Switching to PVH

Requirements

you might need some exotic cpu flags to run a PVH domain, such as ept, not just vmx.

egrep -wo 'vmx|ept|vpid|npt|tpr_shadow|flexpriority|vnmi|lm|aes' /proc/cpuinfo

DomU

vi /data/guests/$guest/$guest

type = "pvh"

Dom0

with mbootpack

vi /etc/lilo.conf

image = /xenux
    label = "XEN-PVH"
    append = "dom0=pvh dom0_mem=1024M,max:2048M loglvl=info noreboot=true -- root=/dev/sda1 ro mitigations=off"
    read-only
    #loglvl=all
    #vt.default_utf8=0

Note dom0_mem is absolutely required here, Dom0 PVH does not work without it.

Acceptance

xl list -l | grep type

Troubleshooting

seen this on a KVM-nested XEN dom0

(XEN) Panic on CPU 0:
(XEN) Presently, iommu must be enabled for PVH hardware domain

==> you need VT-D, not just VT. there’s no point of doing that on a nested kvm/host.

Resources

Xen Project Software Overview https://wiki.xenproject.org/wiki/Xen_Project_Software_Overview

PVH Specification https://xenbits.xen.org/docs/4.6-testing/misc/pvh.html

PVH : an x86 PV guest running in an HVM container. https://xenbits.xen.org/docs/4.6-testing/misc/pvh-readme.txt

domU

Direct Kernel Boot http://xenbits.xen.org/docs/unstable/man/xl.cfg.5.html#Direct-Kernel-Boot

PVH Guest Specific Options http://xenbits.xen.org/docs/unstable/man/xl.cfg.5.html#PVH-Guest-Specific-Options

Linux PVH https://wiki.xenproject.org/wiki/Linux_PVH

Xen PVH http://xgu.ru/wiki/Xen_PVH

dom0

xen/pvh: Dom0 support https://lwn.net/Articles/753982/

dom0=pvh and 4.18 http://xen.1045712.n5.nabble.com/dom0-pvh-and-4-18-td5741954.html

Xen Hypervisor Command Line Options http://xenbits.xen.org/docs/unstable/misc/xen-command-line.html

Towards PVHVM, PVH and SMP dom0 https://mail-index.netbsd.org/port-xen/2018/09/10/msg009328.html

PVH Dom0 https://wiki.xenproject.org/wiki/Xen_Project_4.11_Feature_List#PVH_Dom0