xen: pcpu: make xen_pcpu_subsys const

Now that the driver core can properly handle constant struct bus_type,
move the xen_pcpu_subsys variable to be a constant structure as well,
placing it into rea

xen: pcpu: make xen_pcpu_subsys const

Now that the driver core can properly handle constant struct bus_type,
move the xen_pcpu_subsys variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20240203-bus_cleanup-xen-v1-1-c2f5fe89ed95@marliere.net
Signed-off-by: Juergen Gross <jgross@suse.com>

show more ...

acpi/processor: sanitize _OSC/_PDC capabilities for Xen dom0

The Processor capability bits notify ACPI of the OS capabilities, and
so ACPI can adjust the return of other Processor methods taking the

acpi/processor: sanitize _OSC/_PDC capabilities for Xen dom0

The Processor capability bits notify ACPI of the OS capabilities, and
so ACPI can adjust the return of other Processor methods taking the OS
capabilities into account.

When Linux is running as a Xen dom0, the hypervisor is the entity
in charge of processor power management, and hence Xen needs to make
sure the capabilities reported by _OSC/_PDC match the capabilities of
the driver in Xen.

Introduce a small helper to sanitize the buffer when running as Xen
dom0.

When Xen supports HWP, this serves as the equivalent of commit
a21211672c9a ("ACPI / processor: Request native thermal interrupt
handling via _OSC") to avoid SMM crashes. Xen will set bit
ACPI_PROC_CAP_COLLAB_PROC_PERF (bit 12) in the capability bits and the
_OSC/_PDC call will apply it.

[ jandryuk: Mention Xen HWP's need. Support _OSC & _PDC ]
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Michal Wilczynski <michal.wilczynski@intel.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20231108212517.72279-1-jandryuk@gmail.com
Signed-off-by: Juergen Gross <jgross@suse.com>

show more ...

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 OSP

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: 5d554a7bb064 ("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>

show more ...

xen/pcpu: fix possible memory leak in register_pcpu()

In device_add(), dev_set_name() is called to allocate name, if it returns
error, the name need be freed. As comment of device_register() says, i

xen/pcpu: fix possible memory leak in register_pcpu()

In device_add(), dev_set_name() is called to allocate name, if it returns
error, the name need be freed. As comment of device_register() says, it
should use put_device() to give up the reference in the error path. So fix
this by calling put_device(), then the name can be freed in kobject_cleanup().

Fixes: f65c9bb3fb72 ("xen/pcpu: Xen physical cpus online/offline sys interface")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20221110152441.401630-1-yangyingliang@huawei.com
Signed-off-by: Juergen Gross <jgross@suse.com>

show more ...

xen: Use DEVICE_ATTR_*() macro

Use DEVICE_ATTR_*() helper instead of plain DEVICE_ATTR(),
which makes the code a bit shorter and easier to read.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Re

xen: Use DEVICE_ATTR_*() macro

Use DEVICE_ATTR_*() helper instead of plain DEVICE_ATTR(),
which makes the code a bit shorter and easier to read.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/20210526141019.13752-1-yuehaibing@huawei.com
Signed-off-by: Juergen Gross <jgross@suse.com>

show more ...

xen: Remove support for PV ACPI cpu/memory hotplug

Commit 76fc253723ad ("xen/acpi-stub: Disable it b/c the acpi_processor_add
is no longer called.") declared as BROKEN support for Xen ACPI stub (whi

xen: Remove support for PV ACPI cpu/memory hotplug

Commit 76fc253723ad ("xen/acpi-stub: Disable it b/c the acpi_processor_add
is no longer called.") declared as BROKEN support for Xen ACPI stub (which
is required for xen-acpi-{cpu|memory}-hotplug) and suggested that this
is temporary and will be soon fixed. This was in March 2013.

Further, commit cfafae940381 ("xen: rename dom0_op to platform_op")
renamed an interface used by memory hotplug code without updating that
code (as it was BROKEN and therefore not compiled). This was
in November 2015 and has gone unnoticed for over 5 year.

It is now clear that this code is of no interest to anyone and therefore
should be removed.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/1618336344-3162-1-git-send-email-boris.ostrovsky@oracle.com
Signed-off-by: Juergen Gross <jgross@suse.com>

show more ...

xen: rename dom0_op to platform_op

The dom0_op hypercall has been renamed to platform_op since Xen 3.2,
which is ancient, and modern upstream Linux kernels cannot run as dom0
and it anymore anyway.

xen: rename dom0_op to platform_op

The dom0_op hypercall has been renamed to platform_op since Xen 3.2,
which is ancient, and modern upstream Linux kernels cannot run as dom0
and it anymore anyway.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

show more ...

xen: pcpu: Use static attribute groups for sysfs entry

Instead of manual calls of device_create_file() and
device_remove_file(), assign the static attribute groups to the device
to register. The co

xen: pcpu: Use static attribute groups for sysfs entry

Instead of manual calls of device_create_file() and
device_remove_file(), assign the static attribute groups to the device
to register. The conditional build of sysfs is done in is_visible
callback instead.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

show more ...

drivers: xen: Include appropriate header file in pcpu.c

Include appropriate header file in xen/pcpu.c because include/xen/acpi.h
contains prototype declaration of functions defined in the file.

Thi

drivers: xen: Include appropriate header file in pcpu.c

Include appropriate header file in xen/pcpu.c because include/xen/acpi.h
contains prototype declaration of functions defined in the file.

This eliminates the following warning in xen/pcpu.c:
drivers/xen/pcpu.c:336:6: warning: no previous prototype for ‘xen_pcpu_hotplug_sync’ [-Wmissing-prototypes]
drivers/xen/pcpu.c:346:5: warning: no previous prototype for ‘xen_pcpu_id’ [-Wmissing-prototypes]

Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>

show more ...

xen: Convert printks to pr_<level>

Convert printks to pr_<level> (excludes printk(KERN_DEBUG...)
to be more consistent throughout the xen subsystem.

Add pr_fmt with KBUILD_MODNAME or "xen:" KBUILD_

xen: Convert printks to pr_<level>

Convert printks to pr_<level> (excludes printk(KERN_DEBUG...)
to be more consistent throughout the xen subsystem.

Add pr_fmt with KBUILD_MODNAME or "xen:" KBUILD_MODNAME
Coalesce formats and add missing word spaces
Add missing newlines
Align arguments and reflow to 80 columns
Remove DRV_NAME from formats as pr_fmt adds the same content

This does change some of the prefixes of these messages
but it also does make them more consistent.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

show more ...

xen/acpi: ACPI cpu hotplug

This patch implement real Xen ACPI cpu hotplug driver as module.
When loaded, it replaces Xen stub driver.

For booting existed cpus, the driver enumerates them.
For hotad

xen/acpi: ACPI cpu hotplug

This patch implement real Xen ACPI cpu hotplug driver as module.
When loaded, it replaces Xen stub driver.

For booting existed cpus, the driver enumerates them.
For hotadded cpus, which added at runtime and notify OS via
device or container event, the driver is invoked to add them,
parsing cpu information, hypercalling to Xen hypervisor to add
them, and finally setting up new /sys interface for them.

Signed-off-by: Liu Jinsong <jinsong.liu@intel.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

show more ...

xen: remove redundant NULL check before unregister_and_remove_pcpu().

unregister_and_remove_pcpu on a NULL pointer is a no-op, so the NULL check in
sync_pcpu can be removed.

Signed-off-by: Cyril Ro

xen: remove redundant NULL check before unregister_and_remove_pcpu().

unregister_and_remove_pcpu on a NULL pointer is a no-op, so the NULL check in
sync_pcpu can be removed.

Signed-off-by: Cyril Roelandt <tipecaml@gmail.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

show more ...

xen/pcpu: Xen physical cpus online/offline sys interface

This patch provide Xen physical cpus online/offline sys interface.
User can use it for their own purpose, like power saving:
by offlining som

xen/pcpu: Xen physical cpus online/offline sys interface

This patch provide Xen physical cpus online/offline sys interface.
User can use it for their own purpose, like power saving:
by offlining some cpus when light workload it save power greatly.

Its basic workflow is, user online/offline cpu via sys interface,
then hypercall xen to implement, after done xen inject virq back to dom0,
and then dom0 sync cpu status.

Signed-off-by: Jiang, Yunhong <yunhong.jiang@intel.com>
Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

show more ...