LXR qemu/hw/acpi/cpu

   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/acpi/cpu_hotplug.h"
  14#include "qapi/error.h"
  15#include "hw/core/cpu.h"
  16#include "hw/i386/pc.h"
  17#include "hw/pci/pci.h"
  18#include "qemu/error-report.h"
  19
  20#define CPU_EJECT_METHOD "CPEJ"
  21#define CPU_MAT_METHOD "CPMA"
  22#define CPU_ON_BITMAP "CPON"
  23#define CPU_STATUS_METHOD "CPST"
  24#define CPU_STATUS_MAP "PRS"
  25#define CPU_SCAN_METHOD "PRSC"
  26
  27static uint64_t cpu_status_read(void *opaque, hwaddr addr, unsigned int size)
  28{
  29    AcpiCpuHotplug *cpus = opaque;
  30    uint64_t val = cpus->sts[addr];
  31
  32    return val;
  33}
  34
  35static void cpu_status_write(void *opaque, hwaddr addr, uint64_t data,
  36                             unsigned int size)
  37{
  38    /* firmware never used to write in CPU present bitmap so use
  39       this fact as means to switch QEMU into modern CPU hotplug
  40       mode by writing 0 at the beginning of legacy CPU bitmap
  41     */
  42    if (addr == 0 && data == 0) {
  43        AcpiCpuHotplug *cpus = opaque;
  44        object_property_set_bool(cpus->device, "cpu-hotplug-legacy", false,
  45                                 &error_abort);
  46    }
  47}
  48
  49static const MemoryRegionOps AcpiCpuHotplug_ops = {
  50    .read = cpu_status_read,
  51    .write = cpu_status_write,
  52    .endianness = DEVICE_LITTLE_ENDIAN,
  53    .valid = {
  54        .min_access_size = 1,
  55        .max_access_size = 4,
  56    },
  57    .impl = {
  58        .max_access_size = 1,
  59    },
  60};
  61
  62static void acpi_set_cpu_present_bit(AcpiCpuHotplug *g, CPUState *cpu)
  63{
  64    CPUClass *k = CPU_GET_CLASS(cpu);
  65    int64_t cpu_id;
  66
  67    cpu_id = k->get_arch_id(cpu);
  68    if ((cpu_id / 8) >= ACPI_GPE_PROC_LEN) {
  69        object_property_set_bool(g->device, "cpu-hotplug-legacy", false,
  70                                 &error_abort);
  71        return;
  72    }
  73
  74    g->sts[cpu_id / 8] |= (1 << (cpu_id % 8));
  75}
  76
  77void legacy_acpi_cpu_plug_cb(HotplugHandler *hotplug_dev,
  78                             AcpiCpuHotplug *g, DeviceState *dev, Error **errp)
  79{
  80    acpi_set_cpu_present_bit(g, CPU(dev));
  81    acpi_send_event(DEVICE(hotplug_dev), ACPI_CPU_HOTPLUG_STATUS);
  82}
  83
  84void legacy_acpi_cpu_hotplug_init(MemoryRegion *parent, Object *owner,
  85                                  AcpiCpuHotplug *gpe_cpu, uint16_t base)
  86{
  87    CPUState *cpu;
  88
  89    memory_region_init_io(&gpe_cpu->io, owner, &AcpiCpuHotplug_ops,
  90                          gpe_cpu, "acpi-cpu-hotplug", ACPI_GPE_PROC_LEN);
  91    memory_region_add_subregion(parent, base, &gpe_cpu->io);
  92    gpe_cpu->device = owner;
  93
  94    CPU_FOREACH(cpu) {
  95        acpi_set_cpu_present_bit(gpe_cpu, cpu);
  96    }
  97}
  98
  99void acpi_switch_to_modern_cphp(AcpiCpuHotplug *gpe_cpu,
 100                                CPUHotplugState *cpuhp_state,
 101                                uint16_t io_port)
 102{
 103    MemoryRegion *parent = pci_address_space_io(PCI_DEVICE(gpe_cpu->device));
 104
 105    memory_region_del_subregion(parent, &gpe_cpu->io);
 106    cpu_hotplug_hw_init(parent, gpe_cpu->device, cpuhp_state, io_port);
 107}
 108
 109void build_legacy_cpu_hotplug_aml(Aml *ctx, MachineState *machine,
 110                                  uint16_t io_base)
 111{
 112    Aml *dev;
 113    Aml *crs;
 114    Aml *pkg;
 115    Aml *field;
 116    Aml *method;
 117    Aml *if_ctx;
 118    Aml *else_ctx;
 119    int i, apic_idx;
 120    Aml *sb_scope = aml_scope("_SB");
 121    uint8_t madt_tmpl[8] = {0x00, 0x08, 0x00, 0x00, 0x00, 0, 0, 0};
 122    Aml *cpu_id = aml_arg(1);
 123    Aml *apic_id = aml_arg(0);
 124    Aml *cpu_on = aml_local(0);
 125    Aml *madt = aml_local(1);
 126    Aml *cpus_map = aml_name(CPU_ON_BITMAP);
 127    Aml *zero = aml_int(0);
 128    Aml *one = aml_int(1);
 129    MachineClass *mc = MACHINE_GET_CLASS(machine);
 130    const CPUArchIdList *apic_ids = mc->possible_cpu_arch_ids(machine);
 131    X86MachineState *x86ms = X86_MACHINE(machine);
 132
 133    /*
 134     * _MAT method - creates an madt apic buffer
 135     * apic_id = Arg0 = Local APIC ID
 136     * cpu_id  = Arg1 = Processor ID
 137     * cpu_on = Local0 = CPON flag for this cpu
 138     * madt = Local1 = Buffer (in madt apic form) to return
 139     */
 140    method = aml_method(CPU_MAT_METHOD, 2, AML_NOTSERIALIZED);
 141    aml_append(method,
 142        aml_store(aml_derefof(aml_index(cpus_map, apic_id)), cpu_on));
 143    aml_append(method,
 144        aml_store(aml_buffer(sizeof(madt_tmpl), madt_tmpl), madt));
 145    /* Update the processor id, lapic id, and enable/disable status */
 146    aml_append(method, aml_store(cpu_id, aml_index(madt, aml_int(2))));
 147    aml_append(method, aml_store(apic_id, aml_index(madt, aml_int(3))));
 148    aml_append(method, aml_store(cpu_on, aml_index(madt, aml_int(4))));
 149    aml_append(method, aml_return(madt));
 150    aml_append(sb_scope, method);
 151
 152    /*
 153     * _STA method - return ON status of cpu
 154     * apic_id = Arg0 = Local APIC ID
 155     * cpu_on = Local0 = CPON flag for this cpu
 156     */
 157    method = aml_method(CPU_STATUS_METHOD, 1, AML_NOTSERIALIZED);
 158    aml_append(method,
 159        aml_store(aml_derefof(aml_index(cpus_map, apic_id)), cpu_on));
 160    if_ctx = aml_if(cpu_on);
 161    {
 162        aml_append(if_ctx, aml_return(aml_int(0xF)));
 163    }
 164    aml_append(method, if_ctx);
 165    else_ctx = aml_else();
 166    {
 167        aml_append(else_ctx, aml_return(zero));
 168    }
 169    aml_append(method, else_ctx);
 170    aml_append(sb_scope, method);
 171
 172    method = aml_method(CPU_EJECT_METHOD, 2, AML_NOTSERIALIZED);
 173    aml_append(method, aml_sleep(200));
 174    aml_append(sb_scope, method);
 175
 176    method = aml_method(CPU_SCAN_METHOD, 0, AML_NOTSERIALIZED);
 177    {
 178        Aml *while_ctx, *if_ctx2, *else_ctx2;
 179        Aml *bus_check_evt = aml_int(1);
 180        Aml *remove_evt = aml_int(3);
 181        Aml *status_map = aml_local(5); /* Local5 = active cpu bitmap */
 182        Aml *byte = aml_local(2); /* Local2 = last read byte from bitmap */
 183        Aml *idx = aml_local(0); /* Processor ID / APIC ID iterator */
 184        Aml *is_cpu_on = aml_local(1); /* Local1 = CPON flag for cpu */
 185        Aml *status = aml_local(3); /* Local3 = active state for cpu */
 186
 187        aml_append(method, aml_store(aml_name(CPU_STATUS_MAP), status_map));
 188        aml_append(method, aml_store(zero, byte));
 189        aml_append(method, aml_store(zero, idx));
 190
 191        /* While (idx < SizeOf(CPON)) */
 192        while_ctx = aml_while(aml_lless(idx, aml_sizeof(cpus_map)));
 193        aml_append(while_ctx,
 194            aml_store(aml_derefof(aml_index(cpus_map, idx)), is_cpu_on));
 195
 196        if_ctx = aml_if(aml_and(idx, aml_int(0x07), NULL));
 197        {
 198            /* Shift down previously read bitmap byte */
 199            aml_append(if_ctx, aml_shiftright(byte, one, byte));
 200        }
 201        aml_append(while_ctx, if_ctx);
 202
 203        else_ctx = aml_else();
 204        {
 205            /* Read next byte from cpu bitmap */
 206            aml_append(else_ctx, aml_store(aml_derefof(aml_index(status_map,
 207                       aml_shiftright(idx, aml_int(3), NULL))), byte));
 208        }
 209        aml_append(while_ctx, else_ctx);
 210
 211        aml_append(while_ctx, aml_store(aml_and(byte, one, NULL), status));
 212        if_ctx = aml_if(aml_lnot(aml_equal(is_cpu_on, status)));
 213        {
 214            /* State change - update CPON with new state */
 215            aml_append(if_ctx, aml_store(status, aml_index(cpus_map, idx)));
 216            if_ctx2 = aml_if(aml_equal(status, one));
 217            {
 218                aml_append(if_ctx2,
 219                    aml_call2(AML_NOTIFY_METHOD, idx, bus_check_evt));
 220            }
 221            aml_append(if_ctx, if_ctx2);
 222            else_ctx2 = aml_else();
 223            {
 224                aml_append(else_ctx2,
 225                    aml_call2(AML_NOTIFY_METHOD, idx, remove_evt));
 226            }
 227        }
 228        aml_append(if_ctx, else_ctx2);
 229        aml_append(while_ctx, if_ctx);
 230
 231        aml_append(while_ctx, aml_increment(idx)); /* go to next cpu */
 232        aml_append(method, while_ctx);
 233    }
 234    aml_append(sb_scope, method);
 235
 236    /* The current AML generator can cover the APIC ID range [0..255],
 237     * inclusive, for VCPU hotplug. */
 238    QEMU_BUILD_BUG_ON(ACPI_CPU_HOTPLUG_ID_LIMIT > 256);
 239    if (x86ms->apic_id_limit > ACPI_CPU_HOTPLUG_ID_LIMIT) {
 240        error_report("max_cpus is too large. APIC ID of last CPU is %u",
 241                     x86ms->apic_id_limit - 1);
 242        exit(1);
 243    }
 244
 245    /* create PCI0.PRES device and its _CRS to reserve CPU hotplug MMIO */
 246    dev = aml_device("PCI0." stringify(CPU_HOTPLUG_RESOURCE_DEVICE));
 247    aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A06")));
 248    aml_append(dev,
 249        aml_name_decl("_UID", aml_string("CPU Hotplug resources"))
 250    );
 251    /* device present, functioning, decoding, not shown in UI */
 252    aml_append(dev, aml_name_decl("_STA", aml_int(0xB)));
 253    crs = aml_resource_template();
 254    aml_append(crs,
 255        aml_io(AML_DECODE16, io_base, io_base, 1, ACPI_GPE_PROC_LEN)
 256    );
 257    aml_append(dev, aml_name_decl("_CRS", crs));
 258    aml_append(sb_scope, dev);
 259    /* declare CPU hotplug MMIO region and PRS field to access it */
 260    aml_append(sb_scope, aml_operation_region(
 261        "PRST", AML_SYSTEM_IO, aml_int(io_base), ACPI_GPE_PROC_LEN));
 262    field = aml_field("PRST", AML_BYTE_ACC, AML_NOLOCK, AML_PRESERVE);
 263    aml_append(field, aml_named_field("PRS", 256));
 264    aml_append(sb_scope, field);
 265
 266    /* build Processor object for each processor */
 267    for (i = 0; i < apic_ids->len; i++) {
 268        int apic_id = apic_ids->cpus[i].arch_id;
 269
 270        assert(apic_id < ACPI_CPU_HOTPLUG_ID_LIMIT);
 271
 272        dev = aml_processor(i, 0, 0, "CP%.02X", apic_id);
 273
 274        method = aml_method("_MAT", 0, AML_NOTSERIALIZED);
 275        aml_append(method,
 276            aml_return(aml_call2(CPU_MAT_METHOD, aml_int(apic_id), aml_int(i))
 277        ));
 278        aml_append(dev, method);
 279
 280        method = aml_method("_STA", 0, AML_NOTSERIALIZED);
 281        aml_append(method,
 282            aml_return(aml_call1(CPU_STATUS_METHOD, aml_int(apic_id))));
 283        aml_append(dev, method);
 284
 285        method = aml_method("_EJ0", 1, AML_NOTSERIALIZED);
 286        aml_append(method,
 287            aml_return(aml_call2(CPU_EJECT_METHOD, aml_int(apic_id),
 288                aml_arg(0)))
 289        );
 290        aml_append(dev, method);
 291
 292        aml_append(sb_scope, dev);
 293    }
 294
 295    /* build this code:
 296     *   Method(NTFY, 2) {If (LEqual(Arg0, 0x00)) {Notify(CP00, Arg1)} ...}
 297     */
 298    /* Arg0 = APIC ID */
 299    method = aml_method(AML_NOTIFY_METHOD, 2, AML_NOTSERIALIZED);
 300    for (i = 0; i < apic_ids->len; i++) {
 301        int apic_id = apic_ids->cpus[i].arch_id;
 302
 303        if_ctx = aml_if(aml_equal(aml_arg(0), aml_int(apic_id)));
 304        aml_append(if_ctx,
 305            aml_notify(aml_name("CP%.02X", apic_id), aml_arg(1))
 306        );
 307        aml_append(method, if_ctx);
 308    }
 309    aml_append(sb_scope, method);
 310
 311    /* build "Name(CPON, Package() { One, One, ..., Zero, Zero, ... })"
 312     *
 313     * Note: The ability to create variable-sized packages was first
 314     * introduced in ACPI 2.0. ACPI 1.0 only allowed fixed-size packages
 315     * ith up to 255 elements. Windows guests up to win2k8 fail when
 316     * VarPackageOp is used.
 317     */
 318    pkg = x86ms->apic_id_limit <= 255 ? aml_package(x86ms->apic_id_limit) :
 319                                        aml_varpackage(x86ms->apic_id_limit);
 320
 321    for (i = 0, apic_idx = 0; i < apic_ids->len; i++) {
 322        int apic_id = apic_ids->cpus[i].arch_id;
 323
 324        for (; apic_idx < apic_id; apic_idx++) {
 325            aml_append(pkg, aml_int(0));
 326        }
 327        aml_append(pkg, aml_int(apic_ids->cpus[i].cpu ? 1 : 0));
 328        apic_idx = apic_id + 1;
 329    }
 330    aml_append(sb_scope, aml_name_decl(CPU_ON_BITMAP, pkg));
 331    aml_append(ctx, sb_scope);
 332
 333    method = aml_method("\\_GPE._E02", 0, AML_NOTSERIALIZED);
 334    aml_append(method, aml_call0("\\_SB." CPU_SCAN_METHOD));
 335    aml_append(ctx, method);
 336}
 337