diff --git a/hw/vfio/igd.c b/hw/vfio/igd.c
index 059ed56439..09bd4e5383 100644
--- a/hw/vfio/igd.c
+++ b/hw/vfio/igd.c
@@ -59,33 +59,34 @@
  */
 static int igd_gen(VFIOPCIDevice *vdev)
 {
-    if ((vdev->device_id & 0xfff) == 0xa84) {
-        return 8; /* Broxton */
+    /*
+     * Device IDs for Broxton/Apollo Lake are 0x0a84, 0x1a84, 0x1a85, 0x5a84
+     * and 0x5a85, match bit 11:1 here
+     * Prefix 0x0a is taken by Haswell, this rule should be matched first.
+     */
+    if ((vdev->device_id & 0xffe) == 0xa84) {
+        return 9;
     }
 
     switch (vdev->device_id & 0xff00) {
-    /* SandyBridge, IvyBridge, ValleyView, Haswell */
-    case 0x0100:
-    case 0x0400:
-    case 0x0a00:
-    case 0x0c00:
-    case 0x0d00:
-    case 0x0f00:
+    case 0x0100:    /* SandyBridge, IvyBridge */
         return 6;
-    /* BroadWell, CherryView, SkyLake, KabyLake */
-    case 0x1600:
-    case 0x1900:
-    case 0x2200:
-    case 0x5900:
+    case 0x0400:    /* Haswell */
+    case 0x0a00:    /* Haswell */
+    case 0x0c00:    /* Haswell */
+    case 0x0d00:    /* Haswell */
+    case 0x0f00:    /* Valleyview/Bay Trail */
+        return 7;
+    case 0x1600:    /* Broadwell */
+    case 0x2200:    /* Cherryview */
         return 8;
-    /* CoffeeLake */
-    case 0x3e00:
+    case 0x1900:    /* Skylake */
+    case 0x5900:    /* Kaby Lake */
+    case 0x3e00:    /* Coffee Lake */
         return 9;
-    /* ElkhartLake */
-    case 0x4500:
+    case 0x4500:    /* Elkhart Lake */
         return 11;
-    /* TigerLake */
-    case 0x9A00:
+    case 0x9A00:    /* Tiger Lake */
         return 12;
     }
 
@@ -258,7 +259,7 @@ static int vfio_igd_gtt_max(VFIOPCIDevice *vdev)
 
     gmch = vfio_pci_read_config(&vdev->pdev, IGD_GMCH, sizeof(gmch));
     ggms = (gmch >> (gen < 8 ? 8 : 6)) & 0x3;
-    if (gen > 6 && ggms != 0) {
+    if (gen >= 8 && ggms != 0) {
         ggms = 1 << ggms;
     }
 
@@ -668,7 +669,7 @@ void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
 
     /* Determine the size of stolen memory needed for GTT */
     ggms_mb = (gmch >> (gen < 8 ? 8 : 6)) & 0x3;
-    if (gen > 6 && ggms_mb != 0) {
+    if (gen >= 8 && ggms_mb != 0) {
         ggms_mb = 1 << ggms_mb;
     }