size_t count, loff_t *offp)
 {
        struct intel_ntb_dev *ndev;
+       struct pci_dev *pdev;
        void __iomem *mmio;
        char *buf;
        size_t buf_size;
        ssize_t ret, off;
-       union { u64 v64; u32 v32; u16 v16; } u;
+       union { u64 v64; u32 v32; u16 v16; u8 v8; } u;
 
        ndev = filp->private_data;
+       pdev = ndev_pdev(ndev);
        mmio = ndev->self_mmio;
 
        buf_size = min(count, 0x800ul);
        off += scnprintf(buf + off, buf_size - off,
                         "Doorbell Bell -\t\t%#llx\n", u.v64);
 
+       off += scnprintf(buf + off, buf_size - off,
+                        "\nNTB Window Size:\n");
+
+       pci_read_config_byte(pdev, XEON_PBAR23SZ_OFFSET, &u.v8);
+       off += scnprintf(buf + off, buf_size - off,
+                        "PBAR23SZ %hhu\n", u.v8);
+       if (!ndev->bar4_split) {
+               pci_read_config_byte(pdev, XEON_PBAR45SZ_OFFSET, &u.v8);
+               off += scnprintf(buf + off, buf_size - off,
+                                "PBAR45SZ %hhu\n", u.v8);
+       } else {
+               pci_read_config_byte(pdev, XEON_PBAR4SZ_OFFSET, &u.v8);
+               off += scnprintf(buf + off, buf_size - off,
+                                "PBAR4SZ %hhu\n", u.v8);
+               pci_read_config_byte(pdev, XEON_PBAR5SZ_OFFSET, &u.v8);
+               off += scnprintf(buf + off, buf_size - off,
+                                "PBAR5SZ %hhu\n", u.v8);
+       }
+
+       pci_read_config_byte(pdev, XEON_SBAR23SZ_OFFSET, &u.v8);
+       off += scnprintf(buf + off, buf_size - off,
+                        "SBAR23SZ %hhu\n", u.v8);
+       if (!ndev->bar4_split) {
+               pci_read_config_byte(pdev, XEON_SBAR45SZ_OFFSET, &u.v8);
+               off += scnprintf(buf + off, buf_size - off,
+                                "SBAR45SZ %hhu\n", u.v8);
+       } else {
+               pci_read_config_byte(pdev, XEON_SBAR4SZ_OFFSET, &u.v8);
+               off += scnprintf(buf + off, buf_size - off,
+                                "SBAR4SZ %hhu\n", u.v8);
+               pci_read_config_byte(pdev, XEON_SBAR5SZ_OFFSET, &u.v8);
+               off += scnprintf(buf + off, buf_size - off,
+                                "SBAR5SZ %hhu\n", u.v8);
+       }
+
        off += scnprintf(buf + off, buf_size - off,
                         "\nNTB Incoming XLAT:\n");