linux-dev/drivers/s390/crypto/ap_bus.c, branch linus/master

s390/zcrypt: code cleanup

2022-04-25T11:54:14Z

This patch tries to fix as much as possible of the checkpatch.pl --strict findings: CHECK: Logical continuations should be on the previous line CHECK: No space is necessary after a cast CHECK: Alignment should match open parenthesis CHECK: 'useable' may be misspelled - perhaps 'usable'? WARNING: Possible repeated word: 'is' CHECK: spaces preferred around that '*' (ctx:VxV) CHECK: Comparison to NULL could be written "!msg" CHECK: Prefer kzalloc(sizeof(*zc)...) over kzalloc(sizeof(struct...)...) CHECK: Unnecessary parentheses around resp_type->work CHECK: Avoid CamelCase: There is no functional change comming with this patch, only code cleanup, renaming, whitespaces, indenting, ... but no semantic change in any way. Also the API (zcrypt and pkey header file) is semantically unchanged. Signed-off-by: Harald Freudenberger Reviewed-by: Jürgen Christ Signed-off-by: Heiko Carstens

s390/ap: uevent on apmask/aqpmask change

2022-04-25T11:54:13Z

This patch introduces user space notifications for changes on the apmask or aqmask attributes. So it could be possible to write a udev rule to load/unload the vfio_ap kernel module based on changes of these masks. On chance of the apmask or aqmask an AP change event will be produced with an uevent environment variable showing the new APMASK or AQMASK mask. So a change on the apmask triggers an uvevent like this: KERNEL[490.160396] change /devices/ap (ap) ACTION=change DEVPATH=/devices/ap SUBSYSTEM=ap APMASK=0xffffffdfffffffffffffffffffffffffffffffffffffffffffffffffffffffff SEQNUM=13367 and a change on the aqmask looks like this: KERNEL[283.217642] change /devices/ap (ap) ACTION=change DEVPATH=/devices/ap SUBSYSTEM=ap AQMASK=0xfbffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff SEQNUM=13348 Only real changes to the masks are processed - the old and new masks are compared and no action is done if the values are equal (and thus no uevent). The emit of the uevent is the very last action done when a mask change is processed. However, there is no guarantee that all unbind/bind actions caused by the apmask/aqmask changes are completed when the apmask/aqmask change uevent is received in userspace. Signed-off-by: Harald Freudenberger Tested-by: Thomas Huth Reviewed-by: Jürgen Christ Signed-off-by: Heiko Carstens

s390/zcrypt: handle checkstopped cards with new state

2022-03-07T23:33:00Z

A crypto card may be in checkstopped state. With this patch this is handled as a new state in the ap card and ap queue structs. There is also a new card sysfs attribute /sys/devices/ap/cardxx/chkstop and a new queue sysfs attribute /sys/devices/ap/cardxx/xx.yyyy/chkstop displaying the checkstop state of the card or queue. Please note that the queue's checkstop state is only a copy of the card's checkstop state but makes maintenance much easier. The checkstop state expressed here is the result of an RC 0x04 (CHECKSTOP) during an AP command, mostly the PQAP(TAPQ) command which is 'testing' the queue. Signed-off-by: Harald Freudenberger Reviewed-by: Jürgen Christ Signed-off-by: Vasily Gorbik

s390/zcrypt: CEX8S exploitation support

2022-03-07T23:33:00Z

This patch adds CEX8 exploitation support for the AP bus code, the zcrypt device driver zoo and the vfio device driver. Signed-off-by: Harald Freudenberger Reviewed-by: Jürgen Christ Signed-off-by: Vasily Gorbik

s390/ap: enable sysfs attribute scans to force AP bus rescan

2022-03-01T20:05:10Z

This patch switches the sysfs attribute /sys/bus/ap/scans from read-only to read-write. If there is something written to this attribute, an AP bus rescan is forced. If an AP bus scan is triggered this way a debug feature entry line reports this in /sys/kernel/debug/s390dbf/ap/sprintf. Signed-off-by: Harald Freudenberger Reviewed-by: Jakob Naucke Reviewed-by: Juergen Christ Signed-off-by: Vasily Gorbik

s390/ap: notify drivers on config changed and scan complete callbacks

2022-03-01T20:05:10Z

This patch introduces an extension to the ap bus to notify device drivers when the host AP configuration changes - i.e., adapters, domains or control domains are added or removed. When an adapter or domain is added to the host's AP configuration, the AP bus will create the associated queue devices in the linux sysfs device model. Each new type 10 (i.e., CEX4) or newer queue device with an APQN that is not reserved for the default device driver will get bound to the vfio_ap device driver. Likewise, whan an adapter or domain is removed from the host's AP configuration, the AP bus will remove the associated queue devices from the sysfs device model. Each of the queues that is bound to the vfio_ap device driver will get unbound. With the introduction of hot plug support, binding or unbinding of a queue device will result in plugging or unplugging one or more queues from a guest that is using the queue. If there are multiple changes to the host's AP configuration, it could result in the probe and remove callbacks getting invoked multiple times. Each time queues are plugged into or unplugged from a guest, the guest's VCPUs must be taken out of SIE. If this occurs multiple times due to changes in the host's AP configuration, that can have an undesirable negative affect on the guest's performance. To alleviate this problem, this patch introduces two new callbacks: one to notify the vfio_ap device driver when the AP bus scan routine detects a change to the host's AP configuration; and, one to notify the driver when the AP bus is done scanning. This will allow the vfio_ap driver to do bulk processing of all affected adapters, domains and control domains for affected guests rather than plugging or unplugging them one at a time when the probe or remove callback is invoked. The two new callbacks are: void (*on_config_changed)(struct ap_config_info *new_config_info, struct ap_config_info *old_config_info); This callback is invoked at the start of the AP bus scan function when it determines that the host AP configuration information has changed since the previous scan. This is done by storing an old and current QCI info struct and comparing them. If there is any difference, the callback is invoked. void (*on_scan_complete)(struct ap_config_info *new_config_info, struct ap_config_info *old_config_info); The on_scan_complete callback is invoked after the ap bus scan is completed if the host AP configuration data has changed. Signed-off-by: Tony Krowiak Signed-off-by: Vasily Gorbik

s390/ap: driver callback to indicate resource in use

2022-03-01T20:05:09Z

Introduces a new driver callback to prevent a root user from re-assigning the APQN of a queue that is in use by a non-default host device driver to a default host device driver and vice versa. The callback will be invoked whenever a change to the AP bus's sysfs apmask or aqmask attributes would result in one or more APQNs being re-assigned. If the callback responds in the affirmative for any driver queried, the change to the apmask or aqmask will be rejected with a device busy error. For this patch, only non-default drivers will be queried. Currently, there is only one non-default driver, the vfio_ap device driver. The vfio_ap device driver facilitates pass-through of an AP queue to a guest. The idea here is that a guest may be administered by a different sysadmin than the host and we don't want AP resources to unexpectedly disappear from a guest's AP configuration (i.e., adapters and domains assigned to the matrix mdev). This will enforce the proper procedure for removing AP resources intended for guest usage which is to first unassign them from the matrix mdev, then unbind them from the vfio_ap device driver. Signed-off-by: Tony Krowiak Reviewed-by: Harald Freudenberger Reviewed-by: Halil Pasic Signed-off-by: Vasily Gorbik

s390/ap: function rework based on compiler warning

2021-10-26T13:21:30Z

Slight rework of function __ap_revise_reserved() because of unused variable warning when build with W=1. This patch introduces an additional debug feature warning message when device_reprobe() returns with failure. However, the return value of __ap_revise_reserved() is still hard coded to 0 as this is a callback function to be used together with bus_for_each_dev() and thus the return value indicates to go on with the bus_for_each_dev() loop and not apport on a failure of something within this function. Signed-off-by: Harald Freudenberger Signed-off-by: Vasily Gorbik

s390/ap: new module option ap.useirq

2021-10-26T13:21:29Z

This patch introduces a new AP module option to be able to control if the ap bus code is using interrupts or not. By default if the interrupt support is available it is used. This option makes it possible to disable interrupt use even when interrupt support is available. It should be obvious that this option can't magically enable interrupt support when the hardware or hypervisor layer does not support AP interrupts. On the kernel command line use ap.useirq=0 or ap.useirq=1 to disable or enable (that's the default) interrupt use. Signed-off-by: Harald Freudenberger Signed-off-by: Vasily Gorbik

s390/zcrypt: rework of debug feature messages

2021-10-26T13:21:27Z

This patch reworks all the debug feature invocations to be more uniform. All invocations now use the macro with the level already part of the macro name. All messages now start with %s filled with __func__ (well there are still some exceptions), and some message text has been shortened or reworked. There is no functional code touched with this patch. Signed-off-by: Harald Freudenberger Signed-off-by: Vasily Gorbik