ubuntu dom0 vmx problem

[chenchao]

hi, guys

I am using a dual boot configuration, one with Ubuntu 9.10 and the other with Xen 3.4.2 with Ubuntu 9.10 as Dom0.
I have enabled the VMX support in the BIOS.
Native Linux shows the presence of the VMX flag in /proc/cpuinfo
Xen Dom0 doesn't have the flag set in /proc/cpuinfo
but, xm dmesg shows that VMX is enabled in the BIOS.


How can I resolve this? I want to install a fully virtualized guest OS on Intel Q8400 CPU with VMX support.

I have another question. How to change dom0 cpus?

Please help me.

Thanks

[meatpan]

If 'xm dmesg' mentions that VMX is enabled, you should be ok.

For example, on my system, running 'xm dmesg | grep VMX' returns:
(XEN) VMX: Supported advanced features:
(XEN) VMX: EPT is available.
(XEN) VMX: VPID is available
(XEN) HVM: VMX is enabled.

However, /proc/cpuinfo does not show a vmx flag.

Also, another useful way to check for VMX support is the 'xm info' command. Run this command, and look for 'hvm' somewhere in the xen_caps and virt_caps values.

I'm not sure why /proc/cpuinfo no longer contains the vmx flag. This threw me off a bit at first, too. It hasn't been a problem though, as I'm using nearly all VMX features (including VT-d and HAP) on a set of processors that do not explicitly state 'vmx'.

A quick suggestion: If you can, boot a xen livecd and try to initialize one of the prepackaged HVM's. This will quickly show you the limit of your VMX capabilities.

[chenchao]

Thank you for your help.

I run 'xm info' and find 'hvm' in virt_caps.

But, I still can't use virt-manager to install a fully virtualized guest OS. I cannot choose 'Local install media (ISO image or CDROM)'. It shows 'CDROM/ISO installs not available for paravirt guests.'

I try xenlivecd. Everything is good. I can install an HVM guest OS.

Do you have any good idea?
Please help me. Thank you very much

[meatpan]

How are you certain that you are creating an HVM? Was there a step in the setup process where you selected "Full Virtualization"?

I can't help you much here because I don't use the virt-manager tool. It sounds like your machine is capable of VT, but your toolset is mis-configured or mis-operated.