Introduce Xen PCI Passthrough, PCI config space helpers

A more complete history can be found here:
git://xenbits.xensource.com/qemu-xen-unstable.git

Signed-off-by: Allen Kay <allen.m.kay@intel.com>
Signed-off-by: Guy Zana <guy@neocleus.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

hw/xen_pt.c

@@ -673,6 +673,13 @@ static int xen_pt_initfn(PCIDevice *d)
     /* Handle real device's MMIO/PIO BARs */
     xen_pt_register_regions(s);
 
+    /* reinitialize each config register to be emulated */
+    if (xen_pt_config_init(s)) {
+        XEN_PT_ERR(d, "PCI Config space initialisation failed.\n");
+        xen_host_pci_device_put(&s->real_device);
+        return -1;
+    }
+
     /* Bind interrupt */
     if (!s->dev.config[PCI_INTERRUPT_PIN]) {
         XEN_PT_LOG(d, "no pin interrupt\n");
@@ -771,6 +778,9 @@ static int xen_pt_unregister_device(PCIDevice *d)
         }
     }
 
+    /* delete all emulated config registers */
+    xen_pt_config_delete(s);
+
     xen_pt_unregister_regions(s);
     memory_listener_unregister(&s->memory_listener);
 

hw/xen_pt.h

@@ -62,6 +62,8 @@ typedef int (*xen_pt_conf_byte_read)
 #define XEN_PT_BAR_ALLF 0xFFFFFFFF
 #define XEN_PT_BAR_UNMAPPED (-1)
 
+#define PCI_CAP_MAX 48
+
 
 typedef enum {
     XEN_PT_GRP_TYPE_HARDWIRED = 0,  /* 0 Hardwired reg group */