Index: xen-4.0.2-testing/xen/arch/x86/platform_hypercall.c
===================================================================
--- xen-4.0.2-testing.orig/xen/arch/x86/platform_hypercall.c
+++ xen-4.0.2-testing/xen/arch/x86/platform_hypercall.c
@@ -21,7 +21,7 @@
 #include <xen/acpi.h>
 #include <asm/current.h>
 #include <public/platform.h>
-#include <acpi/cpufreq/processor_perf.h>
+#include <acpi/cpufreq/cpufreq.h>
 #include <asm/edd.h>
 #include <asm/mtrr.h>
 #include "cpu/mtrr/mtrr.h"
@@ -62,6 +62,7 @@ static long cpu_down_helper(void *hdl, v
 ret_t do_platform_op(XEN_GUEST_HANDLE(xen_platform_op_t) u_xenpf_op)
 {
     ret_t ret = 0;
+    struct vcpu *v;
     struct xen_platform_op curop, *op = &curop;
 
     if ( !IS_PRIV(current->domain) )
@@ -488,6 +489,24 @@ ret_t do_platform_op(XEN_GUEST_HANDLE(xe
                       op->u.mem_add.epfn,
                       op->u.mem_add.pxm);
         break;
+
+    case XENPF_get_cpu_freq:
+        if ( op->u.get_cpu_freq.vcpu >= current->domain->max_vcpus ||
+             !(v = current->domain->vcpu[op->u.get_cpu_freq.vcpu]) )
+        {
+            ret = -EINVAL;
+            break;
+        }
+
+        op->u.get_cpu_freq.freq = cpufreq_cpu_policy[v->processor]
+                                  ? cpufreq_driver->get
+                                    ? cpufreq_driver->get(v->processor)
+                                    : cpufreq_cpu_policy[v->processor]->cur
+                                  : 0;
+        if ( copy_field_to_guest(u_xenpf_op, op, u.get_cpu_freq.freq) )
+            ret = -EFAULT;
+        break;
+
     default:
         ret = -ENOSYS;
         break;
Index: xen-4.0.2-testing/xen/include/public/platform.h
===================================================================
--- xen-4.0.2-testing.orig/xen/include/public/platform.h
+++ xen-4.0.2-testing/xen/include/public/platform.h
@@ -355,6 +355,14 @@ struct xenpf_mem_hotadd
     uint32_t flags;
 };
 
+#define XENPF_get_cpu_freq        ('N' << 24)
+struct xenpf_get_cpu_freq {
+    /* IN variables */
+    uint32_t vcpu;
+    /* OUT variables */
+    uint32_t freq; /* in kHz */
+};
+
 struct xen_platform_op {
     uint32_t cmd;
     uint32_t interface_version; /* XENPF_INTERFACE_VERSION */
@@ -374,6 +382,7 @@ struct xen_platform_op {
         struct xenpf_cpu_ol            cpu_ol;
         struct xenpf_cpu_hotadd        cpu_add;
         struct xenpf_mem_hotadd        mem_add;
+        struct xenpf_get_cpu_freq      get_cpu_freq;
         uint8_t                        pad[128];
     } u;
 };