26 files changed, 1416 insertions, 539 deletions

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index c9be69fedb70..7b655b5bb9ab 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -10,7 +10,7 @@ ifdef CONFIG_FTRACE
 # Do not profile debug and lowlevel utilities
 CFLAGS_REMOVE_tsc.o = -pg
 CFLAGS_REMOVE_rtc.o = -pg
-CFLAGS_REMOVE_paravirt.o = -pg
+CFLAGS_REMOVE_paravirt-spinlocks.o = -pg
 endif
 
 #
@@ -90,7 +90,7 @@ obj-$(CONFIG_DEBUG_NX_TEST)	+= test_nx.o
 obj-$(CONFIG_VMI)		+= vmi_32.o vmiclock_32.o
 obj-$(CONFIG_KVM_GUEST)		+= kvm.o
 obj-$(CONFIG_KVM_CLOCK)		+= kvmclock.o
-obj-$(CONFIG_PARAVIRT)		+= paravirt.o paravirt_patch_$(BITS).o
+obj-$(CONFIG_PARAVIRT)		+= paravirt.o paravirt_patch_$(BITS).o paravirt-spinlocks.o
 obj-$(CONFIG_PARAVIRT_CLOCK)	+= pvclock.o
 
 obj-$(CONFIG_PCSPKR_PLATFORM)	+= pcspeaker.o
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 7581b62df184..fb789dd9e691 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1121,16 +1121,5 @@ void __cpuinit cpu_init(void)
 	xsave_init();
 }
 
-#ifdef CONFIG_HOTPLUG_CPU
-void __cpuinit cpu_uninit(void)
-{
-	int cpu = raw_smp_processor_id();
-	cpu_clear(cpu, cpu_initialized);
-
-	/* lazy TLB state */
-	per_cpu(cpu_tlbstate, cpu).state = 0;
-	per_cpu(cpu_tlbstate, cpu).active_mm = &init_mm;
-}
-#endif
 
 #endif
diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c
index 0ed5f939b905..eee32b43fee3 100644
--- a/arch/x86/kernel/ldt.c
+++ b/arch/x86/kernel/ldt.c
@@ -52,6 +52,8 @@ static int alloc_ldt(mm_context_t *pc, int mincount, int reload)
 	memset(newldt + oldsize * LDT_ENTRY_SIZE, 0,
 	       (mincount - oldsize) * LDT_ENTRY_SIZE);
 
+	paravirt_alloc_ldt(newldt, mincount);
+
 #ifdef CONFIG_X86_64
 	/* CHECKME: Do we really need this ? */
 	wmb();
@@ -74,6 +76,7 @@ static int alloc_ldt(mm_context_t *pc, int mincount, int reload)
 #endif
 	}
 	if (oldsize) {
+		paravirt_free_ldt(oldldt, oldsize);
 		if (oldsize * LDT_ENTRY_SIZE > PAGE_SIZE)
 			vfree(oldldt);
 		else
@@ -85,10 +88,13 @@ static int alloc_ldt(mm_context_t *pc, int mincount, int reload)
 static inline int copy_ldt(mm_context_t *new, mm_context_t *old)
 {
 	int err = alloc_ldt(new, old->size, 0);
+	int i;
 
 	if (err < 0)
 		return err;
-	memcpy(new->ldt, old->ldt, old->size * LDT_ENTRY_SIZE);
+
+	for(i = 0; i < old->size; i++)
+		write_ldt_entry(new->ldt, i, old->ldt + i * LDT_ENTRY_SIZE);
 	return 0;
 }
 
@@ -125,6 +131,7 @@ void destroy_context(struct mm_struct *mm)
 		if (mm == current->active_mm)
 			clear_LDT();
 #endif
+		paravirt_free_ldt(mm->context.ldt, mm->context.size);
 		if (mm->context.size * LDT_ENTRY_SIZE > PAGE_SIZE)
 			vfree(mm->context.ldt);
 		else
diff --git a/arch/x86/kernel/paravirt-spinlocks.c b/arch/x86/kernel/paravirt-spinlocks.c
new file mode 100644
index 000000000000..0e9f1982b1dd
--- /dev/null
+++ b/arch/x86/kernel/paravirt-spinlocks.c
@@ -0,0 +1,37 @@
+/*
+ * Split spinlock implementation out into its own file, so it can be
+ * compiled in a FTRACE-compatible way.
+ */
+#include <linux/spinlock.h>
+#include <linux/module.h>
+
+#include <asm/paravirt.h>
+
+static void default_spin_lock_flags(struct raw_spinlock *lock, unsigned long flags)
+{
+	__raw_spin_lock(lock);
+}
+
+struct pv_lock_ops pv_lock_ops = {
+#ifdef CONFIG_SMP
+	.spin_is_locked = __ticket_spin_is_locked,
+	.spin_is_contended = __ticket_spin_is_contended,
+
+	.spin_lock = __ticket_spin_lock,
+	.spin_lock_flags = default_spin_lock_flags,
+	.spin_trylock = __ticket_spin_trylock,
+	.spin_unlock = __ticket_spin_unlock,
+#endif
+};
+EXPORT_SYMBOL(pv_lock_ops);
+
+void __init paravirt_use_bytelocks(void)
+{
+#ifdef CONFIG_SMP
+	pv_lock_ops.spin_is_locked = __byte_spin_is_locked;
+	pv_lock_ops.spin_is_contended = __byte_spin_is_contended;
+	pv_lock_ops.spin_lock = __byte_spin_lock;
+	pv_lock_ops.spin_trylock = __byte_spin_trylock;
+	pv_lock_ops.spin_unlock = __byte_spin_unlock;
+#endif
+}
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index 6b0bb73998dd..e4c8fb608873 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -268,17 +268,6 @@ enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
 	return __get_cpu_var(paravirt_lazy_mode);
 }
 
-void __init paravirt_use_bytelocks(void)
-{
-#ifdef CONFIG_SMP
-	pv_lock_ops.spin_is_locked = __byte_spin_is_locked;
-	pv_lock_ops.spin_is_contended = __byte_spin_is_contended;
-	pv_lock_ops.spin_lock = __byte_spin_lock;
-	pv_lock_ops.spin_trylock = __byte_spin_trylock;
-	pv_lock_ops.spin_unlock = __byte_spin_unlock;
-#endif
-}
-
 struct pv_info pv_info = {
 	.name = "bare hardware",
 	.paravirt_enabled = 0,
@@ -349,6 +338,10 @@ struct pv_cpu_ops pv_cpu_ops = {
 	.write_ldt_entry = native_write_ldt_entry,
 	.write_gdt_entry = native_write_gdt_entry,
 	.write_idt_entry = native_write_idt_entry,
+
+	.alloc_ldt = paravirt_nop,
+	.free_ldt = paravirt_nop,
+
 	.load_sp0 = native_load_sp0,
 
 #if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION)
@@ -460,18 +453,6 @@ struct pv_mmu_ops pv_mmu_ops = {
 	.set_fixmap = native_set_fixmap,
 };
 
-struct pv_lock_ops pv_lock_ops = {
-#ifdef CONFIG_SMP
-	.spin_is_locked = __ticket_spin_is_locked,
-	.spin_is_contended = __ticket_spin_is_contended,
-
-	.spin_lock = __ticket_spin_lock,
-	.spin_trylock = __ticket_spin_trylock,
-	.spin_unlock = __ticket_spin_unlock,
-#endif
-};
-EXPORT_SYMBOL(pv_lock_ops);
-
 EXPORT_SYMBOL_GPL(pv_time_ops);
 EXPORT_SYMBOL    (pv_cpu_ops);
 EXPORT_SYMBOL    (pv_mmu_ops);
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 205188db9626..922c14058f97 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -76,47 +76,12 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
 	return ((unsigned long *)tsk->thread.sp)[3];
 }
 
-#ifdef CONFIG_HOTPLUG_CPU
-#include <asm/nmi.h>
-
-static void cpu_exit_clear(void)
-{
-	int cpu = raw_smp_processor_id();
-
-	idle_task_exit();
-
-	cpu_uninit();
-	irq_ctx_exit(cpu);
-
-	cpu_clear(cpu, cpu_callout_map);
-	cpu_clear(cpu, cpu_callin_map);
-
-	numa_remove_cpu(cpu);
-	c1e_remove_cpu(cpu);
-}
-
-/* We don't actually take CPU down, just spin without interrupts. */
-static inline void play_dead(void)
-{
-	/* This must be done before dead CPU ack */
-	cpu_exit_clear();
-	mb();
-	/* Ack it */
-	__get_cpu_var(cpu_state) = CPU_DEAD;
-
-	/*
-	 * With physical CPU hotplug, we should halt the cpu
-	 */
-	local_irq_disable();
-	/* mask all interrupts, flush any and all caches, and halt */
-	wbinvd_halt();
-}
-#else
+#ifndef CONFIG_SMP
 static inline void play_dead(void)
 {
 	BUG();
 }
-#endif /* CONFIG_HOTPLUG_CPU */
+#endif
 
 /*
  * The idle thread. There's no useful work to be
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 2a8ccb9238b4..18e63350d7d2 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -86,30 +86,12 @@ void exit_idle(void)
 	__exit_idle();
 }
 
-#ifdef CONFIG_HOTPLUG_CPU
-DECLARE_PER_CPU(int, cpu_state);
-
-#include <linux/nmi.h>
-/* We halt the CPU with physical CPU hotplug */
-static inline void play_dead(void)
-{
-	idle_task_exit();
-	c1e_remove_cpu(raw_smp_processor_id());
-
-	mb();
-	/* Ack it */
-	__get_cpu_var(cpu_state) = CPU_DEAD;
-
-	local_irq_disable();
-	/* mask all interrupts, flush any and all caches, and halt */
-	wbinvd_halt();
-}
-#else
+#ifndef CONFIG_SMP
 static inline void play_dead(void)
 {
 	BUG();
 }
-#endif /* CONFIG_HOTPLUG_CPU */
+#endif
 
 /*
  * The idle thread. There's no useful work to be
diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
index 361b7a4c640c..18f9b19f5f8f 100644
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -214,12 +214,16 @@ void smp_call_function_single_interrupt(struct pt_regs *regs)
 struct smp_ops smp_ops = {
 	.smp_prepare_boot_cpu = native_smp_prepare_boot_cpu,
 	.smp_prepare_cpus = native_smp_prepare_cpus,
-	.cpu_up = native_cpu_up,
 	.smp_cpus_done = native_smp_cpus_done,
 
 	.smp_send_stop = native_smp_send_stop,
 	.smp_send_reschedule = native_smp_send_reschedule,
 
+	.cpu_up = native_cpu_up,
+	.cpu_die = native_cpu_die,
+	.cpu_disable = native_cpu_disable,
+	.play_dead = native_play_dead,
+
 	.send_call_func_ipi = native_send_call_func_ipi,
 	.send_call_func_single_ipi = native_send_call_func_single_ipi,
 };
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 9056f7e272c0..76b6f50978f7 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -52,6 +52,7 @@
 #include <asm/desc.h>
 #include <asm/nmi.h>
 #include <asm/irq.h>
+#include <asm/idle.h>
 #include <asm/smp.h>
 #include <asm/trampoline.h>
 #include <asm/cpu.h>
@@ -1344,25 +1345,9 @@ static void __ref remove_cpu_from_maps(int cpu)
 	numa_remove_cpu(cpu);
 }
 
-int __cpu_disable(void)
+void cpu_disable_common(void)
 {
 	int cpu = smp_processor_id();
-
-	/*
-	 * Perhaps use cpufreq to drop frequency, but that could go
-	 * into generic code.
-	 *
-	 * We won't take down the boot processor on i386 due to some
-	 * interrupts only being able to be serviced by the BSP.
-	 * Especially so if we're not using an IOAPIC	-zwane
-	 */
-	if (cpu == 0)
-		return -EBUSY;
-
-	if (nmi_watchdog == NMI_LOCAL_APIC)
-		stop_apic_nmi_watchdog(NULL);
-	clear_local_APIC();
-
 	/*
 	 * HACK:
 	 * Allow any queued timer interrupts to get serviced
@@ -1380,10 +1365,32 @@ int __cpu_disable(void)
 	remove_cpu_from_maps(cpu);
 	unlock_vector_lock();
 	fixup_irqs(cpu_online_map);
+}
+
+int native_cpu_disable(void)
+{
+	int cpu = smp_processor_id();
+
+	/*
+	 * Perhaps use cpufreq to drop frequency, but that could go
+	 * into generic code.
+	 *
+	 * We won't take down the boot processor on i386 due to some
+	 * interrupts only being able to be serviced by the BSP.
+	 * Especially so if we're not using an IOAPIC	-zwane
+	 */
+	if (cpu == 0)
+		return -EBUSY;
+
+	if (nmi_watchdog == NMI_LOCAL_APIC)
+		stop_apic_nmi_watchdog(NULL);
+	clear_local_APIC();
+
+	cpu_disable_common();
 	return 0;
 }
 
-void __cpu_die(unsigned int cpu)
+void native_cpu_die(unsigned int cpu)
 {
 	/* We don't do anything here: idle task is faking death itself. */
 	unsigned int i;
@@ -1400,15 +1407,45 @@ void __cpu_die(unsigned int cpu)
 	}
 	printk(KERN_ERR "CPU %u didn't die...\n", cpu);
 }
+
+void play_dead_common(void)
+{
+	idle_task_exit();
+	reset_lazy_tlbstate();
+	irq_ctx_exit(raw_smp_processor_id());
+	c1e_remove_cpu(raw_smp_processor_id());
+
+	mb();
+	/* Ack it */
+	__get_cpu_var(cpu_state) = CPU_DEAD;
+
+	/*
+	 * With physical CPU hotplug, we should halt the cpu
+	 */
+	local_irq_disable();
+}
+
+void native_play_dead(void)
+{
+	play_dead_common();
+	wbinvd_halt();
+}
+
 #else /* ... !CONFIG_HOTPLUG_CPU */
-int __cpu_disable(void)
+int native_cpu_disable(void)
 {
 	return -ENOSYS;
 }
 
-void __cpu_die(unsigned int cpu)
+void native_cpu_die(unsigned int cpu)
 {
 	/* We said "no" in __cpu_disable */
 	BUG();
 }
+
+void native_play_dead(void)
+{
+	BUG();
+}
+
 #endif
diff --git a/arch/x86/kernel/tlb_32.c b/arch/x86/kernel/tlb_32.c
index fec1ecedc9b7..e00534b33534 100644
--- a/arch/x86/kernel/tlb_32.c
+++ b/arch/x86/kernel/tlb_32.c
@@ -241,3 +241,11 @@ void flush_tlb_all(void)
 	on_each_cpu(do_flush_tlb_all, NULL, 1);
 }
 
+void reset_lazy_tlbstate(void)
+{
+	int cpu = raw_smp_processor_id();
+
+	per_cpu(cpu_tlbstate, cpu).state = 0;
+	per_cpu(cpu_tlbstate, cpu).active_mm = &init_mm;
+}
+
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 8f92cac4e6db..a742d753d5b0 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -914,15 +914,15 @@ LIST_HEAD(pgd_list);
 
 void vmalloc_sync_all(void)
 {
-#ifdef CONFIG_X86_32
-	unsigned long start = VMALLOC_START & PGDIR_MASK;
 	unsigned long address;
 
+#ifdef CONFIG_X86_32
 	if (SHARED_KERNEL_PMD)
 		return;
 
-	BUILD_BUG_ON(TASK_SIZE & ~PGDIR_MASK);
-	for (address = start; address >= TASK_SIZE; address += PGDIR_SIZE) {
+	for (address = VMALLOC_START & PMD_MASK;
+	     address >= TASK_SIZE && address < FIXADDR_TOP;
+	     address += PMD_SIZE) {
 		unsigned long flags;
 		struct page *page;
 
@@ -935,10 +935,8 @@ void vmalloc_sync_all(void)
 		spin_unlock_irqrestore(&pgd_lock, flags);
 	}
 #else /* CONFIG_X86_64 */
-	unsigned long start = VMALLOC_START & PGDIR_MASK;
-	unsigned long address;
-
-	for (address = start; address <= VMALLOC_END; address += PGDIR_SIZE) {
+	for (address = VMALLOC_START & PGDIR_MASK; address <= VMALLOC_END;
+	     address += PGDIR_SIZE) {
 		const pgd_t *pgd_ref = pgd_offset_k(address);
 		unsigned long flags;
 		struct page *page;
diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig
index 3815e425f470..87b9ab166423 100644
--- a/arch/x86/xen/Kconfig
+++ b/arch/x86/xen/Kconfig
@@ -26,5 +26,13 @@ config XEN_MAX_DOMAIN_MEMORY
 
 config XEN_SAVE_RESTORE
        bool
-       depends on PM
-       default y
\ No newline at end of file
+       depends on XEN && PM
+       default y
+
+config XEN_DEBUG_FS
+	bool "Enable Xen debug and tuning parameters in debugfs"
+	depends on XEN && DEBUG_FS
+	default n
+	help
+	  Enable statistics output and various tuning options in debugfs.
+	  Enabling this option may incur a significant performance overhead.
diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile
index 59c1e539aed2..313947940a1a 100644
--- a/arch/x86/xen/Makefile
+++ b/arch/x86/xen/Makefile
@@ -1,4 +1,12 @@
-obj-y		:= enlighten.o setup.o multicalls.o mmu.o \
+ifdef CONFIG_FTRACE
+# Do not profile debug and lowlevel utilities
+CFLAGS_REMOVE_spinlock.o = -pg
+CFLAGS_REMOVE_time.o = -pg
+CFLAGS_REMOVE_irq.o = -pg
+endif
+
+obj-y		:= enlighten.o setup.o multicalls.o mmu.o irq.o \
 			time.o xen-asm_$(BITS).o grant-table.o suspend.o
 
-obj-$(CONFIG_SMP)	+= smp.o
+obj-$(CONFIG_SMP)		+= smp.o spinlock.o
+obj-$(CONFIG_XEN_DEBUG_FS)	+= debugfs.o
\ No newline at end of file
diff --git a/arch/x86/xen/debugfs.c b/arch/x86/xen/debugfs.c
new file mode 100644
index 000000000000..b53225d2cac3
--- /dev/null
+++ b/arch/x86/xen/debugfs.c
@@ -0,0 +1,123 @@
+#include <linux/init.h>
+#include <linux/debugfs.h>
+#include <linux/module.h>
+
+#include "debugfs.h"
+
+static struct dentry *d_xen_debug;
+
+struct dentry * __init xen_init_debugfs(void)
+{
+	if (!d_xen_debug) {
+		d_xen_debug = debugfs_create_dir("xen", NULL);
+
+		if (!d_xen_debug)
+			pr_warning("Could not create 'xen' debugfs directory\n");
+	}
+
+	return d_xen_debug;
+}
+
+struct array_data
+{
+	void *array;
+	unsigned elements;
+};
+
+static int u32_array_open(struct inode *inode, struct file *file)
+{
+	file->private_data = NULL;
+	return nonseekable_open(inode, file);
+}
+
+static size_t format_array(char *buf, size_t bufsize, const char *fmt,
+			   u32 *array, unsigned array_size)
+{
+	size_t ret = 0;
+	unsigned i;
+
+	for(i = 0; i < array_size; i++) {
+		size_t len;
+
+		len = snprintf(buf, bufsize, fmt, array[i]);
+		len++;	/* ' ' or '\n' */
+		ret += len;
+
+		if (buf) {
+			buf += len;
+			bufsize -= len;
+			buf[-1] = (i == array_size-1) ? '\n' : ' ';
+		}
+	}
+
+	ret++;		/* \0 */
+	if (buf)
+		*buf = '\0';
+
+	return ret;
+}
+
+static char *format_array_alloc(const char *fmt, u32 *array, unsigned array_size)
+{
+	size_t len = format_array(NULL, 0, fmt, array, array_size);
+	char *ret;
+
+	ret = kmalloc(len, GFP_KERNEL);
+	if (ret == NULL)
+		return NULL;
+
+	format_array(ret, len, fmt, array, array_size);
+	return ret;
+}
+
+static ssize_t u32_array_read(struct file *file, char __user *buf, size_t len,
+			      loff_t *ppos)
+{
+	struct inode *inode = file->f_path.dentry->d_inode;
+	struct array_data *data = inode->i_private;
+	size_t size;
+
+	if (*ppos == 0) {
+		if (file->private_data) {
+			kfree(file->private_data);
+			file->private_data = NULL;
+		}
+
+		file->private_data = format_array_alloc("%u", data->array, data->elements);
+	}
+
+	size = 0;
+	if (file->private_data)
+		size = strlen(file->private_data);
+
+	return simple_read_from_buffer(buf, len, ppos, file->private_data, size);
+}
+
+static int xen_array_release(struct inode *inode, struct file *file)
+{
+	kfree(file->private_data);
+
+	return 0;
+}
+
+static struct file_operations u32_array_fops = {
+	.owner	= THIS_MODULE,
+	.open	= u32_array_open,
+	.release= xen_array_release,
+	.read	= u32_array_read,
+};
+
+struct dentry *xen_debugfs_create_u32_array(const char *name, mode_t mode,
+					    struct dentry *parent,
+					    u32 *array, unsigned elements)
+{
+	struct array_data *data = kmalloc(sizeof(*data), GFP_KERNEL);
+
+	if (data == NULL)
+		return NULL;
+
+	data->array = array;
+	data->elements = elements;
+
+	return debugfs_create_file(name, mode, parent, data, &u32_array_fops);
+}
diff --git a/arch/x86/xen/debugfs.h b/arch/x86/xen/debugfs.h
new file mode 100644
index 000000000000..e28132084832
--- /dev/null
+++ b/arch/x86/xen/debugfs.h
@@ -0,0 +1,10 @@
+#ifndef _XEN_DEBUGFS_H
+#define _XEN_DEBUGFS_H
+
+struct dentry * __init xen_init_debugfs(void);
+
+struct dentry *xen_debugfs_create_u32_array(const char *name, mode_t mode,
+					    struct dentry *parent,
+					    u32 *array, unsigned elements);
+
+#endif /* _XEN_DEBUGFS_H */
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index a27d562a9744..0013a729b41d 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -30,7 +30,6 @@
 #include <xen/interface/xen.h>
 #include <xen/interface/physdev.h>
 #include <xen/interface/vcpu.h>
-#include <xen/interface/sched.h>
 #include <xen/features.h>
 #include <xen/page.h>
 #include <xen/hvc-console.h>
@@ -58,6 +57,9 @@ EXPORT_SYMBOL_GPL(hypercall_page);
 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
 DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info);
 
+enum xen_domain_type xen_domain_type = XEN_NATIVE;
+EXPORT_SYMBOL_GPL(xen_domain_type);
+
 /*
  * Identity map, in addition to plain kernel map.  This needs to be
  * large enough to allocate page table pages to allocate the rest.
@@ -111,7 +113,14 @@ struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;
  *
  * 0: not available, 1: available
  */
-static int have_vcpu_info_placement = 1;
+static int have_vcpu_info_placement =
+#ifdef CONFIG_X86_32
+	1
+#else
+	0
+#endif
+	;
+
 
 static void xen_vcpu_setup(int cpu)
 {
@@ -227,103 +236,68 @@ static unsigned long xen_get_debugreg(int reg)
 	return HYPERVISOR_get_debugreg(reg);
 }
 
-static unsigned long xen_save_fl(void)
+static void xen_leave_lazy(void)
 {
-	struct vcpu_info *vcpu;
-	unsigned long flags;
-
-	vcpu = x86_read_percpu(xen_vcpu);
-
-	/* flag has opposite sense of mask */
-	flags = !vcpu->evtchn_upcall_mask;
-
-	/* convert to IF type flag
-	   -0 -> 0x00000000
-	   -1 -> 0xffffffff
-	*/
-	return (-flags) & X86_EFLAGS_IF;
+	paravirt_leave_lazy(paravirt_get_lazy_mode());
+	xen_mc_flush();
 }
 
-static void xen_restore_fl(unsigned long flags)
+static unsigned long xen_store_tr(void)
 {
-	struct vcpu_info *vcpu;
-
-	/* convert from IF type flag */
-	flags = !(flags & X86_EFLAGS_IF);
-
-	/* There's a one instruction preempt window here.  We need to
-	   make sure we're don't switch CPUs between getting the vcpu
-	   pointer and updating the mask. */
-	preempt_disable();
-	vcpu = x86_read_percpu(xen_vcpu);
-	vcpu->evtchn_upcall_mask = flags;
-	preempt_enable_no_resched();
-
-	/* Doesn't matter if we get preempted here, because any
-	   pending event will get dealt with anyway. */
-
-	if (flags == 0) {
-		preempt_check_resched();
-		barrier(); /* unmask then check (avoid races) */
-		if (unlikely(vcpu->evtchn_upcall_pending))
-			force_evtchn_callback();
-	}
+	return 0;
 }
 
-static void xen_irq_disable(void)
+/*
+ * Set the page permissions for a particular virtual address.  If the
+ * address is a vmalloc mapping (or other non-linear mapping), then
+ * find the linear mapping of the page and also set its protections to
+ * match.
+ */
+static void set_aliased_prot(void *v, pgprot_t prot)
 {
-	/* There's a one instruction preempt window here.  We need to
-	   make sure we're don't switch CPUs between getting the vcpu
-	   pointer and updating the mask. */
-	preempt_disable();
-	x86_read_percpu(xen_vcpu)->evtchn_upcall_mask = 1;
-	preempt_enable_no_resched();
-}
+	int level;
+	pte_t *ptep;
+	pte_t pte;
+	unsigned long pfn;
+	struct page *page;
 
-static void xen_irq_enable(void)
-{
-	struct vcpu_info *vcpu;
+	ptep = lookup_address((unsigned long)v, &level);
+	BUG_ON(ptep == NULL);
 
-	/* We don't need to worry about being preempted here, since
-	   either a) interrupts are disabled, so no preemption, or b)
-	   the caller is confused and is trying to re-enable interrupts
-	   on an indeterminate processor. */
+	pfn = pte_pfn(*ptep);
+	page = pfn_to_page(pfn);
 
-	vcpu = x86_read_percpu(xen_vcpu);
-	vcpu->evtchn_upcall_mask = 0;
+	pte = pfn_pte(pfn, prot);
 
-	/* Doesn't matter if we get preempted here, because any
-	   pending event will get dealt with anyway. */
+	if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0))
+		BUG();
 
-	barrier(); /* unmask then check (avoid races) */
-	if (unlikely(vcpu->evtchn_upcall_pending))
-		force_evtchn_callback();
-}
+	if (!PageHighMem(page)) {
+		void *av = __va(PFN_PHYS(pfn));
 
-static void xen_safe_halt(void)
-{
-	/* Blocking includes an implicit local_irq_enable(). */
-	if (HYPERVISOR_sched_op(SCHEDOP_block, NULL) != 0)
-		BUG();
+		if (av != v)
+			if (HYPERVISOR_update_va_mapping((unsigned long)av, pte, 0))
+				BUG();
+	} else
+		kmap_flush_unused();
 }
 
-static void xen_halt(void)
+static void xen_alloc_ldt(struct desc_struct *ldt, unsigned entries)
 {
-	if (irqs_disabled())
-		HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL);
-	else
-		xen_safe_halt();
-}
+	const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
+	int i;
 
-static void xen_leave_lazy(void)
-{
-	paravirt_leave_lazy(paravirt_get_lazy_mode());
-	xen_mc_flush();
+	for(i = 0; i < entries; i += entries_per_page)
+		set_aliased_prot(ldt + i, PAGE_KERNEL_RO);
 }
 
-static unsigned long xen_store_tr(void)
+static void xen_free_ldt(struct desc_struct *ldt, unsigned entries)
 {
-	return 0;
+	const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
+	int i;
+
+	for(i = 0; i < entries; i += entries_per_page)
+		set_aliased_prot(ldt + i, PAGE_KERNEL);
 }
 
 static void xen_set_ldt(const void *addr, unsigned entries)
@@ -426,8 +400,7 @@ static void xen_load_gs_index(unsigned int idx)
 static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum,
 				const void *ptr)
 {
-	unsigned long lp = (unsigned long)&dt[entrynum];
-	xmaddr_t mach_lp = virt_to_machine(lp);
+	xmaddr_t mach_lp = arbitrary_virt_to_machine(&dt[entrynum]);
 	u64 entry = *(u64 *)ptr;
 
 	preempt_disable();
@@ -560,7 +533,7 @@ static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
 }
 
 static void xen_load_sp0(struct tss_struct *tss,
-			  struct thread_struct *thread)
+			 struct thread_struct *thread)
 {
 	struct multicall_space mcs = xen_mc_entry(0);
 	MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->sp0);
@@ -835,6 +808,19 @@ static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
 			ret = -EFAULT;
 		break;
 #endif
+
+	case MSR_STAR:
+	case MSR_CSTAR:
+	case MSR_LSTAR:
+	case MSR_SYSCALL_MASK:
+	case MSR_IA32_SYSENTER_CS:
+	case MSR_IA32_SYSENTER_ESP:
+	case MSR_IA32_SYSENTER_EIP:
+		/* Fast syscall setup is all done in hypercalls, so
+		   these are all ignored.  Stub them out here to stop
+		   Xen console noise. */
+		break;
+
 	default:
 		ret = native_write_msr_safe(msr, low, high);
 	}
@@ -878,8 +864,8 @@ static void xen_alloc_ptpage(struct mm_struct *mm, unsigned long pfn, unsigned l
 		SetPagePinned(page);
 
 		if (!PageHighMem(page)) {
-			make_lowmem_page_readonly(__va(PFN_PHYS(pfn)));
-			if (level == PT_PTE)
+			make_lowmem_page_readonly(__va(PFN_PHYS((unsigned long)pfn)));
+			if (level == PT_PTE && USE_SPLIT_PTLOCKS)
 				pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, pfn);
 		} else
 			/* make sure there are no stray mappings of
@@ -947,7 +933,7 @@ static void xen_release_ptpage(unsigned long pfn, unsigned level)
 
 	if (PagePinned(page)) {
 		if (!PageHighMem(page)) {
-			if (level == PT_PTE)
+			if (level == PT_PTE && USE_SPLIT_PTLOCKS)
 				pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn);
 			make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
 		}
@@ -994,6 +980,7 @@ static void *xen_kmap_atomic_pte(struct page *page, enum km_type type)
 }
 #endif
 
+#ifdef CONFIG_X86_32
 static __init pte_t mask_rw_pte(pte_t *ptep, pte_t pte)
 {
 	/* If there's an existing pte, then don't allow _PAGE_RW to be set */
@@ -1012,6 +999,7 @@ static __init void xen_set_pte_init(pte_t *ptep, pte_t pte)
 
 	xen_set_pte(ptep, pte);
 }
+#endif
 
 static __init void xen_pagetable_setup_start(pgd_t *base)
 {
@@ -1078,7 +1066,6 @@ void xen_setup_vcpu_info_placement(void)
 
 	/* xen_vcpu_setup managed to place the vcpu_info within the
 	   percpu area for all cpus, so make use of it */
-#ifdef CONFIG_X86_32
 	if (have_vcpu_info_placement) {
 		printk(KERN_INFO "Xen: using vcpu_info placement\n");
 
@@ -1088,7 +1075,6 @@ void xen_setup_vcpu_info_placement(void)
 		pv_irq_ops.irq_enable = xen_irq_enable_direct;
 		pv_mmu_ops.read_cr2 = xen_read_cr2_direct;
 	}
-#endif
 }
 
 static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
@@ -1109,12 +1095,10 @@ static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
 	goto patch_site
 
 	switch (type) {
-#ifdef CONFIG_X86_32
 		SITE(pv_irq_ops, irq_enable);
 		SITE(pv_irq_ops, irq_disable);
 		SITE(pv_irq_ops, save_fl);
 		SITE(pv_irq_ops, restore_fl);
-#endif /* CONFIG_X86_32 */
 #undef SITE
 
 	patch_site:
@@ -1252,6 +1236,9 @@ static const struct pv_cpu_ops xen_cpu_ops __initdata = {
 	.load_gs_index = xen_load_gs_index,
 #endif
 
+	.alloc_ldt = xen_alloc_ldt,
+	.free_ldt = xen_free_ldt,
+
 	.store_gdt = native_store_gdt,
 	.store_idt = native_store_idt,
 	.store_tr = xen_store_tr,
@@ -1273,36 +1260,6 @@ static const struct pv_cpu_ops xen_cpu_ops __initdata = {
 	},
 };
 
-static void __init __xen_init_IRQ(void)
-{
-#ifdef CONFIG_X86_64
-	int i;
-
-	/* Create identity vector->irq map */
-	for(i = 0; i < NR_VECTORS; i++) {
-		int cpu;
-
-		for_each_possible_cpu(cpu)
-			per_cpu(vector_irq, cpu)[i] = i;
-	}
-#endif	/* CONFIG_X86_64 */
-
-	xen_init_IRQ();
-}
-
-static const struct pv_irq_ops xen_irq_ops __initdata = {
-	.init_IRQ = __xen_init_IRQ,
-	.save_fl = xen_save_fl,
-	.restore_fl = xen_restore_fl,
-	.irq_disable = xen_irq_disable,
-	.irq_enable = xen_irq_enable,
-	.safe_halt = xen_safe_halt,
-	.halt = xen_halt,
-#ifdef CONFIG_X86_64
-	.adjust_exception_frame = xen_adjust_exception_frame,
-#endif
-};
-
 static const struct pv_apic_ops xen_apic_ops __initdata = {
 #ifdef CONFIG_X86_LOCAL_APIC
 	.setup_boot_clock = paravirt_nop,
@@ -1443,7 +1400,7 @@ static void __init xen_reserve_top(void)
 	if (HYPERVISOR_xen_version(XENVER_platform_parameters, &pp) == 0)
 		top = pp.virt_start;
 
-	reserve_top_address(-top + 2 * PAGE_SIZE);
+	reserve_top_address(-top);
 #endif	/* CONFIG_X86_32 */
 }
 
@@ -1477,48 +1434,11 @@ static void *m2v(phys_addr_t maddr)
 	return __ka(m2p(maddr));
 }
 
-#ifdef CONFIG_X86_64
-static void walk(pgd_t *pgd, unsigned long addr)
-{
-	unsigned l4idx = pgd_index(addr);
-	unsigned l3idx = pud_index(addr);
-	unsigned l2idx = pmd_index(addr);
-	unsigned l1idx = pte_index(addr);
-	pgd_t l4;
-	pud_t l3;
-	pmd_t l2;
-	pte_t l1;
-
-	xen_raw_printk("walk %p, %lx -> %d %d %d %d\n",
-		       pgd, addr, l4idx, l3idx, l2idx, l1idx);
-
-	l4 = pgd[l4idx];
-	xen_raw_printk("  l4: %016lx\n", l4.pgd);
-	xen_raw_printk("      %016lx\n", pgd_val(l4));
-
-	l3 = ((pud_t *)(m2v(l4.pgd)))[l3idx];
-	xen_raw_printk("  l3: %016lx\n", l3.pud);
-	xen_raw_printk("      %016lx\n", pud_val(l3));
-
-	l2 = ((pmd_t *)(m2v(l3.pud)))[l2idx];
-	xen_raw_printk("  l2: %016lx\n", l2.pmd);
-	xen_raw_printk("      %016lx\n", pmd_val(l2));
-
-	l1 = ((pte_t *)(m2v(l2.pmd)))[l1idx];
-	xen_raw_printk("  l1: %016lx\n", l1.pte);
-	xen_raw_printk("      %016lx\n", pte_val(l1));
-}
-#endif
-
 static void set_page_prot(void *addr, pgprot_t prot)
 {
 	unsigned long pfn = __pa(addr) >> PAGE_SHIFT;
 	pte_t pte = pfn_pte(pfn, prot);
 
-	xen_raw_printk("addr=%p pfn=%lx mfn=%lx prot=%016llx pte=%016llx\n",
-		       addr, pfn, get_phys_to_machine(pfn),
-		       pgprot_val(prot), pte.pte);
-
 	if (HYPERVISOR_update_va_mapping((unsigned long)addr, pte, 0))
 		BUG();
 }
@@ -1694,6 +1614,8 @@ asmlinkage void __init xen_start_kernel(void)
 	if (!xen_start_info)
 		return;
 
+	xen_domain_type = XEN_PV_DOMAIN;
+
 	BUG_ON(memcmp(xen_start_info->magic, "xen-3", 5) != 0);
 
 	xen_setup_features();
@@ -1703,10 +1625,11 @@ asmlinkage void __init xen_start_kernel(void)
 	pv_init_ops = xen_init_ops;
 	pv_time_ops = xen_time_ops;
 	pv_cpu_ops = xen_cpu_ops;
-	pv_irq_ops = xen_irq_ops;
 	pv_apic_ops = xen_apic_ops;
 	pv_mmu_ops = xen_mmu_ops;
 
+	xen_init_irq_ops();
+
 #ifdef CONFIG_X86_LOCAL_APIC
 	/*
 	 * set up the basic apic ops.
@@ -1737,7 +1660,7 @@ asmlinkage void __init xen_start_kernel(void)
 
 	/* Prevent unwanted bits from being set in PTEs. */
 	__supported_pte_mask &= ~_PAGE_GLOBAL;
-	if (!is_initial_xendomain())
+	if (!xen_initial_domain())
 		__supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
 
 	/* Don't do the full vcpu_info placement stuff until we have a
@@ -1772,7 +1695,7 @@ asmlinkage void __init xen_start_kernel(void)
 	boot_params.hdr.ramdisk_size = xen_start_info->mod_len;
 	boot_params.hdr.cmd_line_ptr = __pa(xen_start_info->cmd_line);
 
-	if (!is_initial_xendomain()) {
+	if (!xen_initial_domain()) {
 		add_preferred_console("xenboot", 0, NULL);
 		add_preferred_console("tty", 0, NULL);
 		add_preferred_console("hvc", 0, NULL);
@@ -1780,15 +1703,6 @@ asmlinkage void __init xen_start_kernel(void)
 
 	xen_raw_console_write("about to get started...\n");
 
-#if 0
-	xen_raw_printk("&boot_params=%p __pa(&boot_params)=%lx __va(__pa(&boot_params))=%lx\n",
-		       &boot_params, __pa_symbol(&boot_params),
-		       __va(__pa_symbol(&boot_params)));
-
-	walk(pgd, &boot_params);
-	walk(pgd, __va(__pa(&boot_params)));
-#endif
-
 	/* Start the world */
 #ifdef CONFIG_X86_32
 	i386_start_kernel();
diff --git a/arch/x86/xen/irq.c b/arch/x86/xen/irq.c
new file mode 100644
index 000000000000..28b85ab8422e
--- /dev/null
+++ b/arch/x86/xen/irq.c
@@ -0,0 +1,143 @@
+#include <linux/hardirq.h>
+
+#include <xen/interface/xen.h>
+#include <xen/interface/sched.h>
+#include <xen/interface/vcpu.h>
+
+#include <asm/xen/hypercall.h>
+#include <asm/xen/hypervisor.h>
+
+#include "xen-ops.h"
+
+/*
+ * Force a proper event-channel callback from Xen after clearing the
+ * callback mask. We do this in a very simple manner, by making a call
+ * down into Xen. The pending flag will be checked by Xen on return.
+ */
+void xen_force_evtchn_callback(void)
+{
+	(void)HYPERVISOR_xen_version(0, NULL);
+}
+
+static void __init __xen_init_IRQ(void)
+{
+#ifdef CONFIG_X86_64
+	int i;
+
+	/* Create identity vector->irq map */
+	for(i = 0; i < NR_VECTORS; i++) {
+		int cpu;
+
+		for_each_possible_cpu(cpu)
+			per_cpu(vector_irq, cpu)[i] = i;
+	}
+#endif	/* CONFIG_X86_64 */
+
+	xen_init_IRQ();
+}
+
+static unsigned long xen_save_fl(void)
+{
+	struct vcpu_info *vcpu;
+	unsigned long flags;
+
+	vcpu = x86_read_percpu(xen_vcpu);
+
+	/* flag has opposite sense of mask */
+	flags = !vcpu->evtchn_upcall_mask;
+
+	/* convert to IF type flag
+	   -0 -> 0x00000000
+	   -1 -> 0xffffffff
+	*/
+	return (-flags) & X86_EFLAGS_IF;
+}
+
+static void xen_restore_fl(unsigned long flags)
+{
+	struct vcpu_info *vcpu;
+
+	/* convert from IF type flag */
+	flags = !(flags & X86_EFLAGS_IF);
+
+	/* There's a one instruction preempt window here.  We need to
+	   make sure we're don't switch CPUs between getting the vcpu
+	   pointer and updating the mask. */
+	preempt_disable();
+	vcpu = x86_read_percpu(xen_vcpu);
+	vcpu->evtchn_upcall_mask = flags;
+	preempt_enable_no_resched();
+
+	/* Doesn't matter if we get preempted here, because any
+	   pending event will get dealt with anyway. */
+
+	if (flags == 0) {
+		preempt_check_resched();
+		barrier(); /* unmask then check (avoid races) */
+		if (unlikely(vcpu->evtchn_upcall_pending))
+			xen_force_evtchn_callback();
+	}
+}
+
+static void xen_irq_disable(void)
+{
+	/* There's a one instruction preempt window here.  We need to
+	   make sure we're don't switch CPUs between getting the vcpu
+	   pointer and updating the mask. */
+	preempt_disable();
+	x86_read_percpu(xen_vcpu)->evtchn_upcall_mask = 1;
+	preempt_enable_no_resched();
+}
+
+static void xen_irq_enable(void)
+{
+	struct vcpu_info *vcpu;
+
+	/* We don't need to worry about being preempted here, since
+	   either a) interrupts are disabled, so no preemption, or b)
+	   the caller is confused and is trying to re-enable interrupts
+	   on an indeterminate processor. */
+
+	vcpu = x86_read_percpu(xen_vcpu);
+	vcpu->evtchn_upcall_mask = 0;
+
+	/* Doesn't matter if we get preempted here, because any
+	   pending event will get dealt with anyway. */
+
+	barrier(); /* unmask then check (avoid races) */
+	if (unlikely(vcpu->evtchn_upcall_pending))
+		xen_force_evtchn_callback();
+}
+
+static void xen_safe_halt(void)
+{
+	/* Blocking includes an implicit local_irq_enable(). */
+	if (HYPERVISOR_sched_op(SCHEDOP_block, NULL) != 0)
+		BUG();
+}
+
+static void xen_halt(void)
+{
+	if (irqs_disabled())
+		HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL);
+	else
+		xen_safe_halt();
+}
+
+static const struct pv_irq_ops xen_irq_ops __initdata = {
+	.init_IRQ = __xen_init_IRQ,
+	.save_fl = xen_save_fl,
+	.restore_fl = xen_restore_fl,
+	.irq_disable = xen_irq_disable,
+	.irq_enable = xen_irq_enable,
+	.safe_halt = xen_safe_halt,
+	.halt = xen_halt,
+#ifdef CONFIG_X86_64
+	.adjust_exception_frame = xen_adjust_exception_frame,
+#endif
+};
+
+void __init xen_init_irq_ops()
+{
+	pv_irq_ops = xen_irq_ops;
+}
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index aa37469da696..ae173f6edd8b 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -40,6 +40,7 @@
  */
 #include <linux/sched.h>
 #include <linux/highmem.h>
+#include <linux/debugfs.h>
 #include <linux/bug.h>
 
 #include <asm/pgtable.h>
@@ -57,6 +58,61 @@
 
 #include "multicalls.h"
 #include "mmu.h"
+#include "debugfs.h"
+
+#define MMU_UPDATE_HISTO	30
+
+#ifdef CONFIG_XEN_DEBUG_FS
+
+static struct {
+	u32 pgd_update;
+	u32 pgd_update_pinned;
+	u32 pgd_update_batched;
+
+	u32 pud_update;
+	u32 pud_update_pinned;
+	u32 pud_update_batched;
+
+	u32 pmd_update;
+	u32 pmd_update_pinned;
+	u32 pmd_update_batched;
+
+	u32 pte_update;
+	u32 pte_update_pinned;
+	u32 pte_update_batched;
+
+	u32 mmu_update;
+	u32 mmu_update_extended;
+	u32 mmu_update_histo[MMU_UPDATE_HISTO];
+
+	u32 prot_commit;
+	u32 prot_commit_batched;
+
+	u32 set_pte_at;
+	u32 set_pte_at_batched;
+	u32 set_pte_at_pinned;
+	u32 set_pte_at_current;
+	u32 set_pte_at_kernel;
+} mmu_stats;
+
+static u8 zero_stats;
+
+static inline void check_zero(void)
+{
+	if (unlikely(zero_stats)) {
+		memset(&mmu_stats, 0, sizeof(mmu_stats));
+		zero_stats = 0;
+	}
+}
+
+#define ADD_STATS(elem, val)			\
+	do { check_zero(); mmu_stats.elem += (val); } while(0)
+
+#else  /* !CONFIG_XEN_DEBUG_FS */
+
+#define ADD_STATS(elem, val)	do { (void)(val); } while(0)
+
+#endif /* CONFIG_XEN_DEBUG_FS */
 
 /*
  * Just beyond the highest usermode address.  STACK_TOP_MAX has a
@@ -229,25 +285,35 @@ void make_lowmem_page_readwrite(void *vaddr)
 }
 
 
-static bool page_pinned(void *ptr)
+static bool xen_page_pinned(void *ptr)
 {
 	struct page *page = virt_to_page(ptr);
 
 	return PagePinned(page);
 }
 
-static void extend_mmu_update(const struct mmu_update *update)
+static void xen_extend_mmu_update(const struct mmu_update *update)
 {
 	struct multicall_space mcs;
 	struct mmu_update *u;
 
 	mcs = xen_mc_extend_args(__HYPERVISOR_mmu_update, sizeof(*u));
 
-	if (mcs.mc != NULL)
+	if (mcs.mc != NULL) {
+		ADD_STATS(mmu_update_extended, 1);
+		ADD_STATS(mmu_update_histo[mcs.mc->args[1]], -1);
+
 		mcs.mc->args[1]++;
-	else {
+
+		if (mcs.mc->args[1] < MMU_UPDATE_HISTO)
+			ADD_STATS(mmu_update_histo[mcs.mc->args[1]], 1);
+		else
+			ADD_STATS(mmu_update_histo[0], 1);
+	} else {
+		ADD_STATS(mmu_update, 1);
 		mcs = __xen_mc_entry(sizeof(*u));
 		MULTI_mmu_update(mcs.mc, mcs.args, 1, NULL, DOMID_SELF);
+		ADD_STATS(mmu_update_histo[1], 1);
 	}
 
 	u = mcs.args;
@@ -265,7 +331,9 @@ void xen_set_pmd_hyper(pmd_t *ptr, pmd_t val)
 	/* ptr may be ioremapped for 64-bit pagetable setup */
 	u.ptr = arbitrary_virt_to_machine(ptr).maddr;
 	u.val = pmd_val_ma(val);
-	extend_mmu_update(&u);
+	xen_extend_mmu_update(&u);
+
+	ADD_STATS(pmd_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
 
 	xen_mc_issue(PARAVIRT_LAZY_MMU);
 
@@ -274,13 +342,17 @@ void xen_set_pmd_hyper(pmd_t *ptr, pmd_t val)
 
 void xen_set_pmd(pmd_t *ptr, pmd_t val)
 {
+	ADD_STATS(pmd_update, 1);
+
 	/* If page is not pinned, we can just update the entry
 	   directly */
-	if (!page_pinned(ptr)) {
+	if (!xen_page_pinned(ptr)) {
 		*ptr = val;
 		return;
 	}
 
+	ADD_STATS(pmd_update_pinned, 1);
+
 	xen_set_pmd_hyper(ptr, val);
 }
 
@@ -300,12 +372,18 @@ void xen_set_pte_at(struct mm_struct *mm, unsigned long addr,
 	if (mm == &init_mm)
 		preempt_disable();
 
+	ADD_STATS(set_pte_at, 1);
+//	ADD_STATS(set_pte_at_pinned, xen_page_pinned(ptep));
+	ADD_STATS(set_pte_at_current, mm == current->mm);
+	ADD_STATS(set_pte_at_kernel, mm == &init_mm);
+
 	if (mm == current->mm || mm == &init_mm) {
 		if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU) {
 			struct multicall_space mcs;
 			mcs = xen_mc_entry(0);
 
 			MULTI_update_va_mapping(mcs.mc, addr, pteval, 0);
+			ADD_STATS(set_pte_at_batched, 1);
 			xen_mc_issue(PARAVIRT_LAZY_MMU);
 			goto out;
 		} else
@@ -334,7 +412,10 @@ void xen_ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
 
 	u.ptr = virt_to_machine(ptep).maddr | MMU_PT_UPDATE_PRESERVE_AD;
 	u.val = pte_val_ma(pte);
-	extend_mmu_update(&u);
+	xen_extend_mmu_update(&u);
+
+	ADD_STATS(prot_commit, 1);
+	ADD_STATS(prot_commit_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
 
 	xen_mc_issue(PARAVIRT_LAZY_MMU);
 }
@@ -400,7 +481,9 @@ void xen_set_pud_hyper(pud_t *ptr, pud_t val)
 	/* ptr may be ioremapped for 64-bit pagetable setup */
 	u.ptr = arbitrary_virt_to_machine(ptr).maddr;
 	u.val = pud_val_ma(val);
-	extend_mmu_update(&u);
+	xen_extend_mmu_update(&u);
+
+	ADD_STATS(pud_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
 
 	xen_mc_issue(PARAVIRT_LAZY_MMU);
 
@@ -409,18 +492,26 @@ void xen_set_pud_hyper(pud_t *ptr, pud_t val)
 
 void xen_set_pud(pud_t *ptr, pud_t val)
 {
+	ADD_STATS(pud_update, 1);
+
 	/* If page is not pinned, we can just update the entry
 	   directly */
-	if (!page_pinned(ptr)) {
+	if (!xen_page_pinned(ptr)) {
 		*ptr = val;
 		return;
 	}
 
+	ADD_STATS(pud_update_pinned, 1);
+
 	xen_set_pud_hyper(ptr, val);
 }
 
 void xen_set_pte(pte_t *ptep, pte_t pte)
 {
+	ADD_STATS(pte_update, 1);
+//	ADD_STATS(pte_update_pinned, xen_page_pinned(ptep));
+	ADD_STATS(pte_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
+
 #ifdef CONFIG_X86_PAE
 	ptep->pte_high = pte.pte_high;
 	smp_wmb();
@@ -490,7 +581,7 @@ static void __xen_set_pgd_hyper(pgd_t *ptr, pgd_t val)
 
 	u.ptr = virt_to_machine(ptr).maddr;
 	u.val = pgd_val_ma(val);
-	extend_mmu_update(&u);
+	xen_extend_mmu_update(&u);
 }
 
 /*
@@ -517,17 +608,22 @@ void xen_set_pgd(pgd_t *ptr, pgd_t val)
 {
 	pgd_t *user_ptr = xen_get_user_pgd(ptr);
 
+	ADD_STATS(pgd_update, 1);
+
 	/* If page is not pinned, we can just update the entry
 	   directly */
-	if (!page_pinned(ptr)) {
+	if (!xen_page_pinned(ptr)) {
 		*ptr = val;
 		if (user_ptr) {
-			WARN_ON(page_pinned(user_ptr));
+			WARN_ON(xen_page_pinned(user_ptr));
 			*user_ptr = val;
 		}
 		return;
 	}
 
+	ADD_STATS(pgd_update_pinned, 1);
+	ADD_STATS(pgd_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
+
 	/* If it's pinned, then we can at least batch the kernel and
 	   user updates together. */
 	xen_mc_batch();
@@ -555,9 +651,12 @@ void xen_set_pgd(pgd_t *ptr, pgd_t val)
  * For 64-bit, we must skip the Xen hole in the middle of the address
  * space, just after the big x86-64 virtual hole.
  */
-static int pgd_walk(pgd_t *pgd, int (*func)(struct page *, enum pt_level),
-		    unsigned long limit)
+static int xen_pgd_walk(struct mm_struct *mm,
+			int (*func)(struct mm_struct *mm, struct page *,
+				    enum pt_level),
+			unsigned long limit)
 {
+	pgd_t *pgd = mm->pgd;
 	int flush = 0;
 	unsigned hole_low, hole_high;
 	unsigned pgdidx_limit, pudidx_limit, pmdidx_limit;
@@ -590,8 +689,6 @@ static int pgd_walk(pgd_t *pgd, int (*func)(struct page *, enum pt_level),
 	pmdidx_limit = 0;
 #endif
 
-	flush |= (*func)(virt_to_page(pgd), PT_PGD);
-
 	for (pgdidx = 0; pgdidx <= pgdidx_limit; pgdidx++) {
 		pud_t *pud;
 
@@ -604,7 +701,7 @@ static int pgd_walk(pgd_t *pgd, int (*func)(struct page *, enum pt_level),
 		pud = pud_offset(&pgd[pgdidx], 0);
 
 		if (PTRS_PER_PUD > 1) /* not folded */
-			flush |= (*func)(virt_to_page(pud), PT_PUD);
+			flush |= (*func)(mm, virt_to_page(pud), PT_PUD);
 
 		for (pudidx = 0; pudidx < PTRS_PER_PUD; pudidx++) {
 			pmd_t *pmd;
@@ -619,7 +716,7 @@ static int pgd_walk(pgd_t *pgd, int (*func)(struct page *, enum pt_level),
 			pmd = pmd_offset(&pud[pudidx], 0);
 
 			if (PTRS_PER_PMD > 1) /* not folded */
-				flush |= (*func)(virt_to_page(pmd), PT_PMD);
+				flush |= (*func)(mm, virt_to_page(pmd), PT_PMD);
 
 			for (pmdidx = 0; pmdidx < PTRS_PER_PMD; pmdidx++) {
 				struct page *pte;
@@ -633,28 +730,34 @@ static int pgd_walk(pgd_t *pgd, int (*func)(struct page *, enum pt_level),
 					continue;
 
 				pte = pmd_page(pmd[pmdidx]);
-				flush |= (*func)(pte, PT_PTE);
+				flush |= (*func)(mm, pte, PT_PTE);
 			}
 		}
 	}
+
 out:
+	/* Do the top level last, so that the callbacks can use it as
+	   a cue to do final things like tlb flushes. */
+	flush |= (*func)(mm, virt_to_page(pgd), PT_PGD);
 
 	return flush;
 }
 
-static spinlock_t *lock_pte(struct page *page)
+/* If we're using split pte locks, then take the page's lock and
+   return a pointer to it.  Otherwise return NULL. */
+static spinlock_t *xen_pte_lock(struct page *page, struct mm_struct *mm)
 {
 	spinlock_t *ptl = NULL;
 
-#if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS
+#if USE_SPLIT_PTLOCKS
 	ptl = __pte_lockptr(page);
-	spin_lock(ptl);
+	spin_lock_nest_lock(ptl, &mm->page_table_lock);
 #endif
 
 	return ptl;
 }
 
-static void do_unlock(void *v)
+static void xen_pte_unlock(void *v)
 {
 	spinlock_t *ptl = v;
 	spin_unlock(ptl);
@@ -672,7 +775,8 @@ static void xen_do_pin(unsigned level, unsigned long pfn)
 	MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
 }
 
-static int pin_page(struct page *page, enum pt_level level)
+static int xen_pin_page(struct mm_struct *mm, struct page *page,
+			enum pt_level level)
 {
 	unsigned pgfl = TestSetPagePinned(page);
 	int flush;
@@ -691,21 +795,40 @@ static int pin_page(struct page *page, enum pt_level level)
 
 		flush = 0;
 
+		/*
+		 * We need to hold the pagetable lock between the time
+		 * we make the pagetable RO and when we actually pin
+		 * it.  If we don't, then other users may come in and
+		 * attempt to update the pagetable by writing it,
+		 * which will fail because the memory is RO but not
+		 * pinned, so Xen won't do the trap'n'emulate.
+		 *
+		 * If we're using split pte locks, we can't hold the
+		 * entire pagetable's worth of locks during the
+		 * traverse, because we may wrap the preempt count (8
+		 * bits).  The solution is to mark RO and pin each PTE
+		 * page while holding the lock.  This means the number
+		 * of locks we end up holding is never more than a
+		 * batch size (~32 entries, at present).
+		 *
+		 * If we're not using split pte locks, we needn't pin
+		 * the PTE pages independently, because we're
+		 * protected by the overall pagetable lock.
+		 */
 		ptl = NULL;
 		if (level == PT_PTE)
-			ptl = lock_pte(page);
+			ptl = xen_pte_lock(page, mm);
 
 		MULTI_update_va_mapping(mcs.mc, (unsigned long)pt,
 					pfn_pte(pfn, PAGE_KERNEL_RO),
 					level == PT_PGD ? UVMF_TLB_FLUSH : 0);
 
-		if (level == PT_PTE)
+		if (ptl) {
 			xen_do_pin(MMUEXT_PIN_L1_TABLE, pfn);
 
-		if (ptl) {
 			/* Queue a deferred unlock for when this batch
 			   is completed. */
-			xen_mc_callback(do_unlock, ptl);
+			xen_mc_callback(xen_pte_unlock, ptl);
 		}
 	}
 
@@ -715,11 +838,11 @@ static int pin_page(struct page *page, enum pt_level level)
 /* This is called just after a mm has been created, but it has not
    been used yet.  We need to make sure that its pagetable is all
    read-only, and can be pinned. */
-void xen_pgd_pin(pgd_t *pgd)
+static void __xen_pgd_pin(struct mm_struct *mm, pgd_t *pgd)
 {
 	xen_mc_batch();
 
-	if (pgd_walk(pgd, pin_page, USER_LIMIT)) {
+	if (xen_pgd_walk(mm, xen_pin_page, USER_LIMIT)) {
 		/* re-enable interrupts for kmap_flush_unused */
 		xen_mc_issue(0);
 		kmap_flush_unused();
@@ -733,25 +856,35 @@ void xen_pgd_pin(pgd_t *pgd)
 		xen_do_pin(MMUEXT_PIN_L4_TABLE, PFN_DOWN(__pa(pgd)));
 
 		if (user_pgd) {
-			pin_page(virt_to_page(user_pgd), PT_PGD);
+			xen_pin_page(mm, virt_to_page(user_pgd), PT_PGD);
 			xen_do_pin(MMUEXT_PIN_L4_TABLE, PFN_DOWN(__pa(user_pgd)));
 		}
 	}
 #else /* CONFIG_X86_32 */
 #ifdef CONFIG_X86_PAE
 	/* Need to make sure unshared kernel PMD is pinnable */
-	pin_page(virt_to_page(pgd_page(pgd[pgd_index(TASK_SIZE)])), PT_PMD);
+	xen_pin_page(mm, virt_to_page(pgd_page(pgd[pgd_index(TASK_SIZE)])),
+		     PT_PMD);
 #endif
 	xen_do_pin(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(pgd)));
 #endif /* CONFIG_X86_64 */
 	xen_mc_issue(0);
 }
 
+static void xen_pgd_pin(struct mm_struct *mm)
+{
+	__xen_pgd_pin(mm, mm->pgd);
+}
+
 /*
  * On save, we need to pin all pagetables to make sure they get their
  * mfns turned into pfns.  Search the list for any unpinned pgds and pin
  * them (unpinned pgds are not currently in use, probably because the
  * process is under construction or destruction).
+ *
+ * Expected to be called in stop_machine() ("equivalent to taking
+ * every spinlock in the system"), so the locking doesn't really
+ * matter all that much.
  */
 void xen_mm_pin_all(void)
 {
@@ -762,7 +895,7 @@ void xen_mm_pin_all(void)
 
 	list_for_each_entry(page, &pgd_list, lru) {
 		if (!PagePinned(page)) {
-			xen_pgd_pin((pgd_t *)page_address(page));
+			__xen_pgd_pin(&init_mm, (pgd_t *)page_address(page));
 			SetPageSavePinned(page);
 		}
 	}
@@ -775,7 +908,8 @@ void xen_mm_pin_all(void)
  * that's before we have page structures to store the bits.  So do all
  * the book-keeping now.
  */
-static __init int mark_pinned(struct page *page, enum pt_level level)
+static __init int xen_mark_pinned(struct mm_struct *mm, struct page *page,
+				  enum pt_level level)
 {
 	SetPagePinned(page);
 	return 0;
@@ -783,10 +917,11 @@ static __init int mark_pinned(struct page *page, enum pt_level level)
 
 void __init xen_mark_init_mm_pinned(void)
 {
-	pgd_walk(init_mm.pgd, mark_pinned, FIXADDR_TOP);
+	xen_pgd_walk(&init_mm, xen_mark_pinned, FIXADDR_TOP);
 }
 
-static int unpin_page(struct page *page, enum pt_level level)
+static int xen_unpin_page(struct mm_struct *mm, struct page *page,
+			  enum pt_level level)
 {
 	unsigned pgfl = TestClearPagePinned(page);
 
@@ -796,10 +931,18 @@ static int unpin_page(struct page *page, enum pt_level level)
 		spinlock_t *ptl = NULL;
 		struct multicall_space mcs;
 
+		/*
+		 * Do the converse to pin_page.  If we're using split
+		 * pte locks, we must be holding the lock for while
+		 * the pte page is unpinned but still RO to prevent
+		 * concurrent updates from seeing it in this
+		 * partially-pinned state.
+		 */
 		if (level == PT_PTE) {
-			ptl = lock_pte(page);
+			ptl = xen_pte_lock(page, mm);
 
-			xen_do_pin(MMUEXT_UNPIN_TABLE, pfn);
+			if (ptl)
+				xen_do_pin(MMUEXT_UNPIN_TABLE, pfn);
 		}
 
 		mcs = __xen_mc_entry(0);
@@ -810,7 +953,7 @@ static int unpin_page(struct page *page, enum pt_level level)
 
 		if (ptl) {
 			/* unlock when batch completed */
-			xen_mc_callback(do_unlock, ptl);
+			xen_mc_callback(xen_pte_unlock, ptl);
 		}
 	}
 
@@ -818,7 +961,7 @@ static int unpin_page(struct page *page, enum pt_level level)
 }
 
 /* Release a pagetables pages back as normal RW */
-static void xen_pgd_unpin(pgd_t *pgd)
+static void __xen_pgd_unpin(struct mm_struct *mm, pgd_t *pgd)
 {
 	xen_mc_batch();
 
@@ -830,21 +973,27 @@ static void xen_pgd_unpin(pgd_t *pgd)
 
 		if (user_pgd) {
 			xen_do_pin(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(user_pgd)));
-			unpin_page(virt_to_page(user_pgd), PT_PGD);
+			xen_unpin_page(mm, virt_to_page(user_pgd), PT_PGD);
 		}
 	}
 #endif
 
 #ifdef CONFIG_X86_PAE
 	/* Need to make sure unshared kernel PMD is unpinned */
-	pin_page(virt_to_page(pgd_page(pgd[pgd_index(TASK_SIZE)])), PT_PMD);
+	xen_unpin_page(mm, virt_to_page(pgd_page(pgd[pgd_index(TASK_SIZE)])),
+		       PT_PMD);
 #endif
 
-	pgd_walk(pgd, unpin_page, USER_LIMIT);
+	xen_pgd_walk(mm, xen_unpin_page, USER_LIMIT);
 
 	xen_mc_issue(0);
 }
 
+static void xen_pgd_unpin(struct mm_struct *mm)
+{
+	__xen_pgd_unpin(mm, mm->pgd);
+}
+
 /*
  * On resume, undo any pinning done at save, so that the rest of the
  * kernel doesn't see any unexpected pinned pagetables.
@@ -859,7 +1008,7 @@ void xen_mm_unpin_all(void)
 	list_for_each_entry(page, &pgd_list, lru) {
 		if (PageSavePinned(page)) {
 			BUG_ON(!PagePinned(page));
-			xen_pgd_unpin((pgd_t *)page_address(page));
+			__xen_pgd_unpin(&init_mm, (pgd_t *)page_address(page));
 			ClearPageSavePinned(page);
 		}
 	}
@@ -870,14 +1019,14 @@ void xen_mm_unpin_all(void)
 void xen_activate_mm(struct mm_struct *prev, struct mm_struct *next)
 {
 	spin_lock(&next->page_table_lock);
-	xen_pgd_pin(next->pgd);
+	xen_pgd_pin(next);
 	spin_unlock(&next->page_table_lock);
 }
 
 void xen_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
 {
 	spin_lock(&mm->page_table_lock);
-	xen_pgd_pin(mm->pgd);
+	xen_pgd_pin(mm);
 	spin_unlock(&mm->page_table_lock);
 }
 
@@ -907,7 +1056,7 @@ static void drop_other_mm_ref(void *info)
 	}
 }
 
-static void drop_mm_ref(struct mm_struct *mm)
+static void xen_drop_mm_ref(struct mm_struct *mm)
 {
 	cpumask_t mask;
 	unsigned cpu;
@@ -937,7 +1086,7 @@ static void drop_mm_ref(struct mm_struct *mm)
 		smp_call_function_mask(mask, drop_other_mm_ref, mm, 1);
 }
 #else
-static void drop_mm_ref(struct mm_struct *mm)
+static void xen_drop_mm_ref(struct mm_struct *mm)
 {
 	if (current->active_mm == mm)
 		load_cr3(swapper_pg_dir);
@@ -961,14 +1110,77 @@ static void drop_mm_ref(struct mm_struct *mm)
 void xen_exit_mmap(struct mm_struct *mm)
 {
 	get_cpu();		/* make sure we don't move around */
-	drop_mm_ref(mm);
+	xen_drop_mm_ref(mm);
 	put_cpu();
 
 	spin_lock(&mm->page_table_lock);
 
 	/* pgd may not be pinned in the error exit path of execve */
-	if (page_pinned(mm->pgd))
-		xen_pgd_unpin(mm->pgd);
+	if (xen_page_pinned(mm->pgd))
+		xen_pgd_unpin(mm);
 
 	spin_unlock(&mm->page_table_lock);
 }
+
+#ifdef CONFIG_XEN_DEBUG_FS
+
+static struct dentry *d_mmu_debug;
+
+static int __init xen_mmu_debugfs(void)
+{
+	struct dentry *d_xen = xen_init_debugfs();
+
+	if (d_xen == NULL)
+		return -ENOMEM;
+
+	d_mmu_debug = debugfs_create_dir("mmu", d_xen);
+
+	debugfs_create_u8("zero_stats", 0644, d_mmu_debug, &zero_stats);
+
+	debugfs_create_u32("pgd_update", 0444, d_mmu_debug, &mmu_stats.pgd_update);
+	debugfs_create_u32("pgd_update_pinned", 0444, d_mmu_debug,
+			   &mmu_stats.pgd_update_pinned);
+	debugfs_create_u32("pgd_update_batched", 0444, d_mmu_debug,
+			   &mmu_stats.pgd_update_pinned);
+
+	debugfs_create_u32("pud_update", 0444, d_mmu_debug, &mmu_stats.pud_update);
+	debugfs_create_u32("pud_update_pinned", 0444, d_mmu_debug,
+			   &mmu_stats.pud_update_pinned);
+	debugfs_create_u32("pud_update_batched", 0444, d_mmu_debug,
+			   &mmu_stats.pud_update_pinned);
+
+	debugfs_create_u32("pmd_update", 0444, d_mmu_debug, &mmu_stats.pmd_update);
+	debugfs_create_u32("pmd_update_pinned", 0444, d_mmu_debug,
+			   &mmu_stats.pmd_update_pinned);
+	debugfs_create_u32("pmd_update_batched", 0444, d_mmu_debug,
+			   &mmu_stats.pmd_update_pinned);
+
+	debugfs_create_u32("pte_update", 0444, d_mmu_debug, &mmu_stats.pte_update);
+//	debugfs_create_u32("pte_update_pinned", 0444, d_mmu_debug,
+//			   &mmu_stats.pte_update_pinned);
+	debugfs_create_u32("pte_update_batched", 0444, d_mmu_debug,
+			   &mmu_stats.pte_update_pinned);
+
+	debugfs_create_u32("mmu_update", 0444, d_mmu_debug, &mmu_stats.mmu_update);
+	debugfs_create_u32("mmu_update_extended", 0444, d_mmu_debug,
+			   &mmu_stats.mmu_update_extended);
+	xen_debugfs_create_u32_array("mmu_update_histo", 0444, d_mmu_debug,
+				     mmu_stats.mmu_update_histo, 20);
+
+	debugfs_create_u32("set_pte_at", 0444, d_mmu_debug, &mmu_stats.set_pte_at);
+	debugfs_create_u32("set_pte_at_batched", 0444, d_mmu_debug,
+			   &mmu_stats.set_pte_at_batched);
+	debugfs_create_u32("set_pte_at_current", 0444, d_mmu_debug,
+			   &mmu_stats.set_pte_at_current);
+	debugfs_create_u32("set_pte_at_kernel", 0444, d_mmu_debug,
+			   &mmu_stats.set_pte_at_kernel);
+
+	debugfs_create_u32("prot_commit", 0444, d_mmu_debug, &mmu_stats.prot_commit);
+	debugfs_create_u32("prot_commit_batched", 0444, d_mmu_debug,
+			   &mmu_stats.prot_commit_batched);
+
+	return 0;
+}
+fs_initcall(xen_mmu_debugfs);
+
+#endif	/* CONFIG_XEN_DEBUG_FS */
diff --git a/arch/x86/xen/mmu.h b/arch/x86/xen/mmu.h
index 0f59bd03f9e3..98d71659da5a 100644
--- a/arch/x86/xen/mmu.h
+++ b/arch/x86/xen/mmu.h
@@ -18,9 +18,6 @@ void xen_activate_mm(struct mm_struct *prev, struct mm_struct *next);
 void xen_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm);
 void xen_exit_mmap(struct mm_struct *mm);
 
-void xen_pgd_pin(pgd_t *pgd);
-//void xen_pgd_unpin(pgd_t *pgd);
-
 pteval_t xen_pte_val(pte_t);
 pmdval_t xen_pmd_val(pmd_t);
 pgdval_t xen_pgd_val(pgd_t);
diff --git a/arch/x86/xen/multicalls.c b/arch/x86/xen/multicalls.c
index 9efd1c6c9776..8ea8a0d0b0de 100644
--- a/arch/x86/xen/multicalls.c
+++ b/arch/x86/xen/multicalls.c
@@ -21,16 +21,20 @@
  */
 #include <linux/percpu.h>
 #include <linux/hardirq.h>
+#include <linux/debugfs.h>
 
 #include <asm/xen/hypercall.h>
 
 #include "multicalls.h"
+#include "debugfs.h"
+
+#define MC_BATCH	32
 
 #define MC_DEBUG	1
 
-#define MC_BATCH	32
 #define MC_ARGS		(MC_BATCH * 16)
 
+
 struct mc_buffer {
 	struct multicall_entry entries[MC_BATCH];
 #if MC_DEBUG
@@ -47,6 +51,76 @@ struct mc_buffer {
 static DEFINE_PER_CPU(struct mc_buffer, mc_buffer);
 DEFINE_PER_CPU(unsigned long, xen_mc_irq_flags);
 
+/* flush reasons 0- slots, 1- args, 2- callbacks */
+enum flush_reasons
+{
+	FL_SLOTS,
+	FL_ARGS,
+	FL_CALLBACKS,
+
+	FL_N_REASONS
+};
+
+#ifdef CONFIG_XEN_DEBUG_FS
+#define NHYPERCALLS	40		/* not really */
+
+static struct {
+	unsigned histo[MC_BATCH+1];
+
+	unsigned issued;
+	unsigned arg_total;
+	unsigned hypercalls;
+	unsigned histo_hypercalls[NHYPERCALLS];
+
+	unsigned flush[FL_N_REASONS];
+} mc_stats;
+
+static u8 zero_stats;
+
+static inline void check_zero(void)
+{
+	if (unlikely(zero_stats)) {
+		memset(&mc_stats, 0, sizeof(mc_stats));
+		zero_stats = 0;
+	}
+}
+
+static void mc_add_stats(const struct mc_buffer *mc)
+{
+	int i;
+
+	check_zero();
+
+	mc_stats.issued++;
+	mc_stats.hypercalls += mc->mcidx;
+	mc_stats.arg_total += mc->argidx;
+
+	mc_stats.histo[mc->mcidx]++;
+	for(i = 0; i < mc->mcidx; i++) {
+		unsigned op = mc->entries[i].op;
+		if (op < NHYPERCALLS)
+			mc_stats.histo_hypercalls[op]++;
+	}
+}
+
+static void mc_stats_flush(enum flush_reasons idx)
+{
+	check_zero();
+
+	mc_stats.flush[idx]++;
+}
+
+#else  /* !CONFIG_XEN_DEBUG_FS */
+
+static inline void mc_add_stats(const struct mc_buffer *mc)
+{
+}
+
+static inline void mc_stats_flush(enum flush_reasons idx)
+{
+}
+#endif	/* CONFIG_XEN_DEBUG_FS */
+
 void xen_mc_flush(void)
 {
 	struct mc_buffer *b = &__get_cpu_var(mc_buffer);
@@ -60,6 +134,8 @@ void xen_mc_flush(void)
 	   something in the middle */
 	local_irq_save(flags);
 
+	mc_add_stats(b);
+
 	if (b->mcidx) {
 #if MC_DEBUG
 		memcpy(b->debug, b->entries,
@@ -115,6 +191,7 @@ struct multicall_space __xen_mc_entry(size_t args)
 
 	if (b->mcidx == MC_BATCH ||
 	    (argidx + args) > MC_ARGS) {
+		mc_stats_flush(b->mcidx == MC_BATCH ? FL_SLOTS : FL_ARGS);
 		xen_mc_flush();
 		argidx = roundup(b->argidx, sizeof(u64));
 	}
@@ -158,10 +235,44 @@ void xen_mc_callback(void (*fn)(void *), void *data)
 	struct mc_buffer *b = &__get_cpu_var(mc_buffer);
 	struct callback *cb;
 
-	if (b->cbidx == MC_BATCH)
+	if (b->cbidx == MC_BATCH) {
+		mc_stats_flush(FL_CALLBACKS);
 		xen_mc_flush();
+	}
 
 	cb = &b->callbacks[b->cbidx++];
 	cb->fn = fn;
 	cb->data = data;
 }
+
+#ifdef CONFIG_XEN_DEBUG_FS
+
+static struct dentry *d_mc_debug;
+
+static int __init xen_mc_debugfs(void)
+{
+	struct dentry *d_xen = xen_init_debugfs();
+
+	if (d_xen == NULL)
+		return -ENOMEM;
+
+	d_mc_debug = debugfs_create_dir("multicalls", d_xen);
+
+	debugfs_create_u8("zero_stats", 0644, d_mc_debug, &zero_stats);
+
+	debugfs_create_u32("batches", 0444, d_mc_debug, &mc_stats.issued);
+	debugfs_create_u32("hypercalls", 0444, d_mc_debug, &mc_stats.hypercalls);
+	debugfs_create_u32("arg_total", 0444, d_mc_debug, &mc_stats.arg_total);
+
+	xen_debugfs_create_u32_array("batch_histo", 0444, d_mc_debug,
+				     mc_stats.histo, MC_BATCH);
+	xen_debugfs_create_u32_array("hypercall_histo", 0444, d_mc_debug,
+				     mc_stats.histo_hypercalls, NHYPERCALLS);
+	xen_debugfs_create_u32_array("flush_reasons", 0444, d_mc_debug,
+				     mc_stats.flush, FL_N_REASONS);
+
+	return 0;
+}
+fs_initcall(xen_mc_debugfs);
+
+#endif	/* CONFIG_XEN_DEBUG_FS */
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index d8faf79a0a1d..d77da613b1d2 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -11,11 +11,8 @@
  * useful topology information for the kernel to make use of.  As a
  * result, all CPUs are treated as if they're single-core and
  * single-threaded.
- *
- * This does not handle HOTPLUG_CPU yet.
  */
 #include <linux/sched.h>
-#include <linux/kernel_stat.h>
 #include <linux/err.h>
 #include <linux/smp.h>
 
@@ -36,8 +33,6 @@
 #include "xen-ops.h"
 #include "mmu.h"
 
-static void __cpuinit xen_init_lock_cpu(int cpu);
-
 cpumask_t xen_cpu_initialized_map;
 
 static DEFINE_PER_CPU(int, resched_irq);
@@ -64,11 +59,12 @@ static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-static __cpuinit void cpu_bringup_and_idle(void)
+static __cpuinit void cpu_bringup(void)
 {
 	int cpu = smp_processor_id();
 
 	cpu_init();
+	touch_softlockup_watchdog();
 	preempt_disable();
 
 	xen_enable_sysenter();
@@ -89,6 +85,11 @@ static __cpuinit void cpu_bringup_and_idle(void)
 	local_irq_enable();
 
 	wmb();			/* make sure everything is out */
+}
+
+static __cpuinit void cpu_bringup_and_idle(void)
+{
+	cpu_bringup();
 	cpu_idle();
 }
 
@@ -212,8 +213,6 @@ static void __init xen_smp_prepare_cpus(unsigned int max_cpus)
 
 		cpu_set(cpu, cpu_present_map);
 	}
-
-	//init_xenbus_allowed_cpumask();
 }
 
 static __cpuinit int
@@ -281,12 +280,6 @@ static int __cpuinit xen_cpu_up(unsigned int cpu)
 	struct task_struct *idle = idle_task(cpu);
 	int rc;
 
-#if 0
-	rc = cpu_up_check(cpu);
-	if (rc)
-		return rc;
-#endif
-
 #ifdef CONFIG_X86_64
 	/* Allocate node local memory for AP pdas */
 	WARN_ON(cpu == 0);
@@ -339,6 +332,60 @@ static void xen_smp_cpus_done(unsigned int max_cpus)
 {
 }
 
+#ifdef CONFIG_HOTPLUG_CPU
+static int xen_cpu_disable(void)
+{
+	unsigned int cpu = smp_processor_id();
+	if (cpu == 0)
+		return -EBUSY;
+
+	cpu_disable_common();
+
+	load_cr3(swapper_pg_dir);
+	return 0;
+}
+
+static void xen_cpu_die(unsigned int cpu)
+{
+	while (HYPERVISOR_vcpu_op(VCPUOP_is_up, cpu, NULL)) {
+		current->state = TASK_UNINTERRUPTIBLE;
+		schedule_timeout(HZ/10);
+	}
+	unbind_from_irqhandler(per_cpu(resched_irq, cpu), NULL);
+	unbind_from_irqhandler(per_cpu(callfunc_irq, cpu), NULL);
+	unbind_from_irqhandler(per_cpu(debug_irq, cpu), NULL);
+	unbind_from_irqhandler(per_cpu(callfuncsingle_irq, cpu), NULL);
+	xen_uninit_lock_cpu(cpu);
+	xen_teardown_timer(cpu);
+
+	if (num_online_cpus() == 1)
+		alternatives_smp_switch(0);
+}
+
+static void xen_play_dead(void)
+{
+	play_dead_common();
+	HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL);
+	cpu_bringup();
+}
+
+#else /* !CONFIG_HOTPLUG_CPU */
+static int xen_cpu_disable(void)
+{
+	return -ENOSYS;
+}
+
+static void xen_cpu_die(unsigned int cpu)
+{
+	BUG();
+}
+
+static void xen_play_dead(void)
+{
+	BUG();
+}
+
+#endif
 static void stop_self(void *v)
 {
 	int cpu = smp_processor_id();
@@ -419,176 +466,16 @@ static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-struct xen_spinlock {
-	unsigned char lock;		/* 0 -> free; 1 -> locked */
-	unsigned short spinners;	/* count of waiting cpus */
-};
-
-static int xen_spin_is_locked(struct raw_spinlock *lock)
-{
-	struct xen_spinlock *xl = (struct xen_spinlock *)lock;
-
-	return xl->lock != 0;
-}
-
-static int xen_spin_is_contended(struct raw_spinlock *lock)
-{
-	struct xen_spinlock *xl = (struct xen_spinlock *)lock;
-
-	/* Not strictly true; this is only the count of contended
-	   lock-takers entering the slow path. */
-	return xl->spinners != 0;
-}
-
-static int xen_spin_trylock(struct raw_spinlock *lock)
-{
-	struct xen_spinlock *xl = (struct xen_spinlock *)lock;
-	u8 old = 1;
-
-	asm("xchgb %b0,%1"
-	    : "+q" (old), "+m" (xl->lock) : : "memory");
-
-	return old == 0;
-}
-
-static DEFINE_PER_CPU(int, lock_kicker_irq) = -1;
-static DEFINE_PER_CPU(struct xen_spinlock *, lock_spinners);
-
-static inline void spinning_lock(struct xen_spinlock *xl)
-{
-	__get_cpu_var(lock_spinners) = xl;
-	wmb();			/* set lock of interest before count */
-	asm(LOCK_PREFIX " incw %0"
-	    : "+m" (xl->spinners) : : "memory");
-}
-
-static inline void unspinning_lock(struct xen_spinlock *xl)
-{
-	asm(LOCK_PREFIX " decw %0"
-	    : "+m" (xl->spinners) : : "memory");
-	wmb();			/* decrement count before clearing lock */
-	__get_cpu_var(lock_spinners) = NULL;
-}
-
-static noinline int xen_spin_lock_slow(struct raw_spinlock *lock)
-{
-	struct xen_spinlock *xl = (struct xen_spinlock *)lock;
-	int irq = __get_cpu_var(lock_kicker_irq);
-	int ret;
-
-	/* If kicker interrupts not initialized yet, just spin */
-	if (irq == -1)
-		return 0;
-
-	/* announce we're spinning */
-	spinning_lock(xl);
-
-	/* clear pending */
-	xen_clear_irq_pending(irq);
-
-	/* check again make sure it didn't become free while
-	   we weren't looking  */
-	ret = xen_spin_trylock(lock);
-	if (ret)
-		goto out;
-
-	/* block until irq becomes pending */
-	xen_poll_irq(irq);
-	kstat_this_cpu.irqs[irq]++;
-
-out:
-	unspinning_lock(xl);
-	return ret;
-}
-
-static void xen_spin_lock(struct raw_spinlock *lock)
-{
-	struct xen_spinlock *xl = (struct xen_spinlock *)lock;
-	int timeout;
-	u8 oldval;
-
-	do {
-		timeout = 1 << 10;
-
-		asm("1: xchgb %1,%0\n"
-		    "   testb %1,%1\n"
-		    "   jz 3f\n"
-		    "2: rep;nop\n"
-		    "   cmpb $0,%0\n"
-		    "   je 1b\n"
-		    "   dec %2\n"
-		    "   jnz 2b\n"
-		    "3:\n"
-		    : "+m" (xl->lock), "=q" (oldval), "+r" (timeout)
-		    : "1" (1)
-		    : "memory");
-
-	} while (unlikely(oldval != 0 && !xen_spin_lock_slow(lock)));
-}
-
-static noinline void xen_spin_unlock_slow(struct xen_spinlock *xl)
-{
-	int cpu;
-
-	for_each_online_cpu(cpu) {
-		/* XXX should mix up next cpu selection */
-		if (per_cpu(lock_spinners, cpu) == xl) {
-			xen_send_IPI_one(cpu, XEN_SPIN_UNLOCK_VECTOR);
-			break;
-		}
-	}
-}
-
-static void xen_spin_unlock(struct raw_spinlock *lock)
-{
-	struct xen_spinlock *xl = (struct xen_spinlock *)lock;
-
-	smp_wmb();		/* make sure no writes get moved after unlock */
-	xl->lock = 0;		/* release lock */
-
-	/* make sure unlock happens before kick */
-	barrier();
-
-	if (unlikely(xl->spinners))
-		xen_spin_unlock_slow(xl);
-}
-
-static __cpuinit void xen_init_lock_cpu(int cpu)
-{
-	int irq;
-	const char *name;
-
-	name = kasprintf(GFP_KERNEL, "spinlock%d", cpu);
-	irq = bind_ipi_to_irqhandler(XEN_SPIN_UNLOCK_VECTOR,
-				     cpu,
-				     xen_reschedule_interrupt,
-				     IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
-				     name,
-				     NULL);
-
-	if (irq >= 0) {
-		disable_irq(irq); /* make sure it's never delivered */
-		per_cpu(lock_kicker_irq, cpu) = irq;
-	}
-
-	printk("cpu %d spinlock event irq %d\n", cpu, irq);
-}
-
-static void __init xen_init_spinlocks(void)
-{
-	pv_lock_ops.spin_is_locked = xen_spin_is_locked;
-	pv_lock_ops.spin_is_contended = xen_spin_is_contended;
-	pv_lock_ops.spin_lock = xen_spin_lock;
-	pv_lock_ops.spin_trylock = xen_spin_trylock;
-	pv_lock_ops.spin_unlock = xen_spin_unlock;
-}
-
 static const struct smp_ops xen_smp_ops __initdata = {
 	.smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu,
 	.smp_prepare_cpus = xen_smp_prepare_cpus,
-	.cpu_up = xen_cpu_up,
 	.smp_cpus_done = xen_smp_cpus_done,
 
+	.cpu_up = xen_cpu_up,
+	.cpu_die = xen_cpu_die,
+	.cpu_disable = xen_cpu_disable,
+	.play_dead = xen_play_dead,
+
 	.smp_send_stop = xen_smp_send_stop,
 	.smp_send_reschedule = xen_smp_send_reschedule,
 
diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c
new file mode 100644
index 000000000000..dd71e3a021cd
--- /dev/null
+++ b/arch/x86/xen/spinlock.c
@@ -0,0 +1,428 @@
+/*
+ * Split spinlock implementation out into its own file, so it can be
+ * compiled in a FTRACE-compatible way.
+ */
+#include <linux/kernel_stat.h>
+#include <linux/spinlock.h>
+#include <linux/debugfs.h>
+#include <linux/log2.h>
+
+#include <asm/paravirt.h>
+
+#include <xen/interface/xen.h>
+#include <xen/events.h>
+
+#include "xen-ops.h"
+#include "debugfs.h"
+
+#ifdef CONFIG_XEN_DEBUG_FS
+static struct xen_spinlock_stats
+{
+	u64 taken;
+	u32 taken_slow;
+	u32 taken_slow_nested;
+	u32 taken_slow_pickup;
+	u32 taken_slow_spurious;
+	u32 taken_slow_irqenable;
+
+	u64 released;
+	u32 released_slow;
+	u32 released_slow_kicked;
+
+#define HISTO_BUCKETS	30
+	u32 histo_spin_total[HISTO_BUCKETS+1];
+	u32 histo_spin_spinning[HISTO_BUCKETS+1];
+	u32 histo_spin_blocked[HISTO_BUCKETS+1];
+
+	u64 time_total;
+	u64 time_spinning;
+	u64 time_blocked;
+} spinlock_stats;
+
+static u8 zero_stats;
+
+static unsigned lock_timeout = 1 << 10;
+#define TIMEOUT lock_timeout
+
+static inline void check_zero(void)
+{
+	if (unlikely(zero_stats)) {
+		memset(&spinlock_stats, 0, sizeof(spinlock_stats));
+		zero_stats = 0;
+	}
+}
+
+#define ADD_STATS(elem, val)			\
+	do { check_zero(); spinlock_stats.elem += (val); } while(0)
+
+static inline u64 spin_time_start(void)
+{
+	return xen_clocksource_read();
+}
+
+static void __spin_time_accum(u64 delta, u32 *array)
+{
+	unsigned index = ilog2(delta);
+
+	check_zero();
+
+	if (index < HISTO_BUCKETS)
+		array[index]++;
+	else
+		array[HISTO_BUCKETS]++;
+}
+
+static inline void spin_time_accum_spinning(u64 start)
+{
+	u32 delta = xen_clocksource_read() - start;
+
+	__spin_time_accum(delta, spinlock_stats.histo_spin_spinning);
+	spinlock_stats.time_spinning += delta;
+}
+
+static inline void spin_time_accum_total(u64 start)
+{
+	u32 delta = xen_clocksource_read() - start;
+
+	__spin_time_accum(delta, spinlock_stats.histo_spin_total);
+	spinlock_stats.time_total += delta;
+}
+
+static inline void spin_time_accum_blocked(u64 start)
+{
+	u32 delta = xen_clocksource_read() - start;
+
+	__spin_time_accum(delta, spinlock_stats.histo_spin_blocked);
+	spinlock_stats.time_blocked += delta;
+}
+#else  /* !CONFIG_XEN_DEBUG_FS */
+#define TIMEOUT			(1 << 10)
+#define ADD_STATS(elem, val)	do { (void)(val); } while(0)
+
+static inline u64 spin_time_start(void)
+{
+	return 0;
+}
+
+static inline void spin_time_accum_total(u64 start)
+{
+}
+static inline void spin_time_accum_spinning(u64 start)
+{
+}
+static inline void spin_time_accum_blocked(u64 start)
+{
+}
+#endif  /* CONFIG_XEN_DEBUG_FS */
+
+struct xen_spinlock {
+	unsigned char lock;		/* 0 -> free; 1 -> locked */
+	unsigned short spinners;	/* count of waiting cpus */
+};
+
+static int xen_spin_is_locked(struct raw_spinlock *lock)
+{
+	struct xen_spinlock *xl = (struct xen_spinlock *)lock;
+
+	return xl->lock != 0;
+}
+
+static int xen_spin_is_contended(struct raw_spinlock *lock)
+{
+	struct xen_spinlock *xl = (struct xen_spinlock *)lock;
+
+	/* Not strictly true; this is only the count of contended
+	   lock-takers entering the slow path. */
+	return xl->spinners != 0;
+}
+
+static int xen_spin_trylock(struct raw_spinlock *lock)
+{
+	struct xen_spinlock *xl = (struct xen_spinlock *)lock;
+	u8 old = 1;
+
+	asm("xchgb %b0,%1"
+	    : "+q" (old), "+m" (xl->lock) : : "memory");
+
+	return old == 0;
+}
+
+static DEFINE_PER_CPU(int, lock_kicker_irq) = -1;
+static DEFINE_PER_CPU(struct xen_spinlock *, lock_spinners);
+
+/*
+ * Mark a cpu as interested in a lock.  Returns the CPU's previous
+ * lock of interest, in case we got preempted by an interrupt.
+ */
+static inline struct xen_spinlock *spinning_lock(struct xen_spinlock *xl)
+{
+	struct xen_spinlock *prev;
+
+	prev = __get_cpu_var(lock_spinners);
+	__get_cpu_var(lock_spinners) = xl;
+
+	wmb();			/* set lock of interest before count */
+
+	asm(LOCK_PREFIX " incw %0"
+	    : "+m" (xl->spinners) : : "memory");
+
+	return prev;
+}
+
+/*
+ * Mark a cpu as no longer interested in a lock.  Restores previous
+ * lock of interest (NULL for none).
+ */
+static inline void unspinning_lock(struct xen_spinlock *xl, struct xen_spinlock *prev)
+{
+	asm(LOCK_PREFIX " decw %0"
+	    : "+m" (xl->spinners) : : "memory");
+	wmb();			/* decrement count before restoring lock */
+	__get_cpu_var(lock_spinners) = prev;
+}
+
+static noinline int xen_spin_lock_slow(struct raw_spinlock *lock, bool irq_enable)
+{
+	struct xen_spinlock *xl = (struct xen_spinlock *)lock;
+	struct xen_spinlock *prev;
+	int irq = __get_cpu_var(lock_kicker_irq);
+	int ret;
+	unsigned long flags;
+	u64 start;
+
+	/* If kicker interrupts not initialized yet, just spin */
+	if (irq == -1)
+		return 0;
+
+	start = spin_time_start();
+
+	/* announce we're spinning */
+	prev = spinning_lock(xl);
+
+	flags = __raw_local_save_flags();
+	if (irq_enable) {
+		ADD_STATS(taken_slow_irqenable, 1);
+		raw_local_irq_enable();
+	}
+
+	ADD_STATS(taken_slow, 1);
+	ADD_STATS(taken_slow_nested, prev != NULL);
+
+	do {
+		/* clear pending */
+		xen_clear_irq_pending(irq);
+
+		/* check again make sure it didn't become free while
+		   we weren't looking  */
+		ret = xen_spin_trylock(lock);
+		if (ret) {
+			ADD_STATS(taken_slow_pickup, 1);
+
+			/*
+			 * If we interrupted another spinlock while it
+			 * was blocking, make sure it doesn't block
+			 * without rechecking the lock.
+			 */
+			if (prev != NULL)
+				xen_set_irq_pending(irq);
+			goto out;
+		}
+
+		/*
+		 * Block until irq becomes pending.  If we're
+		 * interrupted at this point (after the trylock but
+		 * before entering the block), then the nested lock
+		 * handler guarantees that the irq will be left
+		 * pending if there's any chance the lock became free;
+		 * xen_poll_irq() returns immediately if the irq is
+		 * pending.
+		 */
+		xen_poll_irq(irq);
+		ADD_STATS(taken_slow_spurious, !xen_test_irq_pending(irq));
+	} while (!xen_test_irq_pending(irq)); /* check for spurious wakeups */
+
+	kstat_this_cpu.irqs[irq]++;
+
+out:
+	raw_local_irq_restore(flags);
+	unspinning_lock(xl, prev);
+	spin_time_accum_blocked(start);
+
+	return ret;
+}
+
+static inline void __xen_spin_lock(struct raw_spinlock *lock, bool irq_enable)
+{
+	struct xen_spinlock *xl = (struct xen_spinlock *)lock;
+	unsigned timeout;
+	u8 oldval;
+	u64 start_spin;
+
+	ADD_STATS(taken, 1);
+
+	start_spin = spin_time_start();
+
+	do {
+		u64 start_spin_fast = spin_time_start();
+
+		timeout = TIMEOUT;
+
+		asm("1: xchgb %1,%0\n"
+		    "   testb %1,%1\n"
+		    "   jz 3f\n"
+		    "2: rep;nop\n"
+		    "   cmpb $0,%0\n"
+		    "   je 1b\n"
+		    "   dec %2\n"
+		    "   jnz 2b\n"
+		    "3:\n"
+		    : "+m" (xl->lock), "=q" (oldval), "+r" (timeout)
+		    : "1" (1)
+		    : "memory");
+
+		spin_time_accum_spinning(start_spin_fast);
+
+	} while (unlikely(oldval != 0 &&
+			  (TIMEOUT == ~0 || !xen_spin_lock_slow(lock, irq_enable))));
+
+	spin_time_accum_total(start_spin);
+}
+
+static void xen_spin_lock(struct raw_spinlock *lock)
+{
+	__xen_spin_lock(lock, false);
+}
+
+static void xen_spin_lock_flags(struct raw_spinlock *lock, unsigned long flags)
+{
+	__xen_spin_lock(lock, !raw_irqs_disabled_flags(flags));
+}
+
+static noinline void xen_spin_unlock_slow(struct xen_spinlock *xl)
+{
+	int cpu;
+
+	ADD_STATS(released_slow, 1);
+
+	for_each_online_cpu(cpu) {
+		/* XXX should mix up next cpu selection */
+		if (per_cpu(lock_spinners, cpu) == xl) {
+			ADD_STATS(released_slow_kicked, 1);
+			xen_send_IPI_one(cpu, XEN_SPIN_UNLOCK_VECTOR);
+			break;
+		}
+	}
+}
+
+static void xen_spin_unlock(struct raw_spinlock *lock)
+{
+	struct xen_spinlock *xl = (struct xen_spinlock *)lock;
+
+	ADD_STATS(released, 1);
+
+	smp_wmb();		/* make sure no writes get moved after unlock */
+	xl->lock = 0;		/* release lock */
+
+	/* make sure unlock happens before kick */
+	barrier();
+
+	if (unlikely(xl->spinners))
+		xen_spin_unlock_slow(xl);
+}
+
+static irqreturn_t dummy_handler(int irq, void *dev_id)
+{
+	BUG();
+	return IRQ_HANDLED;
+}
+
+void __cpuinit xen_init_lock_cpu(int cpu)
+{
+	int irq;
+	const char *name;
+
+	name = kasprintf(GFP_KERNEL, "spinlock%d", cpu);
+	irq = bind_ipi_to_irqhandler(XEN_SPIN_UNLOCK_VECTOR,
+				     cpu,
+				     dummy_handler,
+				     IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
+				     name,
+				     NULL);
+
+	if (irq >= 0) {
+		disable_irq(irq); /* make sure it's never delivered */
+		per_cpu(lock_kicker_irq, cpu) = irq;
+	}
+
+	printk("cpu %d spinlock event irq %d\n", cpu, irq);
+}
+
+void xen_uninit_lock_cpu(int cpu)
+{
+	unbind_from_irqhandler(per_cpu(lock_kicker_irq, cpu), NULL);
+}
+
+void __init xen_init_spinlocks(void)
+{
+	pv_lock_ops.spin_is_locked = xen_spin_is_locked;
+	pv_lock_ops.spin_is_contended = xen_spin_is_contended;
+	pv_lock_ops.spin_lock = xen_spin_lock;
+	pv_lock_ops.spin_lock_flags = xen_spin_lock_flags;
+	pv_lock_ops.spin_trylock = xen_spin_trylock;
+	pv_lock_ops.spin_unlock = xen_spin_unlock;
+}
+
+#ifdef CONFIG_XEN_DEBUG_FS
+
+static struct dentry *d_spin_debug;
+
+static int __init xen_spinlock_debugfs(void)
+{
+	struct dentry *d_xen = xen_init_debugfs();
+
+	if (d_xen == NULL)
+		return -ENOMEM;
+
+	d_spin_debug = debugfs_create_dir("spinlocks", d_xen);
+
+	debugfs_create_u8("zero_stats", 0644, d_spin_debug, &zero_stats);
+
+	debugfs_create_u32("timeout", 0644, d_spin_debug, &lock_timeout);
+
+	debugfs_create_u64("taken", 0444, d_spin_debug, &spinlock_stats.taken);
+	debugfs_create_u32("taken_slow", 0444, d_spin_debug,
+			   &spinlock_stats.taken_slow);
+	debugfs_create_u32("taken_slow_nested", 0444, d_spin_debug,
+			   &spinlock_stats.taken_slow_nested);
+	debugfs_create_u32("taken_slow_pickup", 0444, d_spin_debug,
+			   &spinlock_stats.taken_slow_pickup);
+	debugfs_create_u32("taken_slow_spurious", 0444, d_spin_debug,
+			   &spinlock_stats.taken_slow_spurious);
+	debugfs_create_u32("taken_slow_irqenable", 0444, d_spin_debug,
+			   &spinlock_stats.taken_slow_irqenable);
+
+	debugfs_create_u64("released", 0444, d_spin_debug, &spinlock_stats.released);
+	debugfs_create_u32("released_slow", 0444, d_spin_debug,
+			   &spinlock_stats.released_slow);
+	debugfs_create_u32("released_slow_kicked", 0444, d_spin_debug,
+			   &spinlock_stats.released_slow_kicked);
+
+	debugfs_create_u64("time_spinning", 0444, d_spin_debug,
+			   &spinlock_stats.time_spinning);
+	debugfs_create_u64("time_blocked", 0444, d_spin_debug,
+			   &spinlock_stats.time_blocked);
+	debugfs_create_u64("time_total", 0444, d_spin_debug,
+			   &spinlock_stats.time_total);
+
+	xen_debugfs_create_u32_array("histo_total", 0444, d_spin_debug,
+				     spinlock_stats.histo_spin_total, HISTO_BUCKETS + 1);
+	xen_debugfs_create_u32_array("histo_spinning", 0444, d_spin_debug,
+				     spinlock_stats.histo_spin_spinning, HISTO_BUCKETS + 1);
+	xen_debugfs_create_u32_array("histo_blocked", 0444, d_spin_debug,
+				     spinlock_stats.histo_spin_blocked, HISTO_BUCKETS + 1);
+
+	return 0;
+}
+fs_initcall(xen_spinlock_debugfs);
+
+#endif	/* CONFIG_XEN_DEBUG_FS */
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index 685b77470fc3..004ba86326ae 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -30,8 +30,6 @@
 #define TIMER_SLOP	100000
 #define NS_PER_TICK	(1000000000LL / HZ)
 
-static cycle_t xen_clocksource_read(void);
-
 /* runstate info updated by Xen */
 static DEFINE_PER_CPU(struct vcpu_runstate_info, runstate);
 
@@ -213,7 +211,7 @@ unsigned long xen_tsc_khz(void)
 	return xen_khz;
 }
 
-static cycle_t xen_clocksource_read(void)
+cycle_t xen_clocksource_read(void)
 {
         struct pvclock_vcpu_time_info *src;
 	cycle_t ret;
@@ -452,6 +450,14 @@ void xen_setup_timer(int cpu)
 	setup_runstate_info(cpu);
 }
 
+void xen_teardown_timer(int cpu)
+{
+	struct clock_event_device *evt;
+	BUG_ON(cpu == 0);
+	evt = &per_cpu(xen_clock_events, cpu);
+	unbind_from_irqhandler(evt->irq, NULL);
+}
+
 void xen_setup_cpu_clockevents(void)
 {
 	BUG_ON(preemptible());
diff --git a/arch/x86/xen/xen-asm_32.S b/arch/x86/xen/xen-asm_32.S
index 2497a30f41de..42786f59d9c0 100644
--- a/arch/x86/xen/xen-asm_32.S
+++ b/arch/x86/xen/xen-asm_32.S
@@ -298,7 +298,7 @@ check_events:
 	push %eax
 	push %ecx
 	push %edx
-	call force_evtchn_callback
+	call xen_force_evtchn_callback
 	pop %edx
 	pop %ecx
 	pop %eax
diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S
index 7f58304fafb3..05794c566e87 100644
--- a/arch/x86/xen/xen-asm_64.S
+++ b/arch/x86/xen/xen-asm_64.S
@@ -26,8 +26,15 @@
 /* Pseudo-flag used for virtual NMI, which we don't implement yet */
 #define XEN_EFLAGS_NMI	0x80000000
 
-#if 0
-#include <asm/percpu.h>
+#if 1
+/*
+	x86-64 does not yet support direct access to percpu variables
+	via a segment override, so we just need to make sure this code
+	never gets used
+ */
+#define BUG			ud2a
+#define PER_CPU_VAR(var, off)	0xdeadbeef
+#endif
 
 /*
 	Enable events.  This clears the event mask and tests the pending
@@ -35,6 +42,8 @@
 	events, then enter the hypervisor to get them handled.
  */
 ENTRY(xen_irq_enable_direct)
+	BUG
+
 	/* Unmask events */
 	movb $0, PER_CPU_VAR(xen_vcpu_info, XEN_vcpu_info_mask)
 
@@ -58,6 +67,8 @@ ENDPATCH(xen_irq_enable_direct)
 	non-zero.
  */
 ENTRY(xen_irq_disable_direct)
+	BUG
+
 	movb $1, PER_CPU_VAR(xen_vcpu_info, XEN_vcpu_info_mask)
 ENDPATCH(xen_irq_disable_direct)
 	ret
@@ -74,6 +85,8 @@ ENDPATCH(xen_irq_disable_direct)
 	Xen and x86 use opposite senses (mask vs enable).
  */
 ENTRY(xen_save_fl_direct)
+	BUG
+
 	testb $0xff, PER_CPU_VAR(xen_vcpu_info, XEN_vcpu_info_mask)
 	setz %ah
 	addb %ah,%ah
@@ -91,6 +104,8 @@ ENDPATCH(xen_save_fl_direct)
 	if so.
  */
 ENTRY(xen_restore_fl_direct)
+	BUG
+
 	testb $X86_EFLAGS_IF>>8, %ah
 	setz PER_CPU_VAR(xen_vcpu_info, XEN_vcpu_info_mask)
 	/* Preempt here doesn't matter because that will deal with
@@ -122,7 +137,7 @@ check_events:
 	push %r9
 	push %r10
 	push %r11
-	call force_evtchn_callback
+	call xen_force_evtchn_callback
 	pop %r11
 	pop %r10
 	pop %r9
@@ -133,7 +148,6 @@ check_events:
 	pop %rcx
 	pop %rax
 	ret
-#endif
 
 ENTRY(xen_adjust_exception_frame)
 	mov 8+0(%rsp),%rcx
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index dd3c23152a2e..d7422dc2a55c 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -2,6 +2,7 @@
 #define XEN_OPS_H
 
 #include <linux/init.h>
+#include <linux/clocksource.h>
 #include <linux/irqreturn.h>
 #include <xen/xen-ops.h>
 
@@ -31,7 +32,10 @@ void xen_vcpu_restore(void);
 
 void __init xen_build_dynamic_phys_to_machine(void);
 
+void xen_init_irq_ops(void);
 void xen_setup_timer(int cpu);
+void xen_teardown_timer(int cpu);
+cycle_t xen_clocksource_read(void);
 void xen_setup_cpu_clockevents(void);
 unsigned long xen_tsc_khz(void);
 void __init xen_time_init(void);
@@ -50,6 +54,10 @@ void __init xen_setup_vcpu_info_placement(void);
 #ifdef CONFIG_SMP
 void xen_smp_init(void);
 
+void __init xen_init_spinlocks(void);
+__cpuinit void xen_init_lock_cpu(int cpu);
+void xen_uninit_lock_cpu(int cpu);
+
 extern cpumask_t xen_cpu_initialized_map;
 #else
 static inline void xen_smp_init(void) {}