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