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/acpi/cpu_hotplug.h"
  14 #include "qapi/error.h"
  15 #include "hw/core/cpu.h"
  16 #include "hw/i386/x86.h"
  17 #include "hw/pci/pci_device.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, "cpu-hotplug-legacy", false,
  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 = 4,
  56     },
  57     .impl = {
  58         .max_access_size = 1,
  59     },
  60 };
  61
  62 static void acpi_set_cpu_present_bit(AcpiCpuHotplug *g, CPUState *cpu,
  63                                      bool *swtchd_to_modern)
  64 {
  65     CPUClass *k = CPU_GET_CLASS(cpu);
  66     int64_t cpu_id;
  67
  68     cpu_id = k->get_arch_id(cpu);
  69     if ((cpu_id / 8) >= ACPI_GPE_PROC_LEN) {
  70         object_property_set_bool(g->device, "cpu-hotplug-legacy", false,
  71                                  &error_abort);
  72         *swtchd_to_modern = true;
  73         return;
  74     }
  75
  76     *swtchd_to_modern = false;
  77     g->sts[cpu_id / 8] |= (1 << (cpu_id % 8));
  78 }
  79
  80 void legacy_acpi_cpu_plug_cb(HotplugHandler *hotplug_dev,
  81                              AcpiCpuHotplug *g, DeviceState *dev, Error **errp)
  82 {
  83     bool swtchd_to_modern;
  84     Error *local_err = NULL;
  85
  86     acpi_set_cpu_present_bit(g, CPU(dev), &swtchd_to_modern);
  87     if (swtchd_to_modern) {
  88         /* propagate the hotplug to the modern interface */
  89         hotplug_handler_plug(hotplug_dev, dev, &local_err);
  90     } else {
  91         acpi_send_event(DEVICE(hotplug_dev), ACPI_CPU_HOTPLUG_STATUS);
  92     }
  93 }
  94
  95 void legacy_acpi_cpu_hotplug_init(MemoryRegion *parent, Object *owner,
  96                                   AcpiCpuHotplug *gpe_cpu, uint16_t base)
  97 {
  98     CPUState *cpu;
  99     bool swtchd_to_modern;
 100
 101     memory_region_init_io(&gpe_cpu->io, owner, &AcpiCpuHotplug_ops,
 102                           gpe_cpu, "acpi-cpu-hotplug", ACPI_GPE_PROC_LEN);
 103     memory_region_add_subregion(parent, base, &gpe_cpu->io);
 104     gpe_cpu->device = owner;
 105
 106     CPU_FOREACH(cpu) {
 107         acpi_set_cpu_present_bit(gpe_cpu, cpu, &swtchd_to_modern);
 108     }
 109 }
 110
 111 void acpi_switch_to_modern_cphp(AcpiCpuHotplug *gpe_cpu,
 112                                 CPUHotplugState *cpuhp_state,
 113                                 uint16_t io_port)
 114 {
 115     MemoryRegion *parent = pci_address_space_io(PCI_DEVICE(gpe_cpu->device));
 116
 117     memory_region_del_subregion(parent, &gpe_cpu->io);
 118     cpu_hotplug_hw_init(parent, gpe_cpu->device, cpuhp_state, io_port);
 119 }
 120
 121 void build_legacy_cpu_hotplug_aml(Aml *ctx, MachineState *machine,
 122                                   uint16_t io_base)
 123 {
 124     Aml *dev;
 125     Aml *crs;
 126     Aml *pkg;
 127     Aml *field;
 128     Aml *method;
 129     Aml *if_ctx;
 130     Aml *else_ctx;
 131     int i, apic_idx;
 132     Aml *sb_scope = aml_scope("_SB");
 133     uint8_t madt_tmpl[8] = {0x00, 0x08, 0x00, 0x00, 0x00, 0, 0, 0};
 134     Aml *cpu_id = aml_arg(1);
 135     Aml *apic_id = aml_arg(0);
 136     Aml *cpu_on = aml_local(0);
 137     Aml *madt = aml_local(1);
 138     Aml *cpus_map = aml_name(CPU_ON_BITMAP);
 139     Aml *zero = aml_int(0);
 140     Aml *one = aml_int(1);
 141     MachineClass *mc = MACHINE_GET_CLASS(machine);
 142     const CPUArchIdList *apic_ids = mc->possible_cpu_arch_ids(machine);
 143     X86MachineState *x86ms = X86_MACHINE(machine);
 144
 145     /*
 146      * _MAT method - creates an madt apic buffer
 147      * apic_id = Arg0 = Local APIC ID
 148      * cpu_id  = Arg1 = Processor ID
 149      * cpu_on = Local0 = CPON flag for this cpu
 150      * madt = Local1 = Buffer (in madt apic form) to return
 151      */
 152     method = aml_method(CPU_MAT_METHOD, 2, AML_NOTSERIALIZED);
 153     aml_append(method,
 154         aml_store(aml_derefof(aml_index(cpus_map, apic_id)), cpu_on));
 155     aml_append(method,
 156         aml_store(aml_buffer(sizeof(madt_tmpl), madt_tmpl), madt));
 157     /* Update the processor id, lapic id, and enable/disable status */
 158     aml_append(method, aml_store(cpu_id, aml_index(madt, aml_int(2))));
 159     aml_append(method, aml_store(apic_id, aml_index(madt, aml_int(3))));
 160     aml_append(method, aml_store(cpu_on, aml_index(madt, aml_int(4))));
 161     aml_append(method, aml_return(madt));
 162     aml_append(sb_scope, method);
 163
 164     /*
 165      * _STA method - return ON status of cpu
 166      * apic_id = Arg0 = Local APIC ID
 167      * cpu_on = Local0 = CPON flag for this cpu
 168      */
 169     method = aml_method(CPU_STATUS_METHOD, 1, AML_NOTSERIALIZED);
 170     aml_append(method,
 171         aml_store(aml_derefof(aml_index(cpus_map, apic_id)), cpu_on));
 172     if_ctx = aml_if(cpu_on);
 173     {
 174         aml_append(if_ctx, aml_return(aml_int(0xF)));
 175     }
 176     aml_append(method, if_ctx);
 177     else_ctx = aml_else();
 178     {
 179         aml_append(else_ctx, aml_return(zero));
 180     }
 181     aml_append(method, else_ctx);
 182     aml_append(sb_scope, method);
 183
 184     method = aml_method(CPU_EJECT_METHOD, 2, AML_NOTSERIALIZED);
 185     aml_append(method, aml_sleep(200));
 186     aml_append(sb_scope, method);
 187
 188     method = aml_method(CPU_SCAN_METHOD, 0, AML_NOTSERIALIZED);
 189     {
 190         Aml *while_ctx, *if_ctx2, *else_ctx2;
 191         Aml *bus_check_evt = aml_int(1);
 192         Aml *remove_evt = aml_int(3);
 193         Aml *status_map = aml_local(5); /* Local5 = active cpu bitmap */
 194         Aml *byte = aml_local(2); /* Local2 = last read byte from bitmap */
 195         Aml *idx = aml_local(0); /* Processor ID / APIC ID iterator */
 196         Aml *is_cpu_on = aml_local(1); /* Local1 = CPON flag for cpu */
 197         Aml *status = aml_local(3); /* Local3 = active state for cpu */
 198
 199         aml_append(method, aml_store(aml_name(CPU_STATUS_MAP), status_map));
 200         aml_append(method, aml_store(zero, byte));
 201         aml_append(method, aml_store(zero, idx));
 202
 203         /* While (idx < SizeOf(CPON)) */
 204         while_ctx = aml_while(aml_lless(idx, aml_sizeof(cpus_map)));
 205         aml_append(while_ctx,
 206             aml_store(aml_derefof(aml_index(cpus_map, idx)), is_cpu_on));
 207
 208         if_ctx = aml_if(aml_and(idx, aml_int(0x07), NULL));
 209         {
 210             /* Shift down previously read bitmap byte */
 211             aml_append(if_ctx, aml_shiftright(byte, one, byte));
 212         }
 213         aml_append(while_ctx, if_ctx);
 214
 215         else_ctx = aml_else();
 216         {
 217             /* Read next byte from cpu bitmap */
 218             aml_append(else_ctx, aml_store(aml_derefof(aml_index(status_map,
 219                        aml_shiftright(idx, aml_int(3), NULL))), byte));
 220         }
 221         aml_append(while_ctx, else_ctx);
 222
 223         aml_append(while_ctx, aml_store(aml_and(byte, one, NULL), status));
 224         if_ctx = aml_if(aml_lnot(aml_equal(is_cpu_on, status)));
 225         {
 226             /* State change - update CPON with new state */
 227             aml_append(if_ctx, aml_store(status, aml_index(cpus_map, idx)));
 228             if_ctx2 = aml_if(aml_equal(status, one));
 229             {
 230                 aml_append(if_ctx2,
 231                     aml_call2(AML_NOTIFY_METHOD, idx, bus_check_evt));
 232             }
 233             aml_append(if_ctx, if_ctx2);
 234             else_ctx2 = aml_else();
 235             {
 236                 aml_append(else_ctx2,
 237                     aml_call2(AML_NOTIFY_METHOD, idx, remove_evt));
 238             }
 239         }
 240         aml_append(if_ctx, else_ctx2);
 241         aml_append(while_ctx, if_ctx);
 242
 243         aml_append(while_ctx, aml_increment(idx)); /* go to next cpu */
 244         aml_append(method, while_ctx);
 245     }
 246     aml_append(sb_scope, method);
 247
 248     /* The current AML generator can cover the APIC ID range [0..255],
 249      * inclusive, for VCPU hotplug. */
 250     QEMU_BUILD_BUG_ON(ACPI_CPU_HOTPLUG_ID_LIMIT > 256);
 251     if (x86ms->apic_id_limit > ACPI_CPU_HOTPLUG_ID_LIMIT) {
 252         error_report("max_cpus is too large. APIC ID of last CPU is %u",
 253                      x86ms->apic_id_limit - 1);
 254         exit(1);
 255     }
 256
 257     /* create PCI0.PRES device and its _CRS to reserve CPU hotplug MMIO */
 258     dev = aml_device("PCI0." stringify(CPU_HOTPLUG_RESOURCE_DEVICE));
 259     aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A06")));
 260     aml_append(dev,
 261         aml_name_decl("_UID", aml_string("CPU Hotplug resources"))
 262     );
 263     /* device present, functioning, decoding, not shown in UI */
 264     aml_append(dev, aml_name_decl("_STA", aml_int(0xB)));
 265     crs = aml_resource_template();
 266     aml_append(crs,
 267         aml_io(AML_DECODE16, io_base, io_base, 1, ACPI_GPE_PROC_LEN)
 268     );
 269     aml_append(dev, aml_name_decl("_CRS", crs));
 270     aml_append(sb_scope, dev);
 271     /* declare CPU hotplug MMIO region and PRS field to access it */
 272     aml_append(sb_scope, aml_operation_region(
 273         "PRST", AML_SYSTEM_IO, aml_int(io_base), ACPI_GPE_PROC_LEN));
 274     field = aml_field("PRST", AML_BYTE_ACC, AML_NOLOCK, AML_PRESERVE);
 275     aml_append(field, aml_named_field("PRS", 256));
 276     aml_append(sb_scope, field);
 277
 278     /* build Processor object for each processor */
 279     for (i = 0; i < apic_ids->len; i++) {
 280         int cpu_apic_id = apic_ids->cpus[i].arch_id;
 281
 282         assert(cpu_apic_id < ACPI_CPU_HOTPLUG_ID_LIMIT);
 283
 284         dev = aml_processor(i, 0, 0, "CP%.02X", cpu_apic_id);
 285
 286         method = aml_method("_MAT", 0, AML_NOTSERIALIZED);
 287         aml_append(method,
 288             aml_return(aml_call2(CPU_MAT_METHOD,
 289                                  aml_int(cpu_apic_id), aml_int(i))
 290         ));
 291         aml_append(dev, method);
 292
 293         method = aml_method("_STA", 0, AML_NOTSERIALIZED);
 294         aml_append(method,
 295             aml_return(aml_call1(CPU_STATUS_METHOD, aml_int(cpu_apic_id))));
 296         aml_append(dev, method);
 297
 298         method = aml_method("_EJ0", 1, AML_NOTSERIALIZED);
 299         aml_append(method,
 300             aml_return(aml_call2(CPU_EJECT_METHOD, aml_int(cpu_apic_id),
 301                 aml_arg(0)))
 302         );
 303         aml_append(dev, method);
 304
 305         aml_append(sb_scope, dev);
 306     }
 307
 308     /* build this code:
 309      *   Method(NTFY, 2) {If (LEqual(Arg0, 0x00)) {Notify(CP00, Arg1)} ...}
 310      */
 311     /* Arg0 = APIC ID */
 312     method = aml_method(AML_NOTIFY_METHOD, 2, AML_NOTSERIALIZED);
 313     for (i = 0; i < apic_ids->len; i++) {
 314         int cpu_apic_id = apic_ids->cpus[i].arch_id;
 315
 316         if_ctx = aml_if(aml_equal(aml_arg(0), aml_int(cpu_apic_id)));
 317         aml_append(if_ctx,
 318             aml_notify(aml_name("CP%.02X", cpu_apic_id), aml_arg(1))
 319         );
 320         aml_append(method, if_ctx);
 321     }
 322     aml_append(sb_scope, method);
 323
 324     /* build "Name(CPON, Package() { One, One, ..., Zero, Zero, ... })"
 325      *
 326      * Note: The ability to create variable-sized packages was first
 327      * introduced in ACPI 2.0. ACPI 1.0 only allowed fixed-size packages
 328      * ith up to 255 elements. Windows guests up to win2k8 fail when
 329      * VarPackageOp is used.
 330      */
 331     pkg = x86ms->apic_id_limit <= 255 ? aml_package(x86ms->apic_id_limit) :
 332                                         aml_varpackage(x86ms->apic_id_limit);
 333
 334     for (i = 0, apic_idx = 0; i < apic_ids->len; i++) {
 335         int cpu_apic_id = apic_ids->cpus[i].arch_id;
 336
 337         for (; apic_idx < cpu_apic_id; apic_idx++) {
 338             aml_append(pkg, aml_int(0));
 339         }
 340         aml_append(pkg, aml_int(apic_ids->cpus[i].cpu ? 1 : 0));
 341         apic_idx = cpu_apic_id + 1;
 342     }
 343     aml_append(sb_scope, aml_name_decl(CPU_ON_BITMAP, pkg));
 344     aml_append(ctx, sb_scope);
 345
 346     method = aml_method("\\_GPE._E02", 0, AML_NOTSERIALIZED);
 347     aml_append(method, aml_call0("\\_SB." CPU_SCAN_METHOD));
 348     aml_append(ctx, method);
 349 }