[PATCH v2] qemu-xen:Correctly expose PCH ISA bridge for IGD passthrough

["G.R." <firemeteor@users.sourceforge.net>]

Fix IGD passthrough logic to properly expose PCH ISA bridge (instead
of exposing as pci-pci bridge). The i915 driver require this to
correctly detect the PCH version and enable version specific code
path.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
Timothy Guo <firemeteor@users.sourceforge.net>

diff --git a/hw/pci.c b/hw/pci.c
index f051de1..d371bd7 100644
--- a/hw/pci.c
+++ b/hw/pci.c
@@ -871,11 +871,6 @@ void pci_unplug_netifs(void)
     }
 }

-typedef struct {
-    PCIDevice dev;
-    PCIBus *bus;
-} PCIBridge;
-
 void pci_bridge_write_config(
PCIDevice *d,
                              uint32_t address, uint32_t val, int len)
 {
diff --git a/hw/pci.h b/hw/pci.h
index edc58b6..c2acab9 100644
--- a/hw/pci.h
+++ b/hw/pci.h
@@ -222,6 +222,11 @@ struct PCIDevice {
     int irq_state[4];
 };

+typedef struct {
+    PCIDevice dev;
+    PCIBus *bus;
+} PCIBridge;
+
 extern char direct_pci_str[];
 extern int direct_pci_msitranslate;
 extern int direct_pci_power_mgmt;
diff --git a/hw/pt-graphics.c b/hw/pt-graphics.c
index c6f8869..de21f90 100644
--- a/hw/pt-graphics.c
+++ b/hw/pt-graphics.c
@@ -3,6 +3,7 @@
  */

 #include "pass-through.h"
+#include "pci.h"
 #include "pci/header.h"
 #include "pci/pci.h"

@@ -40,9 +41,26 @@ void intel_pch_init(PCIBus *bus)
     did = pt_pci_host_read(pci_dev_1f, PCI_DEVICE_ID, 2);
     rid = pt_pci_host_read(pci_dev_1f, PCI_REVISION, 1);

-    if ( vid == PCI_VENDOR_ID_INTEL )
-        pci_bridge_init(bus, PCI_DEVFN(0x1f, 0), vid, did, rid,
-                        pch_map_irq, "intel_bridge_1f");
+    if (vid == PCI_VENDOR_ID_INTEL) {
+        PCIBridge *s = (PCIBridge *)pci_register_device(bus, "intel_bridge_1f",
+                sizeof(PCIBridge), PCI_DEVFN(0x1f, 0), NULL,
pci_bridge_write_config);
+
+        pci_config_set_vendor_id(s->dev.config, vid);
+        pci_config_set_device_id(s->dev.config, did);
+
+        s->dev.config[PCI_COMMAND] = 0x06; // command = bus master, pci mem
+        s->dev.config[PCI_COMMAND + 1] = 0x00;
+        s->dev.config[PCI_STATUS] = 0xa0; // status = fast
back-to-back, 66MHz, no error
+        s->dev.config[PCI_STATUS + 1] = 0x00; // status = fast devsel
+        s->dev.config[PCI_REVISION] = rid;
+        s->dev.config[PCI_CLASS_PROG] = 0x00; // programming i/f
+        pci_config_set_class(s->dev.config, PCI_CLASS_BRIDGE_ISA);
+        s->dev.config[PCI_LATENCY_TIMER] = 0x10;
+        s->dev.config[PCI_HEADER_TYPE] = 0x80;
+        s->dev.config[PCI_SEC_STATUS] = 0xa0;
+
+        s->bus = pci_register_secondary_bus(&s->dev, pch_map_irq);
+    }
 }

 uint32_t igd_read_opregion(struct pt_dev *pci_dev)