Xen devel - Jul 2009 - [patch] xend: pass-through: use identity-mapping of PCI functions

This reverses changeset "xend: pass-through: Implement least-mapping of
virtual" (19854:22067ba1de0d) and reverts the code to identity mapping
physical PCI functions to virtual ones when multi-function virtual devices
are in use. It is my opinion that this is both safer and simpler than
least-mapping, and that in the absence of further analysis identity-mapping
the best choice for now.

Signed-off-by: Simon Horman <horms@verge.net.au>

Index: xen-unstable.hg/tools/python/xen/util/pci.py
==================================================================---
xen-unstable.hg.orig/tools/python/xen/util/pci.py	2009-07-21 20:23:23.000000000
+1000
+++ xen-unstable.hg/tools/python/xen/util/pci.py	2009-07-21 20:23:48.000000000
+1000
@@ -287,13 +287,19 @@ def parse_pci_name_extended(pci_dev_str)
     # Virtual slot assignment takes place here if specified in the bdf,
     # else it is done inside qemu-xen, as it knows which slots are free
     pci = []
-    vfunc = 0;
     func_list = pci_func_list_process(pci_dev_str, template,
                                       pci_dev_info[''func''])
     for func in func_list:
         pci_dev = template.copy()
         pci_dev[''func''] = "0x%x" % func
 
+        if len(func_list) == 1:
+            # For single-function devices vfunc must be 0
+            vfunc = 0
+        else:
+            # For multi-function virtual devices,
+            # identity map the func to vfunc
+            vfunc = func
         if pci_dev_info[''vdevfn''] == '''':
             vdevfn = AUTO_PHP_SLOT | vfunc
         else:
@@ -301,7 +307,6 @@ def parse_pci_name_extended(pci_dev_str)
         pci_dev[''vdevfn''] = "0x%02x" % vdevfn
 
         pci.append(pci_dev)
-        vfunc += 1
 
     # For pci attachment and detachment is it important that virtual
     # function 0 is done last. This is because is virtual function 0 that
Index: xen-unstable.hg/tools/python/xen/xm/main.py
==================================================================---
xen-unstable.hg.orig/tools/python/xen/xm/main.py	2009-07-21 20:23:23.000000000
+1000
+++ xen-unstable.hg/tools/python/xen/xm/main.py	2009-07-21 20:30:03.000000000
+1000
@@ -2226,17 +2226,9 @@ def xm_pci_list(args):
     if len(devs) == 0:
         return
 
-    def f(x):
-        # The vfunc shouldn''t be used for ordering if the vslot
hasn''t been
-        # assigned as the output looks odd beacuse the vfunc isn''t
reported
-        # but the (physical) function is.
-        if x[''vdevfn''] & AUTO_PHP_SLOT:
-            vdevfn = AUTO_PHP_SLOT
-        else:
-            vdevfn = x[''vdevfn'']
-        return (vdevfn << 32) | \
-                   PCI_BDF(x[''domain''],
x[''bus''], x[''slot''],
x[''func''])
-    devs.sort(None, f)
+    devs.sort(None,
+              lambda x: (x[''vdevfn''] -
PCI_FUNC(x[''vdevfn''])) << 32 |
+                         PCI_BDF(x[''domain''],
x[''bus''], x[''slot''],
x[''func'']))
 
     has_vdevfn = False
     for x in devs:

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