vfio/igd: emulate BDSM in mmio bar0 for gen 6-10 devices

A recent commit in i915 driver [1] claims the BDSM register at 0x1080c0
of mmio bar0 has been there since gen 6. Mirror this register to the 32
bit BDSM register at 0x5c in pci config space for gen6-10 devices.

[1] https://patchwork.freedesktop.org/patch/msgid/20240202224340.30647-7-ville.syrjala@linux.intel.com

Reviewed-by: Corvin Köhne <c.koehne@beckhoff.com>
Signed-off-by: Tomita Moeko <tomitamoeko@gmail.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Link: https://lore.kernel.org/r/20241206122749.9893-10-tomitamoeko@gmail.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

diff --git a/hw/vfio/igd.c b/hw/vfio/igd.c
index 828222cad13400034d12e748a982af275f21cda1..c15a14e44546931a44db2e5d144116b5524c0f83 100644 (file)
--- a/hw/vfio/igd.c
+++ b/hw/vfio/igd.c
@@ -489,7 +489,8 @@ static const MemoryRegionOps vfio_igd_quirk_mirror_##name = {           \
 };
 
 VFIO_IGD_QUIRK_MIRROR_REG(IGD_GMCH, ggc)
-VFIO_IGD_QUIRK_MIRROR_REG(IGD_BDSM_GEN11, bdsm)
+VFIO_IGD_QUIRK_MIRROR_REG(IGD_BDSM, bdsm)
+VFIO_IGD_QUIRK_MIRROR_REG(IGD_BDSM_GEN11, bdsm64)
 
 #define IGD_GGC_MMIO_OFFSET     0x108040
 #define IGD_BDSM_MMIO_OFFSET    0x1080C0
@@ -516,7 +517,7 @@ void vfio_probe_igd_bar0_quirk(VFIOPCIDevice *vdev, int nr)
      * into MMIO space and read from MMIO space by the Windows driver.
      */
     gen = igd_gen(vdev);
-    if (gen < 11) {
+    if (gen < 6) {
         return;
     }
 
@@ -530,12 +531,21 @@ void vfio_probe_igd_bar0_quirk(VFIOPCIDevice *vdev, int nr)
                                         IGD_GGC_MMIO_OFFSET, &quirk->mem[0],
                                         1);
 
-    memory_region_init_io(&quirk->mem[1], OBJECT(vdev),
-                          &vfio_igd_quirk_mirror_bdsm, vdev,
-                          "vfio-igd-bdsm-quirk", 8);
-    memory_region_add_subregion_overlap(vdev->bars[0].region.mem,
-                                        IGD_BDSM_MMIO_OFFSET, &quirk->mem[1],
-                                        1);
+    if (gen < 11) {
+        memory_region_init_io(&quirk->mem[1], OBJECT(vdev),
+                              &vfio_igd_quirk_mirror_bdsm, vdev,
+                              "vfio-igd-bdsm-quirk", 4);
+        memory_region_add_subregion_overlap(vdev->bars[0].region.mem,
+                                            IGD_BDSM_MMIO_OFFSET,
+                                            &quirk->mem[1], 1);
+    } else {
+        memory_region_init_io(&quirk->mem[1], OBJECT(vdev),
+                              &vfio_igd_quirk_mirror_bdsm64, vdev,
+                              "vfio-igd-bdsm-quirk", 8);
+        memory_region_add_subregion_overlap(vdev->bars[0].region.mem,
+                                            IGD_BDSM_MMIO_OFFSET,
+                                            &quirk->mem[1], 1);
+    }
 
     QLIST_INSERT_HEAD(&vdev->bars[nr].quirks, quirk, next);
 }