On 9/12/2022 11:36 AM, Tim Woodall wrote: > On Mon, 12 Sep 2022, David Wright wrote: > > > > > AFAICT it had two months in testing without this problem being > > hit and reported. > > > > Unfortunately, g-x-h is probably mostly used on stable or oldstable with > guests running testing. > > I'm not sure if it's possible to run a xen hypervisor in a domu - that > would be an interesting way to run testing. > > Tim. >
I think that xen hypervisor running in a domu is called nested virtualization. The Xen project defines support for this as follows [1]: ### x86/Nested PV This means running a Xen hypervisor inside an HVM domain on a Xen system, with support for PV L2 guests only (i.e., hardware virtualization extensions not provided to the guest). Status, x86 Xen HVM: Tech Preview This works, but has performance limitations because the L1 dom0 can only access emulated L1 devices. Xen may also run inside other hypervisors (KVM, Hyper-V, VMWare), but nobody has reported on performance. ### x86/Nested HVM This means providing hardware virtulization support to guest VMs allowing, for instance, a nested Xen to support both PV and HVM guests. It also implies support for other hypervisors, 739 such as KVM, Hyper-V, Bromium, and so on as guests. Status, x86 HVM: Experimental [1] http://xenbits.xen.org/gitweb/?p=xen.git;a=blob_plain;f=SUPPORT.md;hb=HEAD
