3 files changed, 24 insertions, 1 deletions

diff --git a/arch/x86/include/asm/xen/hypercall.h b/arch/x86/include/asm/xen/hypercall.h
index 417777de5a40..5728852fb90f 100644
--- a/arch/x86/include/asm/xen/hypercall.h
+++ b/arch/x86/include/asm/xen/hypercall.h
@@ -47,6 +47,7 @@
 #include <xen/interface/xen.h>
 #include <xen/interface/sched.h>
 #include <xen/interface/physdev.h>
+#include <xen/interface/platform.h>
 
 /*
  * The hypercall asms have to meet several constraints:
@@ -301,6 +302,13 @@ HYPERVISOR_set_timer_op(u64 timeout)
 }
 
 static inline int
+HYPERVISOR_dom0_op(struct xen_platform_op *platform_op)
+{
+        platform_op->interface_version = XENPF_INTERFACE_VERSION;
+        return _hypercall1(int, dom0_op, platform_op);
+}
+
+static inline int
 HYPERVISOR_set_debugreg(int reg, unsigned long value)
 {
         return _hypercall2(int, set_debugreg, reg, value);
diff --git a/arch/x86/include/asm/xen/interface.h b/arch/x86/include/asm/xen/interface.h
index 5d4922ad4b9b..a1f2db5f1170 100644
--- a/arch/x86/include/asm/xen/interface.h
+++ b/arch/x86/include/asm/xen/interface.h
@@ -55,6 +55,7 @@ DEFINE_GUEST_HANDLE(char);
 DEFINE_GUEST_HANDLE(int);
 DEFINE_GUEST_HANDLE(long);
 DEFINE_GUEST_HANDLE(void);
+DEFINE_GUEST_HANDLE(uint64_t);
 #endif
 
 #ifndef HYPERVISOR_VIRT_START
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index 163b4679556e..0296a9522501 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -201,8 +201,22 @@ static unsigned long xen_get_wallclock(void)
 
 static int xen_set_wallclock(unsigned long now)
 {
+        struct xen_platform_op op;
+        int rc;
+
         /* do nothing for domU */
-        return -1;
+        if (!xen_initial_domain())
+                return -1;
+
+        op.cmd = XENPF_settime;
+        op.u.settime.secs = now;
+        op.u.settime.nsecs = 0;
+        op.u.settime.system_time = xen_clocksource_read();
+
+        rc = HYPERVISOR_dom0_op(&op);
+        WARN(rc != 0, "XENPF_settime failed: now=%ld\n", now);
+
+        return rc;
 }
 
 static struct clocksource xen_clocksource __read_mostly = {