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/hw.h"
  14#include "hw/acpi/cpu_hotplug.h"
  15#include "qapi/error.h"
  16#include "qom/cpu.h"
  17#include "hw/i386/pc.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, false, "cpu-hotplug-legacy",
  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 = 1,
  56    },
  57};
  58
  59static void acpi_set_cpu_present_bit(AcpiCpuHotplug *g, CPUState *cpu,
  60                                     Error **errp)
  61{
  62    CPUClass *k = CPU_GET_CLASS(cpu);
  63    int64_t cpu_id;
  64
  65    cpu_id = k->get_arch_id(cpu);
  66    if ((cpu_id / 8) >= ACPI_GPE_PROC_LEN) {
  67        object_property_set_bool(g->device, false, "cpu-hotplug-legacy",
  68                                 &error_abort);
  69        return;
  70    }
  71
  72    g->sts[cpu_id / 8] |= (1 << (cpu_id % 8));
  73}
  74
  75void legacy_acpi_cpu_plug_cb(HotplugHandler *hotplug_dev,
  76                             AcpiCpuHotplug *g, DeviceState *dev, Error **errp)
  77{
  78    acpi_set_cpu_present_bit(g, CPU(dev), errp);
  79    if (*errp != NULL) {
  80        return;
  81    }
  82    acpi_send_event(DEVICE(hotplug_dev), ACPI_CPU_HOTPLUG_STATUS);
  83}
  84
  85void legacy_acpi_cpu_hotplug_init(MemoryRegion *parent, Object *owner,
  86                                  AcpiCpuHotplug *gpe_cpu, uint16_t base)
  87{
  88    CPUState *cpu;
  89
  90    memory_region_init_io(&gpe_cpu->io, owner, &AcpiCpuHotplug_ops,
  91                          gpe_cpu, "acpi-cpu-hotplug", ACPI_GPE_PROC_LEN);
  92    memory_region_add_subregion(parent, base, &gpe_cpu->io);
  93    gpe_cpu->device = owner;
  94
  95    CPU_FOREACH(cpu) {
  96        acpi_set_cpu_present_bit(gpe_cpu, cpu, &error_abort);
  97    }
  98}
  99
 100void acpi_switch_to_modern_cphp(AcpiCpuHotplug *gpe_cpu,
 101                                CPUHotplugState *cpuhp_state,
 102                                uint16_t io_port)
 103{
 104    MemoryRegion *parent = pci_address_space_io(PCI_DEVICE(gpe_cpu->device));
 105
 106    memory_region_del_subregion(parent, &gpe_cpu->io);
 107    cpu_hotplug_hw_init(parent, gpe_cpu->device, cpuhp_state, io_port);
 108}
 109
 110void build_legacy_cpu_hotplug_aml(Aml *ctx, MachineState *machine,
 111                                  uint16_t io_base)
 112{
 113    Aml *dev;
 114    Aml *crs;
 115    Aml *pkg;
 116    Aml *field;
 117    Aml *method;
 118    Aml *if_ctx;
 119    Aml *else_ctx;
 120    int i, apic_idx;
 121    Aml *sb_scope = aml_scope("_SB");
 122    uint8_t madt_tmpl[8] = {0x00, 0x08, 0x00, 0x00, 0x00, 0, 0, 0};
 123    Aml *cpu_id = aml_arg(1);
 124    Aml *apic_id = aml_arg(0);
 125    Aml *cpu_on = aml_local(0);
 126    Aml *madt = aml_local(1);
 127    Aml *cpus_map = aml_name(CPU_ON_BITMAP);
 128    Aml *zero = aml_int(0);
 129    Aml *one = aml_int(1);
 130    MachineClass *mc = MACHINE_GET_CLASS(machine);
 131    const CPUArchIdList *apic_ids = mc->possible_cpu_arch_ids(machine);
 132    PCMachineState *pcms = PC_MACHINE(machine);
 133
 134    /*
 135     * _MAT method - creates an madt apic buffer
 136     * apic_id = Arg0 = Local APIC ID
 137     * cpu_id  = Arg1 = Processor ID
 138     * cpu_on = Local0 = CPON flag for this cpu
 139     * madt = Local1 = Buffer (in madt apic form) to return
 140     */
 141    method = aml_method(CPU_MAT_METHOD, 2, AML_NOTSERIALIZED);
 142    aml_append(method,
 143        aml_store(aml_derefof(aml_index(cpus_map, apic_id)), cpu_on));
 144    aml_append(method,
 145        aml_store(aml_buffer(sizeof(madt_tmpl), madt_tmpl), madt));
 146    /* Update the processor id, lapic id, and enable/disable status */
 147    aml_append(method, aml_store(cpu_id, aml_index(madt, aml_int(2))));
 148    aml_append(method, aml_store(apic_id, aml_index(madt, aml_int(3))));
 149    aml_append(method, aml_store(cpu_on, aml_index(madt, aml_int(4))));
 150    aml_append(method, aml_return(madt));
 151    aml_append(sb_scope, method);
 152
 153    /*
 154     * _STA method - return ON status of cpu
 155     * apic_id = Arg0 = Local APIC ID
 156     * cpu_on = Local0 = CPON flag for this cpu
 157     */
 158    method = aml_method(CPU_STATUS_METHOD, 1, AML_NOTSERIALIZED);
 159    aml_append(method,
 160        aml_store(aml_derefof(aml_index(cpus_map, apic_id)), cpu_on));
 161    if_ctx = aml_if(cpu_on);
 162    {
 163        aml_append(if_ctx, aml_return(aml_int(0xF)));
 164    }
 165    aml_append(method, if_ctx);
 166    else_ctx = aml_else();
 167    {
 168        aml_append(else_ctx, aml_return(zero));
 169    }
 170    aml_append(method, else_ctx);
 171    aml_append(sb_scope, method);
 172
 173    method = aml_method(CPU_EJECT_METHOD, 2, AML_NOTSERIALIZED);
 174    aml_append(method, aml_sleep(200));
 175    aml_append(sb_scope, method);
 176
 177    method = aml_method(CPU_SCAN_METHOD, 0, AML_NOTSERIALIZED);
 178    {
 179        Aml *while_ctx, *if_ctx2, *else_ctx2;
 180        Aml *bus_check_evt = aml_int(1);
 181        Aml *remove_evt = aml_int(3);
 182        Aml *status_map = aml_local(5); /* Local5 = active cpu bitmap */
 183        Aml *byte = aml_local(2); /* Local2 = last read byte from bitmap */
 184        Aml *idx = aml_local(0); /* Processor ID / APIC ID iterator */
 185        Aml *is_cpu_on = aml_local(1); /* Local1 = CPON flag for cpu */
 186        Aml *status = aml_local(3); /* Local3 = active state for cpu */
 187
 188        aml_append(method, aml_store(aml_name(CPU_STATUS_MAP), status_map));
 189        aml_append(method, aml_store(zero, byte));
 190        aml_append(method, aml_store(zero, idx));
 191
 192        /* While (idx < SizeOf(CPON)) */
 193        while_ctx = aml_while(aml_lless(idx, aml_sizeof(cpus_map)));
 194        aml_append(while_ctx,
 195            aml_store(aml_derefof(aml_index(cpus_map, idx)), is_cpu_on));
 196
 197        if_ctx = aml_if(aml_and(idx, aml_int(0x07), NULL));
 198        {
 199            /* Shift down previously read bitmap byte */
 200            aml_append(if_ctx, aml_shiftright(byte, one, byte));
 201        }
 202        aml_append(while_ctx, if_ctx);
 203
 204        else_ctx = aml_else();
 205        {
 206            /* Read next byte from cpu bitmap */
 207            aml_append(else_ctx, aml_store(aml_derefof(aml_index(status_map,
 208                       aml_shiftright(idx, aml_int(3), NULL))), byte));
 209        }
 210        aml_append(while_ctx, else_ctx);
 211
 212        aml_append(while_ctx, aml_store(aml_and(byte, one, NULL), status));
 213        if_ctx = aml_if(aml_lnot(aml_equal(is_cpu_on, status)));
 214        {
 215            /* State change - update CPON with new state */
 216            aml_append(if_ctx, aml_store(status, aml_index(cpus_map, idx)));
 217            if_ctx2 = aml_if(aml_equal(status, one));
 218            {
 219                aml_append(if_ctx2,
 220                    aml_call2(AML_NOTIFY_METHOD, idx, bus_check_evt));
 221            }
 222            aml_append(if_ctx, if_ctx2);
 223            else_ctx2 = aml_else();
 224            {
 225                aml_append(else_ctx2,
 226                    aml_call2(AML_NOTIFY_METHOD, idx, remove_evt));
 227            }
 228        }
 229        aml_append(if_ctx, else_ctx2);
 230        aml_append(while_ctx, if_ctx);
 231
 232        aml_append(while_ctx, aml_increment(idx)); /* go to next cpu */
 233        aml_append(method, while_ctx);
 234    }
 235    aml_append(sb_scope, method);
 236
 237    /* The current AML generator can cover the APIC ID range [0..255],
 238     * inclusive, for VCPU hotplug. */
 239    QEMU_BUILD_BUG_ON(ACPI_CPU_HOTPLUG_ID_LIMIT > 256);
 240    if (pcms->apic_id_limit > ACPI_CPU_HOTPLUG_ID_LIMIT) {
 241        error_report("max_cpus is too large. APIC ID of last CPU is %u",
 242                     pcms->apic_id_limit - 1);
 243        exit(1);
 244    }
 245
 246    /* create PCI0.PRES device and its _CRS to reserve CPU hotplug MMIO */
 247    dev = aml_device("PCI0." stringify(CPU_HOTPLUG_RESOURCE_DEVICE));
 248    aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A06")));
 249    aml_append(dev,
 250        aml_name_decl("_UID", aml_string("CPU Hotplug resources"))
 251    );
 252    /* device present, functioning, decoding, not shown in UI */
 253    aml_append(dev, aml_name_decl("_STA", aml_int(0xB)));
 254    crs = aml_resource_template();
 255    aml_append(crs,
 256        aml_io(AML_DECODE16, io_base, io_base, 1, ACPI_GPE_PROC_LEN)
 257    );
 258    aml_append(dev, aml_name_decl("_CRS", crs));
 259    aml_append(sb_scope, dev);
 260    /* declare CPU hotplug MMIO region and PRS field to access it */
 261    aml_append(sb_scope, aml_operation_region(
 262        "PRST", AML_SYSTEM_IO, aml_int(io_base), ACPI_GPE_PROC_LEN));
 263    field = aml_field("PRST", AML_BYTE_ACC, AML_NOLOCK, AML_PRESERVE);
 264    aml_append(field, aml_named_field("PRS", 256));
 265    aml_append(sb_scope, field);
 266
 267    /* build Processor object for each processor */
 268    for (i = 0; i < apic_ids->len; i++) {
 269        int apic_id = apic_ids->cpus[i].arch_id;
 270
 271        assert(apic_id < ACPI_CPU_HOTPLUG_ID_LIMIT);
 272
 273        dev = aml_processor(i, 0, 0, "CP%.02X", apic_id);
 274
 275        method = aml_method("_MAT", 0, AML_NOTSERIALIZED);
 276        aml_append(method,
 277            aml_return(aml_call2(CPU_MAT_METHOD, aml_int(apic_id), aml_int(i))
 278        ));
 279        aml_append(dev, method);
 280
 281        method = aml_method("_STA", 0, AML_NOTSERIALIZED);
 282        aml_append(method,
 283            aml_return(aml_call1(CPU_STATUS_METHOD, aml_int(apic_id))));
 284        aml_append(dev, method);
 285
 286        method = aml_method("_EJ0", 1, AML_NOTSERIALIZED);
 287        aml_append(method,
 288            aml_return(aml_call2(CPU_EJECT_METHOD, aml_int(apic_id),
 289                aml_arg(0)))
 290        );
 291        aml_append(dev, method);
 292
 293        aml_append(sb_scope, dev);
 294    }
 295
 296    /* build this code:
 297     *   Method(NTFY, 2) {If (LEqual(Arg0, 0x00)) {Notify(CP00, Arg1)} ...}
 298     */
 299    /* Arg0 = APIC ID */
 300    method = aml_method(AML_NOTIFY_METHOD, 2, AML_NOTSERIALIZED);
 301    for (i = 0; i < apic_ids->len; i++) {
 302        int apic_id = apic_ids->cpus[i].arch_id;
 303
 304        if_ctx = aml_if(aml_equal(aml_arg(0), aml_int(apic_id)));
 305        aml_append(if_ctx,
 306            aml_notify(aml_name("CP%.02X", apic_id), aml_arg(1))
 307        );
 308        aml_append(method, if_ctx);
 309    }
 310    aml_append(sb_scope, method);
 311
 312    /* build "Name(CPON, Package() { One, One, ..., Zero, Zero, ... })"
 313     *
 314     * Note: The ability to create variable-sized packages was first
 315     * introduced in ACPI 2.0. ACPI 1.0 only allowed fixed-size packages
 316     * ith up to 255 elements. Windows guests up to win2k8 fail when
 317     * VarPackageOp is used.
 318     */
 319    pkg = pcms->apic_id_limit <= 255 ? aml_package(pcms->apic_id_limit) :
 320                                       aml_varpackage(pcms->apic_id_limit);
 321
 322    for (i = 0, apic_idx = 0; i < apic_ids->len; i++) {
 323        int apic_id = apic_ids->cpus[i].arch_id;
 324
 325        for (; apic_idx < apic_id; apic_idx++) {
 326            aml_append(pkg, aml_int(0));
 327        }
 328        aml_append(pkg, aml_int(apic_ids->cpus[i].cpu ? 1 : 0));
 329        apic_idx = apic_id + 1;
 330    }
 331    aml_append(sb_scope, aml_name_decl(CPU_ON_BITMAP, pkg));
 332    aml_append(ctx, sb_scope);
 333
 334    method = aml_method("\\_GPE._E02", 0, AML_NOTSERIALIZED);
 335    aml_append(method, aml_call0("\\_SB." CPU_SCAN_METHOD));
 336    aml_append(ctx, method);
 337}
 338