ACPI: add _PDC input override mechanism

In order to have Dom0 call _PDC with input fully representing Xen's
capabilities, and in order to avoid building knowledge of Xen
implementation details into Dom0, this provides a mechanism by which
the Dom0 kernel can, once it filled the _PDC input buffer according to
its own knowledge, present the buffer to Xen to apply overrides for
the parts of the C-, P-, and T-state management that it controls. This
is particularly to address the dependency of Xen using MWAIT to enter
certain C-states on the availability of the break-on-interrupt
extension (which the Dom0 kernel should have no need to know about).

Signed-off-by: Jan Beulich <jbeulich@novell.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/xen/include/public/platform.h b/xen/include/public/platform.h
index 04dbaef64d..805738880b 100644
--- a/xen/include/public/platform.h
+++ b/xen/include/public/platform.h
@@ -304,6 +304,7 @@ DEFINE_XEN_GUEST_HANDLE(xenpf_getidletime_t);
 #define XEN_PM_CX   0
 #define XEN_PM_PX   1
 #define XEN_PM_TX   2
+#define XEN_PM_PDC  3
 
 /* Px sub info type */
 #define XEN_PX_PCT   1
@@ -401,6 +402,7 @@ struct xenpf_set_processor_pminfo {
     union {
         struct xen_processor_power          power;/* Cx: _CST/_CSD */
         struct xen_processor_performance    perf; /* Px: _PPC/_PCT/_PSS/_PSD */
+        XEN_GUEST_HANDLE(uint32)            pdc;  /* _PDC */
     } u;
 };
 typedef struct xenpf_set_processor_pminfo xenpf_set_processor_pminfo_t;