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