tools: fix binding to unsupported driver

The dpdk_nic_bind script will not allow ports to be bound or unbound if none of the
kernel modules supported by DPDK is loaded. This patch relaxes this restriction by
checking if a DPDK module is actually requested. The example below illustrates this
problem:

In virtio test, on the guest
1. Bind virtio port to igb_uio driver;
2. Remove igb_uio module;
3. Bind virtio port to virtio-pci driver, it fails and reports:
   "Error - no supported modules are loaded"

The script should check the to-be-bound driver flag, if it is dpdk driver(igb_uio, vfio etc),
and the corresponding module is not loaded, then exit, otherwise, just report a warning,
and continue to bind the non-dpdk driver(like virtio-pci) to dev.

Signed-off-by: Changchun Ouyang <changchun.ouyang@intel.com>
Tested-by: Qian Xu <qian.q.xu@intel.com>
Acked-by: Michael Qiu <michael.qiu@intel.com>

diff --git a/tools/dpdk_nic_bind.py b/tools/dpdk_nic_bind.py
index 2483056..8523f82 100755 (executable)
--- a/tools/dpdk_nic_bind.py
+++ b/tools/dpdk_nic_bind.py
@@ -175,8 +175,11 @@ def check_modules():
 
     # check if we have at least one loaded module
     if True not in [mod["Found"] for mod in mods] and b_flag is not None:
-        print "Error - no supported modules are loaded"
-        sys.exit(1)
+        if b_flag in dpdk_drivers:
+            print "Error - no supported modules(DPDK driver) are loaded"
+            sys.exit(1)
+        else:
+            print "Warning - no supported modules(DPDK driver) are loaded"
 
     # change DPDK driver list to only contain drivers that are loaded
     dpdk_drivers = [mod["Name"] for mod in mods if mod["Found"]]