Index: hv/tools/python/xen/xend/server/pciif.py
===================================================================
--- hv.orig/tools/python/xen/xend/server/pciif.py
+++ hv/tools/python/xen/xend/server/pciif.py
@@ -493,12 +493,14 @@ class PciController(DevController):
         # DMA transaction, etc
         dev.do_FLR()
 
-        pci_str = "0x%x, 0x%x, 0x%x, 0x%x" % (domain, bus, slot, func)
-        bdf = xc.deassign_device(fe_domid, pci_str)
-        if bdf > 0:
-            raise VmError("Failed to deassign device from IOMMU (%x:%x.%x)"
-                          % (bus, slot, func))
-        log.debug("pci: Deassign device %x:%x.%x" % (bus, slot, func))
+        # qemu would do following in case of HVM
+        if not self.vm.info.is_hvm():
+            pci_str = "0x%x, 0x%x, 0x%x, 0x%x" % (domain, bus, slot, func)
+            bdf = xc.deassign_device(fe_domid, pci_str)
+            if bdf > 0:
+                raise VmError("Failed to deassign device from IOMMU (%x:%x.%x)"
+                              % (bus, slot, func))
+            log.debug("pci: Deassign device %x:%x.%x" % (bus, slot, func))
 
         for (start, size) in dev.ioports:
             log.debug('pci: disabling ioport 0x%x/0x%x'%(start,size))