[fedora-virt] Nested KVM help

[James Slagle]

Hi,

When I try to use nested KVM with Fedora 19, I'm experiencing a hang of the L1
vm.  I eventually have to do a "Force Off" from virt-manager on L0 since the L1
vm is completely unresponsive.

Both my L0 and L1 are F19, x86_64.  L2 doesn't really seem to matter as I can't
even get the guest to start before L1 completely locks up.  Even just
attempting to define a L2 guest that uses kvm virtualization locks up L1
completely.

Here are some more details.

On L0 (i've rebooted L0 after enabling the nested parameter):
[root@dublin ~]# uname -a
Linux dublin 3.10.7-200.fc19.x86_64 #1 SMP Thu Aug 15 23:19:45 UTC 2013 x86_64
x86_64 x86_64 GNU/Linux
[root@dublin ~]# cat /sys/module/kvm_intel/parameters/nested 
Y
[root@dublin ~]# rpm -q libvirt
libvirt-1.0.5.5-1.fc19.x86_64
[root@dublin ~]# lsmod | grep kvm
kvm_intel             138528  3 
kvm                   422809  1 kvm_intel

cpu section of libvirt xml for L1 vm:
  <cpu mode='custom' match='exact'>
    <model fallback='allow'>Nehalem</model>
    <feature policy='require' name='vmx'/>
  </cpu>


On L1:
[root@localhost jslagle]# uname -a
Linux localhost.localdomain 3.10.7-200.fc19.x86_64 #1 SMP Thu Aug 15 23:19:45
UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
[root@localhost jslagle]# rpm -q libvirt
libvirt-1.0.5.5-1.fc19.x86_64
[root@localhost jslagle]# lsmod | grep kvm
kvm_intel             138528  0 
kvm                   422809  1 kvm_intel


I've looked in dmesg output, /var/log/messages, and libvirt logs on both L0 and
L1 and can't see any errors.

Any ideas on how to debug this further?
Let me know if should file a bugzilla, I wasn't sure I had enough to go on to
go ahead and do that yet.

Thanks for any help.

--
-- James Slagle
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