xend: Fix 'xm pci_list_assignable_devices'

The current implementation of 'xm pci-list-assignable-devices' command
has a problem that it directly invokes hypercall using
xen.lowlevel.xc.
This is probably based on an assumption that the command is executed
on the host itself, but in fact there are cases xm commands can be
executed on a remote server through xmlrpc.
So this patch makes the xm command just inquire of xend about the
information of available devices.

Signed-off-by: Yosuke Iwamatsu <y-iwamatsu@ab.jp.nec.com>

tools/python/xen/xend/XendNode.py

@@ -806,6 +806,43 @@ class XendNode:
 
         return [[k, info[k]] for k in ITEM_ORDER]
 
+
+    def pciinfo(self):
+        # Each element of dev_list is a PciDevice
+        dev_list = PciUtil.find_all_devices_owned_by_pciback()
+ 
+        # Each element of devs_list is a list of PciDevice
+        devs_list = PciUtil.check_FLR_capability(dev_list)
+ 
+        devs_list = PciUtil.check_mmio_bar(devs_list)
+ 
+        # Check if the devices have been assigned to guests.
+        final_devs_list = []
+        for dev_list in devs_list:
+            available = True
+            for d in dev_list:
+                pci_str = '0x%x,0x%x,0x%x,0x%x' %(d.domain, d.bus, d.slot, d.func)
+                # Xen doesn't care what the domid is, so we pass 0 here...
+                domid = 0
+                bdf = self.xc.test_assign_device(domid, pci_str)
+                if bdf != 0:
+                    available = False
+                    break
+            if available:
+                final_devs_list = final_devs_list + [dev_list]
+
+        pci_sxp_list = []
+        for dev_list in final_devs_list:
+            for d in dev_list:
+                pci_sxp = ['dev', ['domain', '0x%04x' % d.domain],
+                                  ['bus', '0x%02x' % d.bus],
+                                  ['slot', '0x%02x' % d.slot],
+                                  ['func', '0x%x' % d.func]]
+                pci_sxp_list.append(pci_sxp)
+
+        return pci_sxp_list
+ 
+
     def xenschedinfo(self):
         sched_id = self.xc.sched_id_get()
         if sched_id == xen.lowlevel.xc.XEN_SCHEDULER_SEDF:

tools/python/xen/xend/server/XMLRPCServer.py

@@ -198,7 +198,8 @@ class XMLRPCServer:
                     self.server.register_function(fn, "xend.domain.%s" % name[7:])
 
         # Functions in XendNode and XendDmesg
-        for type, lst, n in [(XendNode, ['info', 'send_debug_keys'], 'node'),
+        for type, lst, n in [(XendNode, ['info', 'pciinfo', 'send_debug_keys'],
+                             'node'),
                              (XendDmesg, ['info', 'clear'], 'node.dmesg')]:
             inst = type.instance()
             for name in lst:

tools/python/xen/xm/main.py

@@ -58,13 +58,6 @@ from xen.util.acmpolicy import ACM_LABEL_UNLABELED_DISPLAY
 
 import XenAPI
 
-import xen.lowlevel.xc
-try:
-    xc = xen.lowlevel.xc.xc()
-except Exception, ex:
-    print >>sys.stderr, ("Is xen kernel running?")
-    sys.exit(1)
-
 import inspect
 from xen.xend import XendOptions
 xoptions = XendOptions.instance()
@@ -2188,34 +2181,28 @@ def xm_pci_list(args):
             hdr = 1
         print ( fmt_str % x )
 
+
+def parse_pci_info(info):
+    def get_info(n, t, d):
+        return t(sxp.child_value(info, n, d))
+    return {
+        'domain' : get_info('domain', parse_hex, 0),
+        'bus'    : get_info('bus', parse_hex, -1),
+        'slot'   : get_info('slot', parse_hex, -1),
+        'func'   : get_info('func', parse_hex, -1)
+        }
+
 def xm_pci_list_assignable_devices(args):
-    # Each element of dev_list is a PciDevice
-    dev_list = find_all_devices_owned_by_pciback()
+    xenapi_unsupported()
+    arg_check(args, "pci-list-assignable-devices", 0)
 
-    # Each element of devs_list is a list of PciDevice
-    devs_list = check_FLR_capability(dev_list)
+    devs =  server.xend.node.pciinfo()
+ 
+    fmt_str = "%(domain)04x:%(bus)02x:%(slot)02x:%(func)01x"
+    for x in devs:
+        pci = parse_pci_info(x)
+        print fmt_str % pci
 
-    devs_list = check_mmio_bar(devs_list)
-
-    # Check if the devices have been assigned to guests.
-    final_devs_list = []
-    for dev_list in devs_list:
-        available = True
-        for d in dev_list:
-            pci_str = '0x%x,0x%x,0x%x,0x%x' %(d.domain, d.bus, d.slot, d.func)
-            # Xen doesn't care what the domid is, so we pass 0 here...
-            domid = 0
-            bdf = xc.test_assign_device(domid, pci_str)
-            if bdf != 0:
-                available = False
-                break
-        if available:
-            final_devs_list = final_devs_list + [dev_list]
-
-    for dev_list in final_devs_list:
-        for d in dev_list:
-            print d.name,
-        print
 
 def vscsi_sort(devs):
     def sort_hctl(ds, l):