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-rw-r--r--hw/pci.c38
1 files changed, 38 insertions, 0 deletions
diff --git a/hw/pci.c b/hw/pci.c
index 6124790f01..57ff7b1098 100644
--- a/hw/pci.c
+++ b/hw/pci.c
@@ -1811,6 +1811,25 @@ static uint8_t pci_find_capability_list(PCIDevice *pdev, uint8_t cap_id,
return next;
}
+static uint8_t pci_find_capability_at_offset(PCIDevice *pdev, uint8_t offset)
+{
+ uint8_t next, prev, found = 0;
+
+ if (!(pdev->used[offset])) {
+ return 0;
+ }
+
+ assert(pdev->config[PCI_STATUS] & PCI_STATUS_CAP_LIST);
+
+ for (prev = PCI_CAPABILITY_LIST; (next = pdev->config[prev]);
+ prev = next + PCI_CAP_LIST_NEXT) {
+ if (next <= offset && next > found) {
+ found = next;
+ }
+ }
+ return found;
+}
+
/* Patch the PCI vendor and device ids in a PCI rom image if necessary.
This is needed for an option rom which is used for more than one device. */
static void pci_patch_ids(PCIDevice *pdev, uint8_t *ptr, int size)
@@ -1952,11 +1971,30 @@ int pci_add_capability(PCIDevice *pdev, uint8_t cap_id,
uint8_t offset, uint8_t size)
{
uint8_t *config;
+ int i, overlapping_cap;
+
if (!offset) {
offset = pci_find_space(pdev, size);
if (!offset) {
return -ENOSPC;
}
+ } 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) {
+ fprintf(stderr, "ERROR: %04x:%02x:%02x.%x "
+ "Attempt to add PCI capability %x at offset "
+ "%x overlaps existing capability %x at offset %x\n",
+ pci_find_domain(pdev->bus), 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;