[PATCH v3 6/7] vfio/pci: Use pci_rom_patch_ids() for IGD ROM ID patching

[Tomita Moeko <tomitamoeko@gmail.com>]

Remove the duplicate inline logic in vfio_pci_load_rom() that patched
the device ID in an IGD option ROM and replace it with a call to
pci_rom_patch_ids(), conditioned on the rom_need_patch_id flag.

Reported-by: K S Maan <kirandeepmaan45@gmail.com>
Signed-off-by: Tomita Moeko <tomitamoeko@gmail.com>
---
 hw/vfio/pci.c | 31 +++----------------------------
 1 file changed, 3 insertions(+), 28 deletions(-)

diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 9c06b25e63..6cbd65126e 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -1029,6 +1029,7 @@ static void vfio_update_msi(VFIOPCIDevice *vdev)
 
 static void vfio_pci_load_rom(VFIOPCIDevice *vdev)
 {
+    PCIDevice *pdev = PCI_DEVICE(vdev);
     VFIODevice *vbasedev = &vdev->vbasedev;
     struct vfio_region_info *reg_info = NULL;
     uint64_t size;
@@ -1084,34 +1085,8 @@ static void vfio_pci_load_rom(VFIOPCIDevice *vdev)
         }
     }
 
-    /*
-     * 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;
-        }
+    if (pdev->rom_need_patch_id) {
+        pci_rom_patch_ids(pdev, vdev->rom, vdev->rom_size);
     }
 }
 
-- 
2.53.0