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(HotplugHandler *hotplug_dev,
  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     acpi_send_event(DEVICE(hotplug_dev), ACPI_CPU_HOTPLUG_STATUS);
  73 }
  74
  75 void legacy_acpi_cpu_hotplug_init(MemoryRegion *parent, Object *owner,
  76                                   AcpiCpuHotplug *gpe_cpu, uint16_t base)
  77 {
  78     CPUState *cpu;
  79
  80     CPU_FOREACH(cpu) {
  81         acpi_set_cpu_present_bit(gpe_cpu, cpu, &error_abort);
  82     }
  83     memory_region_init_io(&gpe_cpu->io, owner, &AcpiCpuHotplug_ops,
  84                           gpe_cpu, "acpi-cpu-hotplug", ACPI_GPE_PROC_LEN);
  85     memory_region_add_subregion(parent, base, &gpe_cpu->io);
  86 }
  87
  88 void build_legacy_cpu_hotplug_aml(Aml *ctx, MachineState *machine,
  89                                   uint16_t io_base)
  90 {
  91     Aml *dev;
  92     Aml *crs;
  93     Aml *pkg;
  94     Aml *field;
  95     Aml *method;
  96     Aml *if_ctx;
  97     Aml *else_ctx;
  98     int i, apic_idx;
  99     Aml *sb_scope = aml_scope("_SB");
 100     uint8_t madt_tmpl[8] = {0x00, 0x08, 0x00, 0x00, 0x00, 0, 0, 0};
 101     Aml *cpu_id = aml_arg(1);
 102     Aml *apic_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      * apic_id = Arg0 = Local APIC ID
 115      * cpu_id  = Arg1 = Processor ID
 116      * cpu_on = Local0 = CPON flag for this cpu
 117      * madt = Local1 = Buffer (in madt apic form) to return
 118      */
 119     method = aml_method(CPU_MAT_METHOD, 2, AML_NOTSERIALIZED);
 120     aml_append(method,
 121         aml_store(aml_derefof(aml_index(cpus_map, apic_id)), cpu_on));
 122     aml_append(method,
 123         aml_store(aml_buffer(sizeof(madt_tmpl), madt_tmpl), madt));
 124     /* Update the processor id, lapic id, and enable/disable status */
 125     aml_append(method, aml_store(cpu_id, aml_index(madt, aml_int(2))));
 126     aml_append(method, aml_store(apic_id, aml_index(madt, aml_int(3))));
 127     aml_append(method, aml_store(cpu_on, aml_index(madt, aml_int(4))));
 128     aml_append(method, aml_return(madt));
 129     aml_append(sb_scope, method);
 130
 131     /*
 132      * _STA method - return ON status of cpu
 133      * apic_id = Arg0 = Local APIC ID
 134      * cpu_on = Local0 = CPON flag for this cpu
 135      */
 136     method = aml_method(CPU_STATUS_METHOD, 1, AML_NOTSERIALIZED);
 137     aml_append(method,
 138         aml_store(aml_derefof(aml_index(cpus_map, apic_id)), cpu_on));
 139     if_ctx = aml_if(cpu_on);
 140     {
 141         aml_append(if_ctx, aml_return(aml_int(0xF)));
 142     }
 143     aml_append(method, if_ctx);
 144     else_ctx = aml_else();
 145     {
 146         aml_append(else_ctx, aml_return(zero));
 147     }
 148     aml_append(method, else_ctx);
 149     aml_append(sb_scope, method);
 150
 151     method = aml_method(CPU_EJECT_METHOD, 2, AML_NOTSERIALIZED);
 152     aml_append(method, aml_sleep(200));
 153     aml_append(sb_scope, method);
 154
 155     method = aml_method(CPU_SCAN_METHOD, 0, AML_NOTSERIALIZED);
 156     {
 157         Aml *while_ctx, *if_ctx2, *else_ctx2;
 158         Aml *bus_check_evt = aml_int(1);
 159         Aml *remove_evt = aml_int(3);
 160         Aml *status_map = aml_local(5); /* Local5 = active cpu bitmap */
 161         Aml *byte = aml_local(2); /* Local2 = last read byte from bitmap */
 162         Aml *idx = aml_local(0); /* Processor ID / APIC ID iterator */
 163         Aml *is_cpu_on = aml_local(1); /* Local1 = CPON flag for cpu */
 164         Aml *status = aml_local(3); /* Local3 = active state for cpu */
 165
 166         aml_append(method, aml_store(aml_name(CPU_STATUS_MAP), status_map));
 167         aml_append(method, aml_store(zero, byte));
 168         aml_append(method, aml_store(zero, idx));
 169
 170         /* While (idx < SizeOf(CPON)) */
 171         while_ctx = aml_while(aml_lless(idx, aml_sizeof(cpus_map)));
 172         aml_append(while_ctx,
 173             aml_store(aml_derefof(aml_index(cpus_map, idx)), is_cpu_on));
 174
 175         if_ctx = aml_if(aml_and(idx, aml_int(0x07), NULL));
 176         {
 177             /* Shift down previously read bitmap byte */
 178             aml_append(if_ctx, aml_shiftright(byte, one, byte));
 179         }
 180         aml_append(while_ctx, if_ctx);
 181
 182         else_ctx = aml_else();
 183         {
 184             /* Read next byte from cpu bitmap */
 185             aml_append(else_ctx, aml_store(aml_derefof(aml_index(status_map,
 186                        aml_shiftright(idx, aml_int(3), NULL))), byte));
 187         }
 188         aml_append(while_ctx, else_ctx);
 189
 190         aml_append(while_ctx, aml_store(aml_and(byte, one, NULL), status));
 191         if_ctx = aml_if(aml_lnot(aml_equal(is_cpu_on, status)));
 192         {
 193             /* State change - update CPON with new state */
 194             aml_append(if_ctx, aml_store(status, aml_index(cpus_map, idx)));
 195             if_ctx2 = aml_if(aml_equal(status, one));
 196             {
 197                 aml_append(if_ctx2,
 198                     aml_call2(AML_NOTIFY_METHOD, idx, bus_check_evt));
 199             }
 200             aml_append(if_ctx, if_ctx2);
 201             else_ctx2 = aml_else();
 202             {
 203                 aml_append(else_ctx2,
 204                     aml_call2(AML_NOTIFY_METHOD, idx, remove_evt));
 205             }
 206         }
 207         aml_append(if_ctx, else_ctx2);
 208         aml_append(while_ctx, if_ctx);
 209
 210         aml_append(while_ctx, aml_increment(idx)); /* go to next cpu */
 211         aml_append(method, while_ctx);
 212     }
 213     aml_append(sb_scope, method);
 214
 215     /* The current AML generator can cover the APIC ID range [0..255],
 216      * inclusive, for VCPU hotplug. */
 217     QEMU_BUILD_BUG_ON(ACPI_CPU_HOTPLUG_ID_LIMIT > 256);
 218     g_assert(pcms->apic_id_limit <= ACPI_CPU_HOTPLUG_ID_LIMIT);
 219
 220     /* create PCI0.PRES device and its _CRS to reserve CPU hotplug MMIO */
 221     dev = aml_device("PCI0." stringify(CPU_HOTPLUG_RESOURCE_DEVICE));
 222     aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A06")));
 223     aml_append(dev,
 224         aml_name_decl("_UID", aml_string("CPU Hotplug resources"))
 225     );
 226     /* device present, functioning, decoding, not shown in UI */
 227     aml_append(dev, aml_name_decl("_STA", aml_int(0xB)));
 228     crs = aml_resource_template();
 229     aml_append(crs,
 230         aml_io(AML_DECODE16, io_base, io_base, 1, ACPI_GPE_PROC_LEN)
 231     );
 232     aml_append(dev, aml_name_decl("_CRS", crs));
 233     aml_append(sb_scope, dev);
 234     /* declare CPU hotplug MMIO region and PRS field to access it */
 235     aml_append(sb_scope, aml_operation_region(
 236         "PRST", AML_SYSTEM_IO, aml_int(io_base), ACPI_GPE_PROC_LEN));
 237     field = aml_field("PRST", AML_BYTE_ACC, AML_NOLOCK, AML_PRESERVE);
 238     aml_append(field, aml_named_field("PRS", 256));
 239     aml_append(sb_scope, field);
 240
 241     /* build Processor object for each processor */
 242     for (i = 0; i < apic_ids->len; i++) {
 243         int apic_id = apic_ids->cpus[i].arch_id;
 244
 245         assert(apic_id < ACPI_CPU_HOTPLUG_ID_LIMIT);
 246
 247         dev = aml_processor(i, 0, 0, "CP%.02X", apic_id);
 248
 249         method = aml_method("_MAT", 0, AML_NOTSERIALIZED);
 250         aml_append(method,
 251             aml_return(aml_call2(CPU_MAT_METHOD, aml_int(apic_id), aml_int(i))
 252         ));
 253         aml_append(dev, method);
 254
 255         method = aml_method("_STA", 0, AML_NOTSERIALIZED);
 256         aml_append(method,
 257             aml_return(aml_call1(CPU_STATUS_METHOD, aml_int(apic_id))));
 258         aml_append(dev, method);
 259
 260         method = aml_method("_EJ0", 1, AML_NOTSERIALIZED);
 261         aml_append(method,
 262             aml_return(aml_call2(CPU_EJECT_METHOD, aml_int(apic_id),
 263                 aml_arg(0)))
 264         );
 265         aml_append(dev, method);
 266
 267         aml_append(sb_scope, dev);
 268     }
 269
 270     /* build this code:
 271      *   Method(NTFY, 2) {If (LEqual(Arg0, 0x00)) {Notify(CP00, Arg1)} ...}
 272      */
 273     /* Arg0 = APIC ID */
 274     method = aml_method(AML_NOTIFY_METHOD, 2, AML_NOTSERIALIZED);
 275     for (i = 0; i < apic_ids->len; i++) {
 276         int apic_id = apic_ids->cpus[i].arch_id;
 277
 278         if_ctx = aml_if(aml_equal(aml_arg(0), aml_int(apic_id)));
 279         aml_append(if_ctx,
 280             aml_notify(aml_name("CP%.02X", apic_id), aml_arg(1))
 281         );
 282         aml_append(method, if_ctx);
 283     }
 284     aml_append(sb_scope, method);
 285
 286     /* build "Name(CPON, Package() { One, One, ..., Zero, Zero, ... })"
 287      *
 288      * Note: The ability to create variable-sized packages was first
 289      * introduced in ACPI 2.0. ACPI 1.0 only allowed fixed-size packages
 290      * ith up to 255 elements. Windows guests up to win2k8 fail when
 291      * VarPackageOp is used.
 292      */
 293     pkg = pcms->apic_id_limit <= 255 ? aml_package(pcms->apic_id_limit) :
 294                                        aml_varpackage(pcms->apic_id_limit);
 295
 296     for (i = 0, apic_idx = 0; i < apic_ids->len; i++) {
 297         int apic_id = apic_ids->cpus[i].arch_id;
 298
 299         for (; apic_idx < apic_id; apic_idx++) {
 300             aml_append(pkg, aml_int(0));
 301         }
 302         aml_append(pkg, aml_int(apic_ids->cpus[i].cpu ? 1 : 0));
 303         apic_idx = apic_id + 1;
 304     }
 305     aml_append(sb_scope, aml_name_decl(CPU_ON_BITMAP, pkg));
 306     g_free(apic_ids);
 307
 308     aml_append(ctx, sb_scope);
 309
 310     method = aml_method("\\_GPE._E02", 0, AML_NOTSERIALIZED);
 311     aml_append(method, aml_call0("\\_SB." CPU_SCAN_METHOD));
 312     aml_append(ctx, method);
 313 }