diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c
index 0f795ea58756..71ce48b644f2 100644
--- a/drivers/thunderbolt/nhi.c
+++ b/drivers/thunderbolt/nhi.c
@@ -1185,6 +1185,7 @@ static struct tb *nhi_select_cm(struct tb_nhi *nhi)
 
 int nhi_probe(struct tb_nhi *nhi)
 {
+	struct pci_dev *pdev = to_pci_dev(nhi->dev);
 	struct device *dev = nhi->dev;
 	struct tb *tb;
 	int res;
@@ -1195,6 +1196,9 @@ int nhi_probe(struct tb_nhi *nhi)
 	if (!nhi->ops->init_interrupts)
 		return dev_err_probe(dev, -EINVAL, "missing required NHI ops\n");
 
+	/* QEMU PCI emulation glitch? */
+	BUG_ON(pci_resource_len(pdev, 0) < REG_CAPS);
+
 	nhi->hop_count = ioread32(nhi->iobase + REG_CAPS) & 0x3ff;
 	dev_dbg(dev, "total paths: %d\n", nhi->hop_count);