xen: add support for MSI message groups

Add support for MSI message groups for Xen Dom0 using the
MAP_PIRQ_TYPE_MULTI_MSI pirq map type.

In order to keep track of which pirq is the first one in the group all
pirqs in the MSI group except for the first one have the newly
introduced PIRQ_MSI_GROUP flag set. This prevents calling
PHYSDEVOP_unmap_pirq on them, since the unmap must be done with the
first pirq in the group.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
diff --git a/include/xen/events.h b/include/xen/events.h
index a6d9237..8bee7a7 100644
--- a/include/xen/events.h
+++ b/include/xen/events.h
@@ -2,6 +2,9 @@
 #define _XEN_EVENTS_H
 
 #include <linux/interrupt.h>
+#ifdef CONFIG_PCI_MSI
+#include <linux/msi.h>
+#endif
 
 #include <xen/interface/event_channel.h>
 #include <asm/xen/hypercall.h>
@@ -101,7 +104,7 @@
 int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc);
 /* Bind an PSI pirq to an irq. */
 int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
-			     int pirq, const char *name, domid_t domid);
+			     int pirq, int nvec, const char *name, domid_t domid);
 #endif
 
 /* De-allocates the above mentioned physical interrupt. */