diff options
Diffstat (limited to 'kernel/arch/x86/xen/smp.c')
| -rw-r--r-- | kernel/arch/x86/xen/smp.c | 780 |
1 files changed, 780 insertions, 0 deletions
diff --git a/kernel/arch/x86/xen/smp.c b/kernel/arch/x86/xen/smp.c new file mode 100644 index 000000000..864843844 --- /dev/null +++ b/kernel/arch/x86/xen/smp.c @@ -0,0 +1,780 @@ +/* + * 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" +#include "smp.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(); + + /* PVH runs in ring 0 and allows us to do native syscalls. Yay! */ + if (!xen_feature(XENFEAT_supervisor_mode_kernel)) { + 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); + + cpu_set_state_online(cpu); /* Implies full memory barrier. */ + + /* We can take interrupts now: we're officially "up". */ + local_irq_enable(); +} + +/* + * Note: cpu parameter is only relevant for PVH. The reason for passing it + * is we can't do smp_processor_id until the percpu segments are loaded, for + * which we need the cpu number! So we pass it in rdi as first parameter. + */ +asmlinkage __visible void cpu_bringup_and_idle(int cpu) +{ +#ifdef CONFIG_XEN_PVH + if (xen_feature(XENFEAT_auto_translated_physmap) && + xen_feature(XENFEAT_supervisor_mode_kernel)) + xen_pvh_secondary_vcpu_init(cpu); +#endif + 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_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_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_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_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_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()) { + if (!xen_feature(XENFEAT_writable_page_tables)) + /* 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; + + /* used to tell cpu_init() that it can proceed with initialization */ + cpumask_set_cpu(cpu, cpu_callout_mask); + 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); + +#ifdef CONFIG_X86_32 + /* Note: PVH is not yet supported on x86_32. */ + ctxt->user_regs.fs = __KERNEL_PERCPU; + ctxt->user_regs.gs = __KERNEL_STACK_CANARY; +#endif + memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt)); + + if (!xen_feature(XENFEAT_auto_translated_physmap)) { + ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle; + ctxt->flags = VGCF_IN_KERNEL; + ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */ + ctxt->user_regs.ds = __USER_DS; + ctxt->user_regs.es = __USER_DS; + ctxt->user_regs.ss = __KERNEL_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; +#else + ctxt->gs_base_kernel = per_cpu_offset(cpu); +#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; + per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir); + } +#ifdef CONFIG_XEN_PVH + else { + /* + * The vcpu comes on kernel page tables which have the NX pte + * bit set. This means before DS/SS is touched, NX in + * EFER must be set. Hence the following assembly glue code. + */ + ctxt->user_regs.eip = (unsigned long)xen_pvh_early_cpu_init; + ctxt->user_regs.rdi = cpu; + ctxt->user_regs.rsi = true; /* entry == true */ + } +#endif + ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs); + 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; + + common_cpu_up(cpu, idle); + + xen_setup_runstate_info(cpu); + xen_setup_timer(cpu); + xen_init_lock_cpu(cpu); + + /* + * PV VCPUs are always successfully taken down (see 'while' loop + * in xen_cpu_die()), so -EBUSY is an error. + */ + rc = cpu_check_up_prepare(cpu); + if (rc) + return rc; + + /* make sure interrupts start blocked */ + per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask = 1; + + rc = cpu_initialize_context(cpu, idle); + if (rc) + return rc; + + rc = xen_smp_intr_init(cpu); + if (rc) + return rc; + + rc = HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL); + BUG_ON(rc); + + while (cpu_report_state(cpu) != CPU_ONLINE) + HYPERVISOR_sched_op(SCHEDOP_yield, NULL); + + 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)) { + __set_current_state(TASK_UNINTERRUPTIBLE); + schedule_timeout(HZ/10); + } + + if (common_cpu_die(cpu) == 0) { + 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; + + /* + * This can happen if CPU was offlined earlier and + * offlining timed out in common_cpu_die(). + */ + if (cpu_report_state(cpu) == CPU_DEAD_FROZEN) { + xen_smp_intr_free(cpu); + xen_uninit_lock_cpu(cpu); + } + + /* + * 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; +} + +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_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; +} |