[PATCH v3 11/11] igd: move igd-passthrough-isa-bridge creation to machine init

[Gerd Hoffmann <kraxel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

This patch moves igd-passthrough-isa-bridge creation out of the xen
passthrough code into machine init.  It is triggered by the
igd-passthru=on machine option.  Advantages:

 * This works for on both xen and kvm.
 * It is activated for the pc machine type only, q35 has a real
   isa bridge on 1f.0 and must be handled differently.  The q35
   plan is https://lkml.org/lkml/2015/11/26/183 (should land in
   the next merge window, i.e. linux 4.5).
 * If we don't need it any more some day (intel is busy removing
   chipset dependencies from the guest driver) we have a single
   machine switch to just turn off all igd passthru chipset
   tweaks.

Signed-off-by: Gerd Hoffmann <kraxel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
 hw/i386/pc_piix.c |  6 ++++++
 hw/xen/xen_pt.c   | 14 --------------
 2 files changed, 6 insertions(+), 14 deletions(-)

diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index f36222e..2afbbd3 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -281,6 +281,12 @@ static void pc_init1(MachineState *machine,
     if (pcmc->pci_enabled) {
         pc_pci_device_init(pci_bus);
     }
+
+#ifdef CONFIG_LINUX
+    if (machine->igd_gfx_passthru) {
+        igd_passthrough_isa_bridge_create(pci_bus);
+    }
+#endif
 }
 
 /* Looking for a pc_compat_2_4() function? It doesn't exist.
diff --git a/hw/xen/xen_pt.c b/hw/xen/xen_pt.c
index 18a7f72..5f626c9 100644
--- a/hw/xen/xen_pt.c
+++ b/hw/xen/xen_pt.c
@@ -685,17 +685,6 @@ static const MemoryListener xen_pt_io_listener = {
     .priority = 10,
 };
 
-static void
-xen_igd_passthrough_isa_bridge_create(XenPCIPassthroughState *s,
-                                      XenHostPCIDevice *dev)
-{
-    uint16_t gpu_dev_id;
-    PCIDevice *d = &s->dev;
-
-    gpu_dev_id = dev->device_id;
-    igd_passthrough_isa_bridge_create(d->bus);
-}
-
 /* destroy. */
 static void xen_pt_destroy(PCIDevice *d) {
 
@@ -810,9 +799,6 @@ static int xen_pt_initfn(PCIDevice *d)
             xen_host_pci_device_put(&s->real_device);
             return -1;
         }
-
-        /* Register ISA bridge for passthrough GFX. */
-        xen_igd_passthrough_isa_bridge_create(s, &s->real_device);
     }
 
     /* Handle real device's MMIO/PIO BARs */
-- 
1.8.3.1