xref: /qemu/hw/vfio/igd.c (revision 2a53c4f5c534a1ab825ba03e0d3ec45a7c2b90d8)
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/boards.h"
19 #include "hw/hw.h"
20 #include "hw/nvram/fw_cfg.h"
21 #include "pci.h"
22 #include "pci-quirks.h"
23 #include "trace.h"
24 
25 /*
26  * Intel IGD support
27  *
28  * Obviously IGD is not a discrete device, this is evidenced not only by it
29  * being integrated into the CPU, but by the various chipset and BIOS
30  * dependencies that it brings along with it.  Intel is trying to move away
31  * from this and Broadwell and newer devices can run in what Intel calls
32  * "Universal Pass-Through" mode, or UPT.  Theoretically in UPT mode, nothing
33  * more is required beyond assigning the IGD device to a VM.  There are
34  * however support limitations to this mode.  It only supports IGD as a
35  * secondary graphics device in the VM and it doesn't officially support any
36  * physical outputs.
37  *
38  * The code here attempts to enable what we'll call legacy mode assignment,
39  * IGD retains most of the capabilities we expect for it to have on bare
40  * metal.  To enable this mode, the IGD device must be assigned to the VM
41  * at PCI address 00:02.0, it must have a ROM, it very likely needs VGA
42  * support, we must have VM BIOS support for reserving and populating some
43  * of the required tables, and we need to tweak the chipset with revisions
44  * and IDs and an LPC/ISA bridge device.  The intention is to make all of
45  * this happen automatically by installing the device at the correct VM PCI
46  * bus address.  If any of the conditions are not met, we cross our fingers
47  * and hope the user knows better.
48  *
49  * NB - It is possible to enable physical outputs in UPT mode by supplying
50  * an OpRegion table.  We don't do this by default because the guest driver
51  * behaves differently if an OpRegion is provided and no monitor is attached
52  * vs no OpRegion and a monitor being attached or not.  Effectively, if a
53  * headless setup is desired, the OpRegion gets in the way of that.
54  */
55 
56 /*
57  * This presumes the device is already known to be an Intel VGA device, so we
58  * take liberties in which device ID bits match which generation.  This should
59  * not be taken as an indication that all the devices are supported, or even
60  * supportable, some of them don't even support VT-d.
61  * See linux:include/drm/i915_pciids.h for IDs.
62  */
igd_gen(VFIOPCIDevice * vdev)63 static int igd_gen(VFIOPCIDevice *vdev)
64 {
65     /*
66      * Device IDs for Broxton/Apollo Lake are 0x0a84, 0x1a84, 0x1a85, 0x5a84
67      * and 0x5a85, match bit 11:1 here
68      * Prefix 0x0a is taken by Haswell, this rule should be matched first.
69      */
70     if ((vdev->device_id & 0xffe) == 0xa84) {
71         return 9;
72     }
73 
74     switch (vdev->device_id & 0xff00) {
75     case 0x0100:    /* SandyBridge, IvyBridge */
76         return 6;
77     case 0x0400:    /* Haswell */
78     case 0x0a00:    /* Haswell */
79     case 0x0c00:    /* Haswell */
80     case 0x0d00:    /* Haswell */
81     case 0x0f00:    /* Valleyview/Bay Trail */
82         return 7;
83     case 0x1600:    /* Broadwell */
84     case 0x2200:    /* Cherryview */
85         return 8;
86     case 0x1900:    /* Skylake */
87     case 0x3100:    /* Gemini Lake */
88     case 0x5900:    /* Kaby Lake */
89     case 0x3e00:    /* Coffee Lake */
90     case 0x9B00:    /* Comet Lake */
91         return 9;
92     case 0x8A00:    /* Ice Lake */
93     case 0x4500:    /* Elkhart Lake */
94     case 0x4E00:    /* Jasper Lake */
95         return 11;
96     case 0x9A00:    /* Tiger Lake */
97     case 0x4C00:    /* Rocket Lake */
98     case 0x4600:    /* Alder Lake */
99     case 0xA700:    /* Raptor Lake */
100         return 12;
101     }
102 
103     /*
104      * Unfortunately, Intel changes it's specification quite often. This makes
105      * it impossible to use a suitable default value for unknown devices.
106      * Return -1 for not applying any generation-specific quirks.
107      */
108     return -1;
109 }
110 
111 #define IGD_ASLS 0xfc /* ASL Storage Register */
112 #define IGD_GMCH 0x50 /* Graphics Control Register */
113 #define IGD_BDSM 0x5c /* Base Data of Stolen Memory */
114 #define IGD_BDSM_GEN11 0xc0 /* Base Data of Stolen Memory of gen 11 and later */
115 
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 
igd_stolen_memory_size(int gen,uint32_t gmch)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  */
vfio_pci_igd_opregion_init(VFIOPCIDevice * vdev,struct vfio_region_info * info,Error ** errp)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 
vfio_pci_igd_opregion_detect(VFIOPCIDevice * vdev,struct vfio_region_info ** opregion)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 (vdev->pdev.qdev.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 
vfio_pci_igd_copy(VFIOPCIDevice * vdev,PCIDevice * pdev,struct vfio_region_info * info,const IGDHostInfo * list,int len)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  */
vfio_pci_igd_host_init(VFIOPCIDevice * vdev,struct vfio_region_info * info)259 static int vfio_pci_igd_host_init(VFIOPCIDevice *vdev,
260                                   struct vfio_region_info *info)
261 {
262     PCIBus *bus;
263     PCIDevice *host_bridge;
264     int ret;
265 
266     bus = pci_device_root_bus(&vdev->pdev);
267     host_bridge = pci_find_device(bus, 0, PCI_DEVFN(0, 0));
268 
269     if (!host_bridge) {
270         error_report("Can't find host bridge");
271         return -ENODEV;
272     }
273 
274     ret = vfio_pci_igd_copy(vdev, host_bridge, info, igd_host_bridge_infos,
275                             ARRAY_SIZE(igd_host_bridge_infos));
276     if (!ret) {
277         trace_vfio_pci_igd_host_bridge_enabled(vdev->vbasedev.name);
278     }
279 
280     return ret;
281 }
282 
283 /*
284  * IGD LPC/ISA bridge support code.  The vBIOS needs this, but we can't write
285  * arbitrary values into just any bridge, so we must create our own.  We try
286  * to handle if the user has created it for us, which they might want to do
287  * to enable multifunction so we don't occupy the whole PCI slot.
288  */
vfio_pci_igd_lpc_bridge_realize(PCIDevice * pdev,Error ** errp)289 static void vfio_pci_igd_lpc_bridge_realize(PCIDevice *pdev, Error **errp)
290 {
291     if (pdev->devfn != PCI_DEVFN(0x1f, 0)) {
292         error_setg(errp, "VFIO dummy ISA/LPC bridge must have address 1f.0");
293     }
294 }
295 
vfio_pci_igd_lpc_bridge_class_init(ObjectClass * klass,const void * data)296 static void vfio_pci_igd_lpc_bridge_class_init(ObjectClass *klass,
297                                                const void *data)
298 {
299     DeviceClass *dc = DEVICE_CLASS(klass);
300     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
301 
302     set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
303     dc->desc = "VFIO dummy ISA/LPC bridge for IGD assignment";
304     dc->hotpluggable = false;
305     k->realize = vfio_pci_igd_lpc_bridge_realize;
306     k->class_id = PCI_CLASS_BRIDGE_ISA;
307 }
308 
309 static const TypeInfo vfio_pci_igd_lpc_bridge_info = {
310     .name = "vfio-pci-igd-lpc-bridge",
311     .parent = TYPE_PCI_DEVICE,
312     .class_init = vfio_pci_igd_lpc_bridge_class_init,
313     .interfaces = (const InterfaceInfo[]) {
314         { INTERFACE_CONVENTIONAL_PCI_DEVICE },
315         { },
316     },
317 };
318 
vfio_pci_igd_register_types(void)319 static void vfio_pci_igd_register_types(void)
320 {
321     type_register_static(&vfio_pci_igd_lpc_bridge_info);
322 }
323 
type_init(vfio_pci_igd_register_types)324 type_init(vfio_pci_igd_register_types)
325 
326 static int vfio_pci_igd_lpc_init(VFIOPCIDevice *vdev,
327                                  struct vfio_region_info *info)
328 {
329     PCIDevice *lpc_bridge;
330     int ret;
331 
332     lpc_bridge = pci_find_device(pci_device_root_bus(&vdev->pdev),
333                                  0, PCI_DEVFN(0x1f, 0));
334     if (!lpc_bridge) {
335         lpc_bridge = pci_create_simple(pci_device_root_bus(&vdev->pdev),
336                                  PCI_DEVFN(0x1f, 0), "vfio-pci-igd-lpc-bridge");
337     }
338 
339     ret = vfio_pci_igd_copy(vdev, lpc_bridge, info, igd_lpc_bridge_infos,
340                             ARRAY_SIZE(igd_lpc_bridge_infos));
341     if (!ret) {
342         trace_vfio_pci_igd_lpc_bridge_enabled(vdev->vbasedev.name);
343     }
344 
345     return ret;
346 }
347 
vfio_pci_igd_setup_lpc_bridge(VFIOPCIDevice * vdev,Error ** errp)348 static bool vfio_pci_igd_setup_lpc_bridge(VFIOPCIDevice *vdev, Error **errp)
349 {
350     struct vfio_region_info *host = NULL;
351     struct vfio_region_info *lpc = NULL;
352     PCIDevice *lpc_bridge;
353     int ret;
354 
355     /*
356      * Copying IDs or creating new devices are not supported on hotplug
357      */
358     if (vdev->pdev.qdev.hotplugged) {
359         error_setg(errp, "IGD LPC is not supported on hotplugged device");
360         return false;
361     }
362 
363     /*
364      * We need to create an LPC/ISA bridge at PCI bus address 00:1f.0 that we
365      * can stuff host values into, so if there's already one there and it's not
366      * one we can hack on, this quirk is no-go.  Sorry Q35.
367      */
368     lpc_bridge = pci_find_device(pci_device_root_bus(&vdev->pdev),
369                                  0, PCI_DEVFN(0x1f, 0));
370     if (lpc_bridge && !object_dynamic_cast(OBJECT(lpc_bridge),
371                                            "vfio-pci-igd-lpc-bridge")) {
372         error_setg(errp,
373                    "Cannot create LPC bridge due to existing device at 1f.0");
374         return false;
375     }
376 
377     /*
378      * Check whether we have all the vfio device specific regions to
379      * support LPC quirk (added in Linux v4.6).
380      */
381     ret = vfio_device_get_region_info_type(&vdev->vbasedev,
382                         VFIO_REGION_TYPE_PCI_VENDOR_TYPE | PCI_VENDOR_ID_INTEL,
383                         VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG, &lpc);
384     if (ret) {
385         error_setg(errp, "IGD LPC bridge access is not supported by kernel");
386         return false;
387     }
388 
389     ret = vfio_device_get_region_info_type(&vdev->vbasedev,
390                         VFIO_REGION_TYPE_PCI_VENDOR_TYPE | PCI_VENDOR_ID_INTEL,
391                         VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG, &host);
392     if (ret) {
393         error_setg(errp, "IGD host bridge access is not supported by kernel");
394         return false;
395     }
396 
397     /* Create/modify LPC bridge */
398     ret = vfio_pci_igd_lpc_init(vdev, lpc);
399     if (ret) {
400         error_setg(errp, "Failed to create/modify LPC bridge for IGD");
401         return false;
402     }
403 
404     /* Stuff some host values into the VM PCI host bridge */
405     ret = vfio_pci_igd_host_init(vdev, host);
406     if (ret) {
407         error_setg(errp, "Failed to modify host bridge for IGD");
408         return false;
409     }
410 
411     return true;
412 }
413 
vfio_pci_igd_override_gms(int gen,uint32_t gms,uint32_t * gmch)414 static bool vfio_pci_igd_override_gms(int gen, uint32_t gms, uint32_t *gmch)
415 {
416     bool ret = false;
417 
418     if (gen == -1) {
419         error_report("x-igd-gms is not supported on this device");
420     } else if (gen < 8) {
421         if (gms <= 0x10) {
422             *gmch &= ~(IGD_GMCH_GEN6_GMS_MASK << IGD_GMCH_GEN6_GMS_SHIFT);
423             *gmch |= gms << IGD_GMCH_GEN6_GMS_SHIFT;
424             ret = true;
425         } else {
426             error_report(QERR_INVALID_PARAMETER_VALUE, "x-igd-gms", "0~0x10");
427         }
428     } else if (gen == 8) {
429         if (gms <= 0x40) {
430             *gmch &= ~(IGD_GMCH_GEN8_GMS_MASK << IGD_GMCH_GEN8_GMS_SHIFT);
431             *gmch |= gms << IGD_GMCH_GEN8_GMS_SHIFT;
432             ret = true;
433         } else {
434             error_report(QERR_INVALID_PARAMETER_VALUE, "x-igd-gms", "0~0x40");
435         }
436     } else {
437         /* 0x0  to 0x40: 32MB increments starting at 0MB */
438         /* 0xf0 to 0xfe: 4MB increments starting at 4MB */
439         if ((gms <= 0x40) || (gms >= 0xf0 && gms <= 0xfe)) {
440             *gmch &= ~(IGD_GMCH_GEN8_GMS_MASK << IGD_GMCH_GEN8_GMS_SHIFT);
441             *gmch |= gms << IGD_GMCH_GEN8_GMS_SHIFT;
442             ret = true;
443         } else {
444             error_report(QERR_INVALID_PARAMETER_VALUE,
445                          "x-igd-gms", "0~0x40 or 0xf0~0xfe");
446         }
447     }
448 
449     return ret;
450 }
451 
452 #define IGD_GGC_MMIO_OFFSET     0x108040
453 #define IGD_BDSM_MMIO_OFFSET    0x1080C0
454 
vfio_probe_igd_bar0_quirk(VFIOPCIDevice * vdev,int nr)455 void vfio_probe_igd_bar0_quirk(VFIOPCIDevice *vdev, int nr)
456 {
457     VFIOQuirk *ggc_quirk, *bdsm_quirk;
458     VFIOConfigMirrorQuirk *ggc_mirror, *bdsm_mirror;
459     int gen;
460 
461     if (!vfio_pci_is(vdev, PCI_VENDOR_ID_INTEL, PCI_ANY_ID) ||
462         !vfio_is_vga(vdev) || nr != 0) {
463         return;
464     }
465 
466     /* Only on IGD Gen6-12 device needs quirks in BAR 0 */
467     gen = igd_gen(vdev);
468     if (gen < 6) {
469         return;
470     }
471 
472     if (vdev->igd_gms) {
473         ggc_quirk = vfio_quirk_alloc(1);
474         ggc_mirror = ggc_quirk->data = g_malloc0(sizeof(*ggc_mirror));
475         ggc_mirror->mem = ggc_quirk->mem;
476         ggc_mirror->vdev = vdev;
477         ggc_mirror->bar = nr;
478         ggc_mirror->offset = IGD_GGC_MMIO_OFFSET;
479         ggc_mirror->config_offset = IGD_GMCH;
480 
481         memory_region_init_io(ggc_mirror->mem, OBJECT(vdev),
482                               &vfio_generic_mirror_quirk, ggc_mirror,
483                               "vfio-igd-ggc-quirk", 2);
484         memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
485                                             ggc_mirror->offset, ggc_mirror->mem,
486                                             1);
487 
488         QLIST_INSERT_HEAD(&vdev->bars[nr].quirks, ggc_quirk, next);
489     }
490 
491     bdsm_quirk = vfio_quirk_alloc(1);
492     bdsm_mirror = bdsm_quirk->data = g_malloc0(sizeof(*bdsm_mirror));
493     bdsm_mirror->mem = bdsm_quirk->mem;
494     bdsm_mirror->vdev = vdev;
495     bdsm_mirror->bar = nr;
496     bdsm_mirror->offset = IGD_BDSM_MMIO_OFFSET;
497     bdsm_mirror->config_offset = (gen < 11) ? IGD_BDSM : IGD_BDSM_GEN11;
498 
499     memory_region_init_io(bdsm_mirror->mem, OBJECT(vdev),
500                           &vfio_generic_mirror_quirk, bdsm_mirror,
501                           "vfio-igd-bdsm-quirk", (gen < 11) ? 4 : 8);
502     memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
503                                         bdsm_mirror->offset, bdsm_mirror->mem,
504                                         1);
505 
506     QLIST_INSERT_HEAD(&vdev->bars[nr].quirks, bdsm_quirk, next);
507 }
508 
vfio_pci_igd_config_quirk(VFIOPCIDevice * vdev,Error ** errp)509 static bool vfio_pci_igd_config_quirk(VFIOPCIDevice *vdev, Error **errp)
510 {
511     struct vfio_region_info *opregion = NULL;
512     int ret, gen;
513     uint64_t gms_size = 0;
514     uint64_t *bdsm_size;
515     uint32_t gmch;
516     bool legacy_mode_enabled = false;
517     Error *err = NULL;
518 
519     if (!vfio_pci_is(vdev, PCI_VENDOR_ID_INTEL, PCI_ANY_ID) ||
520         !vfio_is_vga(vdev)) {
521         return true;
522     }
523 
524     /* IGD device always comes with OpRegion */
525     if (!vfio_pci_igd_opregion_detect(vdev, &opregion)) {
526         return true;
527     }
528     info_report("OpRegion detected on Intel display %x.", vdev->device_id);
529 
530     gen = igd_gen(vdev);
531     gmch = vfio_pci_read_config(&vdev->pdev, IGD_GMCH, 4);
532 
533     /*
534      * For backward compatibility, enable legacy mode when
535      * - Device geneation is 6 to 9 (including both)
536      * - Machine type is i440fx (pc_piix)
537      * - IGD device is at guest BDF 00:02.0
538      * - Not manually disabled by x-igd-legacy-mode=off
539      */
540     if ((vdev->igd_legacy_mode != ON_OFF_AUTO_OFF) &&
541         (gen >= 6 && gen <= 9) &&
542         !strcmp(MACHINE_GET_CLASS(qdev_get_machine())->family, "pc_piix") &&
543         (&vdev->pdev == pci_find_device(pci_device_root_bus(&vdev->pdev),
544         0, PCI_DEVFN(0x2, 0)))) {
545         /*
546          * IGD legacy mode requires:
547          * - VBIOS in ROM BAR or file
548          * - VGA IO/MMIO ranges are claimed by IGD
549          * - OpRegion
550          * - Same LPC bridge and Host bridge VID/DID/SVID/SSID as host
551          */
552         struct vfio_region_info *rom = NULL;
553 
554         legacy_mode_enabled = true;
555         info_report("IGD legacy mode enabled, "
556                     "use x-igd-legacy-mode=off to disable it if unwanted.");
557 
558         /*
559          * Most of what we're doing here is to enable the ROM to run, so if
560          * there's no ROM, there's no point in setting up this quirk.
561          * NB. We only seem to get BIOS ROMs, so UEFI VM would need CSM support.
562          */
563         ret = vfio_device_get_region_info(&vdev->vbasedev,
564                                           VFIO_PCI_ROM_REGION_INDEX, &rom);
565         if ((ret || !rom->size) && !vdev->pdev.romfile) {
566             error_setg(&err, "Device has no ROM");
567             goto error;
568         }
569 
570         /*
571          * If IGD VGA Disable is clear (expected) and VGA is not already
572          * enabled, try to enable it. Probably shouldn't be using legacy mode
573          * without VGA, but also no point in us enabling VGA if disabled in
574          * hardware.
575          */
576         if (!(gmch & 0x2) && !vdev->vga && !vfio_populate_vga(vdev, &err)) {
577             error_setg(&err, "Unable to enable VGA access");
578             goto error;
579         }
580 
581         /* Enable OpRegion and LPC bridge quirk */
582         vdev->features |= VFIO_FEATURE_ENABLE_IGD_OPREGION;
583         vdev->features |= VFIO_FEATURE_ENABLE_IGD_LPC;
584     } else if (vdev->igd_legacy_mode == ON_OFF_AUTO_ON) {
585         error_setg(&err,
586                    "Machine is not i440fx, assigned BDF is not 00:02.0, "
587                    "or device %04x (gen %d) doesn't support legacy mode",
588                    vdev->device_id, gen);
589         goto error;
590     }
591 
592     /* Setup OpRegion access */
593     if ((vdev->features & VFIO_FEATURE_ENABLE_IGD_OPREGION) &&
594         !vfio_pci_igd_opregion_init(vdev, opregion, errp)) {
595         goto error;
596     }
597 
598     /* Setup LPC bridge / Host bridge PCI IDs */
599     if ((vdev->features & VFIO_FEATURE_ENABLE_IGD_LPC) &&
600         !vfio_pci_igd_setup_lpc_bridge(vdev, errp)) {
601         goto error;
602     }
603 
604     /*
605      * ASLS (OpRegion address) is read-only, emulated
606      * It contains HPA, guest firmware need to reprogram it with GPA.
607      */
608     pci_set_long(vdev->pdev.config + IGD_ASLS, 0);
609     pci_set_long(vdev->pdev.wmask + IGD_ASLS, ~0);
610     pci_set_long(vdev->emulated_config_bits + IGD_ASLS, ~0);
611 
612     /*
613      * Allow user to override dsm size using x-igd-gms option, in multiples of
614      * 32MiB. This option should only be used when the desired size cannot be
615      * set from DVMT Pre-Allocated option in host BIOS.
616      */
617     if (vdev->igd_gms) {
618         if (!vfio_pci_igd_override_gms(gen, vdev->igd_gms, &gmch)) {
619             return false;
620         }
621 
622         /* GMCH is read-only, emulated */
623         pci_set_long(vdev->pdev.config + IGD_GMCH, gmch);
624         pci_set_long(vdev->pdev.wmask + IGD_GMCH, 0);
625         pci_set_long(vdev->emulated_config_bits + IGD_GMCH, ~0);
626     }
627 
628     if (gen > 0) {
629         gms_size = igd_stolen_memory_size(gen, gmch);
630 
631         /* BDSM is read-write, emulated. BIOS needs to be able to write it */
632         if (gen < 11) {
633             pci_set_long(vdev->pdev.config + IGD_BDSM, 0);
634             pci_set_long(vdev->pdev.wmask + IGD_BDSM, ~0);
635             pci_set_long(vdev->emulated_config_bits + IGD_BDSM, ~0);
636         } else {
637             pci_set_quad(vdev->pdev.config + IGD_BDSM_GEN11, 0);
638             pci_set_quad(vdev->pdev.wmask + IGD_BDSM_GEN11, ~0);
639             pci_set_quad(vdev->emulated_config_bits + IGD_BDSM_GEN11, ~0);
640         }
641     }
642 
643     /*
644      * Request reserved memory for stolen memory via fw_cfg.  VM firmware
645      * must allocate a 1MB aligned reserved memory region below 4GB with
646      * the requested size (in bytes) for use by the IGD device. The base
647      * address of this reserved memory region must be written to the
648      * device BDSM register.
649      * For newer device without BDSM register, this fw_cfg item is 0.
650      */
651     bdsm_size = g_malloc(sizeof(*bdsm_size));
652     *bdsm_size = cpu_to_le64(gms_size);
653     fw_cfg_add_file(fw_cfg_find(), "etc/igd-bdsm-size",
654                     bdsm_size, sizeof(*bdsm_size));
655 
656     trace_vfio_pci_igd_bdsm_enabled(vdev->vbasedev.name, (gms_size / MiB));
657 
658     return true;
659 
660 error:
661     /*
662      * When legacy mode is implicity enabled, continue on error,
663      * to keep compatibility
664      */
665     if (legacy_mode_enabled && (vdev->igd_legacy_mode == ON_OFF_AUTO_AUTO)) {
666         error_report_err(err);
667         error_report("IGD legacy mode disabled");
668         return true;
669     }
670 
671     error_propagate(errp, err);
672     return false;
673 }
674 
675 /*
676  * KVMGT/GVT-g vGPU exposes an emulated OpRegion. So far, users have to specify
677  * x-igd-opregion=on to enable the access.
678  * TODO: Check VID/DID and enable opregion access automatically
679  */
vfio_pci_kvmgt_config_quirk(VFIOPCIDevice * vdev,Error ** errp)680 static bool vfio_pci_kvmgt_config_quirk(VFIOPCIDevice *vdev, Error **errp)
681 {
682     struct vfio_region_info *opregion = NULL;
683     int gen;
684 
685     if (!vfio_pci_is(vdev, PCI_VENDOR_ID_INTEL, PCI_ANY_ID) ||
686         !vfio_is_vga(vdev)) {
687         return true;
688     }
689 
690     /* FIXME: Cherryview is Gen8, but don't support GVT-g */
691     gen = igd_gen(vdev);
692     if (gen != 8 && gen != 9) {
693         return true;
694     }
695 
696     if (!vfio_pci_igd_opregion_detect(vdev, &opregion)) {
697         /* Should never reach here, KVMGT always emulates OpRegion */
698         return false;
699     }
700 
701     if ((vdev->features & VFIO_FEATURE_ENABLE_IGD_OPREGION) &&
702         !vfio_pci_igd_opregion_init(vdev, opregion, errp)) {
703         return false;
704     }
705 
706     return true;
707 }
708 
vfio_probe_igd_config_quirk(VFIOPCIDevice * vdev,Error ** errp)709 bool vfio_probe_igd_config_quirk(VFIOPCIDevice *vdev, Error **errp)
710 {
711     /* KVMGT/GVT-g vGPU is exposed as mdev */
712     if (vdev->vbasedev.mdev) {
713         return vfio_pci_kvmgt_config_quirk(vdev, errp);
714     }
715 
716     return vfio_pci_igd_config_quirk(vdev, errp);
717 }
718