* [PATCH v2 2/2] docs: rstfy vfio-ap documentation
2020-02-13 16:29 [PATCH v2 0/2] docs: rstfy some s390 docs Cornelia Huck
2020-02-13 16:29 ` [PATCH v2 1/2] docs: rstfy s390 dasd ipl documentation Cornelia Huck
@ 2020-02-13 16:29 ` Cornelia Huck
2020-02-13 18:38 ` Pierre Morel
2020-02-18 13:05 ` [PATCH v2 0/2] docs: rstfy some s390 docs Cornelia Huck
2020-02-21 8:24 ` Cornelia Huck
3 siblings, 1 reply; 9+ messages in thread
From: Cornelia Huck @ 2020-02-13 16:29 UTC (permalink / raw)
To: Tony Krowiak, Jason J . Herne
Cc: Peter Maydell, Thomas Huth, Pierre Morel, Cornelia Huck,
qemu-devel, Halil Pasic, Christian Borntraeger, qemu-s390x
Move to system/, as this is mostly about configuring vfio-ap.
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
---
MAINTAINERS | 2 +-
docs/system/index.rst | 1 +
docs/{vfio-ap.txt => system/vfio-ap.rst} | 796 ++++++++++++-----------
3 files changed, 420 insertions(+), 379 deletions(-)
rename docs/{vfio-ap.txt => system/vfio-ap.rst} (55%)
diff --git a/MAINTAINERS b/MAINTAINERS
index 34b766f89d32..da6d0f412356 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1554,7 +1554,7 @@ F: hw/s390x/ap-bridge.c
F: include/hw/s390x/ap-device.h
F: include/hw/s390x/ap-bridge.h
F: hw/vfio/ap.c
-F: docs/vfio-ap.txt
+F: docs/system/vfio-ap.rst
L: qemu-s390x@nongnu.org
vhost
diff --git a/docs/system/index.rst b/docs/system/index.rst
index f66e6ea585cd..1a4b2c82acef 100644
--- a/docs/system/index.rst
+++ b/docs/system/index.rst
@@ -15,3 +15,4 @@ Contents:
:maxdepth: 2
qemu-block-drivers
+ vfio-ap
diff --git a/docs/vfio-ap.txt b/docs/system/vfio-ap.rst
similarity index 55%
rename from docs/vfio-ap.txt
rename to docs/system/vfio-ap.rst
index b1eb2deeaf2f..3cd84179a2df 100644
--- a/docs/vfio-ap.txt
+++ b/docs/system/vfio-ap.rst
@@ -1,17 +1,11 @@
Adjunct Processor (AP) Device
=============================
-Contents:
-=========
-* Introduction
-* AP Architectural Overview
-* Start Interpretive Execution (SIE) Instruction
-* AP Matrix Configuration on Linux Host
-* Starting a Linux Guest Configured with an AP Matrix
-* Example: Configure AP Matrices for Three Linux Guests
-
-Introduction:
-============
+.. contents::
+
+Introduction
+------------
+
The IBM Adjunct Processor (AP) Cryptographic Facility is comprised
of three AP instructions and from 1 to 256 PCIe cryptographic adapter cards.
These AP devices provide cryptographic functions to all CPUs assigned to a
@@ -21,8 +15,9 @@ On s390x, AP adapter cards are exposed via the AP bus. This document
describes how those cards may be made available to KVM guests using the
VFIO mediated device framework.
-AP Architectural Overview:
-=========================
+AP Architectural Overview
+-------------------------
+
In order understand the terminology used in the rest of this document, let's
start with some definitions:
@@ -75,7 +70,8 @@ start with some definitions:
must be one of the control domains.
Start Interpretive Execution (SIE) Instruction
-==============================================
+----------------------------------------------
+
A KVM guest is started by executing the Start Interpretive Execution (SIE)
instruction. The SIE state description is a control block that contains the
state information for a KVM guest and is supplied as input to the SIE
@@ -114,246 +110,278 @@ 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 the linux host.
- Example 1: Valid configuration:
- ------------------------------
- Guest1: adapters 1,2 domains 5,6
- Guest2: adapter 1,2 domain 7
+Example 1: Valid configuration
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
++----------+--------+--------+
+| | Guest1 | Guest2 |
++==========+========+========+
+| adapters | 1, 2 | 1, 2 |
++----------+--------+--------+
+| domains | 5, 6 | 7 |
++----------+--------+--------+
+
+This is valid because both guests have a unique set of APQNs:
+
+* Guest1 has APQNs (1,5), (1,6), (2,5) and (2,6);
+* Guest2 has APQNs (1,7) and (2,7).
+
+Example 2: Valid configuration
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
++----------+--------+--------+
+| | Guest1 | Guest2 |
++==========+========+========+
+| adapters | 1, 2 | 3, 4 |
++----------+--------+--------+
+| domains | 5, 6 | 5, 6 |
++----------+--------+--------+
- This is valid because both guests have a unique set of APQNs: Guest1 has
- APQNs (1,5), (1,6), (2,5) and (2,6); Guest2 has APQNs (1,7) and (2,7).
+This is also valid because both guests have a unique set of APQNs:
- Example 2: Valid configuration:
- ------------------------------
- Guest1: adapters 1,2 domains 5,6
- Guest2: adapters 3,4 domains 5,6
+* Guest1 has APQNs (1,5), (1,6), (2,5), (2,6);
+* Guest2 has APQNs (3,5), (3,6), (4,5), (4,6)
- 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
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- Example 3: Invalid configuration:
- --------------------------------
- Guest1: adapters 1,2 domains 5,6
- Guest2: adapter 1 domains 6,7
++----------+--------+--------+
+| | Guest1 | Guest2 |
++==========+========+========+
+| adapters | 1, 2 | 1 |
++----------+--------+--------+
+| domains | 5, 6 | 6, 7 |
++----------+--------+--------+
- This is an invalid configuration because both guests have access to
- APQN (1,6).
+This is an invalid configuration because both guests have access to
+APQN (1,6).
+
+AP Matrix Configuration on Linux Host
+-------------------------------------
-AP Matrix Configuration on Linux Host:
-=====================================
A linux system is a guest of the LPAR in which it is running and has access to
the AP resources configured for the LPAR. The LPAR's AP matrix is
configured via its Activation Profile which can be edited on the HMC. When the
linux system is started, the AP bus will detect the AP devices assigned to the
-LPAR and create the following in sysfs:
+LPAR and create the following in sysfs::
-/sys/bus/ap
-... [devices]
-...... xx.yyyy
-...... ...
-...... cardxx
-...... ...
+ /sys/bus/ap
+ ... [devices]
+ ...... xx.yyyy
+ ...... ...
+ ...... cardxx
+ ...... ...
Where:
- cardxx is AP adapter number xx (in hex)
-....xx.yyyy is an APQN with xx specifying the APID and yyyy specifying the
- APQI
+
+``cardxx``
+ is AP adapter number xx (in hex)
+
+``xx.yyyy``
+ is an APQN with xx specifying the APID and yyyy specifying the APQI
For example, if AP adapters 5 and 6 and domains 4, 71 (0x47), 171 (0xab) and
255 (0xff) are configured for the LPAR, the sysfs representation on the linux
-host system would look like this:
-
-/sys/bus/ap
-... [devices]
-...... 05.0004
-...... 05.0047
-...... 05.00ab
-...... 05.00ff
-...... 06.0004
-...... 06.0047
-...... 06.00ab
-...... 06.00ff
-...... card05
-...... card06
+host system would look like this::
+
+ /sys/bus/ap
+ ... [devices]
+ ...... 05.0004
+ ...... 05.0047
+ ...... 05.00ab
+ ...... 05.00ff
+ ...... 06.0004
+ ...... 06.0047
+ ...... 06.00ab
+ ...... 06.00ff
+ ...... card05
+ ...... card06
A set of default device drivers are also created to control each type of AP
-device that can be assigned to the LPAR on which a linux host is running:
-
-/sys/bus/ap
-... [drivers]
-...... [cex2acard] for Crypto Express 2/3 accelerator cards
-...... [cex2aqueue] for AP queues served by Crypto Express 2/3
- accelerator cards
-...... [cex4card] for Crypto Express 4/5/6 accelerator and coprocessor
- cards
-...... [cex4queue] for AP queues served by Crypto Express 4/5/6
- accelerator and coprocessor cards
-...... [pcixcccard] for Crypto Express 2/3 coprocessor cards
-...... [pcixccqueue] for AP queues served by Crypto Express 2/3
- coprocessor cards
+device that can be assigned to the LPAR on which a linux host is running::
+
+ /sys/bus/ap
+ ... [drivers]
+ ...... [cex2acard] for Crypto Express 2/3 accelerator cards
+ ...... [cex2aqueue] for AP queues served by Crypto Express 2/3
+ accelerator cards
+ ...... [cex4card] for Crypto Express 4/5/6 accelerator and coprocessor
+ cards
+ ...... [cex4queue] for AP queues served by Crypto Express 4/5/6
+ accelerator and coprocessor cards
+ ...... [pcixcccard] for Crypto Express 2/3 coprocessor cards
+ ...... [pcixccqueue] for AP queues served by Crypto Express 2/3
+ coprocessor cards
Binding AP devices to device drivers
-------------------------------------
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
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 alternate device
-driver(s). The sysfs locations of the masks are:
+driver(s). The sysfs locations of 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 ``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.
+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:
+Take, for example, the following mask::
0x7dffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
- It indicates:
+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.
+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:
+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:
+ 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:
+ * 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).
+ 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).
+ 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:
+ * 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:
+ The following example::
+
+0,-6,+0x47,-0xf0
- Switches bits 0 and 71 (0x47) on
- Switches bits 6 and 240 (0xf0) off
+ 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.
+ 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:
+ 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:
+ This would create the following masks:
+
+ apmask::
- apmask:
0xffff000000000000000000000000000000000000000000000000000000000000
- aqmask:
+ aqmask::
+
0x4000000000000000000000000000000000000000000000000000000000000000
- Resulting in these two pools:
+ Resulting in these two pools::
default drivers pool: adapter 0-15, domain 1
alternate drivers pool: adapter 16-255, domains 0, 2-255
-Configuring an AP matrix for a linux guest.
-------------------------------------------
+Configuring an AP matrix for a linux guest
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
The sysfs interfaces for configuring an AP matrix for a guest are built on the
VFIO mediated device framework. To configure an AP matrix for a guest, a
-mediated matrix device must first be created for the /sys/devices/vfio_ap/matrix
+mediated matrix device must first be created for the ``/sys/devices/vfio_ap/matrix``
device. When the vfio_ap device driver is loaded, it registers with the VFIO
mediated device framework. When the driver registers, the sysfs interfaces for
-creating mediated matrix devices is created:
+creating mediated matrix devices is created::
-/sys/devices
-... [vfio_ap]
-......[matrix]
-......... [mdev_supported_types]
-............ [vfio_ap-passthrough]
-............... create
-............... [devices]
+ /sys/devices
+ ... [vfio_ap]
+ ......[matrix]
+ ......... [mdev_supported_types]
+ ............ [vfio_ap-passthrough]
+ ............... create
+ ............... [devices]
A mediated AP matrix device is created by writing a UUID to the attribute file
-named 'create', for example:
+named ``create``, for example::
uuidgen > create
- or
+or
+
+::
echo $uuid > create
When a mediated AP matrix device is created, a sysfs directory named after
-the UUID is created in the 'devices' subdirectory:
+the UUID is created in the ``devices`` subdirectory::
-/sys/devices
-... [vfio_ap]
-......[matrix]
-......... [mdev_supported_types]
-............ [vfio_ap-passthrough]
-............... create
-............... [devices]
-.................. [$uuid]
+ /sys/devices
+ ... [vfio_ap]
+ ......[matrix]
+ ......... [mdev_supported_types]
+ ............ [vfio_ap-passthrough]
+ ............... create
+ ............... [devices]
+ .................. [$uuid]
There will also be three sets of attribute files created in the mediated
matrix device's sysfs directory to configure an AP matrix for the
-KVM guest:
-
-/sys/devices
-... [vfio_ap]
-......[matrix]
-......... [mdev_supported_types]
-............ [vfio_ap-passthrough]
-............... create
-............... [devices]
-.................. [$uuid]
-..................... assign_adapter
-..................... assign_control_domain
-..................... assign_domain
-..................... matrix
-..................... unassign_adapter
-..................... unassign_control_domain
-..................... unassign_domain
-
-assign_adapter
+KVM guest::
+
+ /sys/devices
+ ... [vfio_ap]
+ ......[matrix]
+ ......... [mdev_supported_types]
+ ............ [vfio_ap-passthrough]
+ ............... create
+ ............... [devices]
+ .................. [$uuid]
+ ..................... assign_adapter
+ ..................... assign_control_domain
+ ..................... assign_domain
+ ..................... matrix
+ ..................... unassign_adapter
+ ..................... unassign_control_domain
+ ..................... unassign_domain
+
+``assign_adapter``
To assign an AP adapter to the mediated matrix device, its APID is written
- to the 'assign_adapter' file. This may be done multiple times to assign more
+ to the ``assign_adapter`` file. This may be done multiple times to assign more
than one adapter. The APID may be specified using conventional semantics
as a decimal, hexadecimal, or octal number. For example, to assign adapters
4, 5 and 16 to a mediated matrix device in decimal, hexadecimal and octal
- respectively:
+ respectively::
echo 4 > assign_adapter
echo 0x5 > assign_adapter
@@ -373,22 +401,22 @@ assign_adapter
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
+ * 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).
-unassign_adapter
- To unassign an AP adapter, its APID is written to the 'unassign_adapter'
+``unassign_adapter``
+ To unassign an AP adapter, its APID is written to the ``unassign_adapter``
file. This may also be done multiple times to unassign more than one adapter.
-assign_domain
+``assign_domain``
To assign a usage domain, the domain number is written into the
- 'assign_domain' file. This may be done multiple times to assign more than one
+ ``assign_domain`` file. This may be done multiple times to assign more than one
usage domain. The domain number is specified using conventional semantics as
a decimal, hexadecimal, or octal number. For example, to assign usage domains
4, 8, and 71 to a mediated matrix device in decimal, hexadecimal and octal
- respectively:
+ respectively::
echo 4 > assign_domain
echo 0x8 > assign_domain
@@ -408,23 +436,23 @@ assign_domain
APQNs are bound to the driver, the operation will terminate with an
error (EADDRNOTAVAIL).
- No APQN that can be derived from the domain ID being assigned and the IDs
+ * No APQN that can be derived from the domain ID being assigned 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).
-unassign_domain
+``unassign_domain``
To unassign a usage domain, the domain number is written into the
- 'unassign_domain' file. This may be done multiple times to unassign more than
+ ``unassign_domain`` file. This may be done multiple times to unassign more than
one usage domain.
-assign_control_domain
+``assign_control_domain``
To assign a control domain, the domain number is written into the
- 'assign_control_domain' file. This may be done multiple times to
+ ``assign_control_domain`` file. This may be done multiple times to
assign more than one control domain. The domain number may be specified using
conventional semantics as a decimal, hexadecimal, or octal number. For
example, to assign control domains 4, 8, and 71 to a mediated matrix device
- in decimal, hexadecimal and octal respectively:
+ in decimal, hexadecimal and octal respectively::
echo 4 > assign_domain
echo 0x8 > assign_domain
@@ -435,33 +463,34 @@ assign_control_domain
allowed by the machine model. If a control domain number higher than the
maximum is specified, the operation will terminate with an error (ENODEV).
-unassign_control_domain
+``unassign_control_domain``
To unassign a control domain, the domain number is written into the
- 'unassign_domain' file. This may be done multiple times to unassign more than
+ ``unassign_domain`` file. This may be done multiple times to unassign more than
one control domain.
Notes: No changes to the AP matrix will be allowed while a guest using
the mediated matrix device is running. Attempts to assign an adapter,
domain or control domain will be rejected and an error (EBUSY) returned.
-Starting a Linux Guest Configured with an AP Matrix:
-===================================================
+Starting a Linux Guest Configured with an AP Matrix
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
To provide a mediated matrix device for use by a guest, the following option
-must be specified on the QEMU command line:
+must be specified on the QEMU command line::
-device vfio_ap,sysfsdev=$path-to-mdev
The sysfsdev parameter specifies the path to the mediated matrix device.
-There are a number of ways to specify this path:
+There are a number of ways to specify this path::
-/sys/devices/vfio_ap/matrix/$uuid
-/sys/bus/mdev/devices/$uuid
-/sys/bus/mdev/drivers/vfio_mdev/$uuid
-/sys/devices/vfio_ap/matrix/mdev_supported_types/vfio_ap-passthrough/devices/$uuid
+ /sys/devices/vfio_ap/matrix/$uuid
+ /sys/bus/mdev/devices/$uuid
+ /sys/bus/mdev/drivers/vfio_mdev/$uuid
+ /sys/devices/vfio_ap/matrix/mdev_supported_types/vfio_ap-passthrough/devices/$uuid
When the linux guest is started, the guest will open the mediated
matrix device's file descriptor to get information about the mediated matrix
-device. The vfio_ap device driver will update the APM, AQM, and ADM fields in
+device. The ``vfio_ap`` device driver will update the APM, AQM, and ADM fields in
the guest's CRYCB with the adapter, usage domain and control domains assigned
via the mediated matrix device's sysfs attribute files. Programs running on the
linux guest will then:
@@ -486,20 +515,22 @@ facilities:
The AP facilities feature indicates that AP facilities are installed on the
guest. This feature will be exposed for use only if the AP facilities
are installed on the host system. The feature is s390-specific and is
- represented as a parameter of the -cpu option on the QEMU command line:
+ represented as a parameter of the -cpu option on the QEMU command line::
qemu-system-s390x -cpu $model,ap=on|off
- Where:
+ Where:
- $model is the CPU model defined for the guest (defaults to the model of
- the host system if not specified).
+ ``$model``
+ is the CPU model defined for the guest (defaults to the model of
+ the host system if not specified).
- ap=on|off indicates whether AP facilities are installed (on) or not
- (off). The default for CPU models zEC12 or newer
- is ap=on. AP facilities must be installed on the guest if a
- vfio-ap device (-device vfio-ap,sysfsdev=$path) is configured
- for the guest, or the guest will fail to start.
+ ``ap=on|off``
+ indicates whether AP facilities are installed (on) or not
+ (off). The default for CPU models zEC12 or newer
+ is ``ap=on``. AP facilities must be installed on the guest if a
+ vfio-ap device (``-device vfio-ap,sysfsdev=$path``) is configured
+ for the guest, or the guest will fail to start.
2. Query Configuration Information (QCI) facility
@@ -507,27 +538,29 @@ facilities:
configuration of the AP facilities. This facility will be available
only if the QCI facility is installed on the host system. The feature is
s390-specific and is represented as a parameter of the -cpu option on the
- QEMU command line:
+ QEMU command line::
qemu-system-s390x -cpu $model,apqci=on|off
- Where:
+ Where:
- $model is the CPU model defined for the guest
+ ``$model``
+ is the CPU model defined for the guest
- apqci=on|off indicates whether the QCI facility is installed (on) or
- not (off). The default for CPU models zEC12 or newer
- is apqci=on; for older models, QCI will not be installed.
+ ``apqci=on|off``
+ indicates whether the QCI facility is installed (on) or
+ not (off). The default for CPU models zEC12 or newer
+ is ``apqci=on``; for older models, QCI will not be installed.
- If QCI is installed (apqci=on) but AP facilities are not
- (ap=off), an error message will be logged, but the guest
- will be allowed to start. It makes no sense to have QCI
- installed if the AP facilities are not; this is considered
- an invalid configuration.
+ If QCI is installed (``apqci=on``) but AP facilities are not
+ (``ap=off``), an error message will be logged, but the guest
+ will be allowed to start. It makes no sense to have QCI
+ installed if the AP facilities are not; this is considered
+ an invalid configuration.
- If the QCI facility is not installed, APQNs with an APQI
- greater than 15 will not be detected by the AP bus
- running on the guest.
+ If the QCI facility is not installed, APQNs with an APQI
+ greater than 15 will not be detected by the AP bus
+ running on the guest.
3. Adjunct Process Facility Test (APFT) facility
@@ -535,48 +568,51 @@ facilities:
AP facilities available for a given AP queue. This facility will be available
only if the APFT facility is installed on the host system. The feature is
s390-specific and is represented as a parameter of the -cpu option on the
- QEMU command line:
+ QEMU command line::
qemu-system-s390x -cpu $model,apft=on|off
- Where:
+ Where:
+
+ ``$model``
+ is the CPU model defined for the guest (defaults to the model of
+ the host system if not specified).
- $model is the CPU model defined for the guest (defaults to the model of
- the host system if not specified).
+ ``apft=on|off``
+ indicates whether the APFT facility is installed (on) or
+ not (off). The default for CPU models zEC12 and
+ newer is ``apft=on`` for older models, APFT will not be
+ installed.
- apft=on|off indicates whether the APFT facility is installed (on) or
- not (off). The default for CPU models zEC12 and
- newer is apft=on for older models, APFT will not be
- installed.
+ If APFT is installed (``apft=on``) but AP facilities are not
+ (``ap=off``), an error message will be logged, but the guest
+ will be allowed to start. It makes no sense to have APFT
+ installed if the AP facilities are not; this is considered
+ an invalid configuration.
- If APFT is installed (apft=on) but AP facilities are not
- (ap=off), an error message will be logged, but the guest
- will be allowed to start. It makes no sense to have APFT
- installed if the AP facilities are not; this is considered
- an invalid configuration.
+ It also makes no sense to turn APFT off because the AP bus
+ running on the guest will not detect CEX4 and newer devices
+ without it. Since only CEX4 and newer devices are supported
+ for guest usage, no AP devices can be made accessible to a
+ guest started without APFT installed.
- It also makes no sense to turn APFT off because the AP bus
- running on the guest will not detect CEX4 and newer devices
- without it. Since only CEX4 and newer devices are supported
- for guest usage, no AP devices can be made accessible to a
- guest started without APFT installed.
+Hot plug a vfio-ap device into a running guest
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-Hot plug a vfio-ap device into a running guest:
-==============================================
Only one vfio-ap device can be attached to the virtual machine's ap-bus, so a
vfio-ap device can be hot plugged if and only if no vfio-ap device is attached
to the bus already, whether via the QEMU command line or a prior hot plug
action.
-To hot plug a vfio-ap device, use the QEMU device_add command:
+To hot plug a vfio-ap device, use the QEMU ``device_add`` command::
(qemu) device_add vfio-ap,sysfsdev="$path-to-mdev"
- Where the '$path-to-mdev' value specifies the absolute path to a mediated
- device to which AP resources to be used by the guest have been assigned.
+Where the ``$path-to-mdev`` value specifies the absolute path to a mediated
+device to which AP resources to be used by the guest have been assigned.
Note that on Linux guests, the AP devices will be created in the
-/sys/bus/ap/devices directory when the AP bus subsequently performs its periodic
+``/sys/bus/ap/devices`` directory when the AP bus subsequently performs its periodic
scan, so there may be a short delay before the AP devices are accessible on the
guest.
@@ -587,66 +623,69 @@ The command will fail if:
* The CPU model features for controlling guest access to AP facilities are not
enabled (see 'CPU model features' subsection in the previous section).
-Hot unplug a vfio-ap device from a running guest:
-================================================
+Hot unplug a vfio-ap device from a running guest
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
A vfio-ap device can be unplugged from a running KVM guest if a vfio-ap device
has been attached to the virtual machine's ap-bus via the QEMU command line
or a prior hot plug action.
-To hot unplug a vfio-ap device, use the QEMU device_del command:
+To hot unplug a vfio-ap device, use the QEMU ``device_del`` command::
(qemu) device_del vfio-ap,sysfsdev="$path-to-mdev"
- Where $path-to-mdev is the same as the path specified when the vfio-ap
- device was attached to the virtual machine's ap-bus.
+Where ``$path-to-mdev`` is the same as the path specified when the vfio-ap
+device was attached to the virtual machine's ap-bus.
-On a Linux guest, the AP devices will be removed from the /sys/bus/ap/devices
+On a Linux guest, the AP devices will be removed from the ``/sys/bus/ap/devices``
directory on the guest when the AP bus subsequently performs its periodic scan,
so there may be a short delay before the AP devices are no longer accessible by
the guest.
-The command will fail if the $path-to-mdev specified on the device_del command
+The command will fail if the ``$path-to-mdev`` specified on the ``device_del`` command
does not match the value specified when the vfio-ap device was attached to
the virtual machine's ap-bus.
-Example: Configure AP Matrixes for Three Linux Guests:
-=====================================================
+Example: Configure AP Matrices for Three Linux Guests
+-----------------------------------------------------
+
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 (5,4), (5,171), (6,4), (6,171),
-
-Guest3
-------
-CARD.DOMAIN TYPE MODE
-------------------------------
-06 CEX5A Accelerator
-06.0047 CEX5A Accelerator
-06.00ff CEX5A Accelerator
+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
+
+Guest3::
+
+ 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
@@ -657,6 +696,7 @@ These are the steps:
To build the vfio_ap module, the kernel build must be configured with the
following Kconfig elements selected:
+
* IOMMU_SUPPORT
* S390
* ZCRYPT
@@ -666,21 +706,21 @@ These are the steps:
* 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 framework
- -> VFIO driver for Mediated devices
- -> I/O subsystem
- -> VFIO support for AP devices
+ 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 framework
+ -> 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 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 must be removed from the default queue drivers pool
- as follows:
+ as follows::
echo -5,-6 > /sys/bus/ap/apmask
@@ -689,19 +729,19 @@ These are the steps:
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]
+ 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
@@ -712,153 +752,153 @@ These are the steps:
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:
+ to see the hardware type of the queue 05.0004::
- cat /sys/bus/ap/devices/card05/hwtype
+ 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:
+ use by the guests::
- /sys/devices/vfio_ap/matrix/
- --- [mdev_supported_types]
- ------ [vfio_ap-passthrough] (passthrough mediated matrix device type)
- --------- create
- --------- [devices]
+ /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:
+ To create the mediated devices for the three guests::
uuidgen > create
uuidgen > create
uuidgen > create
- or
+ or
- echo $uuid1 > create
- echo $uuid2 > create
- echo $uuid3 > create
+ ::
+
+ echo $uuid1 > create
+ echo $uuid2 > create
+ echo $uuid3 > create
This will create three mediated devices in the [devices] subdirectory named
after the UUID used to create the mediated device. We'll 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
+ $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 $uuid3 (for Guest3).
- This is how the matrix is configured for Guest1:
+ This is how the matrix is configured for Guest1::
echo 5 > assign_adapter
echo 6 > assign_adapter
echo 4 > assign_domain
echo 0xab > assign_domain
- Control domains can similarly be assigned using the assign_control_domain
- sysfs file.
+ Control domains can similarly be assigned using the assign_control_domain
+ sysfs file.
- If a mistake is made configuring an adapter, domain or control domain,
- you can use the unassign_xxx interfaces to unassign the adapter, domain or
- control domain.
+ If a mistake is made configuring an adapter, domain or control domain,
+ you can use the ``unassign_xxx`` interfaces to unassign the adapter, domain or
+ control domain.
- To display the matrix configuration for Guest1:
+ To display the matrix configuration for Guest1::
cat matrix
- The output will display the APQNs in the format xx.yyyy, where xx is
- the adapter number and yyyy is the domain number. The output for Guest1
- will look like this:
+ The output will display the APQNs in the format ``xx.yyyy``, where xx is
+ the adapter number and yyyy is the domain number. The output for Guest1
+ will look like this::
05.0004
05.00ab
06.0004
06.00ab
- This is how the matrix is configured for Guest2:
+ This is how the matrix is configured for Guest2::
echo 5 > assign_adapter
echo 0x47 > assign_domain
echo 0xff > assign_domain
- This is how the matrix is configured for Guest3:
+ This is how the matrix is configured for Guest3::
echo 6 > assign_adapter
echo 0x47 > assign_domain
echo 0xff > assign_domain
-5. Start Guest1:
+5. Start Guest1::
- /usr/bin/qemu-system-s390x ... -cpu host,ap=on,apqci=on,apft=on \
- -device vfio-ap,sysfsdev=/sys/devices/vfio_ap/matrix/$uuid1 ...
+ /usr/bin/qemu-system-s390x ... -cpu host,ap=on,apqci=on,apft=on -device vfio-ap,sysfsdev=/sys/devices/vfio_ap/matrix/$uuid1 ...
-7. Start Guest2:
+7. Start Guest2::
- /usr/bin/qemu-system-s390x ... -cpu host,ap=on,apqci=on,apft=on \
- -device vfio-ap,sysfsdev=/sys/devices/vfio_ap/matrix/$uuid2 ...
+ /usr/bin/qemu-system-s390x ... -cpu host,ap=on,apqci=on,apft=on -device vfio-ap,sysfsdev=/sys/devices/vfio_ap/matrix/$uuid2 ...
-7. Start Guest3:
+7. Start Guest3::
- /usr/bin/qemu-system-s390x ... -cpu host,ap=on,apqci=on,apft=on \
- -device vfio-ap,sysfsdev=/sys/devices/vfio_ap/matrix/$uuid3 ...
+ /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:
+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
+ ... [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.
+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.
+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
@@ -867,10 +907,10 @@ Limitations
device, such as a private key configured specifically for the guest.
* Dynamically assigning AP resources to or unassigning AP resources from a
- mediated matrix device - see 'Configuring an AP matrix for a linux guest'
+ mediated matrix device - see `Configuring an AP matrix for a linux guest`_
section above - while a running guest is using it is currently not supported.
* Live guest migration is not supported for guests using AP devices. If a guest
is using AP devices, the vfio-ap device configured for the guest must be
- unplugged before migrating the guest (see 'Hot unplug a vfio-ap device from a
- running guest' section above.
+ unplugged before migrating the guest (see `Hot unplug a vfio-ap device from a
+ running guest`_ section above.)
--
2.21.1
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