xref: /openbmc/qemu/hw/pci-host/q35.c (revision 51e72bc1)
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/visitor.h"
34 
35 /****************************************************************************
36  * Q35 host
37  */
38 
39 static void q35_host_realize(DeviceState *dev, Error **errp)
40 {
41     PCIHostState *pci = PCI_HOST_BRIDGE(dev);
42     Q35PCIHost *s = Q35_HOST_DEVICE(dev);
43     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
44 
45     sysbus_add_io(sbd, MCH_HOST_BRIDGE_CONFIG_ADDR, &pci->conf_mem);
46     sysbus_init_ioports(sbd, MCH_HOST_BRIDGE_CONFIG_ADDR, 4);
47 
48     sysbus_add_io(sbd, MCH_HOST_BRIDGE_CONFIG_DATA, &pci->data_mem);
49     sysbus_init_ioports(sbd, MCH_HOST_BRIDGE_CONFIG_DATA, 4);
50 
51     pci->bus = pci_bus_new(DEVICE(s), "pcie.0",
52                            s->mch.pci_address_space, s->mch.address_space_io,
53                            0, TYPE_PCIE_BUS);
54     qdev_set_parent_bus(DEVICE(&s->mch), BUS(pci->bus));
55     qdev_init_nofail(DEVICE(&s->mch));
56 }
57 
58 static const char *q35_host_root_bus_path(PCIHostState *host_bridge,
59                                           PCIBus *rootbus)
60 {
61     Q35PCIHost *s = Q35_HOST_DEVICE(host_bridge);
62 
63      /* For backwards compat with old device paths */
64     if (s->mch.short_root_bus) {
65         return "0000";
66     }
67     return "0000:00";
68 }
69 
70 static void q35_host_get_pci_hole_start(Object *obj, Visitor *v,
71                                         void *opaque, const char *name,
72                                         Error **errp)
73 {
74     Q35PCIHost *s = Q35_HOST_DEVICE(obj);
75     uint32_t value = s->mch.pci_info.w32.begin;
76 
77     visit_type_uint32(v, name, &value, errp);
78 }
79 
80 static void q35_host_get_pci_hole_end(Object *obj, Visitor *v,
81                                       void *opaque, const char *name,
82                                       Error **errp)
83 {
84     Q35PCIHost *s = Q35_HOST_DEVICE(obj);
85     uint32_t value = s->mch.pci_info.w32.end;
86 
87     visit_type_uint32(v, name, &value, errp);
88 }
89 
90 static void q35_host_get_pci_hole64_start(Object *obj, Visitor *v,
91                                           void *opaque, const char *name,
92                                           Error **errp)
93 {
94     PCIHostState *h = PCI_HOST_BRIDGE(obj);
95     Range w64;
96 
97     pci_bus_get_w64_range(h->bus, &w64);
98 
99     visit_type_uint64(v, name, &w64.begin, errp);
100 }
101 
102 static void q35_host_get_pci_hole64_end(Object *obj, Visitor *v,
103                                         void *opaque, const char *name,
104                                         Error **errp)
105 {
106     PCIHostState *h = PCI_HOST_BRIDGE(obj);
107     Range w64;
108 
109     pci_bus_get_w64_range(h->bus, &w64);
110 
111     visit_type_uint64(v, name, &w64.end, errp);
112 }
113 
114 static void q35_host_get_mmcfg_size(Object *obj, Visitor *v,
115                                     void *opaque, const char *name,
116                                     Error **errp)
117 {
118     PCIExpressHost *e = PCIE_HOST_BRIDGE(obj);
119     uint32_t value = e->size;
120 
121     visit_type_uint32(v, name, &value, errp);
122 }
123 
124 static Property mch_props[] = {
125     DEFINE_PROP_UINT64(PCIE_HOST_MCFG_BASE, Q35PCIHost, parent_obj.base_addr,
126                         MCH_HOST_BRIDGE_PCIEXBAR_DEFAULT),
127     DEFINE_PROP_SIZE(PCI_HOST_PROP_PCI_HOLE64_SIZE, Q35PCIHost,
128                      mch.pci_hole64_size, DEFAULT_PCI_HOLE64_SIZE),
129     DEFINE_PROP_UINT32("short_root_bus", Q35PCIHost, mch.short_root_bus, 0),
130     DEFINE_PROP_END_OF_LIST(),
131 };
132 
133 static void q35_host_class_init(ObjectClass *klass, void *data)
134 {
135     DeviceClass *dc = DEVICE_CLASS(klass);
136     PCIHostBridgeClass *hc = PCI_HOST_BRIDGE_CLASS(klass);
137 
138     hc->root_bus_path = q35_host_root_bus_path;
139     dc->realize = q35_host_realize;
140     dc->props = mch_props;
141     set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
142     dc->fw_name = "pci";
143 }
144 
145 static void q35_host_initfn(Object *obj)
146 {
147     Q35PCIHost *s = Q35_HOST_DEVICE(obj);
148     PCIHostState *phb = PCI_HOST_BRIDGE(obj);
149 
150     memory_region_init_io(&phb->conf_mem, obj, &pci_host_conf_le_ops, phb,
151                           "pci-conf-idx", 4);
152     memory_region_init_io(&phb->data_mem, obj, &pci_host_data_le_ops, phb,
153                           "pci-conf-data", 4);
154 
155     object_initialize(&s->mch, sizeof(s->mch), TYPE_MCH_PCI_DEVICE);
156     object_property_add_child(OBJECT(s), "mch", OBJECT(&s->mch), NULL);
157     qdev_prop_set_uint32(DEVICE(&s->mch), "addr", PCI_DEVFN(0, 0));
158     qdev_prop_set_bit(DEVICE(&s->mch), "multifunction", false);
159 
160     object_property_add(obj, PCI_HOST_PROP_PCI_HOLE_START, "int",
161                         q35_host_get_pci_hole_start,
162                         NULL, NULL, NULL, NULL);
163 
164     object_property_add(obj, PCI_HOST_PROP_PCI_HOLE_END, "int",
165                         q35_host_get_pci_hole_end,
166                         NULL, NULL, NULL, NULL);
167 
168     object_property_add(obj, PCI_HOST_PROP_PCI_HOLE64_START, "int",
169                         q35_host_get_pci_hole64_start,
170                         NULL, NULL, NULL, NULL);
171 
172     object_property_add(obj, PCI_HOST_PROP_PCI_HOLE64_END, "int",
173                         q35_host_get_pci_hole64_end,
174                         NULL, NULL, NULL, NULL);
175 
176     object_property_add(obj, PCIE_HOST_MCFG_SIZE, "int",
177                         q35_host_get_mmcfg_size,
178                         NULL, NULL, NULL, NULL);
179 
180     /* Leave enough space for the biggest MCFG BAR */
181     /* TODO: this matches current bios behaviour, but
182      * it's not a power of two, which means an MTRR
183      * can't cover it exactly.
184      */
185     s->mch.pci_info.w32.begin = MCH_HOST_BRIDGE_PCIEXBAR_DEFAULT +
186         MCH_HOST_BRIDGE_PCIEXBAR_MAX;
187     s->mch.pci_info.w32.end = IO_APIC_DEFAULT_ADDRESS;
188 }
189 
190 static const TypeInfo q35_host_info = {
191     .name       = TYPE_Q35_HOST_DEVICE,
192     .parent     = TYPE_PCIE_HOST_BRIDGE,
193     .instance_size = sizeof(Q35PCIHost),
194     .instance_init = q35_host_initfn,
195     .class_init = q35_host_class_init,
196 };
197 
198 /****************************************************************************
199  * MCH D0:F0
200  */
201 
202 static uint64_t tseg_blackhole_read(void *ptr, hwaddr reg, unsigned size)
203 {
204     return 0xffffffff;
205 }
206 
207 static void tseg_blackhole_write(void *opaque, hwaddr addr, uint64_t val,
208                                  unsigned width)
209 {
210     /* nothing */
211 }
212 
213 static const MemoryRegionOps tseg_blackhole_ops = {
214     .read = tseg_blackhole_read,
215     .write = tseg_blackhole_write,
216     .endianness = DEVICE_NATIVE_ENDIAN,
217     .valid.min_access_size = 1,
218     .valid.max_access_size = 4,
219     .impl.min_access_size = 4,
220     .impl.max_access_size = 4,
221     .endianness = DEVICE_LITTLE_ENDIAN,
222 };
223 
224 /* PCIe MMCFG */
225 static void mch_update_pciexbar(MCHPCIState *mch)
226 {
227     PCIDevice *pci_dev = PCI_DEVICE(mch);
228     BusState *bus = qdev_get_parent_bus(DEVICE(mch));
229     PCIExpressHost *pehb = PCIE_HOST_BRIDGE(bus->parent);
230 
231     uint64_t pciexbar;
232     int enable;
233     uint64_t addr;
234     uint64_t addr_mask;
235     uint32_t length;
236 
237     pciexbar = pci_get_quad(pci_dev->config + MCH_HOST_BRIDGE_PCIEXBAR);
238     enable = pciexbar & MCH_HOST_BRIDGE_PCIEXBAREN;
239     addr_mask = MCH_HOST_BRIDGE_PCIEXBAR_ADMSK;
240     switch (pciexbar & MCH_HOST_BRIDGE_PCIEXBAR_LENGTH_MASK) {
241     case MCH_HOST_BRIDGE_PCIEXBAR_LENGTH_256M:
242         length = 256 * 1024 * 1024;
243         break;
244     case MCH_HOST_BRIDGE_PCIEXBAR_LENGTH_128M:
245         length = 128 * 1024 * 1024;
246         addr_mask |= MCH_HOST_BRIDGE_PCIEXBAR_128ADMSK |
247             MCH_HOST_BRIDGE_PCIEXBAR_64ADMSK;
248         break;
249     case MCH_HOST_BRIDGE_PCIEXBAR_LENGTH_64M:
250         length = 64 * 1024 * 1024;
251         addr_mask |= MCH_HOST_BRIDGE_PCIEXBAR_64ADMSK;
252         break;
253     case MCH_HOST_BRIDGE_PCIEXBAR_LENGTH_RVD:
254     default:
255         enable = 0;
256         length = 0;
257         abort();
258         break;
259     }
260     addr = pciexbar & addr_mask;
261     pcie_host_mmcfg_update(pehb, enable, addr, length);
262     /* Leave enough space for the MCFG BAR */
263     /*
264      * TODO: this matches current bios behaviour, but it's not a power of two,
265      * which means an MTRR can't cover it exactly.
266      */
267     if (enable) {
268         mch->pci_info.w32.begin = addr + length;
269     } else {
270         mch->pci_info.w32.begin = MCH_HOST_BRIDGE_PCIEXBAR_DEFAULT;
271     }
272 }
273 
274 /* PAM */
275 static void mch_update_pam(MCHPCIState *mch)
276 {
277     PCIDevice *pd = PCI_DEVICE(mch);
278     int i;
279 
280     memory_region_transaction_begin();
281     for (i = 0; i < 13; i++) {
282         pam_update(&mch->pam_regions[i], i,
283                    pd->config[MCH_HOST_BRIDGE_PAM0 + ((i + 1) / 2)]);
284     }
285     memory_region_transaction_commit();
286 }
287 
288 /* SMRAM */
289 static void mch_update_smram(MCHPCIState *mch)
290 {
291     PCIDevice *pd = PCI_DEVICE(mch);
292     bool h_smrame = (pd->config[MCH_HOST_BRIDGE_ESMRAMC] & MCH_HOST_BRIDGE_ESMRAMC_H_SMRAME);
293     uint32_t tseg_size;
294 
295     /* implement SMRAM.D_LCK */
296     if (pd->config[MCH_HOST_BRIDGE_SMRAM] & MCH_HOST_BRIDGE_SMRAM_D_LCK) {
297         pd->config[MCH_HOST_BRIDGE_SMRAM] &= ~MCH_HOST_BRIDGE_SMRAM_D_OPEN;
298         pd->wmask[MCH_HOST_BRIDGE_SMRAM] = MCH_HOST_BRIDGE_SMRAM_WMASK_LCK;
299         pd->wmask[MCH_HOST_BRIDGE_ESMRAMC] = MCH_HOST_BRIDGE_ESMRAMC_WMASK_LCK;
300     }
301 
302     memory_region_transaction_begin();
303 
304     if (pd->config[MCH_HOST_BRIDGE_SMRAM] & SMRAM_D_OPEN) {
305         /* Hide (!) low SMRAM if H_SMRAME = 1 */
306         memory_region_set_enabled(&mch->smram_region, h_smrame);
307         /* Show high SMRAM if H_SMRAME = 1 */
308         memory_region_set_enabled(&mch->open_high_smram, h_smrame);
309     } else {
310         /* Hide high SMRAM and low SMRAM */
311         memory_region_set_enabled(&mch->smram_region, true);
312         memory_region_set_enabled(&mch->open_high_smram, false);
313     }
314 
315     if (pd->config[MCH_HOST_BRIDGE_SMRAM] & SMRAM_G_SMRAME) {
316         memory_region_set_enabled(&mch->low_smram, !h_smrame);
317         memory_region_set_enabled(&mch->high_smram, h_smrame);
318     } else {
319         memory_region_set_enabled(&mch->low_smram, false);
320         memory_region_set_enabled(&mch->high_smram, false);
321     }
322 
323     if (pd->config[MCH_HOST_BRIDGE_ESMRAMC] & MCH_HOST_BRIDGE_ESMRAMC_T_EN) {
324         switch (pd->config[MCH_HOST_BRIDGE_ESMRAMC] &
325                 MCH_HOST_BRIDGE_ESMRAMC_TSEG_SZ_MASK) {
326         case MCH_HOST_BRIDGE_ESMRAMC_TSEG_SZ_1MB:
327             tseg_size = 1024 * 1024;
328             break;
329         case MCH_HOST_BRIDGE_ESMRAMC_TSEG_SZ_2MB:
330             tseg_size = 1024 * 1024 * 2;
331             break;
332         case MCH_HOST_BRIDGE_ESMRAMC_TSEG_SZ_8MB:
333             tseg_size = 1024 * 1024 * 8;
334             break;
335         default:
336             tseg_size = 0;
337             break;
338         }
339     } else {
340         tseg_size = 0;
341     }
342     memory_region_del_subregion(mch->system_memory, &mch->tseg_blackhole);
343     memory_region_set_enabled(&mch->tseg_blackhole, tseg_size);
344     memory_region_set_size(&mch->tseg_blackhole, tseg_size);
345     memory_region_add_subregion_overlap(mch->system_memory,
346                                         mch->below_4g_mem_size - tseg_size,
347                                         &mch->tseg_blackhole, 1);
348 
349     memory_region_set_enabled(&mch->tseg_window, tseg_size);
350     memory_region_set_size(&mch->tseg_window, tseg_size);
351     memory_region_set_address(&mch->tseg_window,
352                               mch->below_4g_mem_size - tseg_size);
353     memory_region_set_alias_offset(&mch->tseg_window,
354                                    mch->below_4g_mem_size - tseg_size);
355 
356     memory_region_transaction_commit();
357 }
358 
359 static void mch_write_config(PCIDevice *d,
360                               uint32_t address, uint32_t val, int len)
361 {
362     MCHPCIState *mch = MCH_PCI_DEVICE(d);
363 
364     pci_default_write_config(d, address, val, len);
365 
366     if (ranges_overlap(address, len, MCH_HOST_BRIDGE_PAM0,
367                        MCH_HOST_BRIDGE_PAM_SIZE)) {
368         mch_update_pam(mch);
369     }
370 
371     if (ranges_overlap(address, len, MCH_HOST_BRIDGE_PCIEXBAR,
372                        MCH_HOST_BRIDGE_PCIEXBAR_SIZE)) {
373         mch_update_pciexbar(mch);
374     }
375 
376     if (ranges_overlap(address, len, MCH_HOST_BRIDGE_SMRAM,
377                        MCH_HOST_BRIDGE_SMRAM_SIZE)) {
378         mch_update_smram(mch);
379     }
380 }
381 
382 static void mch_update(MCHPCIState *mch)
383 {
384     mch_update_pciexbar(mch);
385     mch_update_pam(mch);
386     mch_update_smram(mch);
387 }
388 
389 static int mch_post_load(void *opaque, int version_id)
390 {
391     MCHPCIState *mch = opaque;
392     mch_update(mch);
393     return 0;
394 }
395 
396 static const VMStateDescription vmstate_mch = {
397     .name = "mch",
398     .version_id = 1,
399     .minimum_version_id = 1,
400     .post_load = mch_post_load,
401     .fields = (VMStateField[]) {
402         VMSTATE_PCI_DEVICE(parent_obj, MCHPCIState),
403         /* Used to be smm_enabled, which was basically always zero because
404          * SeaBIOS hardly uses SMM.  SMRAM is now handled by CPU code.
405          */
406         VMSTATE_UNUSED(1),
407         VMSTATE_END_OF_LIST()
408     }
409 };
410 
411 static void mch_reset(DeviceState *qdev)
412 {
413     PCIDevice *d = PCI_DEVICE(qdev);
414     MCHPCIState *mch = MCH_PCI_DEVICE(d);
415 
416     pci_set_quad(d->config + MCH_HOST_BRIDGE_PCIEXBAR,
417                  MCH_HOST_BRIDGE_PCIEXBAR_DEFAULT);
418 
419     d->config[MCH_HOST_BRIDGE_SMRAM] = MCH_HOST_BRIDGE_SMRAM_DEFAULT;
420     d->config[MCH_HOST_BRIDGE_ESMRAMC] = MCH_HOST_BRIDGE_ESMRAMC_DEFAULT;
421     d->wmask[MCH_HOST_BRIDGE_SMRAM] = MCH_HOST_BRIDGE_SMRAM_WMASK;
422     d->wmask[MCH_HOST_BRIDGE_ESMRAMC] = MCH_HOST_BRIDGE_ESMRAMC_WMASK;
423 
424     mch_update(mch);
425 }
426 
427 static AddressSpace *q35_host_dma_iommu(PCIBus *bus, void *opaque, int devfn)
428 {
429     IntelIOMMUState *s = opaque;
430     VTDAddressSpace *vtd_as;
431 
432     assert(0 <= devfn && devfn <= VTD_PCI_DEVFN_MAX);
433 
434     vtd_as = vtd_find_add_as(s, bus, devfn);
435     return &vtd_as->as;
436 }
437 
438 static void mch_init_dmar(MCHPCIState *mch)
439 {
440     PCIBus *pci_bus = PCI_BUS(qdev_get_parent_bus(DEVICE(mch)));
441 
442     mch->iommu = INTEL_IOMMU_DEVICE(qdev_create(NULL, TYPE_INTEL_IOMMU_DEVICE));
443     object_property_add_child(OBJECT(mch), "intel-iommu",
444                               OBJECT(mch->iommu), NULL);
445     qdev_init_nofail(DEVICE(mch->iommu));
446     sysbus_mmio_map(SYS_BUS_DEVICE(mch->iommu), 0, Q35_HOST_BRIDGE_IOMMU_ADDR);
447 
448     pci_setup_iommu(pci_bus, q35_host_dma_iommu, mch->iommu);
449 }
450 
451 static void mch_realize(PCIDevice *d, Error **errp)
452 {
453     int i;
454     MCHPCIState *mch = MCH_PCI_DEVICE(d);
455 
456     /* setup pci memory mapping */
457     pc_pci_as_mapping_init(OBJECT(mch), mch->system_memory,
458                            mch->pci_address_space);
459 
460     /* if *disabled* show SMRAM to all CPUs */
461     memory_region_init_alias(&mch->smram_region, OBJECT(mch), "smram-region",
462                              mch->pci_address_space, 0xa0000, 0x20000);
463     memory_region_add_subregion_overlap(mch->system_memory, 0xa0000,
464                                         &mch->smram_region, 1);
465     memory_region_set_enabled(&mch->smram_region, true);
466 
467     memory_region_init_alias(&mch->open_high_smram, OBJECT(mch), "smram-open-high",
468                              mch->ram_memory, 0xa0000, 0x20000);
469     memory_region_add_subregion_overlap(mch->system_memory, 0xfeda0000,
470                                         &mch->open_high_smram, 1);
471     memory_region_set_enabled(&mch->open_high_smram, false);
472 
473     /* smram, as seen by SMM CPUs */
474     memory_region_init(&mch->smram, OBJECT(mch), "smram", 1ull << 32);
475     memory_region_set_enabled(&mch->smram, true);
476     memory_region_init_alias(&mch->low_smram, OBJECT(mch), "smram-low",
477                              mch->ram_memory, 0xa0000, 0x20000);
478     memory_region_set_enabled(&mch->low_smram, true);
479     memory_region_add_subregion(&mch->smram, 0xa0000, &mch->low_smram);
480     memory_region_init_alias(&mch->high_smram, OBJECT(mch), "smram-high",
481                              mch->ram_memory, 0xa0000, 0x20000);
482     memory_region_set_enabled(&mch->high_smram, true);
483     memory_region_add_subregion(&mch->smram, 0xfeda0000, &mch->high_smram);
484 
485     memory_region_init_io(&mch->tseg_blackhole, OBJECT(mch),
486                           &tseg_blackhole_ops, NULL,
487                           "tseg-blackhole", 0);
488     memory_region_set_enabled(&mch->tseg_blackhole, false);
489     memory_region_add_subregion_overlap(mch->system_memory,
490                                         mch->below_4g_mem_size,
491                                         &mch->tseg_blackhole, 1);
492 
493     memory_region_init_alias(&mch->tseg_window, OBJECT(mch), "tseg-window",
494                              mch->ram_memory, mch->below_4g_mem_size, 0);
495     memory_region_set_enabled(&mch->tseg_window, false);
496     memory_region_add_subregion(&mch->smram, mch->below_4g_mem_size,
497                                 &mch->tseg_window);
498     object_property_add_const_link(qdev_get_machine(), "smram",
499                                    OBJECT(&mch->smram), &error_abort);
500 
501     init_pam(DEVICE(mch), mch->ram_memory, mch->system_memory,
502              mch->pci_address_space, &mch->pam_regions[0],
503              PAM_BIOS_BASE, PAM_BIOS_SIZE);
504     for (i = 0; i < 12; ++i) {
505         init_pam(DEVICE(mch), mch->ram_memory, mch->system_memory,
506                  mch->pci_address_space, &mch->pam_regions[i+1],
507                  PAM_EXPAN_BASE + i * PAM_EXPAN_SIZE, PAM_EXPAN_SIZE);
508     }
509     /* Intel IOMMU (VT-d) */
510     if (object_property_get_bool(qdev_get_machine(), "iommu", NULL)) {
511         mch_init_dmar(mch);
512     }
513 }
514 
515 uint64_t mch_mcfg_base(void)
516 {
517     bool ambiguous;
518     Object *o = object_resolve_path_type("", TYPE_MCH_PCI_DEVICE, &ambiguous);
519     if (!o) {
520         return 0;
521     }
522     return MCH_HOST_BRIDGE_PCIEXBAR_DEFAULT;
523 }
524 
525 static void mch_class_init(ObjectClass *klass, void *data)
526 {
527     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
528     DeviceClass *dc = DEVICE_CLASS(klass);
529 
530     k->realize = mch_realize;
531     k->config_write = mch_write_config;
532     dc->reset = mch_reset;
533     set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
534     dc->desc = "Host bridge";
535     dc->vmsd = &vmstate_mch;
536     k->vendor_id = PCI_VENDOR_ID_INTEL;
537     k->device_id = PCI_DEVICE_ID_INTEL_Q35_MCH;
538     k->revision = MCH_HOST_BRIDGE_REVISION_DEFAULT;
539     k->class_id = PCI_CLASS_BRIDGE_HOST;
540     /*
541      * PCI-facing part of the host bridge, not usable without the
542      * host-facing part, which can't be device_add'ed, yet.
543      */
544     dc->cannot_instantiate_with_device_add_yet = true;
545 }
546 
547 static const TypeInfo mch_info = {
548     .name = TYPE_MCH_PCI_DEVICE,
549     .parent = TYPE_PCI_DEVICE,
550     .instance_size = sizeof(MCHPCIState),
551     .class_init = mch_class_init,
552 };
553 
554 static void q35_register(void)
555 {
556     type_register_static(&mch_info);
557     type_register_static(&q35_host_info);
558 }
559 
560 type_init(q35_register);
561