---
 arch/x86/kernel/smp_32.c     |    2 +
 arch/x86/kernel/smpboot_32.c |    6 ++--
 arch/x86/xen/enlighten.c     |   15 ++++++++++-
 arch/x86/xen/smp.c           |   54 ++++++++++++++++++++++++++++--------------
 arch/x86/xen/xen-ops.h       |    1 
 include/asm-x86/smp_32.h     |   18 ++++++++++++--
 6 files changed, 72 insertions(+), 24 deletions(-)

===================================================================
--- a/arch/x86/kernel/smp_32.c
+++ b/arch/x86/kernel/smp_32.c
@@ -704,4 +704,6 @@ struct smp_ops smp_ops = {
 	.smp_send_stop = native_smp_send_stop,
 	.smp_send_reschedule = native_smp_send_reschedule,
 	.smp_call_function_mask = native_smp_call_function_mask,
+
+	.cpu_disable = native_cpu_disable,
 };
===================================================================
--- a/arch/x86/kernel/smpboot_32.c
+++ b/arch/x86/kernel/smpboot_32.c
@@ -1166,7 +1166,7 @@ void remove_siblinginfo(int cpu)
 	cpu_clear(cpu, cpu_sibling_setup_map);
 }
 
-int __cpu_disable(void)
+int native_cpu_disable(void)
 {
 	cpumask_t map = cpu_online_map;
 	int cpu = smp_processor_id();
@@ -1216,12 +1216,12 @@ void __cpu_die(unsigned int cpu)
  	printk(KERN_ERR "CPU %u didn't die...\n", cpu);
 }
 #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();
===================================================================
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -254,10 +254,21 @@ static void xen_safe_halt(void)
 		BUG();
 }
 
+static void xen_shutdown_cpu(void)
+{
+	int cpu = smp_processor_id();
+
+	/* make sure we're not pinning something down */
+	load_cr3(swapper_pg_dir);
+	/* GDT too? */
+
+	HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL);
+}
+
 static void xen_halt(void)
 {
 	if (irqs_disabled())
-		HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL);
+		xen_shutdown_cpu();
 	else
 		xen_safe_halt();
 }
@@ -1069,6 +1080,8 @@ static const struct smp_ops xen_smp_ops 
 	.smp_send_stop = xen_smp_send_stop,
 	.smp_send_reschedule = xen_smp_send_reschedule,
 	.smp_call_function_mask = xen_smp_call_function_mask,
+
+	.cpu_disable = xen_cpu_disable,
 };
 #endif	/* CONFIG_SMP */
 
===================================================================
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -189,8 +189,14 @@ void __init xen_smp_prepare_cpus(unsigne
 			panic("failed fork for CPU %d", cpu);
 
 		cpu_set(cpu, cpu_present_map);
-	}
-
+
+		smp_store_cpu_info(cpu);
+		init_gdt(cpu);
+		irq_ctx_init(cpu);
+		xen_setup_timer(cpu);
+		xen_smp_intr_init(cpu);
+	}
+
 	//init_xenbus_allowed_cpumask();
 }
 
@@ -198,7 +204,7 @@ cpu_initialize_context(unsigned int cpu,
 cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
 {
 	struct vcpu_guest_context *ctxt;
-	struct gdt_page *gdt = &per_cpu(gdt_page, cpu);
+	struct desc_struct *gdt = get_cpu_gdt_table(cpu);
 
 	if (cpu_test_and_set(cpu, cpu_initialized_map))
 		return 0;
@@ -222,11 +228,11 @@ cpu_initialize_context(unsigned int cpu,
 
 	ctxt->ldt_ents = 0;
 
-	BUG_ON((unsigned long)gdt->gdt & ~PAGE_MASK);
-	make_lowmem_page_readonly(gdt->gdt);
-
-	ctxt->gdt_frames[0] = virt_to_mfn(gdt->gdt);
-	ctxt->gdt_ents      = ARRAY_SIZE(gdt->gdt);
+	BUG_ON((unsigned long)gdt & ~PAGE_MASK);
+	make_lowmem_page_readonly(gdt);
+
+	ctxt->gdt_frames[0] = virt_to_mfn(gdt);
+	ctxt->gdt_ents      = GDT_ENTRIES;
 
 	ctxt->user_regs.cs = __KERNEL_CS;
 	ctxt->user_regs.esp = idle->thread.esp0 - sizeof(struct pt_regs);
@@ -260,26 +266,20 @@ int __cpuinit xen_cpu_up(unsigned int cp
 		return rc;
 #endif
 
-	init_gdt(cpu);
 	per_cpu(current_task, cpu) = idle;
-	irq_ctx_init(cpu);
-	xen_setup_timer(cpu);
 
 	/* make sure interrupts start blocked */
 	per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask = 1;
 
 	rc = cpu_initialize_context(cpu, idle);
 	if (rc)
-		return rc;
+		goto out;
 
 	if (num_online_cpus() == 1)
 		alternatives_smp_switch(1);
 
-	rc = xen_smp_intr_init(cpu);
-	if (rc)
-		return rc;
-
-	smp_store_cpu_info(cpu);
+	get_cpu();		/* set_cpu_sibling_map wants no preempt */
+
 	set_cpu_sibling_map(cpu);
 	/* This must be done before setting cpu_online_map */
 	wmb();
@@ -289,7 +289,10 @@ int __cpuinit xen_cpu_up(unsigned int cp
 	rc = HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL);
 	BUG_ON(rc);
 
-	return 0;
+	put_cpu();
+
+  out:
+	return rc;
 }
 
 void xen_smp_cpus_done(unsigned int max_cpus)
@@ -408,3 +411,18 @@ int xen_smp_call_function_mask(cpumask_t
 
 	return 0;
 }
+
+int xen_cpu_disable(void)
+{
+	cpumask_t map = cpu_online_map;
+	int cpu = smp_processor_id();
+
+	remove_siblinginfo(cpu);
+
+	cpu_clear(cpu, map);
+	fixup_irqs(map);
+	/* It's now safe to remove this processor from the online map */
+	cpu_clear(cpu, cpu_online_map);
+
+	return 0;
+}
===================================================================
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -39,6 +39,7 @@ void xen_smp_prepare_cpus(unsigned int m
 void xen_smp_prepare_cpus(unsigned int max_cpus);
 int xen_cpu_up(unsigned int cpu);
 void xen_smp_cpus_done(unsigned int max_cpus);
+int xen_cpu_disable(void);
 
 void xen_smp_send_stop(void);
 void xen_smp_send_reschedule(int cpu);
===================================================================
--- a/include/asm-x86/smp_32.h
+++ b/include/asm-x86/smp_32.h
@@ -63,6 +63,9 @@ struct smp_ops
 	int (*smp_call_function_mask)(cpumask_t mask,
 				      void (*func)(void *info), void *info,
 				      int wait);
+
+	int (*cpu_disable)(void);
+	void (*cpu_die)(unsigned int cpu);
 };
 
 extern struct smp_ops smp_ops;
@@ -71,14 +74,17 @@ static inline void smp_prepare_boot_cpu(
 {
 	smp_ops.smp_prepare_boot_cpu();
 }
+
 static inline void smp_prepare_cpus(unsigned int max_cpus)
 {
 	smp_ops.smp_prepare_cpus(max_cpus);
 }
+
 static inline int __cpu_up(unsigned int cpu)
 {
 	return smp_ops.cpu_up(cpu);
 }
+
 static inline void smp_cpus_done(unsigned int max_cpus)
 {
 	smp_ops.smp_cpus_done(max_cpus);
@@ -88,10 +94,12 @@ static inline void smp_send_stop(void)
 {
 	smp_ops.smp_send_stop();
 }
+
 static inline void smp_send_reschedule(int cpu)
 {
 	smp_ops.smp_send_reschedule(cpu);
 }
+
 static inline int smp_call_function_mask(cpumask_t mask,
 					 void (*func) (void *info), void *info,
 					 int wait)
@@ -99,10 +107,18 @@ static inline int smp_call_function_mask
 	return smp_ops.smp_call_function_mask(mask, func, info, wait);
 }
 
+static inline int __cpu_disable(void)
+{
+	return smp_ops.cpu_disable();
+}
+
+
 void native_smp_prepare_boot_cpu(void);
 void native_smp_prepare_cpus(unsigned int max_cpus);
 int native_cpu_up(unsigned int cpunum);
 void native_smp_cpus_done(unsigned int max_cpus);
+extern int native_cpu_disable(void);
+extern void __cpu_die(unsigned int cpu);
 
 #ifndef CONFIG_PARAVIRT
 #define startup_ipi_hook(phys_apicid, start_eip, start_esp) 		\
@@ -128,8 +144,6 @@ static inline int num_booting_cpus(void)
 }
 
 extern int safe_smp_processor_id(void);
-extern int __cpu_disable(void);
-extern void __cpu_die(unsigned int cpu);
 extern unsigned int num_processors;
 
 void __cpuinit smp_store_cpu_info(int id);