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authorLinus Torvalds <torvalds@linux-foundation.org>2022-08-06 17:05:21 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-08-06 17:05:21 -0700
commit24cb958695724ffb4488ef4f65892c0767bcd2f2 (patch)
tree87fdf68a4a2b37ba855c99415c890d8c6d3218ef
parentd77771c926671e0362af3fe792391be66072b242 (diff)
parent953503751a426413ea8aee2299ae3ee971b70d9b (diff)
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Merge tag 's390-5.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Alexander Gordeev: - Rework copy_oldmem_page() callback to take an iov_iter. This includes a few prerequisite updates and fixes to the oldmem reading code. - Rework cpufeature implementation to allow for various CPU feature indications, which is not only limited to hardware capabilities, but also allows CPU facilities. - Use the cpufeature rework to autoload Ultravisor module when CPU facility 158 is available. - Add ELF note type for encrypted CPU state of a protected virtual CPU. The zgetdump tool from s390-tools package will decrypt the CPU state using a Customer Communication Key and overwrite respective notes to make the data accessible for crash and other debugging tools. - Use vzalloc() instead of vmalloc() + memset() in ChaCha20 crypto test. - Fix incorrect recovery of kretprobe modified return address in stacktrace. - Switch the NMI handler to use generic irqentry_nmi_enter() and irqentry_nmi_exit() helper functions. - Rework the cryptographic Adjunct Processors (AP) pass-through design to support dynamic changes to the AP matrix of a running guest as well as to implement more of the AP architecture. - Minor boot code cleanups. - Grammar and typo fixes to hmcdrv and tape drivers. * tag 's390-5.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (46 commits) Revert "s390/smp: enforce lowcore protection on CPU restart" Revert "s390/smp: rework absolute lowcore access" Revert "s390/smp,ptdump: add absolute lowcore markers" s390/unwind: fix fgraph return address recovery s390/nmi: use irqentry_nmi_enter()/irqentry_nmi_exit() s390: add ELF note type for encrypted CPU state of a PV VCPU s390/smp,ptdump: add absolute lowcore markers s390/smp: rework absolute lowcore access s390/setup: rearrange absolute lowcore initialization s390/boot: cleanup adjust_to_uv_max() function s390/smp: enforce lowcore protection on CPU restart s390/tape: fix comment typo s390/hmcdrv: fix Kconfig "its" grammar s390/docs: fix warnings for vfio_ap driver doc s390/docs: fix warnings for vfio_ap driver lock usage doc s390/crash: support multi-segment iterators s390/crash: use static swap buffer for copy_to_user_real() s390/crash: move copy_to_user_real() to crash_dump.c s390/zcore: fix race when reading from hardware system area s390/crash: fix incorrect number of bytes to copy to user space ...
-rw-r--r--Documentation/s390/index.rst1
-rw-r--r--Documentation/s390/vfio-ap-locking.rst115
-rw-r--r--Documentation/s390/vfio-ap.rst498
-rw-r--r--MAINTAINERS2
-rw-r--r--arch/s390/boot/startup.c10
-rw-r--r--arch/s390/boot/uv.c5
-rw-r--r--arch/s390/boot/uv.h7
-rw-r--r--arch/s390/crypto/aes_s390.c2
-rw-r--r--arch/s390/crypto/chacha-glue.c2
-rw-r--r--arch/s390/crypto/crc32-vx.c2
-rw-r--r--arch/s390/crypto/des_s390.c2
-rw-r--r--arch/s390/crypto/ghash_s390.c2
-rw-r--r--arch/s390/crypto/prng.c2
-rw-r--r--arch/s390/crypto/sha1_s390.c2
-rw-r--r--arch/s390/crypto/sha256_s390.c2
-rw-r--r--arch/s390/crypto/sha3_256_s390.c2
-rw-r--r--arch/s390/crypto/sha3_512_s390.c2
-rw-r--r--arch/s390/crypto/sha512_s390.c2
-rw-r--r--arch/s390/include/asm/cpufeature.h23
-rw-r--r--arch/s390/include/asm/mmu.h14
-rw-r--r--arch/s390/include/asm/os_info.h17
-rw-r--r--arch/s390/include/asm/sclp.h4
-rw-r--r--arch/s390/include/asm/uaccess.h1
-rw-r--r--arch/s390/include/asm/unwind.h2
-rw-r--r--arch/s390/kernel/Makefile2
-rw-r--r--arch/s390/kernel/cpufeature.c46
-rw-r--r--arch/s390/kernel/crash_dump.c116
-rw-r--r--arch/s390/kernel/nmi.c8
-rw-r--r--arch/s390/kernel/processor.c10
-rw-r--r--arch/s390/kernel/setup.c13
-rw-r--r--arch/s390/mm/maccess.c26
-rw-r--r--drivers/char/hw_random/s390-trng.c2
-rw-r--r--drivers/s390/char/Kconfig2
-rw-r--r--drivers/s390/char/tape_34xx.c2
-rw-r--r--drivers/s390/char/uvdevice.c5
-rw-r--r--drivers/s390/char/zcore.c55
-rw-r--r--drivers/s390/crypto/ap_bus.c31
-rw-r--r--drivers/s390/crypto/pkey_api.c2
-rw-r--r--drivers/s390/crypto/vfio_ap_drv.c124
-rw-r--r--drivers/s390/crypto/vfio_ap_ops.c1441
-rw-r--r--drivers/s390/crypto/vfio_ap_private.h47
-rw-r--r--include/uapi/linux/elf.h1
-rw-r--r--tools/testing/crypto/chacha20-s390/test-cipher.c9
43 files changed, 1842 insertions, 821 deletions
diff --git a/Documentation/s390/index.rst b/Documentation/s390/index.rst
index b10ca9192557..73c79bf586fd 100644
--- a/Documentation/s390/index.rst
+++ b/Documentation/s390/index.rst
@@ -12,6 +12,7 @@ s390 Architecture
qeth
s390dbf
vfio-ap
+ vfio-ap-locking
vfio-ccw
zfcpdump
common_io
diff --git a/Documentation/s390/vfio-ap-locking.rst b/Documentation/s390/vfio-ap-locking.rst
new file mode 100644
index 000000000000..0dfcdb562e21
--- /dev/null
+++ b/Documentation/s390/vfio-ap-locking.rst
@@ -0,0 +1,115 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+======================
+VFIO AP Locks Overview
+======================
+This document describes the locks that are pertinent to the secure operation
+of the vfio_ap device driver. Throughout this document, the following variables
+will be used to denote instances of the structures herein described:
+
+.. code-block:: c
+
+ struct ap_matrix_dev *matrix_dev;
+ struct ap_matrix_mdev *matrix_mdev;
+ struct kvm *kvm;
+
+The Matrix Devices Lock (drivers/s390/crypto/vfio_ap_private.h)
+---------------------------------------------------------------
+
+.. code-block:: c
+
+ struct ap_matrix_dev {
+ ...
+ struct list_head mdev_list;
+ struct mutex mdevs_lock;
+ ...
+ }
+
+The Matrix Devices Lock (matrix_dev->mdevs_lock) is implemented as a global
+mutex contained within the single object of struct ap_matrix_dev. This lock
+controls access to all fields contained within each matrix_mdev
+(matrix_dev->mdev_list). This lock must be held while reading from, writing to
+or using the data from a field contained within a matrix_mdev instance
+representing one of the vfio_ap device driver's mediated devices.
+
+The KVM Lock (include/linux/kvm_host.h)
+---------------------------------------
+
+.. code-block:: c
+
+ struct kvm {
+ ...
+ struct mutex lock;
+ ...
+ }
+
+The KVM Lock (kvm->lock) controls access to the state data for a KVM guest. This
+lock must be held by the vfio_ap device driver while one or more AP adapters,
+domains or control domains are being plugged into or unplugged from the guest.
+
+The KVM pointer is stored in the in the matrix_mdev instance
+(matrix_mdev->kvm = kvm) containing the state of the mediated device that has
+been attached to the KVM guest.
+
+The Guests Lock (drivers/s390/crypto/vfio_ap_private.h)
+-----------------------------------------------------------
+
+.. code-block:: c
+
+ struct ap_matrix_dev {
+ ...
+ struct list_head mdev_list;
+ struct mutex guests_lock;
+ ...
+ }
+
+The Guests Lock (matrix_dev->guests_lock) controls access to the
+matrix_mdev instances (matrix_dev->mdev_list) that represent mediated devices
+that hold the state for the mediated devices that have been attached to a
+KVM guest. This lock must be held:
+
+1. To control access to the KVM pointer (matrix_mdev->kvm) while the vfio_ap
+ device driver is using it to plug/unplug AP devices passed through to the KVM
+ guest.
+
+2. To add matrix_mdev instances to or remove them from matrix_dev->mdev_list.
+ This is necessary to ensure the proper locking order when the list is perused
+ to find an ap_matrix_mdev instance for the purpose of plugging/unplugging
+ AP devices passed through to a KVM guest.
+
+ For example, when a queue device is removed from the vfio_ap device driver,
+ if the adapter is passed through to a KVM guest, it will have to be
+ unplugged. In order to figure out whether the adapter is passed through,
+ the matrix_mdev object to which the queue is assigned will have to be
+ found. The KVM pointer (matrix_mdev->kvm) can then be used to determine if
+ the mediated device is passed through (matrix_mdev->kvm != NULL) and if so,
+ to unplug the adapter.
+
+It is not necessary to take the Guests Lock to access the KVM pointer if the
+pointer is not used to plug/unplug devices passed through to the KVM guest;
+however, in this case, the Matrix Devices Lock (matrix_dev->mdevs_lock) must be
+held in order to access the KVM pointer since it is set and cleared under the
+protection of the Matrix Devices Lock. A case in point is the function that
+handles interception of the PQAP(AQIC) instruction sub-function. This handler
+needs to access the KVM pointer only for the purposes of setting or clearing IRQ
+resources, so only the matrix_dev->mdevs_lock needs to be held.
+
+The PQAP Hook Lock (arch/s390/include/asm/kvm_host.h)
+-----------------------------------------------------
+
+.. code-block:: c
+
+ typedef int (*crypto_hook)(struct kvm_vcpu *vcpu);
+
+ struct kvm_s390_crypto {
+ ...
+ struct rw_semaphore pqap_hook_rwsem;
+ crypto_hook *pqap_hook;
+ ...
+ };
+
+The PQAP Hook Lock is a r/w semaphore that controls access to the function
+pointer of the handler ``(*kvm->arch.crypto.pqap_hook)`` to invoke when the
+PQAP(AQIC) instruction sub-function is intercepted by the host. The lock must be
+held in write mode when pqap_hook value is set, and in read mode when the
+pqap_hook function is called.
diff --git a/Documentation/s390/vfio-ap.rst b/Documentation/s390/vfio-ap.rst
index f57ae621f33e..61a0a3c6c7b4 100644
--- a/Documentation/s390/vfio-ap.rst
+++ b/Documentation/s390/vfio-ap.rst
@@ -123,27 +123,24 @@ 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:
+our main hardware virtualization control block. The CRYCB contains an AP Control
+Block (APCB) that has 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
+ to the KVM guest. Each bit in the mask, from left to right, 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.
+ assigned to the KVM guest. Each bit in the mask, from left to right,
+ 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
+ guest. Each bit in the mask, from left to right, 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.
@@ -151,10 +148,10 @@ 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.
+calculated from the APM and AQM; it is the Cartesian 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
@@ -192,7 +189,7 @@ 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
+3. VFIO AP mediated pass-through device
The VFIO AP device driver
-------------------------
@@ -200,12 +197,13 @@ 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
+2. Sets up the VFIO mediated device interfaces to manage a vfio_ap mediated
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
+3. Configures the APM, AQM and ADM in the APCB contained 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
---------------------------------------------
@@ -235,10 +233,10 @@ reserved::
| | 8 probe | |
+--------^---------+ +--^--^------------+
6 edit | | |
- apmask | +-----------------------------+ | 9 mdev create
+ apmask | +-----------------------------+ | 11 mdev create
aqmask | | 1 modprobe |
+--------+-----+---+ +----------------+-+ +----------------+
- | | | |8 create | mediated |
+ | | | |10 create| mediated |
| admin | | VFIO device core |---------> matrix |
| + | | | device |
+------+-+---------+ +--------^---------+ +--------^-------+
@@ -246,14 +244,14 @@ reserved::
| | 9 create vfio_ap-passthrough | |
| +------------------------------+ |
+-------------------------------------------------------------+
- 10 assign adapter/domain/control domain
+ 12 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.
+ all vfio_ap mediated 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
@@ -269,24 +267,24 @@ The process for reserving an AP queue for use by a KVM guest is:
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
+9. The administrator creates a passthrough type vfio_ap mediated 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
+The VFIO AP device driver utilizes the common interfaces of the VFIO mediated
device core driver to:
-* Register an AP mediated bus driver to add a mediated matrix device to and
+* Register an AP mediated bus driver to add a vfio_ap mediated 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
+* Create and destroy a vfio_ap mediated device
+* Add a vfio_ap mediated device to and remove it from the AP mediated bus driver
+* Add a vfio_ap mediated 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::
+of the VFIO AP mediated device driver::
+-------------+
| |
@@ -343,7 +341,7 @@ matrix device.
* device_api:
the mediated device type's API
* available_instances:
- the number of mediated matrix passthrough devices
+ the number of vfio_ap mediated passthrough devices
that can be created
* device_api:
specifies the VFIO API
@@ -351,29 +349,37 @@ matrix device.
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:
+ structure will be created in the vfio_ap mediated device's directory. The
+ sysfs attributes for a vfio_ap mediated 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.
+ vfio_ap mediated device. To assign/unassign an adapter, the APID of the
+ adapter is echoed into 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 usage domain is echoed to the respective attribute
+ the vfio_ap mediated device. To assign/unassign a domain, the domain
+ number of the usage domain is echoed into 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.
+ A read-only file for displaying the APQNs derived from the Cartesian
+ product of the adapter and domain numbers assigned to the vfio_ap mediated
+ device.
+ guest_matrix:
+ A read-only file for displaying the APQNs derived from the Cartesian
+ product of the adapter and domain numbers assigned to the APM and AQM
+ fields respectively of the KVM guest's CRYCB. This may differ from the
+ the APQNs assigned to the vfio_ap mediated device if any APQN does not
+ reference a queue device bound to the vfio_ap device driver (i.e., the
+ queue is not in the host's AP configuration).
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.
+ to/from the vfio_ap mediated device. To assign/unassign a control domain,
+ the ID of the domain to be assigned/unassigned is echoed into the
+ respective attribute file.
control_domains:
A read-only file for displaying the control domain numbers assigned to the
- mediated matrix device.
+ vfio_ap mediated device.
* functions:
@@ -383,45 +389,75 @@ matrix device.
* 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
+ * Store the AP matrix configuration for the adapters, domains and control
+ domains available to a guest. A guest may not be provided access to APQNs
+ referencing queue devices that do not exist, or are not bound to the
+ vfio_ap device driver.
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.
+ deallocates the vfio_ap mediated device's ap_matrix_mdev structure.
+ This will be allowed only if a running guest is not using the mdev.
* callback interfaces
- open:
+ open_device:
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:
+ VFIO_GROUP_NOTIFY_SET_KVM notifier callback function for the matrix mdev
+ devices. The open_device callback is invoked by userspace to connect the
+ VFIO iommu group for the matrix mdev 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 vfio_ap mediated device's sysfs attribute files.
+
+ close_device:
unregisters the VFIO_GROUP_NOTIFY_SET_KVM notifier callback function for the
- mdev matrix device and deconfigures the guest's AP matrix.
+ matrix mdev 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
+ ioctl:
+ this callback handles the VFIO_DEVICE_GET_INFO and VFIO_DEVICE_RESET ioctls
+ defined by the vfio framework.
+
+Configure the guest's AP resources
+----------------------------------
+Configuring the AP resources 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:
+function is called when userspace connects to KVM. The guest's AP resources are
+configured via it's APCB by:
* Setting the bits in the APM corresponding to the APIDs assigned to the
- mediated matrix device via its 'assign_adapter' interface.
+ vfio_ap mediated 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.
+ vfio_ap mediated 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.
+ vfio_ap mediated device via its 'assign_control_domains' interface.
+
+The linux device model precludes passing a device through to a KVM guest that
+is not bound to the device driver facilitating its pass-through. Consequently,
+an APQN that does not reference a queue device bound to the vfio_ap device
+driver will not be assigned to a KVM guest's matrix. The AP architecture,
+however, does not provide a means to filter individual APQNs from the guest's
+matrix, so the adapters, domains and control domains assigned to vfio_ap
+mediated device via its sysfs 'assign_adapter', 'assign_domain' and
+'assign_control_domain' interfaces will be filtered before providing the AP
+configuration to a guest:
+
+* The APIDs of the adapters, the APQIs of the domains and the domain numbers of
+ the control domains assigned to the matrix mdev that are not also assigned to
+ the host's AP configuration will be filtered.
+
+* Each APQN derived from the Cartesian product of the APIDs and APQIs assigned
+ to the vfio_ap mdev is examined and if any one of them does not reference a
+ queue device bound to the vfio_ap device driver, the adapter will not be
+ plugged into the guest (i.e., the bit corresponding to its APID will not be
+ set in the APM of the guest's APCB).
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:
+The AP stack relies on the presence of the AP instructions as well as three
+facilities: The AP Facilities Test (APFT) facility; the AP Query
+Configuration Information (QCI) facility; and the AP Queue Interruption Control
+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
@@ -435,24 +471,28 @@ available to a KVM guest via the following CPU model features:
can be made available to the guest only if it is available on the host (i.e.,
facility bit 12 is set).
+4. apqi: Indicates AP Queue Interruption Control faclity 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 65 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
+ /usr/bin/qemu-system-s390x ... -cpu z13,ap=on,apqci=on,apft=on,apqi=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
+ /usr/bin/qemu-system-s390x ... -cpu host,ap=off,apqci=off,apft=off,apqi=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.
+will not see any AP devices. The zcrypt device drivers on the guest 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 no
+adapter or domain devices will get created by the AP bus running on the
+guest because only type 10 and newer devices can be configured for guest use.
Example
=======
@@ -471,7 +511,7 @@ CARD.DOMAIN TYPE MODE
05.00ab CEX5C CCA-Coproc
06 CEX5A Accelerator
06.0004 CEX5A Accelerator
-06.00ab CEX5C CCA-Coproc
+06.00ab CEX5A Accelerator
=========== ===== ============
Guest2
@@ -479,9 +519,9 @@ Guest2
=========== ===== ============
CARD.DOMAIN TYPE MODE
=========== ===== ============
-05 CEX5A Accelerator
-05.0047 CEX5A Accelerator
-05.00ff CEX5A Accelerator
+05 CEX5C CCA-Coproc
+05.0047 CEX5C CCA-Coproc
+05.00ff CEX5C CCA-Coproc
=========== ===== ============
Guest3
@@ -529,40 +569,56 @@ These are the steps:
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::
+ bitmasks marking a subset of the APQN range as usable only by the default AP
+ queue device drivers. All remaining APQNs are available for use by
+ any other device driver. The vfio_ap device driver is currently the only
+ non-default 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.
+ (APID). Each bit in the mask, from left to right, corresponds to an APID from
+ 0-255. If a bit is set, the APID belongs to the subset of APQNs marked as
+ available only to the default AP queue device drivers.
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</