it seems I was able to have it recognized this way:

strip these lines from he.xml

>     <ovirt-vm:exitCode type="int">1</ovirt-vm:exitCode>
>     <ovirt-vm:exitMessage>unsupported configuration: unknown CPU feature: tsx-ctrl</ovirt-vm:exitMessage>
>     <ovirt-vm:exitReason type="int">1</ovirt-vm:exitReason>
13a17
>     <ovirt-vm:startTime type="float">1590653346.0201075</ovirt-vm:startTime>
246a251,264
>     <graphics type='vnc' port='-1' autoport='yes' keymap='en-us' passwdValidTo='1970-01-01T00:00:01'>
>       <listen type='network' network='vdsm-ovirtmgmt'/>
>     </graphics>
>     <graphics type='spice' autoport='yes' passwdValidTo='1970-01-01T00:00:01'>
>       <listen type='network' network='vdsm-ovirtmgmt'/>
>       <channel name='main' mode='secure'/>
>       <channel name='display' mode='secure'/>
>       <channel name='inputs' mode='secure'/>
>       <channel name='cursor' mode='secure'/>
>       <channel name='playback' mode='secure'/>
>       <channel name='record' mode='secure'/>
>       <channel name='smartcard' mode='secure'/>
>       <channel name='usbredir' mode='secure'/>
>     </graphics>

I have to understand what to use for graphics but it is not important at the moment....

After failure of deployment the link to the engine storage domain under /var/run/vdsm/storage/3df8f6d4-d572-4d2b-9ab2-8abc456a396f/ has been deleted.

So I go there and create it:

[root@novirt2 ~]# cd /var/run/vdsm/storage/3df8f6d4-d572-4d2b-9ab2-8abc456a396f/

[root@novirt2 ~]# ln -s /rhev/data-center/mnt/glusterSD/novirt2st.storage.local\:_engine/3df8f6d4-d572-4d2b-9ab2-8abc456a396f/images/df02bff9-2c4b-4e14-a0a3-591a84ccaed9 df02bff9-2c4b-4e14-a0a3-591a84ccaed9

Start VM
[root@novirt2 ~]# virsh -c qemu:///system?authfile=/etc/ovirt-hosted-engine/virsh_auth.conf create he.xml
Domain HostedEngine created from he.xml

Access its webadmin gui and now all is as expected, with only one engine vm...

Volumes for data and vmstore are there, but not the storage domains, but I can create them without problems

Also if I exit the global maintenance the state passes from ReinitializeFSM to EngineUp

[root@novirt2 ~]# hosted-engine --vm-status


--== Host novirt2.example.net (id: 1) status ==--

Host ID                            : 1
Host timestamp                     : 38553
Score                              : 3400
Engine status                      : {"vm": "up", "health": "good", "detail": "Up"}
Hostname                           : novirt2.example.net
Local maintenance                  : False
stopped                            : False
crc32                              : 5a3b40e1
conf_on_shared_storage             : True
local_conf_timestamp               : 38553
Status up-to-date                  : True
Extra metadata (valid at timestamp):
metadata_parse_version=1
metadata_feature_version=1
timestamp=38553 (Thu May 28 11:30:51 2020)
host-id=1
score=3400
vm_conf_refresh_time=38553 (Thu May 28 11:30:51 2020)
conf_on_shared_storage=True
maintenance=False
state=EngineUp
stopped=False
[root@novirt2 ~]#

Now go to test further functionalities.....

Gianluca