int pci_add_capability(PCIDevice *pdev, uint8_t cap_id, uint8_t offset, uint8_t size, Error **errp) { uint8_t *config; int i, overlapping_cap; if (!offset) { offset = pci_find_space(pdev, size); /* out of PCI config space is programming error */ assert(offset); } else { /* Verify that capabilities don't overlap. Note: device assignment * depends on this check to verify that the device is not broken. * Should never trigger for emulated devices, but it's helpful * for debugging these. */ for (i = offset; i < offset + size; i++) { overlapping_cap = pci_find_capability_at_offset(pdev, i); if (overlapping_cap) { error_setg(errp, "%s:%02x:%02x.%x " "Attempt to add PCI capability %x at offset " "%x overlaps existing capability %x at offset %x", pci_root_bus_path(pdev), pci_bus_num(pdev->bus), PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn), cap_id, offset, overlapping_cap, i); return -EINVAL; } } } config = pdev->config + offset; config[PCI_CAP_LIST_ID] = cap_id; config[PCI_CAP_LIST_NEXT] = pdev->config[PCI_CAPABILITY_LIST]; pdev->config[PCI_CAPABILITY_LIST] = offset; pdev->config[PCI_STATUS] |= PCI_STATUS_CAP_LIST; memset(pdev->used + offset, 0xFF, QEMU_ALIGN_UP(size, 4)); /* Make capability read-only by default */ memset(pdev->wmask + offset, 0, size); /* Check capability by default */ memset(pdev->cmask + offset, 0xFF, size); return offset; }