[PATCH 04/18] KVM test: Add a get_ifname function

[Lucas Meneghel Rodrigues <lmr@redhat.com>]

It's clearer to use 'nic_mode + nic_index + vnc_port' than 'tap0',
It's also unique for one guest.

Signed-off-by: Amos Kong <akong@redhat.com>
---
 client/tests/kvm/kvm_vm.py |   21 ++++++++++++++++++++-
 1 files changed, 20 insertions(+), 1 deletions(-)

diff --git a/client/tests/kvm/kvm_vm.py b/client/tests/kvm/kvm_vm.py
index 13eaac1..a473bb4 100755
--- a/client/tests/kvm/kvm_vm.py
+++ b/client/tests/kvm/kvm_vm.py
@@ -426,7 +426,7 @@ class VM:
             if tftp:
                 tftp = kvm_utils.get_path(root_dir, tftp)
             qemu_cmd += add_net(help, vlan, nic_params.get("nic_mode", "user"),
-                                nic_params.get("nic_ifname"),
+                                self.get_ifname(vlan),
                                 script, downscript, tftp,
                                 nic_params.get("bootp"), redirs,
                                 self.netdev_id[vlan])
@@ -959,6 +959,25 @@ class VM:
             return self.redirs.get(port)
 
 
+    def get_ifname(self, nic_index=0):
+        """
+        Return the ifname of tap device for the guest nic.
+
+        The vnc_port is unique for each VM, nic_index is unique for each nic
+        of one VM, it can avoid repeated ifname.
+
+        @param nic_index: Index of the NIC
+        """
+        nics = kvm_utils.get_sub_dict_names(self.params, "nics")
+        nic_name = nics[nic_index]
+        nic_params = kvm_utils.get_sub_dict(self.params, nic_name)
+        if nic_params.get("nic_ifname"):
+            return nic_params.get("nic_ifname")
+        else:
+            return "%s_%s_%s" % (nic_params.get("nic_model"),
+                                 nic_index, self.vnc_port)
+
+
     def get_mac_address(self, nic_index=0):
         """
         Return the macaddr of guest nic.
-- 
1.7.2.2