hw/acpi/cpu_hotplug.c

   1 /*
   2  * QEMU ACPI hotplug utilities
   3  *
   4  * Copyright (C) 2013 Red Hat Inc
   5  *
   6  * Authors:
   7  *   Igor Mammedov <imammedo@redhat.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  10  * See the COPYING file in the top-level directory.
  11  */
  12 #include "qemu/osdep.h"
  13 #include "hw/hw.h"
  14 #include "hw/acpi/cpu_hotplug.h"
  15 #include "qapi/error.h"
  16 #include "qom/cpu.h"
  17
  18 static uint64_t cpu_status_read(void *opaque, hwaddr addr, unsigned int size)
  19 {
  20     AcpiCpuHotplug *cpus = opaque;
  21     uint64_t val = cpus->sts[addr];
  22
  23     return val;
  24 }
  25
  26 static void cpu_status_write(void *opaque, hwaddr addr, uint64_t data,
  27                              unsigned int size)
  28 {
  29     /* TODO: implement VCPU removal on guest signal that CPU can be removed */
  30 }
  31
  32 static const MemoryRegionOps AcpiCpuHotplug_ops = {
  33     .read = cpu_status_read,
  34     .write = cpu_status_write,
  35     .endianness = DEVICE_LITTLE_ENDIAN,
  36     .valid = {
  37         .min_access_size = 1,
  38         .max_access_size = 1,
  39     },
  40 };
  41
  42 static void acpi_set_cpu_present_bit(AcpiCpuHotplug *g, CPUState *cpu,
  43                                      Error **errp)
  44 {
  45     CPUClass *k = CPU_GET_CLASS(cpu);
  46     int64_t cpu_id;
  47
  48     cpu_id = k->get_arch_id(cpu);
  49     if ((cpu_id / 8) >= ACPI_GPE_PROC_LEN) {
  50         error_setg(errp, "acpi: invalid cpu id: %" PRIi64, cpu_id);
  51         return;
  52     }
  53
  54     g->sts[cpu_id / 8] |= (1 << (cpu_id % 8));
  55 }
  56
  57 void acpi_cpu_plug_cb(ACPIREGS *ar, qemu_irq irq,
  58                       AcpiCpuHotplug *g, DeviceState *dev, Error **errp)
  59 {
  60     acpi_set_cpu_present_bit(g, CPU(dev), errp);
  61     if (*errp != NULL) {
  62         return;
  63     }
  64
  65     acpi_send_gpe_event(ar, irq, ACPI_CPU_HOTPLUG_STATUS);
  66 }
  67
  68 void acpi_cpu_hotplug_init(MemoryRegion *parent, Object *owner,
  69                            AcpiCpuHotplug *gpe_cpu, uint16_t base)
  70 {
  71     CPUState *cpu;
  72
  73     CPU_FOREACH(cpu) {
  74         acpi_set_cpu_present_bit(gpe_cpu, cpu, &error_abort);
  75     }
  76     memory_region_init_io(&gpe_cpu->io, owner, &AcpiCpuHotplug_ops,
  77                           gpe_cpu, "acpi-cpu-hotplug", ACPI_GPE_PROC_LEN);
  78     memory_region_add_subregion(parent, base, &gpe_cpu->io);
  79 }