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 "hw/hw.h"
  13 #include "hw/acpi/cpu_hotplug.h"
  14
  15 static uint64_t cpu_status_read(void *opaque, hwaddr addr, unsigned int size)
  16 {
  17     AcpiCpuHotplug *cpus = opaque;
  18     uint64_t val = cpus->sts[addr];
  19
  20     return val;
  21 }
  22
  23 static void cpu_status_write(void *opaque, hwaddr addr, uint64_t data,
  24                              unsigned int size)
  25 {
  26     /* TODO: implement VCPU removal on guest signal that CPU can be removed */
  27 }
  28
  29 static const MemoryRegionOps AcpiCpuHotplug_ops = {
  30     .read = cpu_status_read,
  31     .write = cpu_status_write,
  32     .endianness = DEVICE_LITTLE_ENDIAN,
  33     .valid = {
  34         .min_access_size = 1,
  35         .max_access_size = 1,
  36     },
  37 };
  38
  39 static void acpi_set_cpu_present_bit(AcpiCpuHotplug *g, CPUState *cpu,
  40                                      Error **errp)
  41 {
  42     CPUClass *k = CPU_GET_CLASS(cpu);
  43     int64_t cpu_id;
  44
  45     cpu_id = k->get_arch_id(cpu);
  46     if ((cpu_id / 8) >= ACPI_GPE_PROC_LEN) {
  47         error_setg(errp, "acpi: invalid cpu id: %" PRIi64, cpu_id);
  48         return;
  49     }
  50
  51     g->sts[cpu_id / 8] |= (1 << (cpu_id % 8));
  52 }
  53
  54 void acpi_cpu_plug_cb(ACPIREGS *ar, qemu_irq irq,
  55                       AcpiCpuHotplug *g, DeviceState *dev, Error **errp)
  56 {
  57     acpi_set_cpu_present_bit(g, CPU(dev), errp);
  58     if (*errp != NULL) {
  59         return;
  60     }
  61
  62     ar->gpe.sts[0] |= ACPI_CPU_HOTPLUG_STATUS;
  63     acpi_update_sci(ar, irq);
  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 }