piix_pci: Introduces Xen specific call for irq.

This patch introduces Xen specific call in piix_pci.

The specific part for Xen is in write_config, set_irq and get_pirq.

Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/xen-all.c b/xen-all.c
index 0b984b2..acb051c 100644
--- a/xen-all.c
+++ b/xen-all.c
@@ -6,9 +6,40 @@
  *
  */
 
+#include "hw/pci.h"
 #include "hw/xen_common.h"
 #include "hw/xen_backend.h"
 
+/* Xen specific function for piix pci */
+
+int xen_pci_slot_get_pirq(PCIDevice *pci_dev, int irq_num)
+{
+    return irq_num + ((pci_dev->devfn >> 3) << 2);
+}
+
+void xen_piix3_set_irq(void *opaque, int irq_num, int level)
+{
+    xc_hvm_set_pci_intx_level(xen_xc, xen_domid, 0, 0, irq_num >> 2,
+                              irq_num & 3, level);
+}
+
+void xen_piix_pci_write_config_client(uint32_t address, uint32_t val, int len)
+{
+    int i;
+
+    /* Scan for updates to PCI link routes (0x60-0x63). */
+    for (i = 0; i < len; i++) {
+        uint8_t v = (val >> (8 * i)) & 0xff;
+        if (v & 0x80) {
+            v = 0;
+        }
+        v &= 0xf;
+        if (((address + i) >= 0x60) && ((address + i) <= 0x63)) {
+            xc_hvm_set_pci_link_route(xen_xc, xen_domid, address + i - 0x60, v);
+        }
+    }
+}
+
 /* VCPU Operations, MMIO, IO ring ... */
 
 static void xen_reset_vcpu(void *opaque)