Merge tag 'for-linus-4.5-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen updates from David Vrabel:
 "Xen features and fixes for 4.5-rc0:

   - Stolen ticks and PV wallclock support for arm/arm64

   - Add grant copy ioctl to gntdev device"

* tag 'for-linus-4.5-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/gntdev: add ioctl for grant copy
  x86/xen: don't reset vcpu_info on a cancelled suspend
  xen/gntdev: constify mmu_notifier_ops structures
  xen/grant-table: constify gnttab_ops structure
  xen/time: use READ_ONCE
  xen/x86: convert remaining timespec to timespec64 in xen_pvclock_gtod_notify
  xen/x86: support XENPF_settime64
  xen/arm: set the system time in Xen via the XENPF_settime64 hypercall
  xen/arm: introduce xen_read_wallclock
  arm: extend pvclock_wall_clock with sec_hi
  xen: introduce XENPF_settime64
  xen/arm: introduce HYPERVISOR_platform_op on arm and arm64
  xen: rename dom0_op to platform_op
  xen/arm: account for stolen ticks
  arm64: introduce CONFIG_PARAVIRT, PARAVIRT_TIME_ACCOUNTING and pv_time_ops
  arm: introduce CONFIG_PARAVIRT, PARAVIRT_TIME_ACCOUNTING and pv_time_ops
  missing include asm/paravirt.h in cputime.c
  xen: move xen_setup_runstate_info and get_runstate_snapshot to drivers/xen/time.c

arch/arm/Kconfig

@@ -1824,6 +1824,25 @@ config SWIOTLB
 config IOMMU_HELPER
 	def_bool SWIOTLB
 
+config PARAVIRT
+	bool "Enable paravirtualization code"
+	help
+	  This changes the kernel so it can modify itself when it is run
+	  under a hypervisor, potentially improving performance significantly
+	  over full virtualization.
+
+config PARAVIRT_TIME_ACCOUNTING
+	bool "Paravirtual steal time accounting"
+	select PARAVIRT
+	default n
+	help
+	  Select this option to enable fine granularity task steal time
+	  accounting. Time spent executing other tasks in parallel with
+	  the current vCPU is discounted from the vCPU power. To account for
+	  that, there can be a small performance impact.
+
+	  If in doubt, say N here.
+
 config XEN_DOM0
 	def_bool y
 	depends on XEN
@@ -1837,6 +1856,7 @@ config XEN
 	select ARCH_DMA_ADDR_T_64BIT
 	select ARM_PSCI
 	select SWIOTLB_XEN
+	select PARAVIRT
 	help
 	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
 

arch/arm/include/asm/paravirt.h

@@ -0,0 +1,20 @@
+#ifndef _ASM_ARM_PARAVIRT_H
+#define _ASM_ARM_PARAVIRT_H
+
+#ifdef CONFIG_PARAVIRT
+struct static_key;
+extern struct static_key paravirt_steal_enabled;
+extern struct static_key paravirt_steal_rq_enabled;
+
+struct pv_time_ops {
+	unsigned long long (*steal_clock)(int cpu);
+};
+extern struct pv_time_ops pv_time_ops;
+
+static inline u64 paravirt_steal_clock(int cpu)
+{
+	return pv_time_ops.steal_clock(cpu);
+}
+#endif
+
+#endif

arch/arm/include/asm/xen/hypercall.h

@@ -35,6 +35,7 @@
 
 #include <xen/interface/xen.h>
 #include <xen/interface/sched.h>
+#include <xen/interface/platform.h>
 
 long privcmd_call(unsigned call, unsigned long a1,
 		unsigned long a2, unsigned long a3,
@@ -49,6 +50,12 @@ int HYPERVISOR_memory_op(unsigned int cmd, void *arg);
 int HYPERVISOR_physdev_op(int cmd, void *arg);
 int HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args);
 int HYPERVISOR_tmem_op(void *arg);
+int HYPERVISOR_platform_op_raw(void *arg);
+static inline int HYPERVISOR_platform_op(struct xen_platform_op *op)
+{
+	op->interface_version = XENPF_INTERFACE_VERSION;
+	return HYPERVISOR_platform_op_raw(op);
+}
 int HYPERVISOR_multicall(struct multicall_entry *calls, uint32_t nr);
 
 static inline int

arch/arm/include/asm/xen/interface.h

@@ -27,6 +27,8 @@
 		(hnd).p = val;				\
 	} while (0)
 
+#define __HYPERVISOR_platform_op_raw __HYPERVISOR_platform_op
+
 #ifndef __ASSEMBLY__
 /* Explicitly size integers that represent pfns in the interface with
  * Xen so that we can have one ABI that works for 32 and 64 bit guests.
@@ -76,6 +78,7 @@ struct pvclock_wall_clock {
 	u32   version;
 	u32   sec;
 	u32   nsec;
+	u32   sec_hi;
 } __attribute__((__packed__));
 #endif
 

arch/arm/kernel/Makefile

@@ -81,6 +81,7 @@ obj-$(CONFIG_EFI)		+= efi.o
 ifneq ($(CONFIG_ARCH_EBSA110),y)
   obj-y		+= io.o
 endif
+obj-$(CONFIG_PARAVIRT)	+= paravirt.o
 
 head-y			:= head$(MMUEXT).o
 obj-$(CONFIG_DEBUG_LL)	+= debug.o

arch/arm/kernel/paravirt.c

@@ -0,0 +1,25 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * Copyright (C) 2013 Citrix Systems
+ *
+ * Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
+ */
+
+#include <linux/export.h>
+#include <linux/jump_label.h>
+#include <linux/types.h>
+#include <asm/paravirt.h>
+
+struct static_key paravirt_steal_enabled;
+struct static_key paravirt_steal_rq_enabled;
+
+struct pv_time_ops pv_time_ops;
+EXPORT_SYMBOL_GPL(pv_time_ops);

arch/arm/xen/enlighten.c

@@ -12,6 +12,7 @@
 #include <xen/page.h>
 #include <xen/interface/sched.h>
 #include <xen/xen-ops.h>
+#include <asm/paravirt.h>
 #include <asm/xen/hypervisor.h>
 #include <asm/xen/hypercall.h>
 #include <asm/system_misc.h>
@@ -25,6 +26,10 @@
 #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>
 
@@ -79,6 +84,83 @@ int xen_unmap_domain_gfn_range(struct vm_area_struct *vma,
 }
 EXPORT_SYMBOL_GPL(xen_unmap_domain_gfn_range);
 
+static unsigned long long xen_stolen_accounting(int cpu)
+{
+	struct vcpu_runstate_info state;
+
+	BUG_ON(cpu != smp_processor_id());
+
+	xen_get_runstate_snapshot(&state);
+
+	WARN_ON(state.state != RUNSTATE_running);
+
+	return state.time[RUNSTATE_runnable] + state.time[RUNSTATE_offline];
+}
+
+static void xen_read_wallclock(struct timespec64 *ts)
+{
+	u32 version;
+	struct timespec64 now, ts_monotonic;
+	struct shared_info *s = HYPERVISOR_shared_info;
+	struct pvclock_wall_clock *wall_clock = &(s->wc);
+
+	/* get wallclock at system boot */
+	do {
+		version = wall_clock->version;
+		rmb();		/* fetch version before time */
+		now.tv_sec  = ((uint64_t)wall_clock->sec_hi << 32) | wall_clock->sec;
+		now.tv_nsec = wall_clock->nsec;
+		rmb();		/* fetch time before checking version */
+	} while ((wall_clock->version & 1) || (version != wall_clock->version));
+
+	/* time since system boot */
+	ktime_get_ts64(&ts_monotonic);
+	*ts = timespec64_add(now, ts_monotonic);
+}
+
+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.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);
+	(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;
@@ -104,6 +186,8 @@ static void xen_percpu_init(void)
 	BUG_ON(err);
 	per_cpu(xen_vcpu, cpu) = vcpup;
 
+	xen_setup_runstate_info(cpu);
+
 after_register_vcpu_info:
 	enable_percpu_irq(xen_events_irq, 0);
 	put_cpu();
@@ -271,6 +355,11 @@ static int __init xen_guest_init(void)
 
 	register_cpu_notifier(&xen_cpu_notifier);
 
+	pv_time_ops.steal_clock = xen_stolen_accounting;
+	static_key_slow_inc(&paravirt_steal_enabled);
+	if (xen_initial_domain())
+		pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
+
 	return 0;
 }
 early_initcall(xen_guest_init);
@@ -282,6 +371,11 @@ static int __init xen_pm_init(void)
 
 	pm_power_off = xen_power_off;
 	arm_pm_restart = xen_restart;
+	if (!xen_initial_domain()) {
+		struct timespec64 ts;
+		xen_read_wallclock(&ts);
+		do_settimeofday64(&ts);
+	}
 
 	return 0;
 }
@@ -307,5 +401,6 @@ EXPORT_SYMBOL_GPL(HYPERVISOR_memory_op);
 EXPORT_SYMBOL_GPL(HYPERVISOR_physdev_op);
 EXPORT_SYMBOL_GPL(HYPERVISOR_vcpu_op);
 EXPORT_SYMBOL_GPL(HYPERVISOR_tmem_op);
+EXPORT_SYMBOL_GPL(HYPERVISOR_platform_op);
 EXPORT_SYMBOL_GPL(HYPERVISOR_multicall);
 EXPORT_SYMBOL_GPL(privcmd_call);

arch/arm/xen/hypercall.S

@@ -89,6 +89,7 @@ HYPERCALL2(memory_op);
 HYPERCALL2(physdev_op);
 HYPERCALL3(vcpu_op);
 HYPERCALL1(tmem_op);
+HYPERCALL1(platform_op_raw);
 HYPERCALL2(multicall);
 
 ENTRY(privcmd_call)

arch/arm64/Kconfig

@@ -555,6 +555,25 @@ config SECCOMP
 	  and the task is only allowed to execute a few safe syscalls
 	  defined by each seccomp mode.
 
+config PARAVIRT
+	bool "Enable paravirtualization code"
+	help
+	  This changes the kernel so it can modify itself when it is run
+	  under a hypervisor, potentially improving performance significantly
+	  over full virtualization.
+
+config PARAVIRT_TIME_ACCOUNTING
+	bool "Paravirtual steal time accounting"
+	select PARAVIRT
+	default n
+	help
+	  Select this option to enable fine granularity task steal time
+	  accounting. Time spent executing other tasks in parallel with
+	  the current vCPU is discounted from the vCPU power. To account for
+	  that, there can be a small performance impact.
+
+	  If in doubt, say N here.
+
 config XEN_DOM0
 	def_bool y
 	depends on XEN
@@ -563,6 +582,7 @@ config XEN
 	bool "Xen guest support on ARM64"
 	depends on ARM64 && OF
 	select SWIOTLB_XEN
+	select PARAVIRT
 	help
 	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
 

arch/arm64/include/asm/paravirt.h

@@ -0,0 +1,20 @@
+#ifndef _ASM_ARM64_PARAVIRT_H
+#define _ASM_ARM64_PARAVIRT_H
+
+#ifdef CONFIG_PARAVIRT
+struct static_key;
+extern struct static_key paravirt_steal_enabled;
+extern struct static_key paravirt_steal_rq_enabled;
+
+struct pv_time_ops {
+	unsigned long long (*steal_clock)(int cpu);
+};
+extern struct pv_time_ops pv_time_ops;
+
+static inline u64 paravirt_steal_clock(int cpu)
+{
+	return pv_time_ops.steal_clock(cpu);
+}
+#endif
+
+#endif

arch/arm64/kernel/Makefile

@@ -41,6 +41,7 @@ arm64-obj-$(CONFIG_EFI)			+= efi.o efi-entry.stub.o
 arm64-obj-$(CONFIG_PCI)			+= pci.o
 arm64-obj-$(CONFIG_ARMV8_DEPRECATED)	+= armv8_deprecated.o
 arm64-obj-$(CONFIG_ACPI)		+= acpi.o
+arm64-obj-$(CONFIG_PARAVIRT)		+= paravirt.o
 
 obj-y					+= $(arm64-obj-y) vdso/
 obj-m					+= $(arm64-obj-m)

arch/arm64/kernel/paravirt.c

@@ -0,0 +1,25 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * Copyright (C) 2013 Citrix Systems
+ *
+ * Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
+ */
+
+#include <linux/export.h>
+#include <linux/jump_label.h>
+#include <linux/types.h>
+#include <asm/paravirt.h>
+
+struct static_key paravirt_steal_enabled;
+struct static_key paravirt_steal_rq_enabled;
+
+struct pv_time_ops pv_time_ops;
+EXPORT_SYMBOL_GPL(pv_time_ops);

arch/arm64/xen/hypercall.S

@@ -80,6 +80,7 @@ HYPERCALL2(memory_op);
 HYPERCALL2(physdev_op);
 HYPERCALL3(vcpu_op);
 HYPERCALL1(tmem_op);
+HYPERCALL1(platform_op_raw);
 HYPERCALL2(multicall);
 
 ENTRY(privcmd_call)

arch/x86/include/asm/xen/hypercall.h

@@ -310,10 +310,10 @@ HYPERVISOR_mca(struct xen_mc *mc_op)
 }
 
 static inline int
-HYPERVISOR_dom0_op(struct xen_platform_op *platform_op)
+HYPERVISOR_platform_op(struct xen_platform_op *op)
 {
-	platform_op->interface_version = XENPF_INTERFACE_VERSION;
-	return _hypercall1(int, dom0_op, platform_op);
+	op->interface_version = XENPF_INTERFACE_VERSION;
+	return _hypercall1(int, platform_op, op);
 }
 
 static inline int

arch/x86/xen/apic.c

@@ -64,7 +64,7 @@ static u32 xen_apic_read(u32 reg)
 	if (reg != APIC_ID)
 		return 0;
 
-	ret = HYPERVISOR_dom0_op(&op);
+	ret = HYPERVISOR_platform_op(&op);
 	if (ret)
 		return 0;
 

arch/x86/xen/enlighten.c

@@ -415,7 +415,7 @@ static bool __init xen_check_mwait(void)
 
 	set_xen_guest_handle(op.u.set_pminfo.pdc, buf);
 
-	if ((HYPERVISOR_dom0_op(&op) == 0) &&
+	if ((HYPERVISOR_platform_op(&op) == 0) &&
 	    (buf[2] & (ACPI_PDC_C_C1_FFH | ACPI_PDC_C_C2C3_FFH))) {
 		cpuid_leaf5_ecx_val = cx;
 		cpuid_leaf5_edx_val = dx;
@@ -1365,7 +1365,7 @@ static void __init xen_boot_params_init_edd(void)
 		info->params.length = sizeof(info->params);
 		set_xen_guest_handle(op.u.firmware_info.u.disk_info.edd_params,
 				     &info->params);
-		ret = HYPERVISOR_dom0_op(&op);
+		ret = HYPERVISOR_platform_op(&op);
 		if (ret)
 			break;
 
@@ -1383,7 +1383,7 @@ static void __init xen_boot_params_init_edd(void)
 	op.u.firmware_info.type = XEN_FW_DISK_MBR_SIGNATURE;
 	for (nr = 0; nr < EDD_MBR_SIG_MAX; nr++) {
 		op.u.firmware_info.index = nr;
-		ret = HYPERVISOR_dom0_op(&op);
+		ret = HYPERVISOR_platform_op(&op);
 		if (ret)
 			break;
 		mbr_signature[nr] = op.u.firmware_info.u.disk_mbr_signature.mbr_signature;
@@ -1690,7 +1690,7 @@ asmlinkage __visible void __init xen_start_kernel(void)
 		xen_start_info->console.domU.mfn = 0;
 		xen_start_info->console.domU.evtchn = 0;
 
-		if (HYPERVISOR_dom0_op(&op) == 0)
+		if (HYPERVISOR_platform_op(&op) == 0)
 			boot_params.kbd_status = op.u.firmware_info.u.kbd_shift_flags;
 
 		/* Make sure ACS will be enabled */

arch/x86/xen/suspend.c

@@ -34,7 +34,8 @@ static void xen_hvm_post_suspend(int suspend_cancelled)
 {
 #ifdef CONFIG_XEN_PVHVM
 	int cpu;
-	xen_hvm_init_shared_info();
+	if (!suspend_cancelled)
+	    xen_hvm_init_shared_info();
 	xen_callback_vector();
 	xen_unplug_emulated_devices();
 	if (xen_feature(XENFEAT_hvm_safe_pvclock)) {

arch/x86/xen/time.c

@@ -16,6 +16,7 @@
 #include <linux/gfp.h>
 #include <linux/slab.h>
 #include <linux/pvclock_gtod.h>
+#include <linux/timekeeper_internal.h>
 
 #include <asm/pvclock.h>
 #include <asm/xen/hypervisor.h>
@@ -32,86 +33,12 @@
 #define TIMER_SLOP	100000
 #define NS_PER_TICK	(1000000000LL / HZ)
 
-/* runstate info updated by Xen */
-static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate);
-
 /* snapshots of runstate info */
 static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate_snapshot);
 
 /* unused ns of stolen time */
 static DEFINE_PER_CPU(u64, xen_residual_stolen);
 
-/* return an consistent snapshot of 64-bit time/counter value */
-static u64 get64(const u64 *p)
-{
-	u64 ret;
-
-	if (BITS_PER_LONG < 64) {
-		u32 *p32 = (u32 *)p;
-		u32 h, l;
-
-		/*
-		 * Read high then low, and then make sure high is
-		 * still the same; this will only loop if low wraps
-		 * and carries into high.
-		 * XXX some clean way to make this endian-proof?
-		 */
-		do {
-			h = p32[1];
-			barrier();
-			l = p32[0];
-			barrier();
-		} while (p32[1] != h);
-
-		ret = (((u64)h) << 32) | l;
-	} else
-		ret = *p;
-
-	return ret;
-}
-
-/*
- * Runstate accounting
- */
-static void get_runstate_snapshot(struct vcpu_runstate_info *res)
-{
-	u64 state_time;
-	struct vcpu_runstate_info *state;
-
-	BUG_ON(preemptible());
-
-	state = this_cpu_ptr(&xen_runstate);
-
-	/*
-	 * The runstate info is always updated by the hypervisor on
-	 * the current CPU, so there's no need to use anything
-	 * stronger than a compiler barrier when fetching it.
-	 */
-	do {
-		state_time = get64(&state->state_entry_time);
-		barrier();
-		*res = *state;
-		barrier();
-	} while (get64(&state->state_entry_time) != state_time);
-}
-
-/* return true when a vcpu could run but has no real cpu to run on */
-bool xen_vcpu_stolen(int vcpu)
-{
-	return per_cpu(xen_runstate, vcpu).state == RUNSTATE_runnable;
-}
-
-void xen_setup_runstate_info(int cpu)
-{
-	struct vcpu_register_runstate_memory_area area;
-
-	area.addr.v = &per_cpu(xen_runstate, cpu);
-
-	if (HYPERVISOR_vcpu_op(VCPUOP_register_runstate_memory_area,
-			       cpu, &area))
-		BUG();
-}
-
 static void do_stolen_accounting(void)
 {
 	struct vcpu_runstate_info state;
@@ -119,7 +46,7 @@ static void do_stolen_accounting(void)
 	s64 runnable, offline, stolen;
 	cputime_t ticks;
 
-	get_runstate_snapshot(&state);
+	xen_get_runstate_snapshot(&state);
 
 	WARN_ON(state.state != RUNSTATE_running);
 
@@ -194,26 +121,46 @@ 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 timespec next_sync;
+	static struct timespec64 next_sync;
 
 	struct xen_platform_op op;
-	struct timespec now;
+	struct timespec64 now;
+	struct timekeeper *tk = priv;
+	static bool settime64_supported = true;
+	int ret;
 
-	now = __current_kernel_time();
+	now.tv_sec = tk->xtime_sec;
+	now.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
 
 	/*
 	 * We only take the expensive HV call when the clock was set
 	 * or when the 11 minutes RTC synchronization time elapsed.
 	 */
-	if (!was_set && timespec_compare(&now, &next_sync) < 0)
+	if (!was_set && timespec64_compare(&now, &next_sync) < 0)
 		return NOTIFY_OK;
 
-	op.cmd = XENPF_settime;
-	op.u.settime.secs = now.tv_sec;
-	op.u.settime.nsecs = now.tv_nsec;
-	op.u.settime.system_time = xen_clocksource_read();
+again:
+	if (settime64_supported) {
+		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 = xen_clocksource_read();
+	} else {
+		op.cmd = XENPF_settime32;
+		op.u.settime32.secs = now.tv_sec;
+		op.u.settime32.nsecs = now.tv_nsec;
+		op.u.settime32.system_time = xen_clocksource_read();
+	}
 
-	(void)HYPERVISOR_dom0_op(&op);
+	ret = HYPERVISOR_platform_op(&op);
+
+	if (ret == -ENOSYS && settime64_supported) {
+		settime64_supported = false;
+		goto again;
+	}
+	if (ret < 0)
+		return NOTIFY_BAD;
 
 	/*
 	 * Move the next drift compensation time 11 minutes

drivers/xen/Makefile

@@ -1,6 +1,6 @@
 obj-$(CONFIG_HOTPLUG_CPU)		+= cpu_hotplug.o
 obj-$(CONFIG_X86)			+= fallback.o
-obj-y	+= grant-table.o features.o balloon.o manage.o preempt.o
+obj-y	+= grant-table.o features.o balloon.o manage.o preempt.o time.o
 obj-y	+= events/
 obj-y	+= xenbus/
 

drivers/xen/acpi.c

@@ -58,7 +58,7 @@ static int xen_acpi_notify_hypervisor_state(u8 sleep_state,
 		 bits, val_a, val_b))
 		return -1;
 
-	HYPERVISOR_dom0_op(&op);
+	HYPERVISOR_platform_op(&op);
 	return 1;
 }