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 "qom/cpu.h"
  16
  17 static uint64_t cpu_status_read(void *opaque, hwaddr addr, unsigned int size)
  18 {
  19     AcpiCpuHotplug *cpus = opaque;
  20     uint64_t val = cpus->sts[addr];
  21
  22     return val;
  23 }
  24
  25 static void cpu_status_write(void *opaque, hwaddr addr, uint64_t data,
  26                              unsigned int size)
  27 {
  28     /* TODO: implement VCPU removal on guest signal that CPU can be removed */
  29 }
  30
  31 static const MemoryRegionOps AcpiCpuHotplug_ops = {
  32     .read = cpu_status_read,
  33     .write = cpu_status_write,
  34     .endianness = DEVICE_LITTLE_ENDIAN,
  35     .valid = {
  36         .min_access_size = 1,
  37         .max_access_size = 1,
  38     },
  39 };
  40
  41 static void acpi_set_cpu_present_bit(AcpiCpuHotplug *g, CPUState *cpu,
  42                                      Error **errp)
  43 {
  44     CPUClass *k = CPU_GET_CLASS(cpu);
  45     int64_t cpu_id;
  46
  47     cpu_id = k->get_arch_id(cpu);
  48     if ((cpu_id / 8) >= ACPI_GPE_PROC_LEN) {
  49         error_setg(errp, "acpi: invalid cpu id: %" PRIi64, cpu_id);
  50         return;
  51     }
  52
  53     g->sts[cpu_id / 8] |= (1 << (cpu_id % 8));
  54 }
  55
  56 void acpi_cpu_plug_cb(ACPIREGS *ar, qemu_irq irq,
  57                       AcpiCpuHotplug *g, DeviceState *dev, Error **errp)
  58 {
  59     acpi_set_cpu_present_bit(g, CPU(dev), errp);
  60     if (*errp != NULL) {
  61         return;
  62     }
  63
  64     acpi_send_gpe_event(ar, irq, ACPI_CPU_HOTPLUG_STATUS);
  65 }
  66
  67 void acpi_cpu_hotplug_init(MemoryRegion *parent, Object *owner,
  68                            AcpiCpuHotplug *gpe_cpu, uint16_t base)
  69 {
  70     CPUState *cpu;
  71
  72     CPU_FOREACH(cpu) {
  73         acpi_set_cpu_present_bit(gpe_cpu, cpu, &error_abort);
  74     }
  75     memory_region_init_io(&gpe_cpu->io, owner, &AcpiCpuHotplug_ops,
  76                           gpe_cpu, "acpi-cpu-hotplug", ACPI_GPE_PROC_LEN);
  77     memory_region_add_subregion(parent, base, &gpe_cpu->io);
  78 }