| /* |
| * IGD device quirks |
| * |
| * Copyright Red Hat, Inc. 2016 |
| * |
| * Authors: |
| * Alex Williamson <alex.williamson@redhat.com> |
| * |
| * This work is licensed under the terms of the GNU GPL, version 2. See |
| * the COPYING file in the top-level directory. |
| */ |
| |
| #include "qemu/osdep.h" |
| #include "qemu/units.h" |
| #include "qemu/error-report.h" |
| #include "qapi/error.h" |
| #include "hw/hw.h" |
| #include "hw/nvram/fw_cfg.h" |
| #include "pci.h" |
| #include "trace.h" |
| |
| /* |
| * Intel IGD support |
| * |
| * Obviously IGD is not a discrete device, this is evidenced not only by it |
| * being integrated into the CPU, but by the various chipset and BIOS |
| * dependencies that it brings along with it. Intel is trying to move away |
| * from this and Broadwell and newer devices can run in what Intel calls |
| * "Universal Pass-Through" mode, or UPT. Theoretically in UPT mode, nothing |
| * more is required beyond assigning the IGD device to a VM. There are |
| * however support limitations to this mode. It only supports IGD as a |
| * secondary graphics device in the VM and it doesn't officially support any |
| * physical outputs. |
| * |
| * The code here attempts to enable what we'll call legacy mode assignment, |
| * IGD retains most of the capabilities we expect for it to have on bare |
| * metal. To enable this mode, the IGD device must be assigned to the VM |
| * at PCI address 00:02.0, it must have a ROM, it very likely needs VGA |
| * support, we must have VM BIOS support for reserving and populating some |
| * of the required tables, and we need to tweak the chipset with revisions |
| * and IDs and an LPC/ISA bridge device. The intention is to make all of |
| * this happen automatically by installing the device at the correct VM PCI |
| * bus address. If any of the conditions are not met, we cross our fingers |
| * and hope the user knows better. |
| * |
| * NB - It is possible to enable physical outputs in UPT mode by supplying |
| * an OpRegion table. We don't do this by default because the guest driver |
| * behaves differently if an OpRegion is provided and no monitor is attached |
| * vs no OpRegion and a monitor being attached or not. Effectively, if a |
| * headless setup is desired, the OpRegion gets in the way of that. |
| */ |
| |
| /* |
| * This presumes the device is already known to be an Intel VGA device, so we |
| * take liberties in which device ID bits match which generation. This should |
| * not be taken as an indication that all the devices are supported, or even |
| * supportable, some of them don't even support VT-d. |
| * See linux:include/drm/i915_pciids.h for IDs. |
| */ |
| static int igd_gen(VFIOPCIDevice *vdev) |
| { |
| if ((vdev->device_id & 0xfff) == 0xa84) { |
| return 8; /* Broxton */ |
| } |
| |
| switch (vdev->device_id & 0xff00) { |
| /* Old, untested, unavailable, unknown */ |
| case 0x0000: |
| case 0x2500: |
| case 0x2700: |
| case 0x2900: |
| case 0x2a00: |
| case 0x2e00: |
| case 0x3500: |
| case 0xa000: |
| return -1; |
| /* SandyBridge, IvyBridge, ValleyView, Haswell */ |
| case 0x0100: |
| case 0x0400: |
| case 0x0a00: |
| case 0x0c00: |
| case 0x0d00: |
| case 0x0f00: |
| return 6; |
| /* BroadWell, CherryView, SkyLake, KabyLake */ |
| case 0x1600: |
| case 0x1900: |
| case 0x2200: |
| case 0x5900: |
| return 8; |
| } |
| |
| return 8; /* Assume newer is compatible */ |
| } |
| |
| typedef struct VFIOIGDQuirk { |
| struct VFIOPCIDevice *vdev; |
| uint32_t index; |
| uint32_t bdsm; |
| } VFIOIGDQuirk; |
| |
| #define IGD_GMCH 0x50 /* Graphics Control Register */ |
| #define IGD_BDSM 0x5c /* Base Data of Stolen Memory */ |
| |
| |
| /* |
| * The rather short list of registers that we copy from the host devices. |
| * The LPC/ISA bridge values are definitely needed to support the vBIOS, the |
| * host bridge values may or may not be needed depending on the guest OS. |
| * Since we're only munging revision and subsystem values on the host bridge, |
| * we don't require our own device. The LPC/ISA bridge needs to be our very |
| * own though. |
| */ |
| typedef struct { |
| uint8_t offset; |
| uint8_t len; |
| } IGDHostInfo; |
| |
| static const IGDHostInfo igd_host_bridge_infos[] = { |
| {PCI_REVISION_ID, 2}, |
| {PCI_SUBSYSTEM_VENDOR_ID, 2}, |
| {PCI_SUBSYSTEM_ID, 2}, |
| }; |
| |
| static const IGDHostInfo igd_lpc_bridge_infos[] = { |
| {PCI_VENDOR_ID, 2}, |
| {PCI_DEVICE_ID, 2}, |
| {PCI_REVISION_ID, 2}, |
| {PCI_SUBSYSTEM_VENDOR_ID, 2}, |
| {PCI_SUBSYSTEM_ID, 2}, |
| }; |
| |
| static int vfio_pci_igd_copy(VFIOPCIDevice *vdev, PCIDevice *pdev, |
| struct vfio_region_info *info, |
| const IGDHostInfo *list, int len) |
| { |
| int i, ret; |
| |
| for (i = 0; i < len; i++) { |
| ret = pread(vdev->vbasedev.fd, pdev->config + list[i].offset, |
| list[i].len, info->offset + list[i].offset); |
| if (ret != list[i].len) { |
| error_report("IGD copy failed: %m"); |
| return -errno; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Stuff a few values into the host bridge. |
| */ |
| static int vfio_pci_igd_host_init(VFIOPCIDevice *vdev, |
| struct vfio_region_info *info) |
| { |
| PCIBus *bus; |
| PCIDevice *host_bridge; |
| int ret; |
| |
| bus = pci_device_root_bus(&vdev->pdev); |
| host_bridge = pci_find_device(bus, 0, PCI_DEVFN(0, 0)); |
| |
| if (!host_bridge) { |
| error_report("Can't find host bridge"); |
| return -ENODEV; |
| } |
| |
| ret = vfio_pci_igd_copy(vdev, host_bridge, info, igd_host_bridge_infos, |
| ARRAY_SIZE(igd_host_bridge_infos)); |
| if (!ret) { |
| trace_vfio_pci_igd_host_bridge_enabled(vdev->vbasedev.name); |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * IGD LPC/ISA bridge support code. The vBIOS needs this, but we can't write |
| * arbitrary values into just any bridge, so we must create our own. We try |
| * to handle if the user has created it for us, which they might want to do |
| * to enable multifunction so we don't occupy the whole PCI slot. |
| */ |
| static void vfio_pci_igd_lpc_bridge_realize(PCIDevice *pdev, Error **errp) |
| { |
| if (pdev->devfn != PCI_DEVFN(0x1f, 0)) { |
| error_setg(errp, "VFIO dummy ISA/LPC bridge must have address 1f.0"); |
| } |
| } |
| |
| static void vfio_pci_igd_lpc_bridge_class_init(ObjectClass *klass, void *data) |
| { |
| DeviceClass *dc = DEVICE_CLASS(klass); |
| PCIDeviceClass *k = PCI_DEVICE_CLASS(klass); |
| |
| set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories); |
| dc->desc = "VFIO dummy ISA/LPC bridge for IGD assignment"; |
| dc->hotpluggable = false; |
| k->realize = vfio_pci_igd_lpc_bridge_realize; |
| k->class_id = PCI_CLASS_BRIDGE_ISA; |
| } |
| |
| static const TypeInfo vfio_pci_igd_lpc_bridge_info = { |
| .name = "vfio-pci-igd-lpc-bridge", |
| .parent = TYPE_PCI_DEVICE, |
| .class_init = vfio_pci_igd_lpc_bridge_class_init, |
| .interfaces = (InterfaceInfo[]) { |
| { INTERFACE_CONVENTIONAL_PCI_DEVICE }, |
| { }, |
| }, |
| }; |
| |
| static void vfio_pci_igd_register_types(void) |
| { |
| type_register_static(&vfio_pci_igd_lpc_bridge_info); |
| } |
| |
| type_init(vfio_pci_igd_register_types) |
| |
| static int vfio_pci_igd_lpc_init(VFIOPCIDevice *vdev, |
| struct vfio_region_info *info) |
| { |
| PCIDevice *lpc_bridge; |
| int ret; |
| |
| lpc_bridge = pci_find_device(pci_device_root_bus(&vdev->pdev), |
| 0, PCI_DEVFN(0x1f, 0)); |
| if (!lpc_bridge) { |
| lpc_bridge = pci_create_simple(pci_device_root_bus(&vdev->pdev), |
| PCI_DEVFN(0x1f, 0), "vfio-pci-igd-lpc-bridge"); |
| } |
| |
| ret = vfio_pci_igd_copy(vdev, lpc_bridge, info, igd_lpc_bridge_infos, |
| ARRAY_SIZE(igd_lpc_bridge_infos)); |
| if (!ret) { |
| trace_vfio_pci_igd_lpc_bridge_enabled(vdev->vbasedev.name); |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * IGD Gen8 and newer support up to 8MB for the GTT and use a 64bit PTE |
| * entry, older IGDs use 2MB and 32bit. Each PTE maps a 4k page. Therefore |
| * we either have 2M/4k * 4 = 2k or 8M/4k * 8 = 16k as the maximum iobar index |
| * for programming the GTT. |
| * |
| * See linux:include/drm/i915_drm.h for shift and mask values. |
| */ |
| static int vfio_igd_gtt_max(VFIOPCIDevice *vdev) |
| { |
| uint32_t gmch = vfio_pci_read_config(&vdev->pdev, IGD_GMCH, sizeof(gmch)); |
| int ggms, gen = igd_gen(vdev); |
| |
| gmch = vfio_pci_read_config(&vdev->pdev, IGD_GMCH, sizeof(gmch)); |
| ggms = (gmch >> (gen < 8 ? 8 : 6)) & 0x3; |
| if (gen > 6) { |
| ggms = 1 << ggms; |
| } |
| |
| ggms *= MiB; |
| |
| return (ggms / (4 * KiB)) * (gen < 8 ? 4 : 8); |
| } |
| |
| /* |
| * The IGD ROM will make use of stolen memory (GGMS) for support of VESA modes. |
| * Somehow the host stolen memory range is used for this, but how the ROM gets |
| * it is a mystery, perhaps it's hardcoded into the ROM. Thankfully though, it |
| * reprograms the GTT through the IOBAR where we can trap it and transpose the |
| * programming to the VM allocated buffer. That buffer gets reserved by the VM |
| * firmware via the fw_cfg entry added below. Here we're just monitoring the |
| * IOBAR address and data registers to detect a write sequence targeting the |
| * GTTADR. This code is developed by observed behavior and doesn't have a |
| * direct spec reference, unfortunately. |
| */ |
| static uint64_t vfio_igd_quirk_data_read(void *opaque, |
| hwaddr addr, unsigned size) |
| { |
| VFIOIGDQuirk *igd = opaque; |
| VFIOPCIDevice *vdev = igd->vdev; |
| |
| igd->index = ~0; |
| |
| return vfio_region_read(&vdev->bars[4].region, addr + 4, size); |
| } |
| |
| static void vfio_igd_quirk_data_write(void *opaque, hwaddr addr, |
| uint64_t data, unsigned size) |
| { |
| VFIOIGDQuirk *igd = opaque; |
| VFIOPCIDevice *vdev = igd->vdev; |
| uint64_t val = data; |
| int gen = igd_gen(vdev); |
| |
| /* |
| * Programming the GGMS starts at index 0x1 and uses every 4th index (ie. |
| * 0x1, 0x5, 0x9, 0xd,...). For pre-Gen8 each 4-byte write is a whole PTE |
| * entry, with 0th bit enable set. For Gen8 and up, PTEs are 64bit, so |
| * entries 0x5 & 0xd are the high dword, in our case zero. Each PTE points |
| * to a 4k page, which we translate to a page from the VM allocated region, |
| * pointed to by the BDSM register. If this is not set, we fail. |
| * |
| * We trap writes to the full configured GTT size, but we typically only |
| * see the vBIOS writing up to (nearly) the 1MB barrier. In fact it often |
| * seems to miss the last entry for an even 1MB GTT. Doing a gratuitous |
| * write of that last entry does work, but is hopefully unnecessary since |
| * we clear the previous GTT on initialization. |
| */ |
| if ((igd->index % 4 == 1) && igd->index < vfio_igd_gtt_max(vdev)) { |
| if (gen < 8 || (igd->index % 8 == 1)) { |
| uint32_t base; |
| |
| base = pci_get_long(vdev->pdev.config + IGD_BDSM); |
| if (!base) { |
| hw_error("vfio-igd: Guest attempted to program IGD GTT before " |
| "BIOS reserved stolen memory. Unsupported BIOS?"); |
| } |
| |
| val = data - igd->bdsm + base; |
| } else { |
| val = 0; /* upper 32bits of pte, we only enable below 4G PTEs */ |
| } |
| |
| trace_vfio_pci_igd_bar4_write(vdev->vbasedev.name, |
| igd->index, data, val); |
| } |
| |
| vfio_region_write(&vdev->bars[4].region, addr + 4, val, size); |
| |
| igd->index = ~0; |
| } |
| |
| static const MemoryRegionOps vfio_igd_data_quirk = { |
| .read = vfio_igd_quirk_data_read, |
| .write = vfio_igd_quirk_data_write, |
| .endianness = DEVICE_LITTLE_ENDIAN, |
| }; |
| |
| static uint64_t vfio_igd_quirk_index_read(void *opaque, |
| hwaddr addr, unsigned size) |
| { |
| VFIOIGDQuirk *igd = opaque; |
| VFIOPCIDevice *vdev = igd->vdev; |
| |
| igd->index = ~0; |
| |
| return vfio_region_read(&vdev->bars[4].region, addr, size); |
| } |
| |
| static void vfio_igd_quirk_index_write(void *opaque, hwaddr addr, |
| uint64_t data, unsigned size) |
| { |
| VFIOIGDQuirk *igd = opaque; |
| VFIOPCIDevice *vdev = igd->vdev; |
| |
| igd->index = data; |
| |
| vfio_region_write(&vdev->bars[4].region, addr, data, size); |
| } |
| |
| static const MemoryRegionOps vfio_igd_index_quirk = { |
| .read = vfio_igd_quirk_index_read, |
| .write = vfio_igd_quirk_index_write, |
| .endianness = DEVICE_LITTLE_ENDIAN, |
| }; |
| |
| void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr) |
| { |
| struct vfio_region_info *rom = NULL, *opregion = NULL, |
| *host = NULL, *lpc = NULL; |
| VFIOQuirk *quirk; |
| VFIOIGDQuirk *igd; |
| PCIDevice *lpc_bridge; |
| int i, ret, ggms_mb, gms_mb = 0, gen; |
| uint64_t *bdsm_size; |
| uint32_t gmch; |
| uint16_t cmd_orig, cmd; |
| Error *err = NULL; |
| |
| /* |
| * This must be an Intel VGA device at address 00:02.0 for us to even |
| * consider enabling legacy mode. The vBIOS has dependencies on the |
| * PCI bus address. |
| */ |
| if (!vfio_pci_is(vdev, PCI_VENDOR_ID_INTEL, PCI_ANY_ID) || |
| !vfio_is_vga(vdev) || nr != 4 || |
| &vdev->pdev != pci_find_device(pci_device_root_bus(&vdev->pdev), |
| 0, PCI_DEVFN(0x2, 0))) { |
| return; |
| } |
| |
| /* |
| * We need to create an LPC/ISA bridge at PCI bus address 00:1f.0 that we |
| * can stuff host values into, so if there's already one there and it's not |
| * one we can hack on, legacy mode is no-go. Sorry Q35. |
| */ |
| lpc_bridge = pci_find_device(pci_device_root_bus(&vdev->pdev), |
| 0, PCI_DEVFN(0x1f, 0)); |
| if (lpc_bridge && !object_dynamic_cast(OBJECT(lpc_bridge), |
| "vfio-pci-igd-lpc-bridge")) { |
| error_report("IGD device %s cannot support legacy mode due to existing " |
| "devices at address 1f.0", vdev->vbasedev.name); |
| return; |
| } |
| |
| /* |
| * IGD is not a standard, they like to change their specs often. We |
| * only attempt to support back to SandBridge and we hope that newer |
| * devices maintain compatibility with generation 8. |
| */ |
| gen = igd_gen(vdev); |
| if (gen != 6 && gen != 8) { |
| error_report("IGD device %s is unsupported in legacy mode, " |
| "try SandyBridge or newer", vdev->vbasedev.name); |
| return; |
| } |
| |
| /* |
| * Most of what we're doing here is to enable the ROM to run, so if |
| * there's no ROM, there's no point in setting up this quirk. |
| * NB. We only seem to get BIOS ROMs, so a UEFI VM would need CSM support. |
| */ |
| ret = vfio_get_region_info(&vdev->vbasedev, |
| VFIO_PCI_ROM_REGION_INDEX, &rom); |
| if ((ret || !rom->size) && !vdev->pdev.romfile) { |
| error_report("IGD device %s has no ROM, legacy mode disabled", |
| vdev->vbasedev.name); |
| goto out; |
| } |
| |
| /* |
| * Ignore the hotplug corner case, mark the ROM failed, we can't |
| * create the devices we need for legacy mode in the hotplug scenario. |
| */ |
| if (vdev->pdev.qdev.hotplugged) { |
| error_report("IGD device %s hotplugged, ROM disabled, " |
| "legacy mode disabled", vdev->vbasedev.name); |
| vdev->rom_read_failed = true; |
| goto out; |
| } |
| |
| /* |
| * Check whether we have all the vfio device specific regions to |
| * support legacy mode (added in Linux v4.6). If not, bail. |
| */ |
| ret = vfio_get_dev_region_info(&vdev->vbasedev, |
| VFIO_REGION_TYPE_PCI_VENDOR_TYPE | PCI_VENDOR_ID_INTEL, |
| VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION, &opregion); |
| if (ret) { |
| error_report("IGD device %s does not support OpRegion access," |
| "legacy mode disabled", vdev->vbasedev.name); |
| goto out; |
| } |
| |
| ret = vfio_get_dev_region_info(&vdev->vbasedev, |
| VFIO_REGION_TYPE_PCI_VENDOR_TYPE | PCI_VENDOR_ID_INTEL, |
| VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG, &host); |
| if (ret) { |
| error_report("IGD device %s does not support host bridge access," |
| "legacy mode disabled", vdev->vbasedev.name); |
| goto out; |
| } |
| |
| ret = vfio_get_dev_region_info(&vdev->vbasedev, |
| VFIO_REGION_TYPE_PCI_VENDOR_TYPE | PCI_VENDOR_ID_INTEL, |
| VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG, &lpc); |
| if (ret) { |
| error_report("IGD device %s does not support LPC bridge access," |
| "legacy mode disabled", vdev->vbasedev.name); |
| goto out; |
| } |
| |
| gmch = vfio_pci_read_config(&vdev->pdev, IGD_GMCH, 4); |
| |
| /* |
| * If IGD VGA Disable is clear (expected) and VGA is not already enabled, |
| * try to enable it. Probably shouldn't be using legacy mode without VGA, |
| * but also no point in us enabling VGA if disabled in hardware. |
| */ |
| if (!(gmch & 0x2) && !vdev->vga && vfio_populate_vga(vdev, &err)) { |
| error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name); |
| error_report("IGD device %s failed to enable VGA access, " |
| "legacy mode disabled", vdev->vbasedev.name); |
| goto out; |
| } |
| |
| /* Create our LPC/ISA bridge */ |
| ret = vfio_pci_igd_lpc_init(vdev, lpc); |
| if (ret) { |
| error_report("IGD device %s failed to create LPC bridge, " |
| "legacy mode disabled", vdev->vbasedev.name); |
| goto out; |
| } |
| |
| /* Stuff some host values into the VM PCI host bridge */ |
| ret = vfio_pci_igd_host_init(vdev, host); |
| if (ret) { |
| error_report("IGD device %s failed to modify host bridge, " |
| "legacy mode disabled", vdev->vbasedev.name); |
| goto out; |
| } |
| |
| /* Setup OpRegion access */ |
| ret = vfio_pci_igd_opregion_init(vdev, opregion, &err); |
| if (ret) { |
| error_append_hint(&err, "IGD legacy mode disabled\n"); |
| error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name); |
| goto out; |
| } |
| |
| /* Setup our quirk to munge GTT addresses to the VM allocated buffer */ |
| quirk = vfio_quirk_alloc(2); |
| igd = quirk->data = g_malloc0(sizeof(*igd)); |
| igd->vdev = vdev; |
| igd->index = ~0; |
| igd->bdsm = vfio_pci_read_config(&vdev->pdev, IGD_BDSM, 4); |
| igd->bdsm &= ~((1 * MiB) - 1); /* 1MB aligned */ |
| |
| memory_region_init_io(&quirk->mem[0], OBJECT(vdev), &vfio_igd_index_quirk, |
| igd, "vfio-igd-index-quirk", 4); |
| memory_region_add_subregion_overlap(vdev->bars[nr].region.mem, |
| 0, &quirk->mem[0], 1); |
| |
| memory_region_init_io(&quirk->mem[1], OBJECT(vdev), &vfio_igd_data_quirk, |
| igd, "vfio-igd-data-quirk", 4); |
| memory_region_add_subregion_overlap(vdev->bars[nr].region.mem, |
| 4, &quirk->mem[1], 1); |
| |
| QLIST_INSERT_HEAD(&vdev->bars[nr].quirks, quirk, next); |
| |
| /* Determine the size of stolen memory needed for GTT */ |
| ggms_mb = (gmch >> (gen < 8 ? 8 : 6)) & 0x3; |
| if (gen > 6) { |
| ggms_mb = 1 << ggms_mb; |
| } |
| |
| /* |
| * Assume we have no GMS memory, but allow it to be overridden by device |
| * option (experimental). The spec doesn't actually allow zero GMS when |
| * when IVD (IGD VGA Disable) is clear, but the claim is that it's unused, |
| * so let's not waste VM memory for it. |
| */ |
| gmch &= ~((gen < 8 ? 0x1f : 0xff) << (gen < 8 ? 3 : 8)); |
| |
| if (vdev->igd_gms) { |
| if (vdev->igd_gms <= 0x10) { |
| gms_mb = vdev->igd_gms * 32; |
| gmch |= vdev->igd_gms << (gen < 8 ? 3 : 8); |
| } else { |
| error_report("Unsupported IGD GMS value 0x%x", vdev->igd_gms); |
| vdev->igd_gms = 0; |
| } |
| } |
| |
| /* |
| * Request reserved memory for stolen memory via fw_cfg. VM firmware |
| * must allocate a 1MB aligned reserved memory region below 4GB with |
| * the requested size (in bytes) for use by the Intel PCI class VGA |
| * device at VM address 00:02.0. The base address of this reserved |
| * memory region must be written to the device BDSM register at PCI |
| * config offset 0x5C. |
| */ |
| bdsm_size = g_malloc(sizeof(*bdsm_size)); |
| *bdsm_size = cpu_to_le64((ggms_mb + gms_mb) * MiB); |
| fw_cfg_add_file(fw_cfg_find(), "etc/igd-bdsm-size", |
| bdsm_size, sizeof(*bdsm_size)); |
| |
| /* GMCH is read-only, emulated */ |
| pci_set_long(vdev->pdev.config + IGD_GMCH, gmch); |
| pci_set_long(vdev->pdev.wmask + IGD_GMCH, 0); |
| pci_set_long(vdev->emulated_config_bits + IGD_GMCH, ~0); |
| |
| /* BDSM is read-write, emulated. The BIOS needs to be able to write it */ |
| pci_set_long(vdev->pdev.config + IGD_BDSM, 0); |
| pci_set_long(vdev->pdev.wmask + IGD_BDSM, ~0); |
| pci_set_long(vdev->emulated_config_bits + IGD_BDSM, ~0); |
| |
| /* |
| * This IOBAR gives us access to GTTADR, which allows us to write to |
| * the GTT itself. So let's go ahead and write zero to all the GTT |
| * entries to avoid spurious DMA faults. Be sure I/O access is enabled |
| * before talking to the device. |
| */ |
| if (pread(vdev->vbasedev.fd, &cmd_orig, sizeof(cmd_orig), |
| vdev->config_offset + PCI_COMMAND) != sizeof(cmd_orig)) { |
| error_report("IGD device %s - failed to read PCI command register", |
| vdev->vbasedev.name); |
| } |
| |
| cmd = cmd_orig | PCI_COMMAND_IO; |
| |
| if (pwrite(vdev->vbasedev.fd, &cmd, sizeof(cmd), |
| vdev->config_offset + PCI_COMMAND) != sizeof(cmd)) { |
| error_report("IGD device %s - failed to write PCI command register", |
| vdev->vbasedev.name); |
| } |
| |
| for (i = 1; i < vfio_igd_gtt_max(vdev); i += 4) { |
| vfio_region_write(&vdev->bars[4].region, 0, i, 4); |
| vfio_region_write(&vdev->bars[4].region, 4, 0, 4); |
| } |
| |
| if (pwrite(vdev->vbasedev.fd, &cmd_orig, sizeof(cmd_orig), |
| vdev->config_offset + PCI_COMMAND) != sizeof(cmd_orig)) { |
| error_report("IGD device %s - failed to restore PCI command register", |
| vdev->vbasedev.name); |
| } |
| |
| trace_vfio_pci_igd_bdsm_enabled(vdev->vbasedev.name, ggms_mb + gms_mb); |
| |
| out: |
| g_free(rom); |
| g_free(opregion); |
| g_free(host); |
| g_free(lpc); |
| } |
