From fdb9eb9f155bfc0f8dc2fc88f90448b30c78ad97 Mon Sep 17 00:00:00 2001
From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Date: Fri, 26 Mar 2010 11:21:22 -0700
Subject: [PATCH] xen/dom0: set wallclock time in Xen

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
---
 arch/x86/xen/time.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index 5158c505bef9..8c9cdfa24657 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -200,8 +200,22 @@ 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 = {