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Tony Krowiak 49b0109fb3 s390/vfio-ap: introduce shadow APCB
The APCB is a field within the CRYCB that provides the AP configuration
to a KVM guest. Let's introduce a shadow copy of the KVM guest's APCB and
maintain it for the lifespan of the guest.

The shadow APCB serves the following purposes:

1. The shadow APCB can be maintained even when the mediated device is not
   currently in use by a KVM guest. Since the mediated device's AP
   configuration is filtered to ensure that no AP queues are passed through
   to the KVM guest that are not bound to the vfio_ap device driver or
   available to the host, the mediated device's AP configuration may differ
   from the guest's. Having a shadow of a guest's APCB allows us to provide
   a sysfs interface to view the guest's APCB even if the mediated device
   is not currently passed through to a KVM guest. This can aid in
   problem determination when the guest is unexpectedly missing AP
   resources.

2. If filtering was done in-place for the real APCB, the guest could pick
   up a transient state. Doing the filtering on a shadow and transferring
   the AP configuration to the real APCB after the guest is started or when
   AP resources are assigned to or unassigned from the mediated device, or
   when the host configuration changes, the guest's AP configuration will
   never be in a transient state.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:09 +02:00
arch X86 updates: 2022-06-19 09:58:28 -05:00
block block/bfq: Enable I/O statistics 2022-06-16 16:59:28 -06:00
certs certs: fix and refactor CONFIG_SYSTEM_BLACKLIST_HASH_LIST build 2022-06-15 21:52:32 +03:00
crypto crypto: memneq - move into lib/ 2022-06-12 14:51:51 +08:00
Documentation A set of interrupt subsystem updates: 2022-06-19 09:45:16 -05:00
drivers s390/vfio-ap: introduce shadow APCB 2022-07-19 16:18:09 +02:00
fs Fixes for 5.19-rc3: 2022-06-19 09:24:49 -05:00
include Build tool updates: 2022-06-19 09:54:16 -05:00
init gcc-12: disable '-Warray-bounds' universally for now 2022-06-09 10:11:12 -07:00
ipc These changes update the ipc sysctls so that they are fundamentally 2022-06-03 15:54:57 -07:00
kernel A single scheduler fix plugging a race between sched_setscheduler() and 2022-06-19 09:51:00 -05:00
lib Build tool updates: 2022-06-19 09:54:16 -05:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm Merge tag 'fs_for_v5.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2022-06-17 10:09:24 -07:00
net NFS Client Fixes for Linux 5.19-rc 2022-06-17 15:17:57 -05:00
samples drm for 5.19-rc1 2022-05-25 16:18:27 -07:00
scripts Build tool updates: 2022-06-19 09:54:16 -05:00
security selinux: free contexts previously transferred in selinux_add_opt() 2022-06-15 21:20:45 -04:00
sound sound fixes for 5.19-rc2 2022-06-10 10:20:57 -07:00
tools tools/testing/crypto: Use vzalloc instead of vmalloc+memset 2022-07-05 14:46:36 +02:00
usr Not a lot of material this cycle. Many singleton patches against various 2022-05-27 11:22:03 -07:00
virt KVM: x86: disable preemption around the call to kvm_arch_vcpu_{un|}blocking 2022-06-09 10:52:20 -04:00
.clang-format clang-format: Fix space after for_each macros 2022-05-20 19:27:16 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: split the second line of *.mod into *.usyms 2022-05-08 03:16:59 +09:00
.mailmap Hot fixes for 5.19-rc1. 2022-06-05 17:05:38 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: replace a Microchip AT91 maintainer 2022-02-09 11:30:01 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS rectifications and a few minor driver fixes 2022-06-19 09:35:09 -05:00
Makefile Linux 5.19-rc3 2022-06-19 15:06:47 -05:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.