xref: /qemu/hw/acpi/cpu_hotplug.c (revision 76bdd24ec05d9b8d41582a10602e6cf350541c6b)
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)
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(1);
103     Aml *apic_id = aml_arg(0);
104     Aml *cpu_on = aml_local(0);
105     Aml *madt = aml_local(1);
106     Aml *cpus_map = aml_name(CPU_ON_BITMAP);
107     Aml *zero = aml_int(0);
108     Aml *one = aml_int(1);
109     MachineClass *mc = MACHINE_GET_CLASS(machine);
110     CPUArchIdList *apic_ids = mc->possible_cpu_arch_ids(machine);
111     PCMachineState *pcms = PC_MACHINE(machine);
112 
113     /*
114      * _MAT method - creates an madt apic buffer
115      * apic_id = Arg0 = Local APIC ID
116      * cpu_id  = Arg1 = Processor ID
117      * cpu_on = Local0 = CPON flag for this cpu
118      * madt = Local1 = Buffer (in madt apic form) to return
119      */
120     method = aml_method(CPU_MAT_METHOD, 2, AML_NOTSERIALIZED);
121     aml_append(method,
122         aml_store(aml_derefof(aml_index(cpus_map, apic_id)), cpu_on));
123     aml_append(method,
124         aml_store(aml_buffer(sizeof(madt_tmpl), madt_tmpl), madt));
125     /* Update the processor id, lapic id, and enable/disable status */
126     aml_append(method, aml_store(cpu_id, aml_index(madt, aml_int(2))));
127     aml_append(method, aml_store(apic_id, aml_index(madt, aml_int(3))));
128     aml_append(method, aml_store(cpu_on, aml_index(madt, aml_int(4))));
129     aml_append(method, aml_return(madt));
130     aml_append(sb_scope, method);
131 
132     /*
133      * _STA method - return ON status of cpu
134      * apic_id = Arg0 = Local APIC ID
135      * cpu_on = Local0 = CPON flag for this cpu
136      */
137     method = aml_method(CPU_STATUS_METHOD, 1, AML_NOTSERIALIZED);
138     aml_append(method,
139         aml_store(aml_derefof(aml_index(cpus_map, apic_id)), cpu_on));
140     if_ctx = aml_if(cpu_on);
141     {
142         aml_append(if_ctx, aml_return(aml_int(0xF)));
143     }
144     aml_append(method, if_ctx);
145     else_ctx = aml_else();
146     {
147         aml_append(else_ctx, aml_return(zero));
148     }
149     aml_append(method, else_ctx);
150     aml_append(sb_scope, method);
151 
152     method = aml_method(CPU_EJECT_METHOD, 2, AML_NOTSERIALIZED);
153     aml_append(method, aml_sleep(200));
154     aml_append(sb_scope, method);
155 
156     method = aml_method(CPU_SCAN_METHOD, 0, AML_NOTSERIALIZED);
157     {
158         Aml *while_ctx, *if_ctx2, *else_ctx2;
159         Aml *bus_check_evt = aml_int(1);
160         Aml *remove_evt = aml_int(3);
161         Aml *status_map = aml_local(5); /* Local5 = active cpu bitmap */
162         Aml *byte = aml_local(2); /* Local2 = last read byte from bitmap */
163         Aml *idx = aml_local(0); /* Processor ID / APIC ID iterator */
164         Aml *is_cpu_on = aml_local(1); /* Local1 = CPON flag for cpu */
165         Aml *status = aml_local(3); /* Local3 = active state for cpu */
166 
167         aml_append(method, aml_store(aml_name(CPU_STATUS_MAP), status_map));
168         aml_append(method, aml_store(zero, byte));
169         aml_append(method, aml_store(zero, idx));
170 
171         /* While (idx < SizeOf(CPON)) */
172         while_ctx = aml_while(aml_lless(idx, aml_sizeof(cpus_map)));
173         aml_append(while_ctx,
174             aml_store(aml_derefof(aml_index(cpus_map, idx)), is_cpu_on));
175 
176         if_ctx = aml_if(aml_and(idx, aml_int(0x07), NULL));
177         {
178             /* Shift down previously read bitmap byte */
179             aml_append(if_ctx, aml_shiftright(byte, one, byte));
180         }
181         aml_append(while_ctx, if_ctx);
182 
183         else_ctx = aml_else();
184         {
185             /* Read next byte from cpu bitmap */
186             aml_append(else_ctx, aml_store(aml_derefof(aml_index(status_map,
187                        aml_shiftright(idx, aml_int(3), NULL))), byte));
188         }
189         aml_append(while_ctx, else_ctx);
190 
191         aml_append(while_ctx, aml_store(aml_and(byte, one, NULL), status));
192         if_ctx = aml_if(aml_lnot(aml_equal(is_cpu_on, status)));
193         {
194             /* State change - update CPON with new state */
195             aml_append(if_ctx, aml_store(status, aml_index(cpus_map, idx)));
196             if_ctx2 = aml_if(aml_equal(status, one));
197             {
198                 aml_append(if_ctx2,
199                     aml_call2(AML_NOTIFY_METHOD, idx, bus_check_evt));
200             }
201             aml_append(if_ctx, if_ctx2);
202             else_ctx2 = aml_else();
203             {
204                 aml_append(else_ctx2,
205                     aml_call2(AML_NOTIFY_METHOD, idx, remove_evt));
206             }
207         }
208         aml_append(if_ctx, else_ctx2);
209         aml_append(while_ctx, if_ctx);
210 
211         aml_append(while_ctx, aml_increment(idx)); /* go to next cpu */
212         aml_append(method, while_ctx);
213     }
214     aml_append(sb_scope, method);
215 
216     /* The current AML generator can cover the APIC ID range [0..255],
217      * inclusive, for VCPU hotplug. */
218     QEMU_BUILD_BUG_ON(ACPI_CPU_HOTPLUG_ID_LIMIT > 256);
219     g_assert(pcms->apic_id_limit <= ACPI_CPU_HOTPLUG_ID_LIMIT);
220 
221     /* create PCI0.PRES device and its _CRS to reserve CPU hotplug MMIO */
222     dev = aml_device("PCI0." stringify(CPU_HOTPLUG_RESOURCE_DEVICE));
223     aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A06")));
224     aml_append(dev,
225         aml_name_decl("_UID", aml_string("CPU Hotplug resources"))
226     );
227     /* device present, functioning, decoding, not shown in UI */
228     aml_append(dev, aml_name_decl("_STA", aml_int(0xB)));
229     crs = aml_resource_template();
230     aml_append(crs,
231         aml_io(AML_DECODE16, io_base, io_base, 1, ACPI_GPE_PROC_LEN)
232     );
233     aml_append(dev, aml_name_decl("_CRS", crs));
234     aml_append(sb_scope, dev);
235     /* declare CPU hotplug MMIO region and PRS field to access it */
236     aml_append(sb_scope, aml_operation_region(
237         "PRST", AML_SYSTEM_IO, aml_int(io_base), ACPI_GPE_PROC_LEN));
238     field = aml_field("PRST", AML_BYTE_ACC, AML_NOLOCK, AML_PRESERVE);
239     aml_append(field, aml_named_field("PRS", 256));
240     aml_append(sb_scope, field);
241 
242     /* build Processor object for each processor */
243     for (i = 0; i < apic_ids->len; i++) {
244         int apic_id = apic_ids->cpus[i].arch_id;
245 
246         assert(apic_id < ACPI_CPU_HOTPLUG_ID_LIMIT);
247 
248         dev = aml_processor(i, 0, 0, "CP%.02X", apic_id);
249 
250         method = aml_method("_MAT", 0, AML_NOTSERIALIZED);
251         aml_append(method,
252             aml_return(aml_call2(CPU_MAT_METHOD, aml_int(apic_id), aml_int(i))
253         ));
254         aml_append(dev, method);
255 
256         method = aml_method("_STA", 0, AML_NOTSERIALIZED);
257         aml_append(method,
258             aml_return(aml_call1(CPU_STATUS_METHOD, aml_int(apic_id))));
259         aml_append(dev, method);
260 
261         method = aml_method("_EJ0", 1, AML_NOTSERIALIZED);
262         aml_append(method,
263             aml_return(aml_call2(CPU_EJECT_METHOD, aml_int(apic_id),
264                 aml_arg(0)))
265         );
266         aml_append(dev, method);
267 
268         aml_append(sb_scope, dev);
269     }
270 
271     /* build this code:
272      *   Method(NTFY, 2) {If (LEqual(Arg0, 0x00)) {Notify(CP00, Arg1)} ...}
273      */
274     /* Arg0 = APIC ID */
275     method = aml_method(AML_NOTIFY_METHOD, 2, AML_NOTSERIALIZED);
276     for (i = 0; i < apic_ids->len; i++) {
277         int apic_id = apic_ids->cpus[i].arch_id;
278 
279         if_ctx = aml_if(aml_equal(aml_arg(0), aml_int(apic_id)));
280         aml_append(if_ctx,
281             aml_notify(aml_name("CP%.02X", apic_id), aml_arg(1))
282         );
283         aml_append(method, if_ctx);
284     }
285     aml_append(sb_scope, method);
286 
287     /* build "Name(CPON, Package() { One, One, ..., Zero, Zero, ... })"
288      *
289      * Note: The ability to create variable-sized packages was first
290      * introduced in ACPI 2.0. ACPI 1.0 only allowed fixed-size packages
291      * ith up to 255 elements. Windows guests up to win2k8 fail when
292      * VarPackageOp is used.
293      */
294     pkg = pcms->apic_id_limit <= 255 ? aml_package(pcms->apic_id_limit) :
295                                        aml_varpackage(pcms->apic_id_limit);
296 
297     for (i = 0, apic_idx = 0; i < apic_ids->len; i++) {
298         int apic_id = apic_ids->cpus[i].arch_id;
299 
300         for (; apic_idx < apic_id; apic_idx++) {
301             aml_append(pkg, aml_int(0));
302         }
303         aml_append(pkg, aml_int(apic_ids->cpus[i].cpu ? 1 : 0));
304         apic_idx = apic_id + 1;
305     }
306     aml_append(sb_scope, aml_name_decl(CPU_ON_BITMAP, pkg));
307     g_free(apic_ids);
308 
309     aml_append(ctx, sb_scope);
310 
311     method = aml_method("\\_GPE._E02", 0, AML_NOTSERIALIZED);
312     aml_append(method, aml_call0("\\_SB." CPU_SCAN_METHOD));
313     aml_append(ctx, method);
314 }
315