[PATCH 2/5] x86/xen: split smp.c for PV and PVHVM guests

From: Vitaly Kuznetsov
Date: Fri Feb 24 2017 - 11:17:44 EST

More or less mechanically split smp.c into 3 files. XEN_PV_SMP and
XEN_PVHVM_SMP config options added to support the change.

Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
---
arch/x86/xen/Kconfig | 8 +
arch/x86/xen/Makefile | 3 +
arch/x86/xen/enlighten_pv.c | 9 +
arch/x86/xen/smp.c | 531 +-------------------------------------------
arch/x86/xen/smp.h | 23 ++
arch/x86/xen/smp_hvm.c | 58 +++++
arch/x86/xen/smp_pv.c | 499 +++++++++++++++++++++++++++++++++++++++++
7 files changed, 611 insertions(+), 520 deletions(-)
create mode 100644 arch/x86/xen/smp_hvm.c
create mode 100644 arch/x86/xen/smp_pv.c

diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig
index c387560..9ebfd77 100644
--- a/arch/x86/xen/Kconfig
+++ b/arch/x86/xen/Kconfig
@@ -21,6 +21,10 @@ config XEN_PV
help
Support running as a Xen PV guest.

+config XEN_PV_SMP
+ def_bool y
+ depends on XEN_PV && SMP
+
config XEN_DOM0
bool "Xen PV Dom0 support"
default y
@@ -37,6 +41,10 @@ config XEN_PVHVM
help
Support running as a Xen PVHVM guest.

+config XEN_PVHVM_SMP
+ def_bool y
+ depends on XEN_PVHVM && SMP
+
config XEN_512GB
bool "Limit Xen pv-domain memory to 512GB"
depends on XEN_PV && X86_64
diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile
index 750727b..ed6f126 100644
--- a/arch/x86/xen/Makefile
+++ b/arch/x86/xen/Makefile
@@ -22,6 +22,9 @@ obj-$(CONFIG_XEN_PVH) += enlighten_pvh.o
obj-$(CONFIG_EVENT_TRACING) += trace.o

obj-$(CONFIG_SMP) += smp.o
+obj-$(CONFIG_XEN_PV_SMP) += smp_pv.o
+obj-$(CONFIG_XEN_PVHVM_SMP) += smp_hvm.o
+
obj-$(CONFIG_PARAVIRT_SPINLOCKS)+= spinlock.o
obj-$(CONFIG_XEN_DEBUG_FS) += debugfs.o
obj-$(CONFIG_XEN_DOM0) += vga.o
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index b9ff23c..acfd896 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -1478,12 +1478,21 @@ static int xen_cpu_up_prepare_pv(unsigned int cpu)
cpu, rc);
return rc;
}
+
+ rc = xen_smp_intr_init_pv(cpu);
+ if (rc) {
+ WARN(1, "xen_smp_intr_init_pv() for CPU %d failed: %d\n",
+ cpu, rc);
+ return rc;
+ }
+
return 0;
}

static int xen_cpu_dead_pv(unsigned int cpu)
{
xen_smp_intr_free(cpu);
+ xen_smp_intr_free_pv(cpu);

xen_teardown_timer(cpu);

diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 14fd7f3..dd1150e 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -1,62 +1,21 @@
-/*
- * 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 <xen/interface/xenpmu.h>
-
-#include <asm/xen/interface.h>
-#include <asm/xen/hypercall.h>
+#include <linux/slab.h>
+#include <linux/cpumask.h>
+#include <linux/percpu.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"
-#include "pmu.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 DEFINE_PER_CPU(struct xen_common_irq, xen_pmu_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.
@@ -69,42 +28,6 @@ static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id)
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();
-}
-
-asmlinkage __visible void cpu_bringup_and_idle(void)
-{
- cpu_bringup();
- cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
-}
-
void xen_smp_intr_free(unsigned int cpu)
{
if (per_cpu(xen_resched_irq, cpu).irq >= 0) {
@@ -132,27 +55,12 @@ void xen_smp_intr_free(unsigned int cpu)
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;
- }
+}

- if (per_cpu(xen_pmu_irq, cpu).irq >= 0) {
- unbind_from_irqhandler(per_cpu(xen_pmu_irq, cpu).irq, NULL);
- per_cpu(xen_pmu_irq, cpu).irq = -1;
- kfree(per_cpu(xen_pmu_irq, cpu).name);
- per_cpu(xen_pmu_irq, cpu).name = NULL;
- }
-};
int xen_smp_intr_init(unsigned int cpu)
{
int rc;
- char *resched_name, *callfunc_name, *debug_name, *pmu_name;
+ char *resched_name, *callfunc_name, *debug_name;

resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu);
rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR,
@@ -199,37 +107,6 @@ int xen_smp_intr_init(unsigned int cpu)
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;
-
- if (is_xen_pmu(cpu)) {
- pmu_name = kasprintf(GFP_KERNEL, "pmu%d", cpu);
- rc = bind_virq_to_irqhandler(VIRQ_XENPMU, cpu,
- xen_pmu_irq_handler,
- IRQF_PERCPU|IRQF_NOBALANCING,
- pmu_name, NULL);
- if (rc < 0)
- goto fail;
- per_cpu(xen_pmu_irq, cpu).irq = rc;
- per_cpu(xen_pmu_irq, cpu).name = pmu_name;
- }
-
return 0;

fail:
@@ -237,345 +114,13 @@ int xen_smp_intr_init(unsigned int cpu)
return rc;
}

-#ifdef CONFIG_XEN_PV
-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
-
-}
-#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()) {
-#ifdef CONFIG_XEN_PV
- 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();
-#endif
- }
-
- /*
- * Setup vcpu_info for boot CPU.
- */
- if (xen_hvm_domain())
- xen_vcpu_setup(0);
-
- /*
- * 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();
-}
-
-#ifdef CONFIG_XEN_PV
-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);
-
- xen_pmu_init(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
- ctxt->user_regs.fs = __KERNEL_PERCPU;
- ctxt->user_regs.gs = __KERNEL_STACK_CANARY;
-#endif
- memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt));
-
- 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);
-
- ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs);
- ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_gfn(swapper_pg_dir));
- if (HYPERVISOR_vcpu_op(VCPUOP_initialise, xen_vcpu_nr(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);
-
- /*
- * 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;
-
- xen_pmu_init(cpu);
-
- rc = HYPERVISOR_vcpu_op(VCPUOP_up, xen_vcpu_nr(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_play_dead(void) /* used only with HOTPLUG_CPU */
-{
- play_dead_common();
- HYPERVISOR_vcpu_op(VCPUOP_down, xen_vcpu_nr(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();
-
- cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
-}
-
-#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, xen_vcpu_nr(cpu), NULL);
- BUG();
-}
-
-static void xen_stop_other_cpus(int wait)
-{
- smp_call_function(stop_self, NULL, wait);
-}
-#endif /* CONFIG_XEN_PV */
-
-static void xen_cpu_die(unsigned int cpu)
-{
- while (xen_pv_domain() && HYPERVISOR_vcpu_op(VCPUOP_is_up,
- xen_vcpu_nr(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);
- xen_pmu_finish(cpu);
- }
-}
-
-static void xen_smp_send_reschedule(int cpu)
+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)
+ int vector)
{
unsigned cpu;

@@ -583,7 +128,7 @@ static void __xen_send_IPI_mask(const struct cpumask *mask,
xen_send_IPI_one(cpu, vector);
}

-static void xen_smp_send_call_function_ipi(const struct cpumask *mask)
+void xen_smp_send_call_function_ipi(const struct cpumask *mask)
{
int cpu;

@@ -598,10 +143,10 @@ static void xen_smp_send_call_function_ipi(const struct cpumask *mask)
}
}

-static void xen_smp_send_call_function_single_ipi(int cpu)
+void xen_smp_send_call_function_single_ipi(int cpu)
{
__xen_send_IPI_mask(cpumask_of(cpu),
- XEN_CALL_FUNCTION_SINGLE_VECTOR);
+ XEN_CALL_FUNCTION_SINGLE_VECTOR);
}

static inline int xen_map_vector(int vector)
@@ -636,8 +181,7 @@ static inline int xen_map_vector(int vector)
return xen_vector;
}

-void xen_send_IPI_mask(const struct cpumask *mask,
- int vector)
+void xen_send_IPI_mask(const struct cpumask *mask, int vector)
{
int xen_vector = xen_map_vector(vector);

@@ -703,56 +247,3 @@ static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)

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;
-}
-
-#ifdef CONFIG_XEN_PV
-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();
-}
-#endif
-
-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);
-}
-
-void __init xen_hvm_smp_init(void)
-{
- smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus;
- smp_ops.smp_send_reschedule = xen_smp_send_reschedule;
- 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;
-}
diff --git a/arch/x86/xen/smp.h b/arch/x86/xen/smp.h
index 9beef33..b31d43b 100644
--- a/arch/x86/xen/smp.h
+++ b/arch/x86/xen/smp.h
@@ -8,9 +8,22 @@ extern void xen_send_IPI_mask_allbutself(const struct cpumask *mask,
extern void xen_send_IPI_allbutself(int vector);
extern void xen_send_IPI_all(int vector);
extern void xen_send_IPI_self(int vector);
+extern void xen_send_IPI_mask(const struct cpumask *mask, int vector);

extern int xen_smp_intr_init(unsigned int cpu);
extern void xen_smp_intr_free(unsigned int cpu);
+#ifdef CONFIG_XEN_PV
+extern int xen_smp_intr_init_pv(unsigned int cpu);
+extern void xen_smp_intr_free_pv(unsigned int cpu);
+#endif
+extern void xen_smp_send_reschedule(int cpu);
+extern void xen_smp_send_call_function_ipi(const struct cpumask *mask);
+extern void xen_smp_send_call_function_single_ipi(int cpu);
+
+struct xen_common_irq {
+ int irq;
+ char *name;
+};

#else /* CONFIG_SMP */

@@ -18,6 +31,16 @@ static inline int xen_smp_intr_init(unsigned int cpu)
{
return 0;
}
+
+#ifdef CONFIG_XEN_PV
+static inline int xen_smp_intr_init_pv(unsigned int cpu)
+{
+ return 0;
+}
+
+static inline void xen_smp_intr_free_pv(unsigned int cpu) {}
+#endif
+
static inline void xen_smp_intr_free(unsigned int cpu) {}
#endif /* CONFIG_SMP */

diff --git a/arch/x86/xen/smp_hvm.c b/arch/x86/xen/smp_hvm.c
new file mode 100644
index 0000000..8bed434
--- /dev/null
+++ b/arch/x86/xen/smp_hvm.c
@@ -0,0 +1,58 @@
+#include <asm/smp.h>
+
+#include "xen-ops.h"
+#include "smp.h"
+
+
+static void __init xen_hvm_smp_prepare_boot_cpu(void)
+{
+ BUG_ON(smp_processor_id() != 0);
+ native_smp_prepare_boot_cpu();
+
+ /*
+ * Setup vcpu_info for boot CPU.
+ */
+ xen_vcpu_setup(0);
+
+ /*
+ * 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_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);
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static void xen_hvm_cpu_die(unsigned int cpu)
+{
+ if (common_cpu_die(cpu) == 0) {
+ xen_smp_intr_free(cpu);
+ xen_uninit_lock_cpu(cpu);
+ xen_teardown_timer(cpu);
+ }
+}
+#else
+static void xen_hvm_cpu_die(unsigned int cpu)
+{
+ BUG();
+}
+#endif
+
+void __init xen_hvm_smp_init(void)
+{
+ smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus;
+ smp_ops.smp_send_reschedule = xen_smp_send_reschedule;
+ 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_hvm_smp_prepare_boot_cpu;
+}
diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c
new file mode 100644
index 0000000..fc89907
--- /dev/null
+++ b/arch/x86/xen/smp_pv.c
@@ -0,0 +1,499 @@
+/*
+ * 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 <xen/interface/xenpmu.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"
+#include "pmu.h"
+
+cpumask_var_t xen_cpu_initialized_map;
+
+static DEFINE_PER_CPU(struct xen_common_irq, xen_irq_work) = { .irq = -1 };
+static DEFINE_PER_CPU(struct xen_common_irq, xen_pmu_irq) = { .irq = -1 };
+
+static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id);
+
+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();
+}
+
+asmlinkage __visible void cpu_bringup_and_idle(void)
+{
+ cpu_bringup();
+ cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
+}
+
+void xen_smp_intr_free_pv(unsigned int cpu)
+{
+ 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;
+ }
+
+ if (per_cpu(xen_pmu_irq, cpu).irq >= 0) {
+ unbind_from_irqhandler(per_cpu(xen_pmu_irq, cpu).irq, NULL);
+ per_cpu(xen_pmu_irq, cpu).irq = -1;
+ kfree(per_cpu(xen_pmu_irq, cpu).name);
+ per_cpu(xen_pmu_irq, cpu).name = NULL;
+ }
+}
+
+int xen_smp_intr_init_pv(unsigned int cpu)
+{
+ int rc;
+ char *callfunc_name, *pmu_name;
+
+ 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;
+
+ if (is_xen_pmu(cpu)) {
+ pmu_name = kasprintf(GFP_KERNEL, "pmu%d", cpu);
+ rc = bind_virq_to_irqhandler(VIRQ_XENPMU, cpu,
+ xen_pmu_irq_handler,
+ IRQF_PERCPU|IRQF_NOBALANCING,
+ pmu_name, NULL);
+ if (rc < 0)
+ goto fail;
+ per_cpu(xen_pmu_irq, cpu).irq = rc;
+ per_cpu(xen_pmu_irq, cpu).name = pmu_name;
+ }
+
+ return 0;
+
+ fail:
+ xen_smp_intr_free_pv(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_pv_smp_prepare_boot_cpu(void)
+{
+ BUG_ON(smp_processor_id() != 0);
+ native_smp_prepare_boot_cpu();
+
+ if (xen_pv_domain()) {
+#ifdef CONFIG_XEN_PV
+ 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();
+#endif
+ }
+
+ /*
+ * Setup vcpu_info for boot CPU.
+ */
+ if (xen_hvm_domain())
+ xen_vcpu_setup(0);
+
+ /*
+ * 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_pv_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);
+
+ xen_pmu_init(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
+ ctxt->user_regs.fs = __KERNEL_PERCPU;
+ ctxt->user_regs.gs = __KERNEL_STACK_CANARY;
+#endif
+ memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt));
+
+ 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);
+
+ ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs);
+ ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_gfn(swapper_pg_dir));
+ if (HYPERVISOR_vcpu_op(VCPUOP_initialise, xen_vcpu_nr(cpu), ctxt))
+ BUG();
+
+ kfree(ctxt);
+ return 0;
+}
+
+static int xen_pv_cpu_up(unsigned int cpu, struct task_struct *idle)
+{
+ int rc;
+
+ common_cpu_up(cpu, idle);
+
+ xen_setup_runstate_info(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;
+
+ xen_pmu_init(cpu);
+
+ rc = HYPERVISOR_vcpu_op(VCPUOP_up, xen_vcpu_nr(cpu), NULL);
+ BUG_ON(rc);
+
+ while (cpu_report_state(cpu) != CPU_ONLINE)
+ HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
+
+ return 0;
+}
+
+static void xen_pv_smp_cpus_done(unsigned int max_cpus)
+{
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static int xen_pv_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_pv_play_dead(void) /* used only with HOTPLUG_CPU */
+{
+ play_dead_common();
+ HYPERVISOR_vcpu_op(VCPUOP_down, xen_vcpu_nr(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();
+
+ cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
+}
+
+#else /* !CONFIG_HOTPLUG_CPU */
+static int xen_pv_cpu_disable(void)
+{
+ return -ENOSYS;
+}
+
+static void xen_pv_cpu_die(unsigned int cpu)
+{
+ BUG();
+}
+
+static void xen_pv_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, xen_vcpu_nr(cpu), NULL);
+ BUG();
+}
+
+static void xen_pv_stop_other_cpus(int wait)
+{
+ smp_call_function(stop_self, NULL, wait);
+}
+
+static void xen_pv_cpu_die(unsigned int cpu)
+{
+ while (HYPERVISOR_vcpu_op(VCPUOP_is_up,
+ xen_vcpu_nr(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);
+ xen_pmu_finish(cpu);
+ }
+}
+
+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_pv_smp_prepare_boot_cpu,
+ .smp_prepare_cpus = xen_pv_smp_prepare_cpus,
+ .smp_cpus_done = xen_pv_smp_cpus_done,
+
+ .cpu_up = xen_pv_cpu_up,
+ .cpu_die = xen_pv_cpu_die,
+ .cpu_disable = xen_pv_cpu_disable,
+ .play_dead = xen_pv_play_dead,
+
+ .stop_other_cpus = xen_pv_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();
+}
--
2.9.3