With the Xen ACPI stub code (CONFIG_XEN_STUB=y) enabled, the power
C and P states are no longer uploaded to the hypervisor.
The reason is that the Xen CPU hotplug code: xen-acpi-cpuhotplug.c
and the xen-acpi-stub.c register themselves as the "processor" type object.
That means the generic processor (processor_driver.c) stops
working and it does not call (acpi_processor_add) which populates the
per_cpu(processors, pr->id) = pr;
structure. The 'pr' is gathered from the acpi_processor_get_info function
which does the job of finding the C-states and figuring out PBLK address.
The 'processors->pr' is then later used by xen-acpi-processor.c (the one that
uploads C and P states to the hypervisor). Since it is NULL, we end
skip the gathering of _PSD, _PSS, _PCT, etc and never upload the power
management data.
The end result is that enabling the CONFIG_XEN_STUB in the build means that
xen-acpi-processor is not working anymore.
This temporary patch fixes it by marking the XEN_STUB driver as
BROKEN until this can be properly fixed.
CC: jinsong....@intel.com
Signed-off-by: Konrad Rzeszutek Wilk <konrad.w...@oracle.com>
---
drivers/xen/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index 5a32232..67af155 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -182,7 +182,7 @@ config XEN_PRIVCMD
config XEN_STUB
bool "Xen stub drivers"
- depends on XEN && X86_64
+ depends on XEN && X86_64 && BROKEN
default n
help
Allow kernel to install stub drivers, to reserve space for Xen
drivers,
--
1.8.0.2
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