cpu_hotplug.c (11713B)
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 "hw/pci/pci.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 = 1, 56 }, 57 }; 58 59 static void acpi_set_cpu_present_bit(AcpiCpuHotplug *g, CPUState *cpu) 60 { 61 CPUClass *k = CPU_GET_CLASS(cpu); 62 int64_t cpu_id; 63 64 cpu_id = k->get_arch_id(cpu); 65 if ((cpu_id / 8) >= ACPI_GPE_PROC_LEN) { 66 object_property_set_bool(g->device, "cpu-hotplug-legacy", false, 67 &error_abort); 68 return; 69 } 70 71 g->sts[cpu_id / 8] |= (1 << (cpu_id % 8)); 72 } 73 74 void legacy_acpi_cpu_plug_cb(HotplugHandler *hotplug_dev, 75 AcpiCpuHotplug *g, DeviceState *dev, Error **errp) 76 { 77 acpi_set_cpu_present_bit(g, CPU(dev)); 78 acpi_send_event(DEVICE(hotplug_dev), ACPI_CPU_HOTPLUG_STATUS); 79 } 80 81 void legacy_acpi_cpu_hotplug_init(MemoryRegion *parent, Object *owner, 82 AcpiCpuHotplug *gpe_cpu, uint16_t base) 83 { 84 CPUState *cpu; 85 86 memory_region_init_io(&gpe_cpu->io, owner, &AcpiCpuHotplug_ops, 87 gpe_cpu, "acpi-cpu-hotplug", ACPI_GPE_PROC_LEN); 88 memory_region_add_subregion(parent, base, &gpe_cpu->io); 89 gpe_cpu->device = owner; 90 91 CPU_FOREACH(cpu) { 92 acpi_set_cpu_present_bit(gpe_cpu, cpu); 93 } 94 } 95 96 void acpi_switch_to_modern_cphp(AcpiCpuHotplug *gpe_cpu, 97 CPUHotplugState *cpuhp_state, 98 uint16_t io_port) 99 { 100 MemoryRegion *parent = pci_address_space_io(PCI_DEVICE(gpe_cpu->device)); 101 102 memory_region_del_subregion(parent, &gpe_cpu->io); 103 cpu_hotplug_hw_init(parent, gpe_cpu->device, cpuhp_state, io_port); 104 } 105 106 void build_legacy_cpu_hotplug_aml(Aml *ctx, MachineState *machine, 107 uint16_t io_base) 108 { 109 Aml *dev; 110 Aml *crs; 111 Aml *pkg; 112 Aml *field; 113 Aml *method; 114 Aml *if_ctx; 115 Aml *else_ctx; 116 int i, apic_idx; 117 Aml *sb_scope = aml_scope("_SB"); 118 uint8_t madt_tmpl[8] = {0x00, 0x08, 0x00, 0x00, 0x00, 0, 0, 0}; 119 Aml *cpu_id = aml_arg(1); 120 Aml *apic_id = aml_arg(0); 121 Aml *cpu_on = aml_local(0); 122 Aml *madt = aml_local(1); 123 Aml *cpus_map = aml_name(CPU_ON_BITMAP); 124 Aml *zero = aml_int(0); 125 Aml *one = aml_int(1); 126 MachineClass *mc = MACHINE_GET_CLASS(machine); 127 const CPUArchIdList *apic_ids = mc->possible_cpu_arch_ids(machine); 128 X86MachineState *x86ms = X86_MACHINE(machine); 129 130 /* 131 * _MAT method - creates an madt apic buffer 132 * apic_id = Arg0 = Local APIC ID 133 * cpu_id = Arg1 = Processor ID 134 * cpu_on = Local0 = CPON flag for this cpu 135 * madt = Local1 = Buffer (in madt apic form) to return 136 */ 137 method = aml_method(CPU_MAT_METHOD, 2, AML_NOTSERIALIZED); 138 aml_append(method, 139 aml_store(aml_derefof(aml_index(cpus_map, apic_id)), cpu_on)); 140 aml_append(method, 141 aml_store(aml_buffer(sizeof(madt_tmpl), madt_tmpl), madt)); 142 /* Update the processor id, lapic id, and enable/disable status */ 143 aml_append(method, aml_store(cpu_id, aml_index(madt, aml_int(2)))); 144 aml_append(method, aml_store(apic_id, aml_index(madt, aml_int(3)))); 145 aml_append(method, aml_store(cpu_on, aml_index(madt, aml_int(4)))); 146 aml_append(method, aml_return(madt)); 147 aml_append(sb_scope, method); 148 149 /* 150 * _STA method - return ON status of cpu 151 * apic_id = Arg0 = Local APIC ID 152 * cpu_on = Local0 = CPON flag for this cpu 153 */ 154 method = aml_method(CPU_STATUS_METHOD, 1, AML_NOTSERIALIZED); 155 aml_append(method, 156 aml_store(aml_derefof(aml_index(cpus_map, apic_id)), cpu_on)); 157 if_ctx = aml_if(cpu_on); 158 { 159 aml_append(if_ctx, aml_return(aml_int(0xF))); 160 } 161 aml_append(method, if_ctx); 162 else_ctx = aml_else(); 163 { 164 aml_append(else_ctx, aml_return(zero)); 165 } 166 aml_append(method, else_ctx); 167 aml_append(sb_scope, method); 168 169 method = aml_method(CPU_EJECT_METHOD, 2, AML_NOTSERIALIZED); 170 aml_append(method, aml_sleep(200)); 171 aml_append(sb_scope, method); 172 173 method = aml_method(CPU_SCAN_METHOD, 0, AML_NOTSERIALIZED); 174 { 175 Aml *while_ctx, *if_ctx2, *else_ctx2; 176 Aml *bus_check_evt = aml_int(1); 177 Aml *remove_evt = aml_int(3); 178 Aml *status_map = aml_local(5); /* Local5 = active cpu bitmap */ 179 Aml *byte = aml_local(2); /* Local2 = last read byte from bitmap */ 180 Aml *idx = aml_local(0); /* Processor ID / APIC ID iterator */ 181 Aml *is_cpu_on = aml_local(1); /* Local1 = CPON flag for cpu */ 182 Aml *status = aml_local(3); /* Local3 = active state for cpu */ 183 184 aml_append(method, aml_store(aml_name(CPU_STATUS_MAP), status_map)); 185 aml_append(method, aml_store(zero, byte)); 186 aml_append(method, aml_store(zero, idx)); 187 188 /* While (idx < SizeOf(CPON)) */ 189 while_ctx = aml_while(aml_lless(idx, aml_sizeof(cpus_map))); 190 aml_append(while_ctx, 191 aml_store(aml_derefof(aml_index(cpus_map, idx)), is_cpu_on)); 192 193 if_ctx = aml_if(aml_and(idx, aml_int(0x07), NULL)); 194 { 195 /* Shift down previously read bitmap byte */ 196 aml_append(if_ctx, aml_shiftright(byte, one, byte)); 197 } 198 aml_append(while_ctx, if_ctx); 199 200 else_ctx = aml_else(); 201 { 202 /* Read next byte from cpu bitmap */ 203 aml_append(else_ctx, aml_store(aml_derefof(aml_index(status_map, 204 aml_shiftright(idx, aml_int(3), NULL))), byte)); 205 } 206 aml_append(while_ctx, else_ctx); 207 208 aml_append(while_ctx, aml_store(aml_and(byte, one, NULL), status)); 209 if_ctx = aml_if(aml_lnot(aml_equal(is_cpu_on, status))); 210 { 211 /* State change - update CPON with new state */ 212 aml_append(if_ctx, aml_store(status, aml_index(cpus_map, idx))); 213 if_ctx2 = aml_if(aml_equal(status, one)); 214 { 215 aml_append(if_ctx2, 216 aml_call2(AML_NOTIFY_METHOD, idx, bus_check_evt)); 217 } 218 aml_append(if_ctx, if_ctx2); 219 else_ctx2 = aml_else(); 220 { 221 aml_append(else_ctx2, 222 aml_call2(AML_NOTIFY_METHOD, idx, remove_evt)); 223 } 224 } 225 aml_append(if_ctx, else_ctx2); 226 aml_append(while_ctx, if_ctx); 227 228 aml_append(while_ctx, aml_increment(idx)); /* go to next cpu */ 229 aml_append(method, while_ctx); 230 } 231 aml_append(sb_scope, method); 232 233 /* The current AML generator can cover the APIC ID range [0..255], 234 * inclusive, for VCPU hotplug. */ 235 QEMU_BUILD_BUG_ON(ACPI_CPU_HOTPLUG_ID_LIMIT > 256); 236 if (x86ms->apic_id_limit > ACPI_CPU_HOTPLUG_ID_LIMIT) { 237 error_report("max_cpus is too large. APIC ID of last CPU is %u", 238 x86ms->apic_id_limit - 1); 239 exit(1); 240 } 241 242 /* create PCI0.PRES device and its _CRS to reserve CPU hotplug MMIO */ 243 dev = aml_device("PCI0." stringify(CPU_HOTPLUG_RESOURCE_DEVICE)); 244 aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A06"))); 245 aml_append(dev, 246 aml_name_decl("_UID", aml_string("CPU Hotplug resources")) 247 ); 248 /* device present, functioning, decoding, not shown in UI */ 249 aml_append(dev, aml_name_decl("_STA", aml_int(0xB))); 250 crs = aml_resource_template(); 251 aml_append(crs, 252 aml_io(AML_DECODE16, io_base, io_base, 1, ACPI_GPE_PROC_LEN) 253 ); 254 aml_append(dev, aml_name_decl("_CRS", crs)); 255 aml_append(sb_scope, dev); 256 /* declare CPU hotplug MMIO region and PRS field to access it */ 257 aml_append(sb_scope, aml_operation_region( 258 "PRST", AML_SYSTEM_IO, aml_int(io_base), ACPI_GPE_PROC_LEN)); 259 field = aml_field("PRST", AML_BYTE_ACC, AML_NOLOCK, AML_PRESERVE); 260 aml_append(field, aml_named_field("PRS", 256)); 261 aml_append(sb_scope, field); 262 263 /* build Processor object for each processor */ 264 for (i = 0; i < apic_ids->len; i++) { 265 int apic_id = apic_ids->cpus[i].arch_id; 266 267 assert(apic_id < ACPI_CPU_HOTPLUG_ID_LIMIT); 268 269 dev = aml_processor(i, 0, 0, "CP%.02X", apic_id); 270 271 method = aml_method("_MAT", 0, AML_NOTSERIALIZED); 272 aml_append(method, 273 aml_return(aml_call2(CPU_MAT_METHOD, aml_int(apic_id), aml_int(i)) 274 )); 275 aml_append(dev, method); 276 277 method = aml_method("_STA", 0, AML_NOTSERIALIZED); 278 aml_append(method, 279 aml_return(aml_call1(CPU_STATUS_METHOD, aml_int(apic_id)))); 280 aml_append(dev, method); 281 282 method = aml_method("_EJ0", 1, AML_NOTSERIALIZED); 283 aml_append(method, 284 aml_return(aml_call2(CPU_EJECT_METHOD, aml_int(apic_id), 285 aml_arg(0))) 286 ); 287 aml_append(dev, method); 288 289 aml_append(sb_scope, dev); 290 } 291 292 /* build this code: 293 * Method(NTFY, 2) {If (LEqual(Arg0, 0x00)) {Notify(CP00, Arg1)} ...} 294 */ 295 /* Arg0 = APIC ID */ 296 method = aml_method(AML_NOTIFY_METHOD, 2, AML_NOTSERIALIZED); 297 for (i = 0; i < apic_ids->len; i++) { 298 int apic_id = apic_ids->cpus[i].arch_id; 299 300 if_ctx = aml_if(aml_equal(aml_arg(0), aml_int(apic_id))); 301 aml_append(if_ctx, 302 aml_notify(aml_name("CP%.02X", apic_id), aml_arg(1)) 303 ); 304 aml_append(method, if_ctx); 305 } 306 aml_append(sb_scope, method); 307 308 /* build "Name(CPON, Package() { One, One, ..., Zero, Zero, ... })" 309 * 310 * Note: The ability to create variable-sized packages was first 311 * introduced in ACPI 2.0. ACPI 1.0 only allowed fixed-size packages 312 * ith up to 255 elements. Windows guests up to win2k8 fail when 313 * VarPackageOp is used. 314 */ 315 pkg = x86ms->apic_id_limit <= 255 ? aml_package(x86ms->apic_id_limit) : 316 aml_varpackage(x86ms->apic_id_limit); 317 318 for (i = 0, apic_idx = 0; i < apic_ids->len; i++) { 319 int apic_id = apic_ids->cpus[i].arch_id; 320 321 for (; apic_idx < apic_id; apic_idx++) { 322 aml_append(pkg, aml_int(0)); 323 } 324 aml_append(pkg, aml_int(apic_ids->cpus[i].cpu ? 1 : 0)); 325 apic_idx = apic_id + 1; 326 } 327 aml_append(sb_scope, aml_name_decl(CPU_ON_BITMAP, pkg)); 328 aml_append(ctx, sb_scope); 329 330 method = aml_method("\\_GPE._E02", 0, AML_NOTSERIALIZED); 331 aml_append(method, aml_call0("\\_SB." CPU_SCAN_METHOD)); 332 aml_append(ctx, method); 333 }