On 08/19/2013 10:13 PM, James Slagle wrote:
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.
If you're using a full-blown X, maybe you cay try a minimal server setup across L0,
L1,
and L2?
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>
You can also optionally try to do a host CPU pass-through instead of explicitly exposing
the VMX instruction (although that should suffice in most cases).
<cpu mode='host-passthrough'/>
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?
Hm, I've been running some tests on latest Intel Hardware (Haswell), and I have both
L1,
and L2 running consistently fine with rawhide kernels.
Here's my set-up details:
https://github.com/kashyapc/nvmx-haswell/blob/master/SETUP-nVMX.rst
Libvirt XML files for L1 and L2:
https://github.com/kashyapc/nvmx-haswell/tree/master/tests/libvirt-xmls-f...
Hope that helps a bit.
/kashyap