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 #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
  27 static 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
  35 static 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
  49 static 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
  59 static 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
  75 void 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
  85 void 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
 100 void 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
 110 void 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     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     g_free(apic_ids);
 333
 334     aml_append(ctx, sb_scope);
 335
 336     method = aml_method("\\_GPE._E02", 0, AML_NOTSERIALIZED);
 337     aml_append(method, aml_call0("\\_SB." CPU_SCAN_METHOD));
 338     aml_append(ctx, method);
 339 }