko |
+ | | driver  | +----------------------->+              |<-> VFIO user
+ | +---------+ |    probe()/remove()    +--------------+    APIs
+ |             |
+ |  MDEV CORE  |
+ |   MODULE    |
+ |   mdev.ko   |
+ | +---------+ | mdev_register_device() +--------------+
+ | |Physical | +<-----------------------+              |
+ | | device  | |                        |  vfio_ap.ko  |<-> matrix
+ | |interface| +----------------------->+              |    device
+ | +---------+ |       callback         +--------------+
+ +-------------+
+
+During initialization of the vfio_ap module, the matrix device is registered
+with an 'mdev_parent_ops' structure that provides the sysfs attribute
+structures, mdev functions and callback interfaces for managing the mediated
+matrix device.
+
+* sysfs attribute structures:
+  * supported_type_groups
+    The VFIO mediated device framework supports creation of user-defined
+    mediated device types. These mediated device types are specified
+    via the 'supported_type_groups' structure when a device is registered
+    with the mediated device framework. The registration process creates the
+    sysfs structures for each mediated device type specified in the
+    'mdev_supported_types' sub-directory of the device being registered. Along
+    with the device type, the sysfs attributes of the mediated device type are
+    provided.
+
+    The VFIO AP device driver will register one mediated device type for
+    passthrough devices:
+      /sys/devices/vfio_ap/matrix/mdev_supported_types/vfio_ap-passthrough
+    Only the read-only attributes required by the VFIO mdev framework will
+    be provided:
+        ... name
+        ... device_api
+        ... available_instances
+        ... device_api
+        Where:
+        * name: specifies the name of the mediated device type
+        * device_api: the mediated device type's API
+        * available_instances: the number of mediated matrix passthrough devices
+                               that can be created
+        * device_api: specifies the VFIO API
+  * mdev_attr_groups
+    This attribute group identifies the user-defined sysfs attributes of the
+    mediated device. When a device is registered with the VFIO mediated device
+    framework, the sysfs attribute files identified in the 'mdev_attr_groups'
+    structure will be created in the mediated matrix device's directory. The
+    sysfs attributes for a mediated matrix device are:
+    * assign_adapter:
+    * unassign_adapter:
+      Write-only attributes for assigning/unassigning an AP adapter to/from the
+      mediated matrix device. To assign/unassign an adapter, the APID of the
+      adapter is echoed to the respective attribute file.
+    * assign_domain:
+    * unassign_domain:
+      Write-only attributes for assigning/unassigning an AP usage domain to/from
+      the mediated matrix device. To assign/unassign a domain, the domain
+      number of the the usage domain is echoed to the respective attribute
+      file.
+    * matrix:
+      A read-only file for displaying the APQNs derived from the cross product
+      of the adapter and domain numbers assigned to the mediated matrix device.
+    * assign_control_domain:
+    * unassign_control_domain:
+      Write-only attributes for assigning/unassigning an AP control domain
+      to/from the mediated matrix device. To assign/unassign a control domain,
+      the ID of the domain to be assigned/unassigned is echoed to the respective
+      attribute file.
+    * control_domains:
+      A read-only file for displaying the control domain numbers assigned to the
+      mediated matrix device.
+
+* functions:
+  * create:
+    allocates the ap_matrix_mdev structure used by the vfio_ap driver to:
+    * Store the reference to the KVM structure for the guest using the mdev
+    * Store the AP matrix configuration for the adapters, domains, and control
+      domains assigned via the corresponding sysfs attributes files
+  * remove:
+    deallocates the mediated matrix device's ap_matrix_mdev structure. This will
+    be allowed only if a running guest is not using the mdev.
+
+* callback interfaces
+  * open:
+    The vfio_ap driver uses this callback to register a
+    VFIO_GROUP_NOTIFY_SET_KVM notifier callback function for the mdev matrix
+    device. The open is invoked when QEMU connects the VFIO iommu group
+    for the mdev matrix device to the MDEV bus. Access to the KVM structure used
+    to configure the KVM guest is provided via this callback. The KVM structure,
+    is used to configure the guest's access to the AP matrix defined via the
+    mediated matrix device's sysfs attribute files.
+  * release:
+    unregisters the VFIO_GROUP_NOTIFY_SET_KVM notifier callback function for the
+    mdev matrix device and deconfigures the guest's AP matrix.
+
+Configure the APM, AQM and ADM in the CRYCB:
+-------------------------------------------
+Configuring the AP matrix for a KVM guest will be performed when the
+VFIO_GROUP_NOTIFY_SET_KVM notifier callback is invoked. The notifier
+function is called when QEMU connects to KVM. The guest's AP matrix is
+configured via it's CRYCB by:
+* Setting the bits in the APM corresponding to the APIDs assigned to the
+  mediated matrix device via its 'assign_adapter' interface.
+* Setting the bits in the AQM corresponding to the domains assigned to the
+  mediated matrix device via its 'assign_domain' interface.
+* Setting the bits in the ADM corresponding to the domain dIDs assigned to the
+  mediated matrix device via its 'assign_control_domains' interface.
+
+The CPU model features for AP
+-----------------------------
+The AP stack relies on the presence of the AP instructions as well as two
+facilities: The AP Facilities Test (APFT) facility; and the AP Query
+Configuration Information (QCI) facility. These features/facilities are made
+available to a KVM guest via the following CPU model features:
+
+1. ap: Indicates whether the AP instructions are installed on the guest. This
+   feature will be enabled by KVM only if the AP instructions are installed
+   on the host.
+
+2. apft: Indicates the APFT facility is available on the guest. This facility
+   can be made available to the guest only if it is available on the host (i.e.,
+   facility bit 15 is set).
+
+3. apqci: Indicates the AP QCI facility is available on the guest. This facility
+   can be made available to the guest only if it is available on the host (i.e.,
+   facility bit 12 is set).
+
+Note: If the user chooses to specify a CPU model different than the 'host'
+model to QEMU, the CPU model features and facilities need to be turned on
+explicitly; for example:
+
+     /usr/bin/qemu-system-s390x ... -cpu z13,ap=on,apqci=on,apft=on
+
+A guest can be precluded from using AP features/facilities by turning them off
+explicitly; for example:
+
+     /usr/bin/qemu-system-s390x ... -cpu host,ap=off,apqci=off,apft=off
+
+Note: If the APFT facility is turned off (apft=off) for the guest, the guest
+will not see any AP devices. The zcrypt device drivers that register for type 10
+and newer AP devices - i.e., the cex4card and cex4queue device drivers - need
+the APFT facility to ascertain the facilities installed on a given AP device. If
+the APFT facility is not installed on the guest, then the probe of device
+drivers will fail since only type 10 and newer devices can be configured for
+guest use.
+
+Example:
+=======
+Let's now provide an example to illustrate how KVM guests may be given
+access to AP facilities. For this example, we will show how to configure
+three guests such that executing the lszcrypt command on the guests would
+look like this:
+
+Guest1
+------
+CARD.DOMAIN TYPE  MODE
+------------------------------
+05          CEX5C CCA-Coproc
+05.0004     CEX5C CCA-Coproc
+05.00ab     CEX5C CCA-Coproc
+06          CEX5A Accelerator
+06.0004     CEX5A Accelerator
+06.00ab     CEX5C CCA-Coproc
+
+Guest2
+------
+CARD.DOMAIN TYPE  MODE
+------------------------------
+05          CEX5A Accelerator
+05.0047     CEX5A Accelerator
+05.00ff     CEX5A Accelerator
+
+Guest2
+------
+CARD.DOMAIN TYPE  MODE
+------------------------------
+06          CEX5A Accelerator
+06.0047     CEX5A Accelerator
+06.00ff     CEX5A Accelerator
+
+These are the steps:
+
+1. Install the vfio_ap module on the linux host. The dependency chain for the
+   vfio_ap module is:
+   * iommu
+   * s390
+   * zcrypt
+   * vfio
+   * vfio_mdev
+   * vfio_mdev_device
+   * KVM
+
+   To build the vfio_ap module, the kernel build must be configured with the
+   following Kconfig elements selected:
+   * IOMMU_SUPPORT
+   * S390
+   * ZCRYPT
+   * S390_AP_IOMMU
+   * VFIO
+   * VFIO_MDEV
+   * VFIO_MDEV_DEVICE
+   * KVM
+
+   If using make menuconfig select the following to build the vfio_ap module:
+   -> Device Drivers
+      -> IOMMU Hardware Support
+         select S390 AP IOMMU Support
+      -> VFIO Non-Privileged userspace driver framework
+         -> Mediated device driver frramework
+            -> VFIO driver for Mediated devices
+   -> I/O subsystem
+      -> VFIO support for AP devices
+
+2. Secure the AP queues to be used by the three guests so that the host can not
+   access them. To secure them, there are two sysfs files that specify
+   bitmasks marking a subset of the APQN range as 'usable by the default AP
+   queue device drivers' or 'not usable by the default device drivers' and thus
+   available for use by the vfio_ap device driver'. The location of the sysfs
+   files containing the masks are:
+
+   /sys/bus/ap/apmask
+   /sys/bus/ap/aqmask
+
+   The 'apmask' is a 256-bit mask that identifies a set of AP adapter IDs
+   (APID). Each bit in the mask, from left to right (i.e., from most significant
+   to least significant bit in big endian order), corresponds to an APID from
+   0-255. If a bit is set, the APID is marked as usable only by the default AP
+   queue device drivers; otherwise, the APID is usable by the vfio_ap
+   device driver.
+
+   The 'aqmask' is a 256-bit mask that identifies a set of AP queue indexes
+   (APQI). Each bit in the mask, from left to right (i.e., from most significant
+   to least significant bit in big endian order), corresponds to an APQI from
+   0-255. If a bit is set, the APQI is marked as usable only by the default AP
+   queue device drivers; otherwise, the APQI is usable by the vfio_ap device
+   driver.
+
+   Take, for example, the following mask:
+
+      0x7dffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
+
+    It indicates:
+
+      1, 2, 3, 4, 5, and 7-255 belong to the default drivers' pool, and 0 and 6
+      belong to the vfio_ap device driver's pool.
+
+   The APQN of each AP queue device assigned to the linux host is checked by the
+   AP bus against the set of APQNs derived from the cross product of APIDs
+   and APQIs marked as usable only by the default AP queue device drivers. If a
+   match is detected,  only the default AP queue device drivers will be probed;
+   otherwise, the vfio_ap device driver will be probed.
+
+   By default, the two masks are set to reserve all APQNs for use by the default
+   AP queue device drivers. There are two ways the default masks can be changed:
+
+   1. The sysfs mask files can be edited by echoing a string into the
+      respective sysfs mask file in one of two formats:
+
+      * An absolute hex string starting with 0x - like "0x12345678" - sets
+        the mask. If the given string is shorter than the mask, it is padded
+        with 0s on the right; for example, specifying a mask value of 0x41 is
+        the same as specifying:
+
+           0x4100000000000000000000000000000000000000000000000000000000000000
+
+        Keep in mind that the mask reads from left to right (i.e., most
+        significant to least significant bit in big endian order), so the mask
+        above identifies device numbers 1 and 7 (01000001).
+
+        If the string is longer than the mask, the operation is terminated with
+        an error (EINVAL).
+
+      * Individual bits in the mask can be switched on and off by specifying
+        each bit number to be switched in a comma separated list. Each bit
+        number string must be prepended with a ('+') or minus ('-') to indicate
+        the corresponding bit is to be switched on ('+') or off ('-'). Some
+        valid values are:
+
+           "+0"    switches bit 0 on
+           "-13"   switches bit 13 off
+           "+0x41" switches bit 65 on
+           "-0xff" switches bit 255 off
+
+           The following example:
+              +0,-6,+0x47,-0xf0
+
+              Switches bits 0 and 71 (0x47) on
+              Switches bits 6 and 240 (0xf0) off
+
+        Note that the bits not specified in the list remain as they were before
+        the operation.
+
+   2. The masks can also be changed at boot time via parameters on the kernel
+      command line like this:
+
+         ap.apmask=0xffff ap.aqmask=0x40
+
+         This would create the following masks:
+
+            apmask:
+            0xffff000000000000000000000000000000000000000000000000000000000000
+
+            aqmask:
+            0x4000000000000000000000000000000000000000000000000000000000000000
+
+         Resulting in these two pools:
+
+            default drivers pool:    adapter 0-15, domain 1
+            alternate drivers pool:  adapter 16-255, domains 0, 2-255
+
+   Securing the APQNs for our example:
+   ----------------------------------
+   To secure the AP queues 05.0004, 05.0047, 05.00ab, 05.00ff, 06.0004, 06.0047,
+   06.00ab, and 06.00ff for use by the vfio_ap device driver, the corresponding
+   APQNs can either be removed from the default masks:
+
+      echo -5,-6 > /sys/bus/ap/apmask
+
+      echo -4,-0x47,-0xab,-0xff > /sys/bus/ap/aqmask
+
+   Or the masks can be set as follows:
+
+      echo 0xf9ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff \
+      > apmask
+
+      echo 0xf7fffffffffffffffeffffffffffffffffffffffffeffffffffffffffffffffe \
+      > aqmask
+
+   This will result in AP queues 05.0004, 05.0047, 05.00ab, 05.00ff, 06.0004,
+   06.0047, 06.00ab, and 06.00ff getting bound to the vfio_ap device driver. The
+   sysfs directory for the vfio_ap device driver will now contain symbolic links
+   to the AP queue devices bound to it:
+
+   /sys/bus/ap
+   ... [drivers]
+   ...... [vfio_ap]
+   ......... [05.0004]
+   ......... [05.0047]
+   ......... [05.00ab]
+   ......... [05.00ff]
+   ......... [06.0004]
+   ......... [06.0047]
+   ......... [06.00ab]
+   ......... [06.00ff]
+
+   Keep in mind that only type 10 and newer adapters (i.e., CEX4 and later)
+   can be bound to the vfio_ap device driver. The reason for this is to
+   simplify the implementation by not needlessly complicating the design by
+   supporting older devices that will go out of service in the relatively near
+   future and for which there are few older systems on which to test.
+
+   The administrator, therefore, must take care to secure only AP queues that
+   can be bound to the vfio_ap device driver. The device type for a given AP
+   queue device can be read from the parent card's sysfs directory. For example,
+   to see the hardware type of the queue 05.0004:
+
+   cat /sys/bus/ap/devices/card05/hwtype
+
+   The hwtype must be 10 or higher (CEX4 or newer) in order to be bound to the
+   vfio_ap device driver.
+
+3. Create the mediated devices needed to configure the AP matrixes for the
+   three guests and to provide an interface to the vfio_ap driver for
+   use by the guests:
+
+   /sys/devices/vfio_ap/matrix/
+   --- [mdev_supported_types]
+   ------ [vfio_ap-passthrough] (passthrough mediated matrix device type)
+   --------- create
+   --------- [devices]
+
+   To create the mediated devices for the three guests:
+
+	uuidgen > create
+	uuidgen > create
+	uuidgen > create
+
+        or
+
+        echo $uuid1 > create
+        echo $uuid2 > create
+        echo $uuid3 > create
+
+   This will create three mediated devices in the [devices] subdirectory named
+   after the UUID written to the create attribute file. We call them $uuid1,
+   $uuid2 and $uuid3 and this is the sysfs directory structure after creation:
+
+   /sys/devices/vfio_ap/matrix/
+   --- [mdev_supported_types]
+   ------ [vfio_ap-passthrough]
+   --------- [devices]
+   ------------ [$uuid1]
+   --------------- assign_adapter
+   --------------- assign_control_domain
+   --------------- assign_domain
+   --------------- matrix
+   --------------- unassign_adapter
+   --------------- unassign_control_domain
+   --------------- unassign_domain
+
+   ------------ [$uuid2]
+   --------------- assign_adapter
+   --------------- assign_control_domain
+   --------------- assign_domain
+   --------------- matrix
+   --------------- unassign_adapter
+   ----------------unassign_control_domain
+   ----------------unassign_domain
+
+   ------------ [$uuid3]
+   --------------- assign_adapter
+   --------------- assign_control_domain
+   --------------- assign_domain
+   --------------- matrix
+   --------------- unassign_adapter
+   ----------------unassign_control_domain
+   ----------------unassign_domain
+
+4. The administrator now needs to configure the matrixes for the mediated
+   devices $uuid1 (for Guest1), $uuid2 (for Guest2) and $uuid3 (for Guest3).
+
+   This is how the matrix is configured for Guest1:
+
+      echo 5 > assign_adapter
+      echo 6 > assign_adapter
+      echo 4 > assign_domain
+      echo 0xab > assign_domain
+
+      Control domains can similarly be assigned using the assign_control_domain
+      sysfs file.
+
+      If a mistake is made configuring an adapter, domain or control domain,
+      you can use the unassign_xxx files to unassign the adapter, domain or
+      control domain.
+
+      To display the matrix configuration for Guest1:
+
+         cat matrix
+
+   This is how the matrix is configured for Guest2:
+
+      echo 5 > assign_adapter
+      echo 0x47 > assign_domain
+      echo 0xff > assign_domain
+
+   This is how the matrix is configured for Guest3:
+
+      echo 6 > assign_adapter
+      echo 0x47 > assign_domain
+      echo 0xff > assign_domain
+
+   In order to successfully assign an adapter:
+
+   * The adapter number specified must represent a value from 0 up to the
+     maximum adapter number configured for the system. If an adapter number
+     higher than the maximum is specified, the operation will terminate with
+     an error (ENODEV).
+
+   * All APQNs that can be derived from the adapter ID and the IDs of
+     the previously assigned domains must be bound to the vfio_ap device
+     driver. If no domains have yet been assigned, then there must be at least
+     one APQN with the specified APID bound to the vfio_ap driver. If no such
+     APQNs are bound to the driver, the operation will terminate with an
+     error (EADDRNOTAVAIL).
+
+     No APQN that can be derived from the adapter ID and the IDs of the
+     previously assigned domains can be assigned to another mediated matrix
+     device. If an APQN is assigned to another mediated matrix device, the
+     operation will terminate with an error (EADDRINUSE).
+
+   In order to successfully assign a domain:
+
+   * The domain number specified must represent a value from 0 up to the
+     maximum domain number configured for the system. If a domain number
+     higher than the maximum is specified, the operation will terminate with
+     an error (ENODEV).
+
+   * All APQNs that can be derived from the domain ID and the IDs of
+     the previously assigned adapters must be bound to the vfio_ap device
+     driver. If no domains have yet been assigned, then there must be at least
+     one APQN with the specified APQI bound to the vfio_ap driver. If no such
+     APQNs are bound to the driver, the operation will terminate with an
+     error (EADDRNOTAVAIL).
+
+     No APQN that can be derived from the domain ID and the IDs of the
+     previously assigned adapters can be assigned to another mediated matrix
+     device. If an APQN is assigned to another mediated matrix device, the
+     operation will terminate with an error (EADDRINUSE).
+
+   In order to successfully assign a control domain, the domain number
+   specified must represent a value from 0 up to the maximum domain number
+   configured for the system. If a control domain number higher than the maximum
+   is specified, the operation will terminate with an error (ENODEV).
+
+5. Start Guest1:
+
+   /usr/bin/qemu-system-s390x ... -cpu host,ap=on,apqci=on,apft=on \
+      -device vfio-ap,sysfsdev=/sys/devices/vfio_ap/matrix/$uuid1 ...
+
+7. Start Guest2:
+
+   /usr/bin/qemu-system-s390x ... -cpu host,ap=on,apqci=on,apft=on \
+      -device vfio-ap,sysfsdev=/sys/devices/vfio_ap/matrix/$uuid2 ...
+
+7. Start Guest3:
+
+   /usr/bin/qemu-system-s390x ... -cpu host,ap=on,apqci=on,apft=on \
+      -device vfio-ap,sysfsdev=/sys/devices/vfio_ap/matrix/$uuid3 ...
+
+When the guest is shut down, the mediated matrix devices may be removed.
+
+Using our example again, to remove the mediated matrix device $uuid1:
+
+   /sys/devices/vfio_ap/matrix/
+      --- [mdev_supported_types]
+      ------ [vfio_ap-passthrough]
+      --------- [devices]
+      ------------ [$uuid1]
+      --------------- remove
+
+
+   echo 1 > remove
+
+   This will remove all of the mdev matrix device's sysfs structures including
+   the mdev device itself. To recreate and reconfigure the mdev matrix device,
+   all of the steps starting with step 3 will have to be performed again. Note
+   that the remove will fail if a guest using the mdev is still running.
+
+   It is not necessary to remove an mdev matrix device, but one may want to
+   remove it if no guest will use it during the remaining lifetime of the linux
+   host. If the mdev matrix device is removed, one may want to also reconfigure
+   the pool of adapters and queues reserved for use by the default drivers.
+
+Limitations
+===========
+* The KVM/kernel interfaces do not provide a way to prevent restoring an APQN
+  to the default drivers pool of a queue that is still assigned to a mediated
+  device in use by a guest. It is incumbent upon the administrator to
+  ensure there is no mediated device in use by a guest to which the APQN is
+  assigned lest the host be given access to the private data of the AP queue
+  device such as a private key configured specifically for the guest.
+
+* Dynamically modifying the AP matrix for a running guest (which would amount to
+  hot(un)plug of AP devices for the guest) is currently not supported
+
+* Live guest migration is not supported for guests using AP devices.
diff --git a/MAINTAINERS b/MAINTAINERS
index 4ece30f..a2e401f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12668,6 +12668,18 @@
 S:	Supported
 F:	drivers/s390/crypto/
 
+S390 VFIO AP DRIVER
+M:	Tony Krowiak <akrowiak@linux.ibm.com>
+M:	Pierre Morel <pmorel@linux.ibm.com>
+M:	Halil Pasic <pasic@linux.ibm.com>
+L:	linux-s390@vger.kernel.org
+W:	http://www.ibm.com/developerworks/linux/linux390/
+S:	Supported
+F:	drivers/s390/crypto/vfio_ap_drv.c
+F:	drivers/s390/crypto/vfio_ap_private.h
+F:	drivers/s390/crypto/vfio_ap_ops.c
+F:	Documentation/s390/vfio-ap.txt
+
 S390 ZFCP DRIVER
 M:	Steffen Maier <maier@linux.ibm.com>
 M:	Benjamin Block <bblock@linux.ibm.com>
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 9a9c7a6..8cc8f25 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -773,6 +773,17 @@
 	  To compile this driver as a module, choose M here: the
 	  module will be called vfio_ccw.
 
+config VFIO_AP
+	def_tristate n
+	prompt "VFIO support for AP devices"
+	depends on S390_AP_IOMMU && VFIO_MDEV_DEVICE && KVM
+	help
+		This driver grants access to Adjunct Processor (AP) devices
+		via the VFIO mediated device interface.
+
+		To compile this driver as a module, choose M here: the module
+		will be called vfio_ap.
+
 endmenu
 
 menu "Dump support"
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 47a5a25..febd170 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -44,6 +44,7 @@
 #define KVM_REQ_ICPT_OPEREXC	KVM_ARCH_REQ(2)
 #define KVM_REQ_START_MIGRATION KVM_ARCH_REQ(3)
 #define KVM_REQ_STOP_MIGRATION  KVM_ARCH_REQ(4)
+#define KVM_REQ_VSIE_RESTART	KVM_ARCH_REQ(5)
 
 #define SIGP_CTRL_C		0x80
 #define SIGP_CTRL_SCN_MASK	0x3f
@@ -186,6 +187,7 @@
 #define ECA_AIV		0x00200000
 #define ECA_VX		0x00020000
 #define ECA_PROTEXCI	0x00002000
+#define ECA_APIE	0x00000008
 #define ECA_SII		0x00000001
 	__u32	eca;			/* 0x004c */
 #define ICPT_INST	0x04
@@ -259,6 +261,8 @@
 	__u8	reservede4[4];		/* 0x00e4 */
 	__u64	tecmc;			/* 0x00e8 */
 	__u8	reservedf0[12];		/* 0x00f0 */
+#define CRYCB_FORMAT_MASK 0x00000003
+#define CRYCB_FORMAT0 0x00000000
 #define CRYCB_FORMAT1 0x00000001
 #define CRYCB_FORMAT2 0x00000003
 	__u32	crycbd;			/* 0x00fc */
@@ -719,6 +723,7 @@
 	__u32 crycbd;
 	__u8 aes_kw;
 	__u8 dea_kw;
+	__u8 apie;
 };
 
 #define APCB0_MASK_SIZE 1
@@ -859,6 +864,8 @@
 void kvm_arch_async_page_present(struct kvm_vcpu *vcpu,
 				 struct kvm_async_pf *work);
 
+void kvm_arch_crypto_clear_masks(struct kvm *kvm);
+
 extern int sie64a(struct kvm_s390_sie_block *, u64 *);
 extern char sie_exit;
 
diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h
index 9a50f02..16511d9 100644
--- a/arch/s390/include/uapi/asm/kvm.h
+++ b/arch/s390/include/uapi/asm/kvm.h
@@ -160,6 +160,8 @@
 #define KVM_S390_VM_CRYPTO_ENABLE_DEA_KW	1
 #define KVM_S390_VM_CRYPTO_DISABLE_AES_KW	2
 #define KVM_S390_VM_CRYPTO_DISABLE_DEA_KW	3
+#define KVM_S390_VM_CRYPTO_ENABLE_APIE		4
+#define KVM_S390_VM_CRYPTO_DISABLE_APIE		5
 
 /* kvm attributes for migration mode */
 #define KVM_S390_VM_MIGRATION_STOP	0
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index a1e8205..e3c6873 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -40,6 +40,7 @@
 #include <asm/sclp.h>
 #include <asm/cpacf.h>
 #include <asm/timex.h>
+#include <asm/ap.h>
 #include "kvm-s390.h"
 #include "gaccess.h"
 
@@ -844,20 +845,22 @@
 
 	kvm_s390_vcpu_block_all(kvm);
 
-	kvm_for_each_vcpu(i, vcpu, kvm)
+	kvm_for_each_vcpu(i, vcpu, kvm) {
 		kvm_s390_vcpu_crypto_setup(vcpu);
+		/* recreate the shadow crycb by leaving the VSIE handler */
+		kvm_s390_sync_request(KVM_REQ_VSIE_RESTART, vcpu);
+	}
 
 	kvm_s390_vcpu_unblock_all(kvm);
 }
 
 static int kvm_s390_vm_set_crypto(struct kvm *kvm, struct kvm_device_attr *attr)
 {
-	if (!test_kvm_facility(kvm, 76))
-		return -EINVAL;
-
 	mutex_lock(&kvm->lock);
 	switch (attr->attr) {
 	case KVM_S390_VM_CRYPTO_ENABLE_AES_KW:
+		if (!test_kvm_facility(kvm, 76))
+			return -EINVAL;
 		get_random_bytes(
 			kvm->arch.crypto.crycb->aes_wrapping_key_mask,
 			sizeof(kvm->arch.crypto.crycb->aes_wrapping_key_mask));
@@ -865,6 +868,8 @@
 		VM_EVENT(kvm, 3, "%s", "ENABLE: AES keywrapping support");
 		break;
 	case KVM_S390_VM_CRYPTO_ENABLE_DEA_KW:
+		if (!test_kvm_facility(kvm, 76))
+			return -EINVAL;
 		get_random_bytes(
 			kvm->arch.crypto.crycb->dea_wrapping_key_mask,
 			sizeof(kvm->arch.crypto.crycb->dea_wrapping_key_mask));
@@ -872,17 +877,35 @@
 		VM_EVENT(kvm, 3, "%s", "ENABLE: DEA keywrapping support");
 		break;
 	case KVM_S390_VM_CRYPTO_DISABLE_AES_KW:
+		if (!test_kvm_facility(kvm, 76))
+			return -EINVAL;
 		kvm->arch.crypto.aes_kw = 0;
 		memset(kvm->arch.crypto.crycb->aes_wrapping_key_mask, 0,
 			sizeof(kvm->arch.crypto.crycb->aes_wrapping_key_mask));
 		VM_EVENT(kvm, 3, "%s", "DISABLE: AES keywrapping support");
 		break;
 	case KVM_S390_VM_CRYPTO_DISABLE_DEA_KW:
+		if (!test_kvm_facility(kvm, 76))
+			return -EINVAL;
 		kvm->arch.crypto.dea_kw = 0;
 		memset(kvm->arch.crypto.crycb->dea_wrapping_key_mask, 0,
 			sizeof(kvm->arch.crypto.crycb->dea_wrapping_key_mask));
 		VM_EVENT(kvm, 3, "%s", "DISABLE: DEA keywrapping support");
 		break;
+	case KVM_S390_VM_CRYPTO_ENABLE_APIE:
+		if (!ap_instructions_available()) {
+			mutex_unlock(&kvm->lock);
+			return -EOPNOTSUPP;
+		}
+		kvm->arch.crypto.apie = 1;
+		break;
+	case KVM_S390_VM_CRYPTO_DISABLE_APIE:
+		if (!ap_instructions_available()) {
+			mutex_unlock(&kvm->lock);
+			return -EOPNOTSUPP;
+		}
+		kvm->arch.crypto.apie = 0;
+		break;
 	default:
 		mutex_unlock(&kvm->lock);
 		return -ENXIO;
@@ -1491,6 +1514,10 @@
 		case KVM_S390_VM_CRYPTO_DISABLE_DEA_KW:
 			ret = 0;
 			break;
+		case KVM_S390_VM_CRYPTO_ENABLE_APIE:
+		case KVM_S390_VM_CRYPTO_DISABLE_APIE:
+			ret = ap_instructions_available() ? 0 : -ENXIO;
+			break;
 		default:
 			ret = -ENXIO;
 			break;
@@ -1992,55 +2019,60 @@
 	return r;
 }
 
-static int kvm_s390_query_ap_config(u8 *config)
-{
-	u32 fcn_code = 0x04000000UL;
-	u32 cc = 0;
-
-	memset(config, 0, 128);
-	asm volatile(
-		"lgr 0,%1\n"
-		"lgr 2,%2\n"
-		".long 0xb2af0000\n"		/* PQAP(QCI) */
-		"0: ipm %0\n"
-		"srl %0,28\n"
-		"1:\n"
-		EX_TABLE(0b, 1b)
-		: "+r" (cc)
-		: "r" (fcn_code), "r" (config)
-		: "cc", "0", "2", "memory"
-	);
-
-	return cc;
-}
-
 static int kvm_s390_apxa_installed(void)
 {
-	u8 config[128];
-	int cc;
+	struct ap_config_info info;
 
-	if (test_facility(12)) {
-		cc = kvm_s390_query_ap_config(config);
-
-		if (cc)
-			pr_err("PQAP(QCI) failed with cc=%d", cc);
-		else
-			return config[0] & 0x40;
+	if (ap_instructions_available()) {
+		if (ap_qci(&info) == 0)
+			return info.apxa;
 	}
 
 	return 0;
 }
 
+/*
+ * The format of the crypto control block (CRYCB) is specified in the 3 low
+ * order bits of the CRYCB designation (CRYCBD) field as follows:
+ * Format 0: Neither the message security assist extension 3 (MSAX3) nor the
+ *	     AP extended addressing (APXA) facility are installed.
+ * Format 1: The APXA facility is not installed but the MSAX3 facility is.
+ * Format 2: Both the APXA and MSAX3 facilities are installed
+ */
 static void kvm_s390_set_crycb_format(struct kvm *kvm)
 {
 	kvm->arch.crypto.crycbd = (__u32)(unsigned long) kvm->arch.crypto.crycb;
 
+	/* Clear the CRYCB format bits - i.e., set format 0 by default */
+	kvm->arch.crypto.crycbd &= ~(CRYCB_FORMAT_MASK);
+
+	/* Check whether MSAX3 is installed */
+	if (!test_kvm_facility(kvm, 76))
+		return;
+
 	if (kvm_s390_apxa_installed())
 		kvm->arch.crypto.crycbd |= CRYCB_FORMAT2;
 	else
 		kvm->arch.crypto.crycbd |= CRYCB_FORMAT1;
 }
 
+void kvm_arch_crypto_clear_masks(struct kvm *kvm)
+{
+	mutex_lock(&kvm->lock);
+	kvm_s390_vcpu_block_all(kvm);
+
+	memset(&kvm->arch.crypto.crycb->apcb0, 0,
+	       sizeof(kvm->arch.crypto.crycb->apcb0));
+	memset(&kvm->arch.crypto.crycb->apcb1, 0,
+	       sizeof(kvm->arch.crypto.crycb->apcb1));
+
+	/* recreate the shadow crycb for each vcpu */
+	kvm_s390_sync_request_broadcast(kvm, KVM_REQ_VSIE_RESTART);
+	kvm_s390_vcpu_unblock_all(kvm);
+	mutex_unlock(&kvm->lock);
+}
+EXPORT_SYMBOL_GPL(kvm_arch_crypto_clear_masks);
+
 static u64 kvm_s390_get_initial_cpuid(void)
 {
 	struct cpuid cpuid;
@@ -2052,12 +2084,12 @@
 
 static void kvm_s390_crypto_init(struct kvm *kvm)
 {
-	if (!test_kvm_facility(kvm, 76))
-		return;
-
 	kvm->arch.crypto.crycb = &kvm->arch.sie_page2->crycb;
 	kvm_s390_set_crycb_format(kvm);
 
+	if (!test_kvm_facility(kvm, 76))
+		return;
+
 	/* Enable AES/DEA protected key functions by default */
 	kvm->arch.crypto.aes_kw = 1;
 	kvm->arch.crypto.dea_kw = 1;
@@ -2583,17 +2615,25 @@
 
 static void kvm_s390_vcpu_crypto_setup(struct kvm_vcpu *vcpu)
 {
-	if (!test_kvm_facility(vcpu->kvm, 76))
+	/*
+	 * If the AP instructions are not being interpreted and the MSAX3
+	 * facility is not configured for the guest, there is nothing to set up.
+	 */
+	if (!vcpu->kvm->arch.crypto.apie && !test_kvm_facility(vcpu->kvm, 76))
 		return;
 
+	vcpu->arch.sie_block->crycbd = vcpu->kvm->arch.crypto.crycbd;
 	vcpu->arch.sie_block->ecb3 &= ~(ECB3_AES | ECB3_DEA);
+	vcpu->arch.sie_block->eca &= ~ECA_APIE;
 
+	if (vcpu->kvm->arch.crypto.apie)
+		vcpu->arch.sie_block->eca |= ECA_APIE;
+
+	/* Set up protected key support */
 	if (vcpu->kvm->arch.crypto.aes_kw)
 		vcpu->arch.sie_block->ecb3 |= ECB3_AES;
 	if (vcpu->kvm->arch.crypto.dea_kw)
 		vcpu->arch.sie_block->ecb3 |= ECB3_DEA;
-
-	vcpu->arch.sie_block->crycbd = vcpu->kvm->arch.crypto.crycbd;
 }
 
 void kvm_s390_vcpu_unsetup_cmma(struct kvm_vcpu *vcpu)
@@ -2770,18 +2810,25 @@
 	exit_sie(vcpu);
 }
 
+bool kvm_s390_vcpu_sie_inhibited(struct kvm_vcpu *vcpu)
+{
+	return atomic_read(&vcpu->arch.sie_block->prog20) &
+	       (PROG_BLOCK_SIE | PROG_REQUEST);
+}
+
 static void kvm_s390_vcpu_request_handled(struct kvm_vcpu *vcpu)
 {
 	atomic_andnot(PROG_REQUEST, &vcpu->arch.sie_block->prog20);
 }
 
 /*
- * Kick a guest cpu out of SIE and wait until SIE is not running.
+ * Kick a guest cpu out of (v)SIE and wait until (v)SIE is not running.
  * If the CPU is not running (e.g. waiting as idle) the function will
  * return immediately. */
 void exit_sie(struct kvm_vcpu *vcpu)
 {
 	kvm_s390_set_cpuflags(vcpu, CPUSTAT_STOP_INT);
+	kvm_s390_vsie_kick(vcpu);
 	while (vcpu->arch.sie_block->prog0c & PROG_IN_SIE)
 		cpu_relax();
 }
@@ -3198,6 +3245,8 @@
 
 	/* nothing to do, just clear the request */
 	kvm_clear_request(KVM_REQ_UNHALT, vcpu);
+	/* we left the vsie handler, nothing to do, just clear the request */
+	kvm_clear_request(KVM_REQ_VSIE_RESTART, vcpu);
 
 	return 0;
 }
diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
index 981e3ba..1f6e36c 100644
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -290,6 +290,7 @@
 void kvm_s390_vcpu_stop(struct kvm_vcpu *vcpu);
 void kvm_s390_vcpu_block(struct kvm_vcpu *vcpu);
 void kvm_s390_vcpu_unblock(struct kvm_vcpu *vcpu);
+bool kvm_s390_vcpu_sie_inhibited(struct kvm_vcpu *vcpu);
 void exit_sie(struct kvm_vcpu *vcpu);
 void kvm_s390_sync_request(int req, struct kvm_vcpu *vcpu);
 int kvm_s390_vcpu_setup_cmma(struct kvm_vcpu *vcpu);
diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c
index 41eab96..a153257 100644
--- a/arch/s390/kvm/vsie.c
+++ b/arch/s390/kvm/vsie.c
@@ -135,14 +135,148 @@
 	atomic_set(&scb_s->cpuflags, newflags);
 	return 0;
 }
+/* Copy to APCB FORMAT1 from APCB FORMAT0 */
+static int setup_apcb10(struct kvm_vcpu *vcpu, struct kvm_s390_apcb1 *apcb_s,
+			unsigned long apcb_o, struct kvm_s390_apcb1 *apcb_h)
+{
+	struct kvm_s390_apcb0 tmp;
 
-/*
+	if (read_guest_real(vcpu, apcb_o, &tmp, sizeof(struct kvm_s390_apcb0)))
+		return -EFAULT;
+
+	apcb_s->apm[0] = apcb_h->apm[0] & tmp.apm[0];
+	apcb_s->aqm[0] = apcb_h->aqm[0] & tmp.aqm[0] & 0xffff000000000000UL;
+	apcb_s->adm[0] = apcb_h->adm[0] & tmp.adm[0] & 0xffff000000000000UL;
+
+	return 0;
+
+}
+
+/**
+ * setup_apcb00 - Copy to APCB FORMAT0 from APCB FORMAT0
+ * @vcpu: pointer to the virtual CPU
+ * @apcb_s: pointer to start of apcb in the shadow crycb
+ * @apcb_o: pointer to start of original apcb in the guest2
+ * @apcb_h: pointer to start of apcb in the guest1
+ *
+ * Returns 0 and -EFAULT on error reading guest apcb
+ */
+static int setup_apcb00(struct kvm_vcpu *vcpu, unsigned long *apcb_s,
+			unsigned long apcb_o, unsigned long *apcb_h)
+{
+	if (read_guest_real(vcpu, apcb_o, apcb_s,
+			    sizeof(struct kvm_s390_apcb0)))
+		return -EFAULT;
+
+	bitmap_and(apcb_s, apcb_s, apcb_h, sizeof(struct kvm_s390_apcb0));
+
+	return 0;
+}
+
+/**
+ * setup_apcb11 - Copy the FORMAT1 APCB from the guest to the shadow CRYCB
+ * @vcpu: pointer to the virtual CPU
+ * @apcb_s: pointer to start of apcb in the shadow crycb
+ * @apcb_o: pointer to start of original guest apcb
+ * @apcb_h: pointer to start of apcb in the host
+ *
+ * Returns 0 and -EFAULT on error reading guest apcb
+ */
+static int setup_apcb11(struct kvm_vcpu *vcpu, unsigned long *apcb_s,
+			unsigned long apcb_o,
+			unsigned long *apcb_h)
+{
+	if (read_guest_real(vcpu, apcb_o, apcb_s,
+			    sizeof(struct kvm_s390_apcb1)))
+		return -EFAULT;
+
+	bitmap_and(apcb_s, apcb_s, apcb_h, sizeof(struct kvm_s390_apcb1));
+
+	return 0;
+}
+
+/**
+ * setup_apcb - Create a shadow copy of the apcb.
+ * @vcpu: pointer to the virtual CPU
+ * @crycb_s: pointer to shadow crycb
+ * @crycb_o: pointer to original guest crycb
+ * @crycb_h: pointer to the host crycb
+ * @fmt_o: format of the original guest crycb.
+ * @fmt_h: format of the host crycb.
+ *
+ * Checks the compatibility between the guest and host crycb and calls the
+ * appropriate copy function.
+ *
+ * Return 0 or an error number if the guest and host crycb are incompatible.
+ */
+static int setup_apcb(struct kvm_vcpu *vcpu, struct kvm_s390_crypto_cb *crycb_s,
+	       const u32 crycb_o,
+	       struct kvm_s390_crypto_cb *crycb_h,
+	       int fmt_o, int fmt_h)
+{
+	struct kvm_s390_crypto_cb *crycb;
+
+	crycb = (struct kvm_s390_crypto_cb *) (unsigned long)crycb_o;
+
+	switch (fmt_o) {
+	case CRYCB_FORMAT2:
+		if ((crycb_o & PAGE_MASK) != ((crycb_o + 256) & PAGE_MASK))
+			return -EACCES;
+		if (fmt_h != CRYCB_FORMAT2)
+			return -EINVAL;
+		return setup_apcb11(vcpu, (unsigned long *)&crycb_s->apcb1,
+				    (unsigned long) &crycb->apcb1,
+				    (unsigned long *)&crycb_h->apcb1);
+	case CRYCB_FORMAT1:
+		switch (fmt_h) {
+		case CRYCB_FORMAT2:
+			return setup_apcb10(vcpu, &crycb_s->apcb1,
+					    (unsigned long) &crycb->apcb0,
+					    &crycb_h->apcb1);
+		case CRYCB_FORMAT1:
+			return setup_apcb00(vcpu,
+					    (unsigned long *) &crycb_s->apcb0,
+					    (unsigned long) &crycb->apcb0,
+					    (unsigned long *) &crycb_h->apcb0);
+		}
+		break;
+	case CRYCB_FORMAT0:
+		if ((crycb_o & PAGE_MASK) != ((crycb_o + 32) & PAGE_MASK))
+			return -EACCES;
+
+		switch (fmt_h) {
+		case CRYCB_FORMAT2:
+			return setup_apcb10(vcpu, &crycb_s->apcb1,
+					    (unsigned long) &crycb->apcb0,
+					    &crycb_h->apcb1);
+		case CRYCB_FORMAT1:
+		case CRYCB_FORMAT0:
+			return setup_apcb00(vcpu,
+					    (unsigned long *) &crycb_s->apcb0,
+					    (unsigned long) &crycb->apcb0,
+					    (unsigned long *) &crycb_h->apcb0);
+		}
+	}
+	return -EINVAL;
+}
+
+/**
+ * shadow_crycb - Create a shadow copy of the crycb block
+ * @vcpu: a pointer to the virtual CPU
+ * @vsie_page: a pointer to internal date used for the vSIE
+ *
  * Create a shadow copy of the crycb block and setup key wrapping, if
  * requested for guest 3 and enabled for guest 2.
  *
- * We only accept format-1 (no AP in g2), but convert it into format-2
+ * We accept format-1 or format-2, but we convert format-1 into format-2
+ * in the shadow CRYCB.
+ * Using format-2 enables the firmware to choose the right format when
+ * scheduling the SIE.
  * There is nothing to do for format-0.
  *
+ * This function centralize the issuing of set_validity_icpt() for all
+ * the subfunctions working on the crycb.
+ *
  * Returns: - 0 if shadowed or nothing to do
  *          - > 0 if control has to be given to guest 2
  */
@@ -154,23 +288,40 @@
 	const u32 crycb_addr = crycbd_o & 0x7ffffff8U;
 	unsigned long *b1, *b2;
 	u8 ecb3_flags;
+	int apie_h;
+	int key_msk = test_kvm_facility(vcpu->kvm, 76);
+	int fmt_o = crycbd_o & CRYCB_FORMAT_MASK;
+	int fmt_h = vcpu->arch.sie_block->crycbd & CRYCB_FORMAT_MASK;
+	int ret = 0;
 
 	scb_s->crycbd = 0;
-	if (!(crycbd_o & vcpu->arch.sie_block->crycbd & CRYCB_FORMAT1))
+
+	apie_h = vcpu->arch.sie_block->eca & ECA_APIE;
+	if (!apie_h && !key_msk)
 		return 0;
-	/* format-1 is supported with message-security-assist extension 3 */
-	if (!test_kvm_facility(vcpu->kvm, 76))
-		return 0;
+
+	if (!crycb_addr)
+		return set_validity_icpt(scb_s, 0x0039U);
+
+	if (fmt_o == CRYCB_FORMAT1)
+		if ((crycb_addr & PAGE_MASK) !=
+		    ((crycb_addr + 128) & PAGE_MASK))
+			return set_validity_icpt(scb_s, 0x003CU);
+
+	if (apie_h && (scb_o->eca & ECA_APIE)) {
+		ret = setup_apcb(vcpu, &vsie_page->crycb, crycb_addr,
+				 vcpu->kvm->arch.crypto.crycb,
+				 fmt_o, fmt_h);
+		if (ret)
+			goto end;
+		scb_s->eca |= scb_o->eca & ECA_APIE;
+	}
+
 	/* we may only allow it if enabled for guest 2 */
 	ecb3_flags = scb_o->ecb3 & vcpu->arch.sie_block->ecb3 &
 		     (ECB3_AES | ECB3_DEA);
 	if (!ecb3_flags)
-		return 0;
-
-	if ((crycb_addr & PAGE_MASK) != ((crycb_addr + 128) & PAGE_MASK))
-		return set_validity_icpt(scb_s, 0x003CU);
-	else if (!crycb_addr)
-		return set_validity_icpt(scb_s, 0x0039U);
+		goto end;
 
 	/* copy only the wrapping keys */
 	if (read_guest_real(vcpu, crycb_addr + 72,
@@ -178,8 +329,6 @@
 		return set_validity_icpt(scb_s, 0x0035U);
 
 	scb_s->ecb3 |= ecb3_flags;
-	scb_s->crycbd = ((__u32)(__u64) &vsie_page->crycb) | CRYCB_FORMAT1 |
-			CRYCB_FORMAT2;
 
 	/* xor both blocks in one run */
 	b1 = (unsigned long *) vsie_page->crycb.dea_wrapping_key_mask;
@@ -187,6 +336,16 @@
 			    vcpu->kvm->arch.crypto.crycb->dea_wrapping_key_mask;
 	/* as 56%8 == 0, bitmap_xor won't overwrite any data */
 	bitmap_xor(b1, b1, b2, BITS_PER_BYTE * 56);
+end:
+	switch (ret) {
+	case -EINVAL:
+		return set_validity_icpt(scb_s, 0x0020U);
+	case -EFAULT:
+		return set_validity_icpt(scb_s, 0x0035U);
+	case -EACCES:
+		return set_validity_icpt(scb_s, 0x003CU);
+	}
+	scb_s->crycbd = ((__u32)(__u64) &vsie_page->crycb) | CRYCB_FORMAT2;
 	return 0;
 }
 
@@ -832,7 +991,7 @@
 	struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
 	struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
 	int guest_bp_isolation;
-	int rc;
+	int rc = 0;
 
 	handle_last_fault(vcpu, vsie_page);
 
@@ -860,7 +1019,18 @@
 	guest_enter_irqoff();
 	local_irq_enable();
 
-	rc = sie64a(scb_s, vcpu->run->s.regs.gprs);
+	/*
+	 * Simulate a SIE entry of the VCPU (see sie64a), so VCPU blocking
+	 * and VCPU requests also hinder the vSIE from running and lead
+	 * to an immediate exit. kvm_s390_vsie_kick() has to be used to
+	 * also kick the vSIE.
+	 */
+	vcpu->arch.sie_block->prog0c |= PROG_IN_SIE;
+	barrier();
+	if (!kvm_s390_vcpu_sie_inhibited(vcpu))
+		rc = sie64a(scb_s, vcpu->run->s.regs.gprs);
+	barrier();
+	vcpu->arch.sie_block->prog0c &= ~PROG_IN_SIE;
 
 	local_irq_disable();
 	guest_exit_irqoff();
@@ -1007,7 +1177,8 @@
 		if (rc == -EAGAIN)
 			rc = 0;
 		if (rc || scb_s->icptcode || signal_pending(current) ||
-		    kvm_s390_vcpu_has_irq(vcpu, 0))
+		    kvm_s390_vcpu_has_irq(vcpu, 0) ||
+		    kvm_s390_vcpu_sie_inhibited(vcpu))
 			break;
 	}
 
@@ -1124,7 +1295,8 @@
 	if (unlikely(scb_addr & 0x1ffUL))
 		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
 
-	if (signal_pending(current) || kvm_s390_vcpu_has_irq(vcpu, 0))
+	if (signal_pending(current) || kvm_s390_vcpu_has_irq(vcpu, 0) ||
+	    kvm_s390_vcpu_sie_inhibited(vcpu))
 		return 0;
 
 	vsie_page = get_vsie_page(vcpu->kvm, scb_addr);
diff --git a/arch/s390/tools/gen_facilities.c b/arch/s390/tools/gen_facilities.c
index 0c85aed..fd788e0 100644
--- a/arch/s390/tools/gen_facilities.c
+++ b/arch/s390/tools/gen_facilities.c
@@ -106,6 +106,8 @@
 
 		.name = "FACILITIES_KVM_CPUMODEL",
 		.bits = (int[]){
+			12, /* AP Query Configuration Information */
+			15, /* AP Facilities Test */
 			156, /* etoken facility */
 			-1  /* END */
 		}
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index c60395b..83e6d99 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -372,6 +372,14 @@
 	  Enables bits of IOMMU API required by VFIO. The iommu_ops
 	  is not implemented as it is not necessary for VFIO.
 
+config S390_AP_IOMMU
+	bool "S390 AP IOMMU Support"
+	depends on S390 && ZCRYPT
+	select IOMMU_API
+	help
+	  Enables bits of IOMMU API required by VFIO. The iommu_ops
+	  is not implemented as it is not necessary for VFIO.
+
 config MTK_IOMMU
 	bool "MTK IOMMU Support"
 	depends on ARM || ARM64
diff --git a/drivers/s390/crypto/Makefile b/drivers/s390/crypto/Makefile
index b59af54..8d36b05 100644
--- a/drivers/s390/crypto/Makefile
+++ b/drivers/s390/crypto/Makefile
@@ -15,3 +15,7 @@
 # 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 0000000..8b51821
--- /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);
+}
+
+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;
+}
+
+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 0000000..d3d9eb7
--- /dev/null
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -0,0 +1,968 @@
+// 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);
+}
+
+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));
+}
+
+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);
+}
+
+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;
+}
+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;
+}
+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;
+}
+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;
+}
+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;
+}
+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;
+}
+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;
+}
+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
+};
+
+static void vfio_ap_mdev_copy_masks(struct ap_matrix_mdev *matrix_mdev)
+{
+	int nbytes;
+	unsigned long *apm, *aqm, *adm;
+	struct kvm_s390_crypto_cb *crycb = matrix_mdev->kvm->arch.crypto.crycb;
+
+	switch (matrix_mdev->kvm->arch.crypto.crycbd & CRYCB_FORMAT_MASK) {
+	case CRYCB_FORMAT2:
+		apm = (unsigned long *)crycb->apcb1.apm;
+		aqm = (unsigned long *)crycb->apcb1.aqm;
+		adm = (unsigned long *)crycb->apcb1.adm;
+		break;
+	case CRYCB_FORMAT1:
+	case CRYCB_FORMAT0:
+		apm = (unsigned long *)crycb->apcb0.apm;
+		aqm = (unsigned long *)crycb->apcb0.aqm;
+		adm = (unsigned long *)crycb->apcb0.adm;
+		break;
+	default:
+		/* cannot happen */
+		return;
+	}
+
+	nbytes = DIV_ROUND_UP(matrix_mdev->matrix.apm_max + 1, BITS_PER_BYTE);
+	memcpy(apm, matrix_mdev->matrix.apm, nbytes);
+	nbytes = DIV_ROUND_UP(matrix_mdev->matrix.aqm_max + 1, BITS_PER_BYTE);
+	memcpy(aqm, matrix_mdev->matrix.aqm, nbytes);
+	nbytes = DIV_ROUND_UP(matrix_mdev->matrix.adm_max + 1, BITS_PER_BYTE);
+	memcpy(adm, matrix_mdev->matrix.adm, nbytes);
+}
+
+/**
+ * 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;
+
+	vfio_ap_mdev_copy_masks(matrix_mdev);
+
+	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 0000000..5675492
--- /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_ */
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 1aa7b82..f378b98 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -200,6 +200,7 @@
 #define VFIO_DEVICE_FLAGS_PLATFORM (1 << 2)	/* vfio-platform device */
 #define VFIO_DEVICE_FLAGS_AMBA  (1 << 3)	/* vfio-amba device */
 #define VFIO_DEVICE_FLAGS_CCW	(1 << 4)	/* vfio-ccw device */
+#define VFIO_DEVICE_FLAGS_AP	(1 << 5)	/* vfio-ap device */
 	__u32	num_regions;	/* Max region index + 1 */
 	__u32	num_irqs;	/* Max IRQ index + 1 */
 };
@@ -215,6 +216,7 @@
 #define VFIO_DEVICE_API_PLATFORM_STRING		"vfio-platform"
 #define VFIO_DEVICE_API_AMBA_STRING		"vfio-amba"
 #define VFIO_DEVICE_API_CCW_STRING		"vfio-ccw"
+#define VFIO_DEVICE_API_AP_STRING		"vfio-ap"
 
 /**
  * VFIO_DEVICE_GET_REGION_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 8,