diff options
| -rw-r--r-- | hw/vfio/pci.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index 82c3771..ebbc9d6 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -832,6 +832,36 @@ static void vfio_pci_load_rom(VFIOPCIDevice *vdev) break; } } + + /* + * Test the ROM signature against our device, if the vendor is correct + * but the device ID doesn't match, store the correct device ID and + * recompute the checksum. Intel IGD devices need this and are known + * to have bogus checksums so we can't simply adjust the checksum. + */ + if (pci_get_word(vdev->rom) == 0xaa55 && + pci_get_word(vdev->rom + 0x18) + 8 < vdev->rom_size && + !memcmp(vdev->rom + pci_get_word(vdev->rom + 0x18), "PCIR", 4)) { + uint16_t vid, did; + + vid = pci_get_word(vdev->rom + pci_get_word(vdev->rom + 0x18) + 4); + did = pci_get_word(vdev->rom + pci_get_word(vdev->rom + 0x18) + 6); + + if (vid == vdev->vendor_id && did != vdev->device_id) { + int i; + uint8_t csum, *data = vdev->rom; + + pci_set_word(vdev->rom + pci_get_word(vdev->rom + 0x18) + 6, + vdev->device_id); + data[6] = 0; + + for (csum = 0, i = 0; i < vdev->rom_size; i++) { + csum += data[i]; + } + + data[6] = -csum; + } + } } static uint64_t vfio_rom_read(void *opaque, hwaddr addr, unsigned size) |