[Pkg-xen-devel] [PATCH] xen init script: don't fail when being run in domU

[Hans van Kranenburg]

On 2/21/19 4:05 PM, Ian Jackson wrote:
> Hans van Kranenburg writes ("[PATCH] xen init script: don't fail when being run in domU"):
>> When installing xen-utils-V in a driver domain domU, it drags in
>> xen-utils-common, which also contains the init script for xenstored and
>> xenconsoled.
> 
> Acked-by: Ian Jackson <ijackson at chiark.greenend.org.uk>
> 
> Marek, it is actually possible to set a non-0000 uid for dom0.  I'm
> afraid the right way to tell is indeed to mount /proc/xen and look for
> control_d.
> 
> So if you really want to reduce the use of /proc/xen

Current one will just work fine. There is no need to mount /proc/xen in
domU at all, since the absence will just mean that the script will think
it's not in a dom0, which is exactly what you want.

> you could send
> patches to Linux to advertise the relevant thing in a sane way in
> /sys.
> 
> I did notice this difference:
> 
> dom0
> /sys/hypervisor/properties/features:000028f0
> 
> domU
> /sys/hypervisor/properties/features:000020f0
> 
> I suspect, without looking it up, thant 0x0800 is "control domain".
> But, really, let us not go there...

Hans