@@ -28,7 +28,10 @@
#include <linux/cpufreq.h>
#include <linux/cpu.h>
#include <linux/console.h>
+#include <linux/pvclock_gtod.h>
+#include <linux/time64.h>
#include <linux/timekeeping.h>
+#include <linux/timekeeper_internal.h>
#include <linux/mm.h>
@@ -120,6 +123,54 @@ static void xen_read_wallclock(struct timespec64 *ts)
*ts = ns_to_timespec64(delta);
}
+static int xen_pvclock_gtod_notify(struct notifier_block *nb,
+ unsigned long was_set, void *priv)
+{
+ /* Protected by the calling core code serialization */
+ static struct timespec64 next_sync;
+
+ struct xen_platform_op op;
+ struct timespec64 now, system_time;
+ struct timekeeper *tk = priv;
+
+ now.tv_sec = tk->xtime_sec;
+ now.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
+ system_time = timespec64_add(now, tk->wall_to_monotonic);
+
+ /*
+ * We only take the expensive HV call when the clock was set
+ * or when the 11 minutes RTC synchronization time elapsed.
+ */
+ if (!was_set && timespec64_compare(&now, &next_sync) < 0)
+ return NOTIFY_OK;
+
+ op.interface_version = XENPF_INTERFACE_VERSION;
+ op.cmd = XENPF_settime64;
+ op.u.settime64.mbz = 0;
+ op.u.settime64.secs = now.tv_sec;
+ op.u.settime64.nsecs = now.tv_nsec;
+ op.u.settime64.system_time = timespec64_to_ns(&system_time);
+ printk("GTOD: Setting to %llu.%09u at %llu\n",
+ op.u.settime64.secs,
+ op.u.settime64.nsecs,
+ op.u.settime64.system_time);
+ (void)HYPERVISOR_platform_op(&op);
+
+ /*
+ * Move the next drift compensation time 11 minutes
+ * ahead. That's emulating the sync_cmos_clock() update for
+ * the hardware RTC.
+ */
+ next_sync = now;
+ next_sync.tv_sec += 11 * 60;
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block xen_pvclock_gtod_notifier = {
+ .notifier_call = xen_pvclock_gtod_notify,
+};
+
static void xen_percpu_init(void)
{
struct vcpu_register_vcpu_info info;
@@ -316,7 +367,9 @@ static int __init xen_guest_init(void)
pv_time_ops.steal_clock = xen_stolen_accounting;
static_key_slow_inc(¶virt_steal_enabled);
-
+ if (xen_initial_domain())
+ pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
+
return 0;
}
early_initcall(xen_guest_init);
If Linux is running as dom0, call XENPF_settime64 to update the system time in Xen on pvclock_gtod notifications. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> --- Changes in v3: - s/%llu.%0u/%llu.%09u - in xen_pvclock_gtod_notify use the passed struct timekeeper pointer rather than calling __current_kernel_time64 - use the passed struct timekeeper pointer to get the system time too Changes in v2: - properly convert arch_timer ticker to nsec - rename dom0_op to platform_op - use timespec64 interfaces - use XENPF_settime64 --- arch/arm/xen/enlighten.c | 55 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 54 insertions(+), 1 deletion(-)