android_kernel_motorola_sm6225/arch/x86/xen/smp.c
Frediano Ziglio 7cde9b27e7 xen: Fix possible user space selector corruption
Due to the way kernel is initialized under Xen is possible that the
ring1 selector used by the kernel for the boot cpu end up to be copied
to userspace leading to segmentation fault in the userspace.

Xen code in the kernel initialize no-boot cpus with correct selectors (ds
and es set to __USER_DS) but the boot one keep the ring1 (passed by Xen).
On task context switch (switch_to) we assume that ds, es and cs already
point to __USER_DS and __KERNEL_CSso these selector are not changed.

If processor is an Intel that support sysenter instruction sysenter/sysexit
is used so ds and es are not restored switching back from kernel to
userspace. In the case the selectors point to a ring1 instead of __USER_DS
the userspace code will crash on first memory access attempt (to be
precise Xen on the emulated iret used to do sysexit will detect and set ds
and es to zero which lead to GPF anyway).

Now if an userspace process call kernel using sysenter and get rescheduled
(for me it happen on a specific init calling wait4) could happen that the
ring1 selector is set to ds and es.

This is quite hard to detect cause after a while these selectors are fixed
(__USER_DS seems sticky).

Bisecting the code commit 7076aada10 appears
to be the first one that have this issue.

Signed-off-by: Frediano Ziglio <frediano.ziglio@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
2013-10-10 14:39:37 +00:00

758 lines
18 KiB
C

/*
* Xen SMP support
*
* This file implements the Xen versions of smp_ops. SMP under Xen is
* very straightforward. Bringing a CPU up is simply a matter of
* loading its initial context and setting it running.
*
* IPIs are handled through the Xen event mechanism.
*
* Because virtual CPUs can be scheduled onto any real CPU, there's no
* 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.
*/
#include <linux/sched.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/smp.h>
#include <linux/irq_work.h>
#include <linux/tick.h>
#include <asm/paravirt.h>
#include <asm/desc.h>
#include <asm/pgtable.h>
#include <asm/cpu.h>
#include <xen/interface/xen.h>
#include <xen/interface/vcpu.h>
#include <asm/xen/interface.h>
#include <asm/xen/hypercall.h>
#include <xen/xen.h>
#include <xen/page.h>
#include <xen/events.h>
#include <xen/hvc-console.h>
#include "xen-ops.h"
#include "mmu.h"
cpumask_var_t xen_cpu_initialized_map;
struct xen_common_irq {
int irq;
char *name;
};
static DEFINE_PER_CPU(struct xen_common_irq, xen_resched_irq) = { .irq = -1 };
static DEFINE_PER_CPU(struct xen_common_irq, xen_callfunc_irq) = { .irq = -1 };
static DEFINE_PER_CPU(struct xen_common_irq, xen_callfuncsingle_irq) = { .irq = -1 };
static DEFINE_PER_CPU(struct xen_common_irq, xen_irq_work) = { .irq = -1 };
static DEFINE_PER_CPU(struct xen_common_irq, xen_debug_irq) = { .irq = -1 };
static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id);
static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id);
static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id);
/*
* Reschedule call back.
*/
static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id)
{
inc_irq_stat(irq_resched_count);
scheduler_ipi();
return IRQ_HANDLED;
}
static void cpu_bringup(void)
{
int cpu;
cpu_init();
touch_softlockup_watchdog();
preempt_disable();
xen_enable_sysenter();
xen_enable_syscall();
cpu = smp_processor_id();
smp_store_cpu_info(cpu);
cpu_data(cpu).x86_max_cores = 1;
set_cpu_sibling_map(cpu);
xen_setup_cpu_clockevents();
notify_cpu_starting(cpu);
set_cpu_online(cpu, true);
this_cpu_write(cpu_state, CPU_ONLINE);
wmb();
/* We can take interrupts now: we're officially "up". */
local_irq_enable();
wmb(); /* make sure everything is out */
}
static void cpu_bringup_and_idle(void)
{
cpu_bringup();
cpu_startup_entry(CPUHP_ONLINE);
}
static void xen_smp_intr_free(unsigned int cpu)
{
if (per_cpu(xen_resched_irq, cpu).irq >= 0) {
unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu).irq, NULL);
per_cpu(xen_resched_irq, cpu).irq = -1;
kfree(per_cpu(xen_resched_irq, cpu).name);
per_cpu(xen_resched_irq, cpu).name = NULL;
}
if (per_cpu(xen_callfunc_irq, cpu).irq >= 0) {
unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu).irq, NULL);
per_cpu(xen_callfunc_irq, cpu).irq = -1;
kfree(per_cpu(xen_callfunc_irq, cpu).name);
per_cpu(xen_callfunc_irq, cpu).name = NULL;
}
if (per_cpu(xen_debug_irq, cpu).irq >= 0) {
unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu).irq, NULL);
per_cpu(xen_debug_irq, cpu).irq = -1;
kfree(per_cpu(xen_debug_irq, cpu).name);
per_cpu(xen_debug_irq, cpu).name = NULL;
}
if (per_cpu(xen_callfuncsingle_irq, cpu).irq >= 0) {
unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu).irq,
NULL);
per_cpu(xen_callfuncsingle_irq, cpu).irq = -1;
kfree(per_cpu(xen_callfuncsingle_irq, cpu).name);
per_cpu(xen_callfuncsingle_irq, cpu).name = NULL;
}
if (xen_hvm_domain())
return;
if (per_cpu(xen_irq_work, cpu).irq >= 0) {
unbind_from_irqhandler(per_cpu(xen_irq_work, cpu).irq, NULL);
per_cpu(xen_irq_work, cpu).irq = -1;
kfree(per_cpu(xen_irq_work, cpu).name);
per_cpu(xen_irq_work, cpu).name = NULL;
}
};
static int xen_smp_intr_init(unsigned int cpu)
{
int rc;
char *resched_name, *callfunc_name, *debug_name;
resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu);
rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR,
cpu,
xen_reschedule_interrupt,
IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
resched_name,
NULL);
if (rc < 0)
goto fail;
per_cpu(xen_resched_irq, cpu).irq = rc;
per_cpu(xen_resched_irq, cpu).name = resched_name;
callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu);
rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR,
cpu,
xen_call_function_interrupt,
IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
callfunc_name,
NULL);
if (rc < 0)
goto fail;
per_cpu(xen_callfunc_irq, cpu).irq = rc;
per_cpu(xen_callfunc_irq, cpu).name = callfunc_name;
debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu);
rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu, xen_debug_interrupt,
IRQF_DISABLED | IRQF_PERCPU | IRQF_NOBALANCING,
debug_name, NULL);
if (rc < 0)
goto fail;
per_cpu(xen_debug_irq, cpu).irq = rc;
per_cpu(xen_debug_irq, cpu).name = debug_name;
callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu);
rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR,
cpu,
xen_call_function_single_interrupt,
IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
callfunc_name,
NULL);
if (rc < 0)
goto fail;
per_cpu(xen_callfuncsingle_irq, cpu).irq = rc;
per_cpu(xen_callfuncsingle_irq, cpu).name = callfunc_name;
/*
* The IRQ worker on PVHVM goes through the native path and uses the
* IPI mechanism.
*/
if (xen_hvm_domain())
return 0;
callfunc_name = kasprintf(GFP_KERNEL, "irqwork%d", cpu);
rc = bind_ipi_to_irqhandler(XEN_IRQ_WORK_VECTOR,
cpu,
xen_irq_work_interrupt,
IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
callfunc_name,
NULL);
if (rc < 0)
goto fail;
per_cpu(xen_irq_work, cpu).irq = rc;
per_cpu(xen_irq_work, cpu).name = callfunc_name;
return 0;
fail:
xen_smp_intr_free(cpu);
return rc;
}
static void __init xen_fill_possible_map(void)
{
int i, rc;
if (xen_initial_domain())
return;
for (i = 0; i < nr_cpu_ids; i++) {
rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL);
if (rc >= 0) {
num_processors++;
set_cpu_possible(i, true);
}
}
}
static void __init xen_filter_cpu_maps(void)
{
int i, rc;
unsigned int subtract = 0;
if (!xen_initial_domain())
return;
num_processors = 0;
disabled_cpus = 0;
for (i = 0; i < nr_cpu_ids; i++) {
rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL);
if (rc >= 0) {
num_processors++;
set_cpu_possible(i, true);
} else {
set_cpu_possible(i, false);
set_cpu_present(i, false);
subtract++;
}
}
#ifdef CONFIG_HOTPLUG_CPU
/* This is akin to using 'nr_cpus' on the Linux command line.
* Which is OK as when we use 'dom0_max_vcpus=X' we can only
* have up to X, while nr_cpu_ids is greater than X. This
* normally is not a problem, except when CPU hotplugging
* is involved and then there might be more than X CPUs
* in the guest - which will not work as there is no
* hypercall to expand the max number of VCPUs an already
* running guest has. So cap it up to X. */
if (subtract)
nr_cpu_ids = nr_cpu_ids - subtract;
#endif
}
static void __init xen_smp_prepare_boot_cpu(void)
{
BUG_ON(smp_processor_id() != 0);
native_smp_prepare_boot_cpu();
if (xen_pv_domain()) {
/* We've switched to the "real" per-cpu gdt, so make sure the
old memory can be recycled */
make_lowmem_page_readwrite(xen_initial_gdt);
#ifdef CONFIG_X86_32
/*
* Xen starts us with XEN_FLAT_RING1_DS, but linux code
* expects __USER_DS
*/
loadsegment(ds, __USER_DS);
loadsegment(es, __USER_DS);
#endif
xen_filter_cpu_maps();
xen_setup_vcpu_info_placement();
}
/*
* The alternative logic (which patches the unlock/lock) runs before
* the smp bootup up code is activated. Hence we need to set this up
* the core kernel is being patched. Otherwise we will have only
* modules patched but not core code.
*/
xen_init_spinlocks();
}
static void __init xen_smp_prepare_cpus(unsigned int max_cpus)
{
unsigned cpu;
unsigned int i;
if (skip_ioapic_setup) {
char *m = (max_cpus == 0) ?
"The nosmp parameter is incompatible with Xen; " \
"use Xen dom0_max_vcpus=1 parameter" :
"The noapic parameter is incompatible with Xen";
xen_raw_printk(m);
panic(m);
}
xen_init_lock_cpu(0);
smp_store_boot_cpu_info();
cpu_data(0).x86_max_cores = 1;
for_each_possible_cpu(i) {
zalloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL);
zalloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL);
zalloc_cpumask_var(&per_cpu(cpu_llc_shared_map, i), GFP_KERNEL);
}
set_cpu_sibling_map(0);
if (xen_smp_intr_init(0))
BUG();
if (!alloc_cpumask_var(&xen_cpu_initialized_map, GFP_KERNEL))
panic("could not allocate xen_cpu_initialized_map\n");
cpumask_copy(xen_cpu_initialized_map, cpumask_of(0));
/* Restrict the possible_map according to max_cpus. */
while ((num_possible_cpus() > 1) && (num_possible_cpus() > max_cpus)) {
for (cpu = nr_cpu_ids - 1; !cpu_possible(cpu); cpu--)
continue;
set_cpu_possible(cpu, false);
}
for_each_possible_cpu(cpu)
set_cpu_present(cpu, true);
}
static int
cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
{
struct vcpu_guest_context *ctxt;
struct desc_struct *gdt;
unsigned long gdt_mfn;
if (cpumask_test_and_set_cpu(cpu, xen_cpu_initialized_map))
return 0;
ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
if (ctxt == NULL)
return -ENOMEM;
gdt = get_cpu_gdt_table(cpu);
ctxt->flags = VGCF_IN_KERNEL;
ctxt->user_regs.ss = __KERNEL_DS;
#ifdef CONFIG_X86_32
ctxt->user_regs.fs = __KERNEL_PERCPU;
ctxt->user_regs.gs = __KERNEL_STACK_CANARY;
#else
ctxt->gs_base_kernel = per_cpu_offset(cpu);
#endif
ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle;
memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt));
{
ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */
ctxt->user_regs.ds = __USER_DS;
ctxt->user_regs.es = __USER_DS;
xen_copy_trap_info(ctxt->trap_ctxt);
ctxt->ldt_ents = 0;
BUG_ON((unsigned long)gdt & ~PAGE_MASK);
gdt_mfn = arbitrary_virt_to_mfn(gdt);
make_lowmem_page_readonly(gdt);
make_lowmem_page_readonly(mfn_to_virt(gdt_mfn));
ctxt->gdt_frames[0] = gdt_mfn;
ctxt->gdt_ents = GDT_ENTRIES;
ctxt->kernel_ss = __KERNEL_DS;
ctxt->kernel_sp = idle->thread.sp0;
#ifdef CONFIG_X86_32
ctxt->event_callback_cs = __KERNEL_CS;
ctxt->failsafe_callback_cs = __KERNEL_CS;
#endif
ctxt->event_callback_eip =
(unsigned long)xen_hypervisor_callback;
ctxt->failsafe_callback_eip =
(unsigned long)xen_failsafe_callback;
}
ctxt->user_regs.cs = __KERNEL_CS;
ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs);
per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir);
ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir));
if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt))
BUG();
kfree(ctxt);
return 0;
}
static int xen_cpu_up(unsigned int cpu, struct task_struct *idle)
{
int rc;
per_cpu(current_task, cpu) = idle;
#ifdef CONFIG_X86_32
irq_ctx_init(cpu);
#else
clear_tsk_thread_flag(idle, TIF_FORK);
per_cpu(kernel_stack, cpu) =
(unsigned long)task_stack_page(idle) -
KERNEL_STACK_OFFSET + THREAD_SIZE;
#endif
xen_setup_runstate_info(cpu);
xen_setup_timer(cpu);
xen_init_lock_cpu(cpu);
per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
/* make sure interrupts start blocked */
per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask = 1;
rc = cpu_initialize_context(cpu, idle);
if (rc)
return rc;
if (num_online_cpus() == 1)
/* Just in case we booted with a single CPU. */
alternatives_enable_smp();
rc = xen_smp_intr_init(cpu);
if (rc)
return rc;
rc = HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL);
BUG_ON(rc);
while(per_cpu(cpu_state, cpu) != CPU_ONLINE) {
HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
barrier();
}
return 0;
}
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 (xen_pv_domain() && HYPERVISOR_vcpu_op(VCPUOP_is_up, cpu, NULL)) {
current->state = TASK_UNINTERRUPTIBLE;
schedule_timeout(HZ/10);
}
xen_smp_intr_free(cpu);
xen_uninit_lock_cpu(cpu);
xen_teardown_timer(cpu);
}
static void xen_play_dead(void) /* used only with HOTPLUG_CPU */
{
play_dead_common();
HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL);
cpu_bringup();
/*
* commit 4b0c0f294 (tick: Cleanup NOHZ per cpu data on cpu down)
* clears certain data that the cpu_idle loop (which called us
* and that we return from) expects. The only way to get that
* data back is to call:
*/
tick_nohz_idle_enter();
}
#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();
/* make sure we're not pinning something down */
load_cr3(swapper_pg_dir);
/* should set up a minimal gdt */
set_cpu_online(cpu, false);
HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL);
BUG();
}
static void xen_stop_other_cpus(int wait)
{
smp_call_function(stop_self, NULL, wait);
}
static void xen_smp_send_reschedule(int cpu)
{
xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR);
}
static void __xen_send_IPI_mask(const struct cpumask *mask,
int vector)
{
unsigned cpu;
for_each_cpu_and(cpu, mask, cpu_online_mask)
xen_send_IPI_one(cpu, vector);
}
static void xen_smp_send_call_function_ipi(const struct cpumask *mask)
{
int cpu;
__xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR);
/* Make sure other vcpus get a chance to run if they need to. */
for_each_cpu(cpu, mask) {
if (xen_vcpu_stolen(cpu)) {
HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
break;
}
}
}
static void xen_smp_send_call_function_single_ipi(int cpu)
{
__xen_send_IPI_mask(cpumask_of(cpu),
XEN_CALL_FUNCTION_SINGLE_VECTOR);
}
static inline int xen_map_vector(int vector)
{
int xen_vector;
switch (vector) {
case RESCHEDULE_VECTOR:
xen_vector = XEN_RESCHEDULE_VECTOR;
break;
case CALL_FUNCTION_VECTOR:
xen_vector = XEN_CALL_FUNCTION_VECTOR;
break;
case CALL_FUNCTION_SINGLE_VECTOR:
xen_vector = XEN_CALL_FUNCTION_SINGLE_VECTOR;
break;
case IRQ_WORK_VECTOR:
xen_vector = XEN_IRQ_WORK_VECTOR;
break;
#ifdef CONFIG_X86_64
case NMI_VECTOR:
case APIC_DM_NMI: /* Some use that instead of NMI_VECTOR */
xen_vector = XEN_NMI_VECTOR;
break;
#endif
default:
xen_vector = -1;
printk(KERN_ERR "xen: vector 0x%x is not implemented\n",
vector);
}
return xen_vector;
}
void xen_send_IPI_mask(const struct cpumask *mask,
int vector)
{
int xen_vector = xen_map_vector(vector);
if (xen_vector >= 0)
__xen_send_IPI_mask(mask, xen_vector);
}
void xen_send_IPI_all(int vector)
{
int xen_vector = xen_map_vector(vector);
if (xen_vector >= 0)
__xen_send_IPI_mask(cpu_online_mask, xen_vector);
}
void xen_send_IPI_self(int vector)
{
int xen_vector = xen_map_vector(vector);
if (xen_vector >= 0)
xen_send_IPI_one(smp_processor_id(), xen_vector);
}
void xen_send_IPI_mask_allbutself(const struct cpumask *mask,
int vector)
{
unsigned cpu;
unsigned int this_cpu = smp_processor_id();
int xen_vector = xen_map_vector(vector);
if (!(num_online_cpus() > 1) || (xen_vector < 0))
return;
for_each_cpu_and(cpu, mask, cpu_online_mask) {
if (this_cpu == cpu)
continue;
xen_send_IPI_one(cpu, xen_vector);
}
}
void xen_send_IPI_allbutself(int vector)
{
xen_send_IPI_mask_allbutself(cpu_online_mask, vector);
}
static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id)
{
irq_enter();
generic_smp_call_function_interrupt();
inc_irq_stat(irq_call_count);
irq_exit();
return IRQ_HANDLED;
}
static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
{
irq_enter();
generic_smp_call_function_single_interrupt();
inc_irq_stat(irq_call_count);
irq_exit();
return IRQ_HANDLED;
}
static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id)
{
irq_enter();
irq_work_run();
inc_irq_stat(apic_irq_work_irqs);
irq_exit();
return IRQ_HANDLED;
}
static const struct smp_ops xen_smp_ops __initconst = {
.smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu,
.smp_prepare_cpus = xen_smp_prepare_cpus,
.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,
.stop_other_cpus = xen_stop_other_cpus,
.smp_send_reschedule = xen_smp_send_reschedule,
.send_call_func_ipi = xen_smp_send_call_function_ipi,
.send_call_func_single_ipi = xen_smp_send_call_function_single_ipi,
};
void __init xen_smp_init(void)
{
smp_ops = xen_smp_ops;
xen_fill_possible_map();
}
static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus)
{
native_smp_prepare_cpus(max_cpus);
WARN_ON(xen_smp_intr_init(0));
xen_init_lock_cpu(0);
}
static int xen_hvm_cpu_up(unsigned int cpu, struct task_struct *tidle)
{
int rc;
/*
* xen_smp_intr_init() needs to run before native_cpu_up()
* so that IPI vectors are set up on the booting CPU before
* it is marked online in native_cpu_up().
*/
rc = xen_smp_intr_init(cpu);
WARN_ON(rc);
if (!rc)
rc = native_cpu_up(cpu, tidle);
/*
* We must initialize the slowpath CPU kicker _after_ the native
* path has executed. If we initialized it before none of the
* unlocker IPI kicks would reach the booting CPU as the booting
* CPU had not set itself 'online' in cpu_online_mask. That mask
* is checked when IPIs are sent (on HVM at least).
*/
xen_init_lock_cpu(cpu);
return rc;
}
static void xen_hvm_cpu_die(unsigned int cpu)
{
xen_cpu_die(cpu);
native_cpu_die(cpu);
}
void __init xen_hvm_smp_init(void)
{
if (!xen_have_vector_callback)
return;
smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus;
smp_ops.smp_send_reschedule = xen_smp_send_reschedule;
smp_ops.cpu_up = xen_hvm_cpu_up;
smp_ops.cpu_die = xen_hvm_cpu_die;
smp_ops.send_call_func_ipi = xen_smp_send_call_function_ipi;
smp_ops.send_call_func_single_ipi = xen_smp_send_call_function_single_ipi;
smp_ops.smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu;
}