xref: /openbmc/qemu/hw/acpi/cpu_hotplug.c (revision 6630bc04bccadcf868165ad6bca5a964bb69b067)
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  
cpu_status_read(void * opaque,hwaddr addr,unsigned int size)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  
cpu_status_write(void * opaque,hwaddr addr,uint64_t data,unsigned int size)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  
acpi_set_cpu_present_bit(AcpiCpuHotplug * g,CPUState * cpu,bool * swtchd_to_modern)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  
legacy_acpi_cpu_plug_cb(HotplugHandler * hotplug_dev,AcpiCpuHotplug * g,DeviceState * dev,Error ** errp)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  
legacy_acpi_cpu_hotplug_init(MemoryRegion * parent,Object * owner,AcpiCpuHotplug * gpe_cpu,uint16_t base)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  
acpi_switch_to_modern_cphp(AcpiCpuHotplug * gpe_cpu,CPUHotplugState * cpuhp_state,uint16_t io_port)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  
build_legacy_cpu_hotplug_aml(Aml * ctx,MachineState * machine,uint16_t io_base)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  }
350