qemu.tests: Add a qemu subtest script multi_vms_nics.py

Mainly test steps:
1. Check if the NIC number in guest matches that specified in config file.
2. Get the ip-mac pair in guest.
3. Gather the ping info by tcpdump.
4. Check if the ip-mac info matches in the tcpdump output.
5. Check if the ping count matches the given number.

Signed-off-by: Bear <byang@redhat.com>
Signed-off-by: Ken Cao <kcao@redhat.com>
Signed-off-by: Yolkfull Chow <yzhou@redhat.com>
Signed-off-by: Feng Yang <fyang@redhat.com>
KVM-test: Multi nic test case improve
Signed-off-by: Yiqiao Pu <ypu@redhat.com>
KVM Test: multi_nics: Fix argument order for scp_between_remotes
Signed-off-by: Qingtang Zhou <qzhou@redhat.com>
KVM Test: Refactor multi_nics.py test script
Rename multi_nics.py to multi_vms_nics.py
Support multi vms and multi nics.
Signed-off-by: Feng Yang <fyang@redhat.com>
qemu: Fix syntax error in multi_nics.py
Signed-off-by: Feng Yang <fyang@redhat.com>
qemu.tests.cfg: Add multi_vms_nic test case config.

This case test ping and file transfer during multi vms.
It also can support multi nics in multi vms.
Now we only test one nic in every vm.

Signed-off-by: Feng Yang <fyang@redhat.com>