I was not clear, sorry for confusion. The idea was to use R80.20.M1 management and R80.10 Cloudguard gateway (both are GA). This combo (or anything with R80.20.M1) is not covered in sk114518.
The issue I am facing is this: Cloudguard controller is integrated in R80.20.M1, but there is no equivalent of vSEC Service Registration v5 Hotfix for R80.10 Management Server. On R80.10 management, this hotfix brings cloudguard_config command. In the sk128612 it is written that during the upgrade from R80.10 to R80.20.M1 the hotfix needs to be uninstalled but it does not say anything about installing a new one for R80.20.M1. I expected that functionality of the hotfix was integrated in R80.20.M1, but I was probably wrong. So, I will change my question and ask if service registration is supported in R80.20.M1 with R80.10 Cloudguard gateway for NSX?
I also tried to start with R80.10 management with the idea to use R80.10 management to deploy R80.10 gateways and immediately upgrade management to R80.20.M1 (keeping GWs at R80.10). However, it seems that even my NSX version is too recent. Basically, it looks that VMware made a change which throws Cloudguard off. When registering service, Cloudguard is checking https://nsx-manager.your.domain//api/2.0/global/heartbeat. With that call, NSX 6.3 returns:
<?xml version="1.0" encoding="UTF-8"?>
<vsmGlobalConfig xmlns="vmware.vshield.edge.2.0">
<versionInfo>6.4</versionInfo>
</vsmGlobalConfig>
while NSX 6.4.2 returns (please note there is no red text from above):
<?xml version="1.0" encoding="UTF-8"?>
<vsmGlobalConfig>
<versionInfo>6.4</versionInfo>
</vsmGlobalConfig>
The bottom line is that with 6.4.2 the registration fails and $FWDIR/log/vsec_config.elg records this error:
ERROR [main] (RestRequest.java:113) - Parsing the XML failed..
DEBUG [main] (RestRequest.java:70) - Stack trace:
javax.xml.bind.UnmarshalException: unexpected element (uri:"", local:"vsmGlobalConfig"). Expected elements are <{vmware.vshield.edge.2.0}vsmGlobalConfig>
As this is lab environment, I cannot open service request for this but I guess it will need to be fixed anyway.
I will downgrade my NSX but since I spent some time on this, I wanted to report it as it would be wasted time otherwise.