linux-stable/include/xen/xen.h
Roger Pau Monne 1975bf0259 ACPI: processor: Fix evaluating _PDC method when running as Xen dom0
[ Upstream commit 073828e954 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-11 23:03:11 +09:00

85 lines
2.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _XEN_XEN_H
#define _XEN_XEN_H
enum xen_domain_type {
XEN_NATIVE, /* running on bare hardware */
XEN_PV_DOMAIN, /* running in a PV domain */
XEN_HVM_DOMAIN, /* running in a Xen hvm domain */
};
#ifdef CONFIG_XEN
extern enum xen_domain_type xen_domain_type;
#else
#define xen_domain_type XEN_NATIVE
#endif
#ifdef CONFIG_XEN_PVH
extern bool xen_pvh;
#else
#define xen_pvh 0
#endif
#define xen_domain() (xen_domain_type != XEN_NATIVE)
#define xen_pv_domain() (xen_domain_type == XEN_PV_DOMAIN)
#define xen_hvm_domain() (xen_domain_type == XEN_HVM_DOMAIN)
#define xen_pvh_domain() (xen_pvh)
#include <linux/types.h>
extern uint32_t xen_start_flags;
#include <xen/interface/hvm/start_info.h>
extern struct hvm_start_info pvh_start_info;
#ifdef CONFIG_XEN_DOM0
#include <xen/interface/xen.h>
#include <asm/xen/hypervisor.h>
#define xen_initial_domain() (xen_domain() && \
(xen_start_flags & SIF_INITDOMAIN))
#else /* !CONFIG_XEN_DOM0 */
#define xen_initial_domain() (0)
#endif /* CONFIG_XEN_DOM0 */
struct bio_vec;
struct page;
bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
const struct page *page);
#if defined(CONFIG_MEMORY_HOTPLUG) && defined(CONFIG_XEN_BALLOON)
extern u64 xen_saved_max_mem_size;
#endif
#ifdef CONFIG_XEN_UNPOPULATED_ALLOC
int xen_alloc_unpopulated_pages(unsigned int nr_pages, struct page **pages);
void xen_free_unpopulated_pages(unsigned int nr_pages, struct page **pages);
#include <linux/ioport.h>
int arch_xen_unpopulated_init(struct resource **res);
#else
#include <xen/balloon.h>
static inline int xen_alloc_unpopulated_pages(unsigned int nr_pages,
struct page **pages)
{
return xen_alloc_ballooned_pages(nr_pages, pages);
}
static inline void xen_free_unpopulated_pages(unsigned int nr_pages,
struct page **pages)
{
xen_free_ballooned_pages(nr_pages, pages);
}
#endif
#if defined(CONFIG_XEN_DOM0) && defined(CONFIG_ACPI) && defined(CONFIG_X86)
bool __init xen_processor_present(uint32_t acpi_id);
#else
#include <linux/bug.h>
static inline bool xen_processor_present(uint32_t acpi_id)
{
BUG();
return false;
}
#endif
#endif /* _XEN_XEN_H */