xref: /openbmc/qemu/hw/pci-host/q35.c (revision 10d01f73e39100701028c7badd6ece52990cf758)
1 /*
2  * QEMU MCH/ICH9 PCI Bridge Emulation
3  *
4  * Copyright (c) 2006 Fabrice Bellard
5  * Copyright (c) 2009, 2010, 2011
6  *               Isaku Yamahata <yamahata at valinux co jp>
7  *               VA Linux Systems Japan K.K.
8  * Copyright (C) 2012 Jason Baron <jbaron@redhat.com>
9  *
10  * This is based on piix.c, but heavily modified.
11  *
12  * Permission is hereby granted, free of charge, to any person obtaining a copy
13  * of this software and associated documentation files (the "Software"), to deal
14  * in the Software without restriction, including without limitation the rights
15  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
16  * copies of the Software, and to permit persons to whom the Software is
17  * furnished to do so, subject to the following conditions:
18  *
19  * The above copyright notice and this permission notice shall be included in
20  * all copies or substantial portions of the Software.
21  *
22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
23  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
25  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
26  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
27  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
28  * THE SOFTWARE.
29  */
30 #include "qemu/osdep.h"
31 #include "hw/hw.h"
32 #include "hw/pci-host/q35.h"
33 #include "qapi/error.h"
34 #include "qapi/visitor.h"
35 
36 /****************************************************************************
37  * Q35 host
38  */
39 
40 static void q35_host_realize(DeviceState *dev, Error **errp)
41 {
42     PCIHostState *pci = PCI_HOST_BRIDGE(dev);
43     Q35PCIHost *s = Q35_HOST_DEVICE(dev);
44     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
45 
46     sysbus_add_io(sbd, MCH_HOST_BRIDGE_CONFIG_ADDR, &pci->conf_mem);
47     sysbus_init_ioports(sbd, MCH_HOST_BRIDGE_CONFIG_ADDR, 4);
48 
49     sysbus_add_io(sbd, MCH_HOST_BRIDGE_CONFIG_DATA, &pci->data_mem);
50     sysbus_init_ioports(sbd, MCH_HOST_BRIDGE_CONFIG_DATA, 4);
51 
52     pci->bus = pci_bus_new(DEVICE(s), "pcie.0",
53                            s->mch.pci_address_space, s->mch.address_space_io,
54                            0, TYPE_PCIE_BUS);
55     PC_MACHINE(qdev_get_machine())->bus = pci->bus;
56     qdev_set_parent_bus(DEVICE(&s->mch), BUS(pci->bus));
57     qdev_init_nofail(DEVICE(&s->mch));
58 }
59 
60 static const char *q35_host_root_bus_path(PCIHostState *host_bridge,
61                                           PCIBus *rootbus)
62 {
63     Q35PCIHost *s = Q35_HOST_DEVICE(host_bridge);
64 
65      /* For backwards compat with old device paths */
66     if (s->mch.short_root_bus) {
67         return "0000";
68     }
69     return "0000:00";
70 }
71 
72 static void q35_host_get_pci_hole_start(Object *obj, Visitor *v,
73                                         const char *name, void *opaque,
74                                         Error **errp)
75 {
76     Q35PCIHost *s = Q35_HOST_DEVICE(obj);
77     uint32_t value = s->mch.pci_info.w32.begin;
78 
79     visit_type_uint32(v, name, &value, errp);
80 }
81 
82 static void q35_host_get_pci_hole_end(Object *obj, Visitor *v,
83                                       const char *name, void *opaque,
84                                       Error **errp)
85 {
86     Q35PCIHost *s = Q35_HOST_DEVICE(obj);
87     uint32_t value = s->mch.pci_info.w32.end;
88 
89     visit_type_uint32(v, name, &value, errp);
90 }
91 
92 static void q35_host_get_pci_hole64_start(Object *obj, Visitor *v,
93                                           const char *name, void *opaque,
94                                           Error **errp)
95 {
96     PCIHostState *h = PCI_HOST_BRIDGE(obj);
97     Range w64;
98 
99     pci_bus_get_w64_range(h->bus, &w64);
100 
101     visit_type_uint64(v, name, &w64.begin, errp);
102 }
103 
104 static void q35_host_get_pci_hole64_end(Object *obj, Visitor *v,
105                                         const char *name, void *opaque,
106                                         Error **errp)
107 {
108     PCIHostState *h = PCI_HOST_BRIDGE(obj);
109     Range w64;
110 
111     pci_bus_get_w64_range(h->bus, &w64);
112 
113     visit_type_uint64(v, name, &w64.end, errp);
114 }
115 
116 static void q35_host_get_mmcfg_size(Object *obj, Visitor *v, const char *name,
117                                     void *opaque, Error **errp)
118 {
119     PCIExpressHost *e = PCIE_HOST_BRIDGE(obj);
120     uint32_t value = e->size;
121 
122     visit_type_uint32(v, name, &value, errp);
123 }
124 
125 static Property mch_props[] = {
126     DEFINE_PROP_UINT64(PCIE_HOST_MCFG_BASE, Q35PCIHost, parent_obj.base_addr,
127                         MCH_HOST_BRIDGE_PCIEXBAR_DEFAULT),
128     DEFINE_PROP_SIZE(PCI_HOST_PROP_PCI_HOLE64_SIZE, Q35PCIHost,
129                      mch.pci_hole64_size, DEFAULT_PCI_HOLE64_SIZE),
130     DEFINE_PROP_UINT32("short_root_bus", Q35PCIHost, mch.short_root_bus, 0),
131     DEFINE_PROP_SIZE(PCI_HOST_BELOW_4G_MEM_SIZE, Q35PCIHost,
132                      mch.below_4g_mem_size, 0),
133     DEFINE_PROP_SIZE(PCI_HOST_ABOVE_4G_MEM_SIZE, Q35PCIHost,
134                      mch.above_4g_mem_size, 0),
135     DEFINE_PROP_END_OF_LIST(),
136 };
137 
138 static void q35_host_class_init(ObjectClass *klass, void *data)
139 {
140     DeviceClass *dc = DEVICE_CLASS(klass);
141     PCIHostBridgeClass *hc = PCI_HOST_BRIDGE_CLASS(klass);
142 
143     hc->root_bus_path = q35_host_root_bus_path;
144     dc->realize = q35_host_realize;
145     dc->props = mch_props;
146     /* Reason: needs to be wired up by pc_q35_init */
147     dc->cannot_instantiate_with_device_add_yet = true;
148     set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
149     dc->fw_name = "pci";
150 }
151 
152 static void q35_host_initfn(Object *obj)
153 {
154     Q35PCIHost *s = Q35_HOST_DEVICE(obj);
155     PCIHostState *phb = PCI_HOST_BRIDGE(obj);
156 
157     memory_region_init_io(&phb->conf_mem, obj, &pci_host_conf_le_ops, phb,
158                           "pci-conf-idx", 4);
159     memory_region_init_io(&phb->data_mem, obj, &pci_host_data_le_ops, phb,
160                           "pci-conf-data", 4);
161 
162     object_initialize(&s->mch, sizeof(s->mch), TYPE_MCH_PCI_DEVICE);
163     object_property_add_child(OBJECT(s), "mch", OBJECT(&s->mch), NULL);
164     qdev_prop_set_uint32(DEVICE(&s->mch), "addr", PCI_DEVFN(0, 0));
165     qdev_prop_set_bit(DEVICE(&s->mch), "multifunction", false);
166 
167     object_property_add(obj, PCI_HOST_PROP_PCI_HOLE_START, "int",
168                         q35_host_get_pci_hole_start,
169                         NULL, NULL, NULL, NULL);
170 
171     object_property_add(obj, PCI_HOST_PROP_PCI_HOLE_END, "int",
172                         q35_host_get_pci_hole_end,
173                         NULL, NULL, NULL, NULL);
174 
175     object_property_add(obj, PCI_HOST_PROP_PCI_HOLE64_START, "int",
176                         q35_host_get_pci_hole64_start,
177                         NULL, NULL, NULL, NULL);
178 
179     object_property_add(obj, PCI_HOST_PROP_PCI_HOLE64_END, "int",
180                         q35_host_get_pci_hole64_end,
181                         NULL, NULL, NULL, NULL);
182 
183     object_property_add(obj, PCIE_HOST_MCFG_SIZE, "int",
184                         q35_host_get_mmcfg_size,
185                         NULL, NULL, NULL, NULL);
186 
187     object_property_add_link(obj, MCH_HOST_PROP_RAM_MEM, TYPE_MEMORY_REGION,
188                              (Object **) &s->mch.ram_memory,
189                              qdev_prop_allow_set_link_before_realize, 0, NULL);
190 
191     object_property_add_link(obj, MCH_HOST_PROP_PCI_MEM, TYPE_MEMORY_REGION,
192                              (Object **) &s->mch.pci_address_space,
193                              qdev_prop_allow_set_link_before_realize, 0, NULL);
194 
195     object_property_add_link(obj, MCH_HOST_PROP_SYSTEM_MEM, TYPE_MEMORY_REGION,
196                              (Object **) &s->mch.system_memory,
197                              qdev_prop_allow_set_link_before_realize, 0, NULL);
198 
199     object_property_add_link(obj, MCH_HOST_PROP_IO_MEM, TYPE_MEMORY_REGION,
200                              (Object **) &s->mch.address_space_io,
201                              qdev_prop_allow_set_link_before_realize, 0, NULL);
202 
203     /* Leave enough space for the biggest MCFG BAR */
204     /* TODO: this matches current bios behaviour, but
205      * it's not a power of two, which means an MTRR
206      * can't cover it exactly.
207      */
208     s->mch.pci_info.w32.begin = MCH_HOST_BRIDGE_PCIEXBAR_DEFAULT +
209         MCH_HOST_BRIDGE_PCIEXBAR_MAX;
210     s->mch.pci_info.w32.end = IO_APIC_DEFAULT_ADDRESS;
211 }
212 
213 static const TypeInfo q35_host_info = {
214     .name       = TYPE_Q35_HOST_DEVICE,
215     .parent     = TYPE_PCIE_HOST_BRIDGE,
216     .instance_size = sizeof(Q35PCIHost),
217     .instance_init = q35_host_initfn,
218     .class_init = q35_host_class_init,
219 };
220 
221 /****************************************************************************
222  * MCH D0:F0
223  */
224 
225 static uint64_t tseg_blackhole_read(void *ptr, hwaddr reg, unsigned size)
226 {
227     return 0xffffffff;
228 }
229 
230 static void tseg_blackhole_write(void *opaque, hwaddr addr, uint64_t val,
231                                  unsigned width)
232 {
233     /* nothing */
234 }
235 
236 static const MemoryRegionOps tseg_blackhole_ops = {
237     .read = tseg_blackhole_read,
238     .write = tseg_blackhole_write,
239     .endianness = DEVICE_NATIVE_ENDIAN,
240     .valid.min_access_size = 1,
241     .valid.max_access_size = 4,
242     .impl.min_access_size = 4,
243     .impl.max_access_size = 4,
244     .endianness = DEVICE_LITTLE_ENDIAN,
245 };
246 
247 /* PCIe MMCFG */
248 static void mch_update_pciexbar(MCHPCIState *mch)
249 {
250     PCIDevice *pci_dev = PCI_DEVICE(mch);
251     BusState *bus = qdev_get_parent_bus(DEVICE(mch));
252     PCIExpressHost *pehb = PCIE_HOST_BRIDGE(bus->parent);
253 
254     uint64_t pciexbar;
255     int enable;
256     uint64_t addr;
257     uint64_t addr_mask;
258     uint32_t length;
259 
260     pciexbar = pci_get_quad(pci_dev->config + MCH_HOST_BRIDGE_PCIEXBAR);
261     enable = pciexbar & MCH_HOST_BRIDGE_PCIEXBAREN;
262     addr_mask = MCH_HOST_BRIDGE_PCIEXBAR_ADMSK;
263     switch (pciexbar & MCH_HOST_BRIDGE_PCIEXBAR_LENGTH_MASK) {
264     case MCH_HOST_BRIDGE_PCIEXBAR_LENGTH_256M:
265         length = 256 * 1024 * 1024;
266         break;
267     case MCH_HOST_BRIDGE_PCIEXBAR_LENGTH_128M:
268         length = 128 * 1024 * 1024;
269         addr_mask |= MCH_HOST_BRIDGE_PCIEXBAR_128ADMSK |
270             MCH_HOST_BRIDGE_PCIEXBAR_64ADMSK;
271         break;
272     case MCH_HOST_BRIDGE_PCIEXBAR_LENGTH_64M:
273         length = 64 * 1024 * 1024;
274         addr_mask |= MCH_HOST_BRIDGE_PCIEXBAR_64ADMSK;
275         break;
276     case MCH_HOST_BRIDGE_PCIEXBAR_LENGTH_RVD:
277     default:
278         enable = 0;
279         length = 0;
280         abort();
281         break;
282     }
283     addr = pciexbar & addr_mask;
284     pcie_host_mmcfg_update(pehb, enable, addr, length);
285     /* Leave enough space for the MCFG BAR */
286     /*
287      * TODO: this matches current bios behaviour, but it's not a power of two,
288      * which means an MTRR can't cover it exactly.
289      */
290     if (enable) {
291         mch->pci_info.w32.begin = addr + length;
292     } else {
293         mch->pci_info.w32.begin = MCH_HOST_BRIDGE_PCIEXBAR_DEFAULT;
294     }
295 }
296 
297 /* PAM */
298 static void mch_update_pam(MCHPCIState *mch)
299 {
300     PCIDevice *pd = PCI_DEVICE(mch);
301     int i;
302 
303     memory_region_transaction_begin();
304     for (i = 0; i < 13; i++) {
305         pam_update(&mch->pam_regions[i], i,
306                    pd->config[MCH_HOST_BRIDGE_PAM0 + ((i + 1) / 2)]);
307     }
308     memory_region_transaction_commit();
309 }
310 
311 /* SMRAM */
312 static void mch_update_smram(MCHPCIState *mch)
313 {
314     PCIDevice *pd = PCI_DEVICE(mch);
315     bool h_smrame = (pd->config[MCH_HOST_BRIDGE_ESMRAMC] & MCH_HOST_BRIDGE_ESMRAMC_H_SMRAME);
316     uint32_t tseg_size;
317 
318     /* implement SMRAM.D_LCK */
319     if (pd->config[MCH_HOST_BRIDGE_SMRAM] & MCH_HOST_BRIDGE_SMRAM_D_LCK) {
320         pd->config[MCH_HOST_BRIDGE_SMRAM] &= ~MCH_HOST_BRIDGE_SMRAM_D_OPEN;
321         pd->wmask[MCH_HOST_BRIDGE_SMRAM] = MCH_HOST_BRIDGE_SMRAM_WMASK_LCK;
322         pd->wmask[MCH_HOST_BRIDGE_ESMRAMC] = MCH_HOST_BRIDGE_ESMRAMC_WMASK_LCK;
323     }
324 
325     memory_region_transaction_begin();
326 
327     if (pd->config[MCH_HOST_BRIDGE_SMRAM] & SMRAM_D_OPEN) {
328         /* Hide (!) low SMRAM if H_SMRAME = 1 */
329         memory_region_set_enabled(&mch->smram_region, h_smrame);
330         /* Show high SMRAM if H_SMRAME = 1 */
331         memory_region_set_enabled(&mch->open_high_smram, h_smrame);
332     } else {
333         /* Hide high SMRAM and low SMRAM */
334         memory_region_set_enabled(&mch->smram_region, true);
335         memory_region_set_enabled(&mch->open_high_smram, false);
336     }
337 
338     if (pd->config[MCH_HOST_BRIDGE_SMRAM] & SMRAM_G_SMRAME) {
339         memory_region_set_enabled(&mch->low_smram, !h_smrame);
340         memory_region_set_enabled(&mch->high_smram, h_smrame);
341     } else {
342         memory_region_set_enabled(&mch->low_smram, false);
343         memory_region_set_enabled(&mch->high_smram, false);
344     }
345 
346     if (pd->config[MCH_HOST_BRIDGE_ESMRAMC] & MCH_HOST_BRIDGE_ESMRAMC_T_EN) {
347         switch (pd->config[MCH_HOST_BRIDGE_ESMRAMC] &
348                 MCH_HOST_BRIDGE_ESMRAMC_TSEG_SZ_MASK) {
349         case MCH_HOST_BRIDGE_ESMRAMC_TSEG_SZ_1MB:
350             tseg_size = 1024 * 1024;
351             break;
352         case MCH_HOST_BRIDGE_ESMRAMC_TSEG_SZ_2MB:
353             tseg_size = 1024 * 1024 * 2;
354             break;
355         case MCH_HOST_BRIDGE_ESMRAMC_TSEG_SZ_8MB:
356             tseg_size = 1024 * 1024 * 8;
357             break;
358         default:
359             tseg_size = 0;
360             break;
361         }
362     } else {
363         tseg_size = 0;
364     }
365     memory_region_del_subregion(mch->system_memory, &mch->tseg_blackhole);
366     memory_region_set_enabled(&mch->tseg_blackhole, tseg_size);
367     memory_region_set_size(&mch->tseg_blackhole, tseg_size);
368     memory_region_add_subregion_overlap(mch->system_memory,
369                                         mch->below_4g_mem_size - tseg_size,
370                                         &mch->tseg_blackhole, 1);
371 
372     memory_region_set_enabled(&mch->tseg_window, tseg_size);
373     memory_region_set_size(&mch->tseg_window, tseg_size);
374     memory_region_set_address(&mch->tseg_window,
375                               mch->below_4g_mem_size - tseg_size);
376     memory_region_set_alias_offset(&mch->tseg_window,
377                                    mch->below_4g_mem_size - tseg_size);
378 
379     memory_region_transaction_commit();
380 }
381 
382 static void mch_write_config(PCIDevice *d,
383                               uint32_t address, uint32_t val, int len)
384 {
385     MCHPCIState *mch = MCH_PCI_DEVICE(d);
386 
387     pci_default_write_config(d, address, val, len);
388 
389     if (ranges_overlap(address, len, MCH_HOST_BRIDGE_PAM0,
390                        MCH_HOST_BRIDGE_PAM_SIZE)) {
391         mch_update_pam(mch);
392     }
393 
394     if (ranges_overlap(address, len, MCH_HOST_BRIDGE_PCIEXBAR,
395                        MCH_HOST_BRIDGE_PCIEXBAR_SIZE)) {
396         mch_update_pciexbar(mch);
397     }
398 
399     if (ranges_overlap(address, len, MCH_HOST_BRIDGE_SMRAM,
400                        MCH_HOST_BRIDGE_SMRAM_SIZE)) {
401         mch_update_smram(mch);
402     }
403 }
404 
405 static void mch_update(MCHPCIState *mch)
406 {
407     mch_update_pciexbar(mch);
408     mch_update_pam(mch);
409     mch_update_smram(mch);
410 }
411 
412 static int mch_post_load(void *opaque, int version_id)
413 {
414     MCHPCIState *mch = opaque;
415     mch_update(mch);
416     return 0;
417 }
418 
419 static const VMStateDescription vmstate_mch = {
420     .name = "mch",
421     .version_id = 1,
422     .minimum_version_id = 1,
423     .post_load = mch_post_load,
424     .fields = (VMStateField[]) {
425         VMSTATE_PCI_DEVICE(parent_obj, MCHPCIState),
426         /* Used to be smm_enabled, which was basically always zero because
427          * SeaBIOS hardly uses SMM.  SMRAM is now handled by CPU code.
428          */
429         VMSTATE_UNUSED(1),
430         VMSTATE_END_OF_LIST()
431     }
432 };
433 
434 static void mch_reset(DeviceState *qdev)
435 {
436     PCIDevice *d = PCI_DEVICE(qdev);
437     MCHPCIState *mch = MCH_PCI_DEVICE(d);
438 
439     pci_set_quad(d->config + MCH_HOST_BRIDGE_PCIEXBAR,
440                  MCH_HOST_BRIDGE_PCIEXBAR_DEFAULT);
441 
442     d->config[MCH_HOST_BRIDGE_SMRAM] = MCH_HOST_BRIDGE_SMRAM_DEFAULT;
443     d->config[MCH_HOST_BRIDGE_ESMRAMC] = MCH_HOST_BRIDGE_ESMRAMC_DEFAULT;
444     d->wmask[MCH_HOST_BRIDGE_SMRAM] = MCH_HOST_BRIDGE_SMRAM_WMASK;
445     d->wmask[MCH_HOST_BRIDGE_ESMRAMC] = MCH_HOST_BRIDGE_ESMRAMC_WMASK;
446 
447     mch_update(mch);
448 }
449 
450 static void mch_realize(PCIDevice *d, Error **errp)
451 {
452     int i;
453     MCHPCIState *mch = MCH_PCI_DEVICE(d);
454 
455     /* setup pci memory mapping */
456     pc_pci_as_mapping_init(OBJECT(mch), mch->system_memory,
457                            mch->pci_address_space);
458 
459     /* if *disabled* show SMRAM to all CPUs */
460     memory_region_init_alias(&mch->smram_region, OBJECT(mch), "smram-region",
461                              mch->pci_address_space, 0xa0000, 0x20000);
462     memory_region_add_subregion_overlap(mch->system_memory, 0xa0000,
463                                         &mch->smram_region, 1);
464     memory_region_set_enabled(&mch->smram_region, true);
465 
466     memory_region_init_alias(&mch->open_high_smram, OBJECT(mch), "smram-open-high",
467                              mch->ram_memory, 0xa0000, 0x20000);
468     memory_region_add_subregion_overlap(mch->system_memory, 0xfeda0000,
469                                         &mch->open_high_smram, 1);
470     memory_region_set_enabled(&mch->open_high_smram, false);
471 
472     /* smram, as seen by SMM CPUs */
473     memory_region_init(&mch->smram, OBJECT(mch), "smram", 1ull << 32);
474     memory_region_set_enabled(&mch->smram, true);
475     memory_region_init_alias(&mch->low_smram, OBJECT(mch), "smram-low",
476                              mch->ram_memory, 0xa0000, 0x20000);
477     memory_region_set_enabled(&mch->low_smram, true);
478     memory_region_add_subregion(&mch->smram, 0xa0000, &mch->low_smram);
479     memory_region_init_alias(&mch->high_smram, OBJECT(mch), "smram-high",
480                              mch->ram_memory, 0xa0000, 0x20000);
481     memory_region_set_enabled(&mch->high_smram, true);
482     memory_region_add_subregion(&mch->smram, 0xfeda0000, &mch->high_smram);
483 
484     memory_region_init_io(&mch->tseg_blackhole, OBJECT(mch),
485                           &tseg_blackhole_ops, NULL,
486                           "tseg-blackhole", 0);
487     memory_region_set_enabled(&mch->tseg_blackhole, false);
488     memory_region_add_subregion_overlap(mch->system_memory,
489                                         mch->below_4g_mem_size,
490                                         &mch->tseg_blackhole, 1);
491 
492     memory_region_init_alias(&mch->tseg_window, OBJECT(mch), "tseg-window",
493                              mch->ram_memory, mch->below_4g_mem_size, 0);
494     memory_region_set_enabled(&mch->tseg_window, false);
495     memory_region_add_subregion(&mch->smram, mch->below_4g_mem_size,
496                                 &mch->tseg_window);
497     object_property_add_const_link(qdev_get_machine(), "smram",
498                                    OBJECT(&mch->smram), &error_abort);
499 
500     init_pam(DEVICE(mch), mch->ram_memory, mch->system_memory,
501              mch->pci_address_space, &mch->pam_regions[0],
502              PAM_BIOS_BASE, PAM_BIOS_SIZE);
503     for (i = 0; i < 12; ++i) {
504         init_pam(DEVICE(mch), mch->ram_memory, mch->system_memory,
505                  mch->pci_address_space, &mch->pam_regions[i+1],
506                  PAM_EXPAN_BASE + i * PAM_EXPAN_SIZE, PAM_EXPAN_SIZE);
507     }
508 }
509 
510 uint64_t mch_mcfg_base(void)
511 {
512     bool ambiguous;
513     Object *o = object_resolve_path_type("", TYPE_MCH_PCI_DEVICE, &ambiguous);
514     if (!o) {
515         return 0;
516     }
517     return MCH_HOST_BRIDGE_PCIEXBAR_DEFAULT;
518 }
519 
520 static void mch_class_init(ObjectClass *klass, void *data)
521 {
522     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
523     DeviceClass *dc = DEVICE_CLASS(klass);
524 
525     k->realize = mch_realize;
526     k->config_write = mch_write_config;
527     dc->reset = mch_reset;
528     set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
529     dc->desc = "Host bridge";
530     dc->vmsd = &vmstate_mch;
531     k->vendor_id = PCI_VENDOR_ID_INTEL;
532     k->device_id = PCI_DEVICE_ID_INTEL_Q35_MCH;
533     k->revision = MCH_HOST_BRIDGE_REVISION_DEFAULT;
534     k->class_id = PCI_CLASS_BRIDGE_HOST;
535     /*
536      * PCI-facing part of the host bridge, not usable without the
537      * host-facing part, which can't be device_add'ed, yet.
538      */
539     dc->cannot_instantiate_with_device_add_yet = true;
540 }
541 
542 static const TypeInfo mch_info = {
543     .name = TYPE_MCH_PCI_DEVICE,
544     .parent = TYPE_PCI_DEVICE,
545     .instance_size = sizeof(MCHPCIState),
546     .class_init = mch_class_init,
547 };
548 
549 static void q35_register(void)
550 {
551     type_register_static(&mch_info);
552     type_register_static(&q35_host_info);
553 }
554 
555 type_init(q35_register);
556