linux/include/xen
Roger Pau Monne 073828e954 ACPI: processor: Fix evaluating _PDC method when running as Xen dom0
In ACPI systems, the OS can direct power management, as opposed to the
firmware.  This OS-directed Power Management is called OSPM.  Part of
telling the firmware that the OS going to direct power management is
making ACPI "_PDC" (Processor Driver Capabilities) calls.  These _PDC
methods must be evaluated for every processor object.  If these _PDC
calls are not completed for every processor it can lead to
inconsistency and later failures in things like the CPU frequency
driver.

In a Xen system, the dom0 kernel is responsible for system-wide power
management.  The dom0 kernel is in charge of OSPM.  However, the
number of CPUs available to dom0 can be different than the number of
CPUs physically present on the system.

This leads to a problem: the dom0 kernel needs to evaluate _PDC for
all the processors, but it can't always see them.

In dom0 kernels, ignore the existing ACPI method for determining if a
processor is physically present because it might not be accurate.
Instead, ask the hypervisor for this information.

Fix this by introducing a custom function to use when running as Xen
dom0 in order to check whether a processor object matches a CPU that's
online.  Such checking is done using the existing information fetched
by the Xen pCPU subsystem, extending it to also store the ACPI ID.

This ensures that _PDC method gets evaluated for all physically online
CPUs, regardless of the number of CPUs made available to dom0.

Fixes: 5d554a7bb0 ("ACPI: processor: add internal processor_physically_present()")
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-03-22 19:36:31 +01:00
..
arm xen/virtio: Optimize the setup of "xen-grant-dma" devices 2022-12-05 12:59:49 +01:00
interface x86/PVH: obtain VGA console info in Dom0 2023-03-14 15:20:51 +01:00
acpi.h xen: Remove support for PV ACPI cpu/memory hotplug 2021-04-23 09:31:50 +02:00
balloon.h xen/balloon: Bring alloc(free)_xenballooned_pages helpers back 2022-01-06 09:53:35 +01:00
events.h xen: Allow platform PCI interrupt to be shared 2023-02-13 06:53:20 +01:00
features.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
grant_table.h xen/grants: support allocating consecutive grants 2022-06-06 08:54:35 +02:00
hvc-console.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hvm.h x86/xen: Add support for HVMOP_set_evtchn_upcall_vector 2022-08-12 11:28:21 +02:00
mem-reservation.h xen/balloon: add runtime control for scrubbing ballooned out pages 2018-09-14 08:51:10 -04:00
page.h swiotlb-xen: remove XEN_PFN_PHYS 2020-08-04 07:50:43 +02:00
pci.h xen-pciback: allow compiling on other archs than x86 2021-11-02 08:03:43 -05:00
platform_pci.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
swiotlb-xen.h swiotlb-xen: fix DMA_ATTR_NO_KERNEL_MAPPING on arm 2022-05-11 19:48:32 +02:00
xen-front-pgdir-shbuf.h xen: Introduce shared buffer helpers for page directory... 2018-12-18 12:15:55 -05:00
xen-ops.h xen/virtio: Optimize the setup of "xen-grant-dma" devices 2022-12-05 12:59:49 +01:00
xen.h ACPI: processor: Fix evaluating _PDC method when running as Xen dom0 2023-03-22 19:36:31 +01:00
xenbus_dev.h xen: xenbus_dev.h: delete incorrect file name 2022-02-03 08:16:32 +01:00
xenbus.h driver core: make struct bus_type.uevent() take a const * 2023-01-27 13:45:52 +01:00