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