Bug 1047949

Description of problem:

I am able to create a VM having name (for example) 56 characters long. I can start such VM. But I cannot stop it. in RHEV-M UI it is presented like "Not Responding", but such VM is still running.

Version-Release number of selected component (if applicable):

RHEV Hypervisor - 6.5 - 20131204.0.3.2.el6_5
vdsm-4.10.2-27.0.el6ev

How reproducible: always


Steps to Reproduce:
1. create a VM with name longer than 52 characters
2. start it
3. stop it

Actual results:

VM cannot be stopped, node running such VM cannot switch to maintanance

Expected results:

RHEV must correctly handle VMs with longer name or RHEV-M REST API or UI must not allow VM name with such long name.

I am setting severity as URGENT, because hitting this bug causes big workload for system administrators.

Error in VDSM log file:

Thread-1767::ERROR::2014-01-02 16:08:52,360::BindingXMLRPC::932::vds::(wrapper) unexpected error
Traceback (most recent call last):
  File "/usr/share/vdsm/BindingXMLRPC.py", line 918, in wrapper
  File "/usr/share/vdsm/BindingXMLRPC.py", line 194, in vmDestroy
  File "/usr/share/vdsm/API.py", line 315, in destroy
  File "/usr/share/vdsm/libvirtvm.py", line 2654, in destroy
  File "/usr/share/vdsm/libvirtvm.py", line 2606, in releaseVm
  File "/usr/share/vdsm/guestIF.py", line 239, in stop
AttributeError: GuestAgent instance has no attribute '_sock'

Additional info:

Issue seems to be in virtio channel socket file. Underlying qemu-kvm process runs with

-chardev socket,id=charchannel1,path=/var/lib/libvirt/qemu/channels/xxguyen-jonlab-jon-gsqbx-bc-jonqe-lab-eng-bos-redhat-com.org.qemu.guest_agent.0,server,nowait 

but on file system, there's a file called /var/lib/libvirt/qemu/channels/xxguyen-jonlab-jon-gsqbx-bc-jonqe-lab-eng-bos-redhat-com.org.qemu.guest_agen

Socket file name is trimmed down to 76 characters (which leaves  52 for VM name) this can explain why wdsm cannot initialize channel socket.