Re: Kernel modules on 10.1

[Brad Spencer <brad%anduin.eldar.org@localhost>]

Stephen Borrill <netbsd%precedence.co.uk@localhost> writes:

[snip]

> Support for PVH is somewhat vague in the xapi toolstack (XenServer, 
> XCP-ng). I have tried a NetBSD 10.1 PV VM that works on earlier versions 
> on the latest XenServer 8.4. It fails to start in PV mode with the 
> following error:
> Domain.Domain_build_pre_failed("Calling 'shadow_allocation_set 10 MiB' 
> failed: Xenctrl.Error(\"22: Invalid argument\")")
>
> I think this is because of the following change as part of the update to 
> Xen 4.17:
>
> - PV32, PV_LINEAR_PT and SHADOW_PAGING now compiled out
>
> (from https://koji.xcp-ng.org/buildinfo?buildID=3568 )
>
> It looks like you can set domain-type=pv-in-pvh on the VM (even it is only 
> documented having pv and hvm values). This does attempt to start the VM, 
> but it stops quickly afterwards. Perhaps this is because of PV_LINEAR_PT 
> being removed or is this not relevant with PVH mode?

Something called 'pv-in-pvh' sounds like pvshim.  I don't know what this
particular provider does for configs, but on self hosted Xen, you have
to put the following in the Xen config to get pvshim to work:

.
.
type="pvh"
pvshim=1
.
.


This will run a pure PV guest in a PVH container which runs under the
hypervisor.  It is a way to get some more security and maybe performance
out of a PV guest that can't do PVH or PVHVM itself.







-- 
Brad Spencer - brad%anduin.eldar.org@localhost