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 "qapi/error.h"
  16 #include "qom/cpu.h"
  17 #include "hw/i386/pc.h"
  18
  19 #define CPU_EJECT_METHOD "CPEJ"
  20 #define CPU_MAT_METHOD "CPMA"
  21 #define CPU_ON_BITMAP "CPON"
  22 #define CPU_STATUS_METHOD "CPST"
  23 #define CPU_STATUS_MAP "PRS"
  24 #define CPU_SCAN_METHOD "PRSC"
  25
  26 static uint64_t cpu_status_read(void *opaque, hwaddr addr, unsigned int size)
  27 {
  28     AcpiCpuHotplug *cpus = opaque;
  29     uint64_t val = cpus->sts[addr];
  30
  31     return val;
  32 }
  33
  34 static void cpu_status_write(void *opaque, hwaddr addr, uint64_t data,
  35                              unsigned int size)
  36 {
  37     /* firmware never used to write in CPU present bitmap so use
  38        this fact as means to switch QEMU into modern CPU hotplug
  39        mode by writing 0 at the beginning of legacy CPU bitmap
  40      */
  41     if (addr == 0 && data == 0) {
  42         AcpiCpuHotplug *cpus = opaque;
  43         object_property_set_bool(cpus->device, false, "cpu-hotplug-legacy",
  44                                  &error_abort);
  45     }
  46 }
  47
  48 static const MemoryRegionOps AcpiCpuHotplug_ops = {
  49     .read = cpu_status_read,
  50     .write = cpu_status_write,
  51     .endianness = DEVICE_LITTLE_ENDIAN,
  52     .valid = {
  53         .min_access_size = 1,
  54         .max_access_size = 1,
  55     },
  56 };
  57
  58 static void acpi_set_cpu_present_bit(AcpiCpuHotplug *g, CPUState *cpu,
  59                                      Error **errp)
  60 {
  61     CPUClass *k = CPU_GET_CLASS(cpu);
  62     int64_t cpu_id;
  63
  64     cpu_id = k->get_arch_id(cpu);
  65     if ((cpu_id / 8) >= ACPI_GPE_PROC_LEN) {
  66         error_setg(errp, "acpi: invalid cpu id: %" PRIi64, cpu_id);
  67         return;
  68     }
  69
  70     g->sts[cpu_id / 8] |= (1 << (cpu_id % 8));
  71 }
  72
  73 void legacy_acpi_cpu_plug_cb(HotplugHandler *hotplug_dev,
  74                              AcpiCpuHotplug *g, DeviceState *dev, Error **errp)
  75 {
  76     acpi_set_cpu_present_bit(g, CPU(dev), errp);
  77     if (*errp != NULL) {
  78         return;
  79     }
  80     acpi_send_event(DEVICE(hotplug_dev), ACPI_CPU_HOTPLUG_STATUS);
  81 }
  82
  83 void legacy_acpi_cpu_hotplug_init(MemoryRegion *parent, Object *owner,
  84                                   AcpiCpuHotplug *gpe_cpu, uint16_t base)
  85 {
  86     CPUState *cpu;
  87
  88     CPU_FOREACH(cpu) {
  89         acpi_set_cpu_present_bit(gpe_cpu, cpu, &error_abort);
  90     }
  91     memory_region_init_io(&gpe_cpu->io, owner, &AcpiCpuHotplug_ops,
  92                           gpe_cpu, "acpi-cpu-hotplug", ACPI_GPE_PROC_LEN);
  93     memory_region_add_subregion(parent, base, &gpe_cpu->io);
  94     gpe_cpu->device = owner;
  95 }
  96
  97 void acpi_switch_to_modern_cphp(AcpiCpuHotplug *gpe_cpu,
  98                                 CPUHotplugState *cpuhp_state,
  99                                 uint16_t io_port)
 100 {
 101     MemoryRegion *parent = pci_address_space_io(PCI_DEVICE(gpe_cpu->device));
 102
 103     memory_region_del_subregion(parent, &gpe_cpu->io);
 104     cpu_hotplug_hw_init(parent, gpe_cpu->device, cpuhp_state, io_port);
 105 }
 106
 107 void build_legacy_cpu_hotplug_aml(Aml *ctx, MachineState *machine,
 108                                   uint16_t io_base)
 109 {
 110     Aml *dev;
 111     Aml *crs;
 112     Aml *pkg;
 113     Aml *field;
 114     Aml *method;
 115     Aml *if_ctx;
 116     Aml *else_ctx;
 117     int i, apic_idx;
 118     Aml *sb_scope = aml_scope("_SB");
 119     uint8_t madt_tmpl[8] = {0x00, 0x08, 0x00, 0x00, 0x00, 0, 0, 0};
 120     Aml *cpu_id = aml_arg(1);
 121     Aml *apic_id = aml_arg(0);
 122     Aml *cpu_on = aml_local(0);
 123     Aml *madt = aml_local(1);
 124     Aml *cpus_map = aml_name(CPU_ON_BITMAP);
 125     Aml *zero = aml_int(0);
 126     Aml *one = aml_int(1);
 127     MachineClass *mc = MACHINE_GET_CLASS(machine);
 128     CPUArchIdList *apic_ids = mc->possible_cpu_arch_ids(machine);
 129     PCMachineState *pcms = PC_MACHINE(machine);
 130
 131     /*
 132      * _MAT method - creates an madt apic buffer
 133      * apic_id = Arg0 = Local APIC ID
 134      * cpu_id  = Arg1 = Processor ID
 135      * cpu_on = Local0 = CPON flag for this cpu
 136      * madt = Local1 = Buffer (in madt apic form) to return
 137      */
 138     method = aml_method(CPU_MAT_METHOD, 2, AML_NOTSERIALIZED);
 139     aml_append(method,
 140         aml_store(aml_derefof(aml_index(cpus_map, apic_id)), cpu_on));
 141     aml_append(method,
 142         aml_store(aml_buffer(sizeof(madt_tmpl), madt_tmpl), madt));
 143     /* Update the processor id, lapic id, and enable/disable status */
 144     aml_append(method, aml_store(cpu_id, aml_index(madt, aml_int(2))));
 145     aml_append(method, aml_store(apic_id, aml_index(madt, aml_int(3))));
 146     aml_append(method, aml_store(cpu_on, aml_index(madt, aml_int(4))));
 147     aml_append(method, aml_return(madt));
 148     aml_append(sb_scope, method);
 149
 150     /*
 151      * _STA method - return ON status of cpu
 152      * apic_id = Arg0 = Local APIC ID
 153      * cpu_on = Local0 = CPON flag for this cpu
 154      */
 155     method = aml_method(CPU_STATUS_METHOD, 1, AML_NOTSERIALIZED);
 156     aml_append(method,
 157         aml_store(aml_derefof(aml_index(cpus_map, apic_id)), cpu_on));
 158     if_ctx = aml_if(cpu_on);
 159     {
 160         aml_append(if_ctx, aml_return(aml_int(0xF)));
 161     }
 162     aml_append(method, if_ctx);
 163     else_ctx = aml_else();
 164     {
 165         aml_append(else_ctx, aml_return(zero));
 166     }
 167     aml_append(method, else_ctx);
 168     aml_append(sb_scope, method);
 169
 170     method = aml_method(CPU_EJECT_METHOD, 2, AML_NOTSERIALIZED);
 171     aml_append(method, aml_sleep(200));
 172     aml_append(sb_scope, method);
 173
 174     method = aml_method(CPU_SCAN_METHOD, 0, AML_NOTSERIALIZED);
 175     {
 176         Aml *while_ctx, *if_ctx2, *else_ctx2;
 177         Aml *bus_check_evt = aml_int(1);
 178         Aml *remove_evt = aml_int(3);
 179         Aml *status_map = aml_local(5); /* Local5 = active cpu bitmap */
 180         Aml *byte = aml_local(2); /* Local2 = last read byte from bitmap */
 181         Aml *idx = aml_local(0); /* Processor ID / APIC ID iterator */
 182         Aml *is_cpu_on = aml_local(1); /* Local1 = CPON flag for cpu */
 183         Aml *status = aml_local(3); /* Local3 = active state for cpu */
 184
 185         aml_append(method, aml_store(aml_name(CPU_STATUS_MAP), status_map));
 186         aml_append(method, aml_store(zero, byte));
 187         aml_append(method, aml_store(zero, idx));
 188
 189         /* While (idx < SizeOf(CPON)) */
 190         while_ctx = aml_while(aml_lless(idx, aml_sizeof(cpus_map)));
 191         aml_append(while_ctx,
 192             aml_store(aml_derefof(aml_index(cpus_map, idx)), is_cpu_on));
 193
 194         if_ctx = aml_if(aml_and(idx, aml_int(0x07), NULL));
 195         {
 196             /* Shift down previously read bitmap byte */
 197             aml_append(if_ctx, aml_shiftright(byte, one, byte));
 198         }
 199         aml_append(while_ctx, if_ctx);
 200
 201         else_ctx = aml_else();
 202         {
 203             /* Read next byte from cpu bitmap */
 204             aml_append(else_ctx, aml_store(aml_derefof(aml_index(status_map,
 205                        aml_shiftright(idx, aml_int(3), NULL))), byte));
 206         }
 207         aml_append(while_ctx, else_ctx);
 208
 209         aml_append(while_ctx, aml_store(aml_and(byte, one, NULL), status));
 210         if_ctx = aml_if(aml_lnot(aml_equal(is_cpu_on, status)));
 211         {
 212             /* State change - update CPON with new state */
 213             aml_append(if_ctx, aml_store(status, aml_index(cpus_map, idx)));
 214             if_ctx2 = aml_if(aml_equal(status, one));
 215             {
 216                 aml_append(if_ctx2,
 217                     aml_call2(AML_NOTIFY_METHOD, idx, bus_check_evt));
 218             }
 219             aml_append(if_ctx, if_ctx2);
 220             else_ctx2 = aml_else();
 221             {
 222                 aml_append(else_ctx2,
 223                     aml_call2(AML_NOTIFY_METHOD, idx, remove_evt));
 224             }
 225         }
 226         aml_append(if_ctx, else_ctx2);
 227         aml_append(while_ctx, if_ctx);
 228
 229         aml_append(while_ctx, aml_increment(idx)); /* go to next cpu */
 230         aml_append(method, while_ctx);
 231     }
 232     aml_append(sb_scope, method);
 233
 234     /* The current AML generator can cover the APIC ID range [0..255],
 235      * inclusive, for VCPU hotplug. */
 236     QEMU_BUILD_BUG_ON(ACPI_CPU_HOTPLUG_ID_LIMIT > 256);
 237     g_assert(pcms->apic_id_limit <= ACPI_CPU_HOTPLUG_ID_LIMIT);
 238
 239     /* create PCI0.PRES device and its _CRS to reserve CPU hotplug MMIO */
 240     dev = aml_device("PCI0." stringify(CPU_HOTPLUG_RESOURCE_DEVICE));
 241     aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A06")));
 242     aml_append(dev,
 243         aml_name_decl("_UID", aml_string("CPU Hotplug resources"))
 244     );
 245     /* device present, functioning, decoding, not shown in UI */
 246     aml_append(dev, aml_name_decl("_STA", aml_int(0xB)));
 247     crs = aml_resource_template();
 248     aml_append(crs,
 249         aml_io(AML_DECODE16, io_base, io_base, 1, ACPI_GPE_PROC_LEN)
 250     );
 251     aml_append(dev, aml_name_decl("_CRS", crs));
 252     aml_append(sb_scope, dev);
 253     /* declare CPU hotplug MMIO region and PRS field to access it */
 254     aml_append(sb_scope, aml_operation_region(
 255         "PRST", AML_SYSTEM_IO, aml_int(io_base), ACPI_GPE_PROC_LEN));
 256     field = aml_field("PRST", AML_BYTE_ACC, AML_NOLOCK, AML_PRESERVE);
 257     aml_append(field, aml_named_field("PRS", 256));
 258     aml_append(sb_scope, field);
 259
 260     /* build Processor object for each processor */
 261     for (i = 0; i < apic_ids->len; i++) {
 262         int apic_id = apic_ids->cpus[i].arch_id;
 263
 264         assert(apic_id < ACPI_CPU_HOTPLUG_ID_LIMIT);
 265
 266         dev = aml_processor(i, 0, 0, "CP%.02X", apic_id);
 267
 268         method = aml_method("_MAT", 0, AML_NOTSERIALIZED);
 269         aml_append(method,
 270             aml_return(aml_call2(CPU_MAT_METHOD, aml_int(apic_id), aml_int(i))
 271         ));
 272         aml_append(dev, method);
 273
 274         method = aml_method("_STA", 0, AML_NOTSERIALIZED);
 275         aml_append(method,
 276             aml_return(aml_call1(CPU_STATUS_METHOD, aml_int(apic_id))));
 277         aml_append(dev, method);
 278
 279         method = aml_method("_EJ0", 1, AML_NOTSERIALIZED);
 280         aml_append(method,
 281             aml_return(aml_call2(CPU_EJECT_METHOD, aml_int(apic_id),
 282                 aml_arg(0)))
 283         );
 284         aml_append(dev, method);
 285
 286         aml_append(sb_scope, dev);
 287     }
 288
 289     /* build this code:
 290      *   Method(NTFY, 2) {If (LEqual(Arg0, 0x00)) {Notify(CP00, Arg1)} ...}
 291      */
 292     /* Arg0 = APIC ID */
 293     method = aml_method(AML_NOTIFY_METHOD, 2, AML_NOTSERIALIZED);
 294     for (i = 0; i < apic_ids->len; i++) {
 295         int apic_id = apic_ids->cpus[i].arch_id;
 296
 297         if_ctx = aml_if(aml_equal(aml_arg(0), aml_int(apic_id)));
 298         aml_append(if_ctx,
 299             aml_notify(aml_name("CP%.02X", apic_id), aml_arg(1))
 300         );
 301         aml_append(method, if_ctx);
 302     }
 303     aml_append(sb_scope, method);
 304
 305     /* build "Name(CPON, Package() { One, One, ..., Zero, Zero, ... })"
 306      *
 307      * Note: The ability to create variable-sized packages was first
 308      * introduced in ACPI 2.0. ACPI 1.0 only allowed fixed-size packages
 309      * ith up to 255 elements. Windows guests up to win2k8 fail when
 310      * VarPackageOp is used.
 311      */
 312     pkg = pcms->apic_id_limit <= 255 ? aml_package(pcms->apic_id_limit) :
 313                                        aml_varpackage(pcms->apic_id_limit);
 314
 315     for (i = 0, apic_idx = 0; i < apic_ids->len; i++) {
 316         int apic_id = apic_ids->cpus[i].arch_id;
 317
 318         for (; apic_idx < apic_id; apic_idx++) {
 319             aml_append(pkg, aml_int(0));
 320         }
 321         aml_append(pkg, aml_int(apic_ids->cpus[i].cpu ? 1 : 0));
 322         apic_idx = apic_id + 1;
 323     }
 324     aml_append(sb_scope, aml_name_decl(CPU_ON_BITMAP, pkg));
 325     g_free(apic_ids);
 326
 327     aml_append(ctx, sb_scope);
 328
 329     method = aml_method("\\_GPE._E02", 0, AML_NOTSERIALIZED);
 330     aml_append(method, aml_call0("\\_SB." CPU_SCAN_METHOD));
 331     aml_append(ctx, method);
 332 }