Converting HVM To PV Kernel CentOS7

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Hi,

I have installed CentOS 7 HVM kernel. I would like to convert it to CentOS
7 PV kernel.

When googled about it, I found that this can be done by following commands

yum install xen or yum install kernel-xen

But, when I tried the below commands, I am getting the error *”No package kernel-xen available.**”*

What am I missing here. Any help is much appreciated.

6 thoughts on - Converting HVM To PV Kernel CentOS7

  • what version were those instructions for ? AFAIK, there’s no xen specific kernel in EL7, Red Hat and therefore CentOS supports KVM as their native virtualization, and the PV drivers for KVM are built in.

  • Thanks for the reply. Sorry for the typo in the earlier mail. I have PV-HVM of CentOS 7 & I need to convert it to PV kernel.

    Basically here I am trying to see whether my PV_HVM kernel is vulenrable to this issue given in the following link http://seclists.org/oss-sec/2015/q3/212

    In the above link, it was mentioned that the PV kernel is not vulnerable to this bug, but HVM is. It didnt say anything about PV-HVM.

    Can you please help me in this regard?

  • that is talking about a problem with QEMU and emulated cdroms, and as far as I can tell, the bug is in the qemu emulator, not in the VM’s.
    it merely states that if you only use PV VM’s you won’t trigger the bug, but the correct fix is to update your QEMU so there is no bug.

    https://access.redhat.com/security/cve/CVE-2015-5154 suggests QEMU has been fixed as of July 27/28, at least for KVM servers, see the 4 RHSA
    Errata linked there.

    again, RHEL7 and therefore CentOS 7 is all about KVM not Xen.

    If you’re running someone’s xen server, you need to ensure its patched against this bug.

  • Thanks for the reply.

    If we want to have PV kernel for CentOS 7 , are there any guidelines to follow?
    How we can know before hand itself that this kernel is PV or HVM, without installing kernel?

  • All modern kernels are PV compatible. You can take the same Linux image and run it HVM or PV.

  • I have taken the latest CentOS 7 base image, and after the installation &
    customization I came to know that it is HVM. So, I wanted to know before hand itself whether its HVM or PV. How can I do it?
    are there any specific steps we need to follow?