master
c 841 lines 27.9 KB
Raw
1 /*
2 * IGD device quirks
3 *
4 * Copyright Red Hat, Inc. 2016
5 *
6 * Authors:
7 * Alex Williamson <alex.williamson@redhat.com>
8 *
9 * This work is licensed under the terms of the GNU GPL, version 2. See
10 * the COPYING file in the top-level directory.
11 */
12
13 #include "qemu/osdep.h"
14 #include "qemu/units.h"
15 #include "qemu/error-report.h"
16 #include "qapi/error.h"
17 #include "qapi/qmp/qerror.h"
18 #include "hw/core/boards.h"
19 #include "hw/nvram/fw_cfg.h"
20 #include "pci.h"
21 #include "pci-quirks.h"
22 #include "trace.h"
23
24 /*
25 * Intel IGD support
26 *
27 * Obviously IGD is not a discrete device, this is evidenced not only by it
28 * being integrated into the CPU, but by the various chipset and BIOS
29 * dependencies that it brings along with it. Intel is trying to move away
30 * from this and Broadwell and newer devices can run in what Intel calls
31 * "Universal Pass-Through" mode, or UPT. Theoretically in UPT mode, nothing
32 * more is required beyond assigning the IGD device to a VM. There are
33 * however support limitations to this mode. It only supports IGD as a
34 * secondary graphics device in the VM and it doesn't officially support any
35 * physical outputs.
36 *
37 * The code here attempts to enable what we'll call legacy mode assignment,
38 * IGD retains most of the capabilities we expect for it to have on bare
39 * metal. To enable this mode, the IGD device must be assigned to the VM
40 * at PCI address 00:02.0, it must have a ROM, it very likely needs VGA
41 * support, we must have VM BIOS support for reserving and populating some
42 * of the required tables, and we need to tweak the chipset with revisions
43 * and IDs and an LPC/ISA bridge device. The intention is to make all of
44 * this happen automatically by installing the device at the correct VM PCI
45 * bus address. If any of the conditions are not met, we cross our fingers
46 * and hope the user knows better.
47 *
48 * NB - It is possible to enable physical outputs in UPT mode by supplying
49 * an OpRegion table. We don't do this by default because the guest driver
50 * behaves differently if an OpRegion is provided and no monitor is attached
51 * vs no OpRegion and a monitor being attached or not. Effectively, if a
52 * headless setup is desired, the OpRegion gets in the way of that.
53 */
54
55 /*
56 * This presumes the device is already known to be an Intel VGA device, so we
57 * take liberties in which device ID bits match which generation. This should
58 * not be taken as an indication that all the devices are supported, or even
59 * supportable, some of them don't even support VT-d.
60 * See linux:include/drm/i915_pciids.h for IDs.
61 */
62 static int igd_gen(VFIOPCIDevice *vdev)
63 {
64 /*
65 * Device IDs for Broxton/Apollo Lake are 0x0a84, 0x1a84, 0x1a85, 0x5a84
66 * and 0x5a85, match bit 11:1 here
67 * Prefix 0x0a is taken by Haswell, this rule should be matched first.
68 */
69 if ((vdev->device_id & 0xffe) == 0xa84) {
70 return 9;
71 }
72
73 switch (vdev->device_id & 0xff00) {
74 case 0x0100: /* SandyBridge, IvyBridge */
75 return 6;
76 case 0x0400: /* Haswell */
77 case 0x0a00: /* Haswell */
78 case 0x0c00: /* Haswell */
79 case 0x0d00: /* Haswell */
80 case 0x0f00: /* Valleyview/Bay Trail */
81 return 7;
82 case 0x1600: /* Broadwell */
83 case 0x2200: /* Cherryview */
84 return 8;
85 case 0x1900: /* Skylake */
86 case 0x3100: /* Gemini Lake */
87 case 0x5900: /* Kaby Lake */
88 case 0x3e00: /* Coffee Lake */
89 case 0x9B00: /* Comet Lake */
90 return 9;
91 case 0x8A00: /* Ice Lake */
92 case 0x4500: /* Elkhart Lake */
93 case 0x4E00: /* Jasper Lake */
94 return 11;
95 case 0x9A00: /* Tiger Lake */
96 case 0x4C00: /* Rocket Lake */
97 case 0x4600: /* Alder Lake */
98 case 0xA700: /* Raptor Lake */
99 return 12;
100 }
101
102 /*
103 * Unfortunately, Intel changes it's specification quite often. This makes
104 * it impossible to use a suitable default value for unknown devices.
105 * Return -1 for not applying any generation-specific quirks.
106 */
107 return -1;
108 }
109
110 #define IGD_ASLS 0xfc /* ASL Storage Register */
111 #define IGD_GMCH 0x50 /* Graphics Control Register */
112 #define IGD_BDSM 0x5c /* Base Data of Stolen Memory */
113 #define IGD_BDSM_GEN11 0xc0 /* Base Data of Stolen Memory of gen 11 and later */
114
115 #define IGD_GMCH_VGA_DISABLE BIT(1)
116 #define IGD_GMCH_GEN6_GMS_SHIFT 3 /* SNB_GMCH in i915 */
117 #define IGD_GMCH_GEN6_GMS_MASK 0x1f
118 #define IGD_GMCH_GEN8_GMS_SHIFT 8 /* BDW_GMCH in i915 */
119 #define IGD_GMCH_GEN8_GMS_MASK 0xff
120
121 static uint64_t igd_stolen_memory_size(int gen, uint32_t gmch)
122 {
123 uint64_t gms;
124
125 if (gen < 8) {
126 gms = (gmch >> IGD_GMCH_GEN6_GMS_SHIFT) & IGD_GMCH_GEN6_GMS_MASK;
127 } else {
128 gms = (gmch >> IGD_GMCH_GEN8_GMS_SHIFT) & IGD_GMCH_GEN8_GMS_MASK;
129 }
130
131 if (gen < 9) {
132 return gms * 32 * MiB;
133 } else {
134 if (gms < 0xf0) {
135 return gms * 32 * MiB;
136 } else {
137 return (gms - 0xf0 + 1) * 4 * MiB;
138 }
139 }
140
141 return 0;
142 }
143
144 /*
145 * The OpRegion includes the Video BIOS Table, which seems important for
146 * telling the driver what sort of outputs it has. Without this, the device
147 * may work in the guest, but we may not get output. This also requires BIOS
148 * support to reserve and populate a section of guest memory sufficient for
149 * the table and to write the base address of that memory to the ASLS register
150 * of the IGD device.
151 */
152 static bool vfio_pci_igd_opregion_init(VFIOPCIDevice *vdev,
153 struct vfio_region_info *info,
154 Error **errp)
155 {
156 int ret;
157
158 vdev->igd_opregion = g_malloc0(info->size);
159 ret = pread(vdev->vbasedev.fd, vdev->igd_opregion,
160 info->size, info->offset);
161 if (ret != info->size) {
162 error_setg(errp, "failed to read IGD OpRegion");
163 g_free(vdev->igd_opregion);
164 vdev->igd_opregion = NULL;
165 return false;
166 }
167
168 /*
169 * Provide fw_cfg with a copy of the OpRegion which the VM firmware is to
170 * allocate 32bit reserved memory for, copy these contents into, and write
171 * the reserved memory base address to the device ASLS register at 0xFC.
172 * Alignment of this reserved region seems flexible, but using a 4k page
173 * alignment seems to work well. This interface assumes a single IGD
174 * device, which may be at VM address 00:02.0 in legacy mode or another
175 * address in UPT mode.
176 *
177 * NB, there may be future use cases discovered where the VM should have
178 * direct interaction with the host OpRegion, in which case the write to
179 * the ASLS register would trigger MemoryRegion setup to enable that.
180 */
181 fw_cfg_add_file(fw_cfg_find(), "etc/igd-opregion",
182 vdev->igd_opregion, info->size);
183
184 trace_vfio_pci_igd_opregion_enabled(vdev->vbasedev.name);
185
186 return true;
187 }
188
189 static bool vfio_pci_igd_opregion_detect(VFIOPCIDevice *vdev,
190 struct vfio_region_info **opregion)
191 {
192 int ret;
193
194 ret = vfio_device_get_region_info_type(&vdev->vbasedev,
195 VFIO_REGION_TYPE_PCI_VENDOR_TYPE | PCI_VENDOR_ID_INTEL,
196 VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION, opregion);
197 if (ret) {
198 return false;
199 }
200
201 /* Hotplugging is not supported for opregion access */
202 if (DEVICE(vdev)->hotplugged) {
203 warn_report("IGD device detected, but OpRegion is not supported "
204 "on hotplugged device.");
205 return false;
206 }
207
208 return true;
209 }
210
211 /*
212 * The rather short list of registers that we copy from the host devices.
213 * The LPC/ISA bridge values are definitely needed to support the vBIOS, the
214 * host bridge values may or may not be needed depending on the guest OS.
215 * Since we're only munging revision and subsystem values on the host bridge,
216 * we don't require our own device. The LPC/ISA bridge needs to be our very
217 * own though.
218 */
219 typedef struct {
220 uint8_t offset;
221 uint8_t len;
222 } IGDHostInfo;
223
224 static const IGDHostInfo igd_host_bridge_infos[] = {
225 {PCI_REVISION_ID, 2},
226 {PCI_SUBSYSTEM_VENDOR_ID, 2},
227 {PCI_SUBSYSTEM_ID, 2},
228 };
229
230 static const IGDHostInfo igd_lpc_bridge_infos[] = {
231 {PCI_VENDOR_ID, 2},
232 {PCI_DEVICE_ID, 2},
233 {PCI_REVISION_ID, 2},
234 {PCI_SUBSYSTEM_VENDOR_ID, 2},
235 {PCI_SUBSYSTEM_ID, 2},
236 };
237
238 static int vfio_pci_igd_copy(VFIOPCIDevice *vdev, PCIDevice *pdev,
239 struct vfio_region_info *info,
240 const IGDHostInfo *list, int len)
241 {
242 int i, ret;
243
244 for (i = 0; i < len; i++) {
245 ret = pread(vdev->vbasedev.fd, pdev->config + list[i].offset,
246 list[i].len, info->offset + list[i].offset);
247 if (ret != list[i].len) {
248 error_report("IGD copy failed: %m");
249 return -errno;
250 }
251 }
252
253 return 0;
254 }
255
256 /*
257 * Stuff a few values into the host bridge.
258 */
259 static int vfio_pci_igd_host_init(VFIOPCIDevice *vdev,
260 struct vfio_region_info *info)
261 {
262 PCIDevice *pdev = PCI_DEVICE(vdev);
263 PCIBus *bus;
264 PCIDevice *host_bridge;
265 int ret;
266
267 bus = pci_device_root_bus(pdev);
268 host_bridge = pci_find_device(bus, 0, PCI_DEVFN(0, 0));
269
270 if (!host_bridge) {
271 error_report("Can't find host bridge");
272 return -ENODEV;
273 }
274
275 ret = vfio_pci_igd_copy(vdev, host_bridge, info, igd_host_bridge_infos,
276 ARRAY_SIZE(igd_host_bridge_infos));
277 if (!ret) {
278 trace_vfio_pci_igd_host_bridge_enabled(vdev->vbasedev.name);
279 }
280
281 return ret;
282 }
283
284 /*
285 * IGD LPC/ISA bridge support code. The vBIOS needs this, but we can't write
286 * arbitrary values into just any bridge, so we must create our own. We try
287 * to handle if the user has created it for us, which they might want to do
288 * to enable multifunction so we don't occupy the whole PCI slot.
289 */
290 static void vfio_pci_igd_lpc_bridge_realize(PCIDevice *pdev, Error **errp)
291 {
292 if (pdev->devfn != PCI_DEVFN(0x1f, 0)) {
293 error_setg(errp, "VFIO dummy ISA/LPC bridge must have address 1f.0");
294 }
295 }
296
297 static void vfio_pci_igd_lpc_bridge_class_init(ObjectClass *klass,
298 const void *data)
299 {
300 DeviceClass *dc = DEVICE_CLASS(klass);
301 PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
302
303 set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
304 dc->desc = "VFIO dummy ISA/LPC bridge for IGD assignment";
305 dc->hotpluggable = false;
306 k->realize = vfio_pci_igd_lpc_bridge_realize;
307 k->class_id = PCI_CLASS_BRIDGE_ISA;
308 }
309
310 static const TypeInfo vfio_pci_igd_lpc_bridge_info = {
311 .name = "vfio-pci-igd-lpc-bridge",
312 .parent = TYPE_PCI_DEVICE,
313 .class_init = vfio_pci_igd_lpc_bridge_class_init,
314 .interfaces = (const InterfaceInfo[]) {
315 { INTERFACE_CONVENTIONAL_PCI_DEVICE },
316 { },
317 },
318 };
319
320 static void vfio_pci_igd_register_types(void)
321 {
322 type_register_static(&vfio_pci_igd_lpc_bridge_info);
323 }
324
325 type_init(vfio_pci_igd_register_types)
326
327 static int vfio_pci_igd_lpc_init(VFIOPCIDevice *vdev,
328 struct vfio_region_info *info)
329 {
330 PCIDevice *pdev = PCI_DEVICE(vdev);
331 PCIDevice *lpc_bridge;
332 int ret;
333
334 lpc_bridge = pci_find_device(pci_device_root_bus(pdev),
335 0, PCI_DEVFN(0x1f, 0));
336 if (!lpc_bridge) {
337 lpc_bridge = pci_create_simple(pci_device_root_bus(pdev),
338 PCI_DEVFN(0x1f, 0), "vfio-pci-igd-lpc-bridge");
339 }
340
341 ret = vfio_pci_igd_copy(vdev, lpc_bridge, info, igd_lpc_bridge_infos,
342 ARRAY_SIZE(igd_lpc_bridge_infos));
343 if (!ret) {
344 trace_vfio_pci_igd_lpc_bridge_enabled(vdev->vbasedev.name);
345 }
346
347 return ret;
348 }
349
350 static bool vfio_pci_igd_setup_lpc_bridge(VFIOPCIDevice *vdev, Error **errp)
351 {
352 struct vfio_region_info *host = NULL;
353 struct vfio_region_info *lpc = NULL;
354 PCIDevice *pdev = PCI_DEVICE(vdev);
355 PCIDevice *lpc_bridge;
356 int ret;
357
358 /*
359 * Copying IDs or creating new devices are not supported on hotplug
360 */
361 if (DEVICE(vdev)->hotplugged) {
362 error_setg(errp, "IGD LPC is not supported on hotplugged device");
363 return false;
364 }
365
366 /*
367 * We need to create an LPC/ISA bridge at PCI bus address 00:1f.0 that we
368 * can stuff host values into, so if there's already one there and it's not
369 * one we can hack on, this quirk is no-go. Sorry Q35.
370 */
371 lpc_bridge = pci_find_device(pci_device_root_bus(pdev),
372 0, PCI_DEVFN(0x1f, 0));
373 if (lpc_bridge && !object_dynamic_cast(OBJECT(lpc_bridge),
374 "vfio-pci-igd-lpc-bridge")) {
375 error_setg(errp,
376 "Cannot create LPC bridge due to existing device at 1f.0");
377 return false;
378 }
379
380 /*
381 * Check whether we have all the vfio device specific regions to
382 * support LPC quirk (added in Linux v4.6).
383 */
384 ret = vfio_device_get_region_info_type(&vdev->vbasedev,
385 VFIO_REGION_TYPE_PCI_VENDOR_TYPE | PCI_VENDOR_ID_INTEL,
386 VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG, &lpc);
387 if (ret) {
388 error_setg(errp, "IGD LPC bridge access is not supported by kernel");
389 return false;
390 }
391
392 ret = vfio_device_get_region_info_type(&vdev->vbasedev,
393 VFIO_REGION_TYPE_PCI_VENDOR_TYPE | PCI_VENDOR_ID_INTEL,
394 VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG, &host);
395 if (ret) {
396 error_setg(errp, "IGD host bridge access is not supported by kernel");
397 return false;
398 }
399
400 /* Create/modify LPC bridge */
401 ret = vfio_pci_igd_lpc_init(vdev, lpc);
402 if (ret) {
403 error_setg(errp, "Failed to create/modify LPC bridge for IGD");
404 return false;
405 }
406
407 /* Stuff some host values into the VM PCI host bridge */
408 ret = vfio_pci_igd_host_init(vdev, host);
409 if (ret) {
410 error_setg(errp, "Failed to modify host bridge for IGD");
411 return false;
412 }
413
414 return true;
415 }
416
417 static bool vfio_pci_igd_override_gms(int gen, uint32_t gms, uint32_t *gmch)
418 {
419 bool ret = false;
420
421 if (gen == -1) {
422 error_report("x-igd-gms is not supported on this device");
423 } else if (gen < 8) {
424 if (gms <= 0x10) {
425 *gmch &= ~(IGD_GMCH_GEN6_GMS_MASK << IGD_GMCH_GEN6_GMS_SHIFT);
426 *gmch |= gms << IGD_GMCH_GEN6_GMS_SHIFT;
427 ret = true;
428 } else {
429 error_report(QERR_INVALID_PARAMETER_VALUE, "x-igd-gms", "0~0x10");
430 }
431 } else if (gen == 8) {
432 if (gms <= 0x40) {
433 *gmch &= ~(IGD_GMCH_GEN8_GMS_MASK << IGD_GMCH_GEN8_GMS_SHIFT);
434 *gmch |= gms << IGD_GMCH_GEN8_GMS_SHIFT;
435 ret = true;
436 } else {
437 error_report(QERR_INVALID_PARAMETER_VALUE, "x-igd-gms", "0~0x40");
438 }
439 } else {
440 /* 0x0 to 0x40: 32MB increments starting at 0MB */
441 /* 0xf0 to 0xfe: 4MB increments starting at 4MB */
442 if ((gms <= 0x40) || (gms >= 0xf0 && gms <= 0xfe)) {
443 *gmch &= ~(IGD_GMCH_GEN8_GMS_MASK << IGD_GMCH_GEN8_GMS_SHIFT);
444 *gmch |= gms << IGD_GMCH_GEN8_GMS_SHIFT;
445 ret = true;
446 } else {
447 error_report(QERR_INVALID_PARAMETER_VALUE,
448 "x-igd-gms", "0~0x40 or 0xf0~0xfe");
449 }
450 }
451
452 return ret;
453 }
454
455 #define IGD_GGC_MMIO_OFFSET 0x108040
456 #define IGD_BDSM_MMIO_OFFSET 0x1080C0
457
458 void vfio_probe_igd_bar0_quirk(VFIOPCIDevice *vdev, int nr)
459 {
460 VFIOQuirk *ggc_quirk, *bdsm_quirk;
461 VFIOConfigMirrorQuirk *ggc_mirror, *bdsm_mirror;
462 int gen;
463
464 if (!vfio_pci_is(vdev, PCI_VENDOR_ID_INTEL, PCI_ANY_ID) ||
465 !vfio_is_base_display(vdev) || nr != 0) {
466 return;
467 }
468
469 /* Only on IGD Gen6-12 device needs quirks in BAR 0 */
470 gen = igd_gen(vdev);
471 if (gen < 6) {
472 return;
473 }
474
475 if (vdev->igd_gms) {
476 ggc_quirk = vfio_quirk_alloc(1);
477 ggc_mirror = ggc_quirk->data = g_malloc0(sizeof(*ggc_mirror));
478 ggc_mirror->mem = ggc_quirk->mem;
479 ggc_mirror->vdev = vdev;
480 ggc_mirror->bar = nr;
481 ggc_mirror->offset = IGD_GGC_MMIO_OFFSET;
482 ggc_mirror->config_offset = IGD_GMCH;
483
484 memory_region_init_io(ggc_mirror->mem, OBJECT(vdev),
485 &vfio_generic_mirror_quirk, ggc_mirror,
486 "vfio-igd-ggc-quirk", 2);
487 memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
488 ggc_mirror->offset, ggc_mirror->mem,
489 1);
490
491 QLIST_INSERT_HEAD(&vdev->bars[nr].quirks, ggc_quirk, next);
492 }
493
494 bdsm_quirk = vfio_quirk_alloc(1);
495 bdsm_mirror = bdsm_quirk->data = g_malloc0(sizeof(*bdsm_mirror));
496 bdsm_mirror->mem = bdsm_quirk->mem;
497 bdsm_mirror->vdev = vdev;
498 bdsm_mirror->bar = nr;
499 bdsm_mirror->offset = IGD_BDSM_MMIO_OFFSET;
500 bdsm_mirror->config_offset = (gen < 11) ? IGD_BDSM : IGD_BDSM_GEN11;
501
502 memory_region_init_io(bdsm_mirror->mem, OBJECT(vdev),
503 &vfio_generic_mirror_quirk, bdsm_mirror,
504 "vfio-igd-bdsm-quirk", (gen < 11) ? 4 : 8);
505 memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
506 bdsm_mirror->offset, bdsm_mirror->mem,
507 1);
508
509 QLIST_INSERT_HEAD(&vdev->bars[nr].quirks, bdsm_quirk, next);
510 }
511
512 static bool vfio_pci_igd_config_quirk(VFIOPCIDevice *vdev, Error **errp)
513 {
514 struct vfio_region_info *opregion = NULL;
515 PCIDevice *pdev = PCI_DEVICE(vdev);
516 int ret, gen;
517 uint64_t gms_size = 0;
518 uint64_t *bdsm_size;
519 uint32_t gmch;
520 bool legacy_mode_enabled = false;
521 Error *err = NULL;
522
523 if (!vfio_pci_is(vdev, PCI_VENDOR_ID_INTEL, PCI_ANY_ID) ||
524 !vfio_is_base_display(vdev)) {
525 return true;
526 }
527
528 /* IGD device always comes with OpRegion */
529 if (!vfio_pci_igd_opregion_detect(vdev, &opregion)) {
530 return true;
531 }
532 info_report("OpRegion detected on Intel display %x.", vdev->device_id);
533
534 gen = igd_gen(vdev);
535 gmch = vfio_pci_read_config(pdev, IGD_GMCH, 4);
536
537 /*
538 * For backward compatibility, enable legacy mode when
539 * - Device geneation is 6 to 9 (including both)
540 * - IGD exposes itself as VGA controller and claims VGA cycles on host
541 * - Machine type is i440fx (pc_piix)
542 * - IGD device is at guest BDF 00:02.0
543 * - Not manually disabled by x-igd-legacy-mode=off
544 */
545 if ((vdev->igd_legacy_mode != ON_OFF_AUTO_OFF) &&
546 vfio_is_vga(vdev) &&
547 (gen >= 6 && gen <= 9) &&
548 !(gmch & IGD_GMCH_VGA_DISABLE) &&
549 !strcmp(MACHINE_GET_CLASS(qdev_get_machine())->family, "pc_piix") &&
550 (pdev == pci_find_device(pci_device_root_bus(pdev),
551 0, PCI_DEVFN(0x2, 0)))) {
552 /*
553 * IGD legacy mode requires:
554 * - VBIOS in ROM BAR or file
555 * - VGA IO/MMIO ranges are claimed by IGD
556 * - OpRegion
557 * - Same LPC bridge and Host bridge VID/DID/SVID/SSID as host
558 */
559 struct vfio_region_info *rom = NULL;
560
561 legacy_mode_enabled = true;
562 info_report("IGD legacy mode enabled, "
563 "use x-igd-legacy-mode=off to disable it if unwanted.");
564
565 /*
566 * Most of what we're doing here is to enable the ROM to run, so if
567 * there's no ROM, there's no point in setting up this quirk.
568 * NB. We only seem to get BIOS ROMs, so UEFI VM would need CSM support.
569 */
570 ret = vfio_device_get_region_info(&vdev->vbasedev,
571 VFIO_PCI_ROM_REGION_INDEX, &rom);
572 if ((ret || !rom->size) && !pdev->romfile) {
573 error_setg(&err, "Device has no ROM");
574 goto error;
575 }
576
577 /*
578 * If VGA is not already enabled, try to enable it. We shouldn't be
579 * using legacy mode without VGA.
580 */
581 if (!vdev->vga) {
582 if (vfio_populate_vga(vdev, &err)) {
583 vfio_pci_config_register_vga(vdev);
584 } else {
585 error_setg(&err, "Unable to enable VGA access");
586 goto error;
587 }
588 }
589
590 /* Enable OpRegion and LPC bridge quirk */
591 vdev->features |= VFIO_FEATURE_ENABLE_IGD_OPREGION;
592 vdev->features |= VFIO_FEATURE_ENABLE_IGD_LPC;
593 } else if (vdev->igd_legacy_mode == ON_OFF_AUTO_ON) {
594 error_setg(&err,
595 "Machine is not i440fx, assigned BDF is not 00:02.0, "
596 "or device %04x (gen %d) doesn't support legacy mode",
597 vdev->device_id, gen);
598 goto error;
599 }
600
601 /* Setup OpRegion access */
602 if ((vdev->features & VFIO_FEATURE_ENABLE_IGD_OPREGION) &&
603 !vfio_pci_igd_opregion_init(vdev, opregion, errp)) {
604 goto error;
605 }
606
607 /* Setup LPC bridge / Host bridge PCI IDs */
608 if ((vdev->features & VFIO_FEATURE_ENABLE_IGD_LPC) &&
609 !vfio_pci_igd_setup_lpc_bridge(vdev, errp)) {
610 goto error;
611 }
612
613 /*
614 * ASLS (OpRegion address) is read-only, emulated
615 * It contains HPA, guest firmware need to reprogram it with GPA.
616 */
617 pci_set_long(pdev->config + IGD_ASLS, 0);
618 pci_set_long(pdev->wmask + IGD_ASLS, ~0);
619 pci_set_long(vdev->emulated_config_bits + IGD_ASLS, ~0);
620
621 /*
622 * Allow user to override dsm size using x-igd-gms option, in multiples of
623 * 32MiB. This option should only be used when the desired size cannot be
624 * set from DVMT Pre-Allocated option in host BIOS.
625 */
626 if (vdev->igd_gms) {
627 if (!vfio_pci_igd_override_gms(gen, vdev->igd_gms, &gmch)) {
628 return false;
629 }
630
631 /* GMCH is read-only, emulated */
632 pci_set_long(pdev->config + IGD_GMCH, gmch);
633 pci_set_long(pdev->wmask + IGD_GMCH, 0);
634 pci_set_long(vdev->emulated_config_bits + IGD_GMCH, ~0);
635 }
636
637 if (gen > 0) {
638 gms_size = igd_stolen_memory_size(gen, gmch);
639
640 /* BDSM is read-write, emulated. BIOS needs to be able to write it */
641 if (gen < 11) {
642 pci_set_long(pdev->config + IGD_BDSM, 0);
643 pci_set_long(pdev->wmask + IGD_BDSM, ~0);
644 pci_set_long(vdev->emulated_config_bits + IGD_BDSM, ~0);
645 } else {
646 pci_set_quad(pdev->config + IGD_BDSM_GEN11, 0);
647 pci_set_quad(pdev->wmask + IGD_BDSM_GEN11, ~0);
648 pci_set_quad(vdev->emulated_config_bits + IGD_BDSM_GEN11, ~0);
649 }
650 }
651
652 /*
653 * Request reserved memory for stolen memory via fw_cfg. VM firmware
654 * must allocate a 1MB aligned reserved memory region below 4GB with
655 * the requested size (in bytes) for use by the IGD device. The base
656 * address of this reserved memory region must be written to the
657 * device BDSM register.
658 * For newer device without BDSM register, this fw_cfg item is 0.
659 */
660 bdsm_size = g_malloc(sizeof(*bdsm_size));
661 *bdsm_size = cpu_to_le64(gms_size);
662 fw_cfg_add_file(fw_cfg_find(), "etc/igd-bdsm-size",
663 bdsm_size, sizeof(*bdsm_size));
664
665 trace_vfio_pci_igd_bdsm_enabled(vdev->vbasedev.name, (gms_size / MiB));
666
667 return true;
668
669 error:
670 /*
671 * When legacy mode is implicity enabled, continue on error,
672 * to keep compatibility
673 */
674 if (legacy_mode_enabled && (vdev->igd_legacy_mode == ON_OFF_AUTO_AUTO)) {
675 error_report_err(err);
676 error_report("IGD legacy mode disabled");
677 return true;
678 }
679
680 error_propagate(errp, err);
681 return false;
682 }
683
684 /*
685 * KVMGT/GVT-g vGPU exposes an emulated OpRegion. So far, users have to specify
686 * x-igd-opregion=on to enable the access.
687 * TODO: Check VID/DID and enable opregion access automatically
688 */
689 static bool vfio_pci_kvmgt_config_quirk(VFIOPCIDevice *vdev, Error **errp)
690 {
691 struct vfio_region_info *opregion = NULL;
692 int gen;
693
694 if (!vfio_pci_is(vdev, PCI_VENDOR_ID_INTEL, PCI_ANY_ID) ||
695 !vfio_is_vga(vdev)) {
696 return true;
697 }
698
699 /* FIXME: Cherryview is Gen8, but don't support GVT-g */
700 gen = igd_gen(vdev);
701 if (gen != 8 && gen != 9) {
702 return true;
703 }
704
705 if (!vfio_pci_igd_opregion_detect(vdev, &opregion)) {
706 /* Should never reach here, KVMGT always emulates OpRegion */
707 return false;
708 }
709
710 if ((vdev->features & VFIO_FEATURE_ENABLE_IGD_OPREGION) &&
711 !vfio_pci_igd_opregion_init(vdev, opregion, errp)) {
712 return false;
713 }
714
715 return true;
716 }
717
718 bool vfio_probe_igd_config_quirk(VFIOPCIDevice *vdev, Error **errp)
719 {
720 /* KVMGT/GVT-g vGPU is exposed as mdev */
721 if (vdev->vbasedev.mdev) {
722 return vfio_pci_kvmgt_config_quirk(vdev, errp);
723 }
724
725 return vfio_pci_igd_config_quirk(vdev, errp);
726 }
727
728 /*
729 * IGD ROM BAR read from kernel is actually the host VBIOS shadow RAM region,
730 * which contains host modifications. In Gen 6-9 VBIOS, the routine below is
731 * used to get BDSM value when programming the initial GTT.
732 * xx xx xx xx v: .long ? # saved value
733 * 66 53 push %ebx
734 * 66 2e 83 3e xx xx 00 cmpl $0x0,%cs:v # is saved value empty?
735 * 74 07 je 1f # if zero, go compute
736 * 66 2e a1 xx xx mov %cs:v,%eax # else return saved value
737 * eb 0f jmp 2f
738 * b8 5e 10 1: mov $0x105e,%ax # dev 00:02.0, offset 5E
739 * e8 xx xx call pci_read_cfg_word
740 * 66 c1 e0 10 shl $0x10,%eax # left shift 16 bits
741 * 66 2e a3 xx xx mov %eax,%cs:v # save the result
742 * 66 5b 2: pop %ebx
743 * c3 ret
744 * When running the VBIOS in guest, saved value still reflects the host stolen
745 * memory base address, which is not correct in guest. So we need to patch the
746 * VBIOS to clear the saved value.
747 *
748 * The unique 19-byte starts at `cmpl $0,%cs:v` and ends at `mov $0x105e,%ax`
749 * anchors the match to the routine. Both `cs:` displacements must reference
750 * the same offset.
751 */
752 static int igd_vbios_find_saved_bdsm(const uint8_t *rom, size_t rom_size,
753 uint16_t *bdsm_offset)
754 {
755 static const uint8_t start[] = { 0x66, 0x2e, 0x83, 0x3e };
756 static const uint8_t middle[] = { 0x00, 0x74, 0x07, 0x66, 0x2e, 0xa1 };
757 static const uint8_t end[] = { 0xeb, 0x0f, 0xb8, 0x5e, 0x10 };
758 uint16_t val;
759 size_t i;
760 bool found = false;
761
762 if (rom_size < 19) {
763 return -ENOENT;
764 }
765
766 for (i = 0; i + 19 <= rom_size; i++) {
767 if (memcmp(rom + i, start, sizeof(start)) != 0 ||
768 memcmp(rom + i + 6, middle, sizeof(middle)) != 0 ||
769 memcmp(rom + i + 14, end, sizeof(end)) != 0) {
770 continue;
771 }
772
773 /* same saved value address? */
774 if (rom[i + 4] != rom[i + 12] || rom[i + 5] != rom[i + 13]) {
775 continue;
776 }
777
778 if (found) {
779 return -EEXIST;
780 }
781
782 val = rom[i + 4] | ((uint16_t)rom[i + 5] << 8);
783 if (val + sizeof(uint32_t) <= rom_size) {
784 *bdsm_offset = val;
785 found = true;
786 }
787 }
788
789 if (!found) {
790 return -ENOENT;
791 }
792
793 return 0;
794 }
795
796 void vfio_igd_legacy_rom_quirk(VFIOPCIDevice *vdev)
797 {
798 uint8_t *rom = vdev->rom;
799 int gen;
800 uint16_t pcir_offset;
801 uint16_t bdsm_offset = 0;
802 uint8_t checksum = 0;
803 uint32_t i;
804
805 if (!vfio_pci_is(vdev, PCI_VENDOR_ID_INTEL, PCI_ANY_ID) ||
806 !vfio_is_vga(vdev) || !vdev->vga) {
807 return;
808 }
809
810 /* Only Gen 6~9 devices have legacy VBIOS as Option ROM */
811 gen = igd_gen(vdev);
812 if (gen < 6 || gen > 9) {
813 return;
814 }
815
816 if (pci_get_word(rom) != 0xaa55) {
817 return;
818 }
819
820 /* Must be a legacy ROM */
821 pcir_offset = pci_get_word(rom + 0x18);
822 if (pcir_offset + 0x14 >= vdev->rom_size ||
823 memcmp(rom + pcir_offset, "PCIR", 4) ||
824 pci_get_byte(rom + pcir_offset + 0x14) != 0x00) {
825 return;
826 }
827
828 /* Search and clear the saved BDSM value */
829 if (igd_vbios_find_saved_bdsm(rom, vdev->rom_size, &bdsm_offset)) {
830 return;
831 }
832 memset(rom + bdsm_offset, 0, sizeof(uint32_t));
833
834 /* Recalculate checksum and patch it. */
835 for (i = 0; i < vdev->rom_size; i++) {
836 checksum += rom[i];
837 }
838 rom[6] -= checksum;
839
840 trace_vfio_pci_igd_vbios_patched(vdev->vbasedev.name);
841 }