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[Xen-users] Re: HVM or PV

Geert Janssens wrote:
On Thursday 13 August 2009, brun wrote:
Ronaldo Zacarias Afonso wrote:
Well, I have a suggestion that could works out if you are running your
image in a Intel or AMD processor.Try looking at /proc/cpuinfo.
If you don't find a flag like these:

For Intel: vmx
For AMD: svm

I'm almost pretty sure you have a PV Xen.
Well, there is no flag. So is this definitely not hvm, or just unlikely

I'm just an average xen user, but I'm not really sure this is a valid or reliable test. I have got a Dual CPU, dual core AMD Opteron 221 machine running xen. So I would expect the svm flag in /proc/cpuinfo. I don't see it, neither in dom0, nor in any of my PV domUs.

This test makes no sense at all, you wont see the vmx/svm flag in either the dom0 or any (PV|HVM) domU.

Most often 'uname -a' already helps, if its a distribution kernel (such as Centos) it will contain -xen if it's PV. You can also check loaded modules, xenblk and xennet are a good indicator or the type of consoles available (hvc/xvc would suggest PV).

Finally you could use lspci to look for qemu emulated devices (such as the RTL8139 nic) as an indicator for HVM (in PV lspci should return nothing unless you are passing through a "real" PCI device).

Best regards,

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