"Hardware-assisted virtualization is not enabled on this host" even though platform:exp-nested-hvm=true is set

[abudef]

But I have a suspicion that it hasn't worked since the last or second to last batch of updates for XCP-ng, that it worked before.

[abudef]

But I have a suspicion that it hasn't worked since the last or second to last batch of updates for XCP-ng, that it worked before.

I can confirm this; on another lab I updated XCP-ng with the last fifty or so updates from the end of April, and nested XCP-ng also appears to have virtualization support not enabled...

[olivierlambert]

You mean 8.2 or 8.3?

[abudef]

I use version 8.3.

[olivierlambert]

That might be interesting to check if it works with the same context on 8.2

[abudef]

Nested virtualization seems to work correctly in version 8.2.1 with the latest updates (native host).

[abudef]

Nested virtualization seems to work correctly in version 8.2.1 with the latest updates (native host).

On the contrary; the problem is related to virtualized XCP-ng version 8.3 with the latest updates, not to the native host.

[abudef]

Nested virtualization seems to work correctly in version 8.2.1 with the latest updates (native host).

On the contrary; the problem is related to virtualized XCP-ng version 8.3 with the latest updates, not to the native host.

The combination (8.3latest(8.x)) does not work either. Nested virtualization simply doesn't work if 8.3 is either a native host, a virtualized host, or both.

[olivierlambert]

And 8.3 with Xen 4.13 instead of 4.17?

[abudef]

Well, it seems that the problem is caused by Xen 4.17...

[abudef]

I temporarily moved the entire XCP-ng lab to ESXi. I need a few different hosts for scenario testing, migration and backup testing, XO proxies testing etc. and of course I can't dedicate a hw server for each of them in the lab. Please let me know when the nested virtualization support will be operational again on version 8.3.

[olivierlambert]

Well, you are the first to report this regression, so we'll need time to reproduce and investigate.

[olivierlambert]

Add @stormi so we create a card internally.

[stormi]

Noted! If this happens on our hardware too, this will be very annoying for our own virtual XCP-ng that we use all the time for development and testing.

[abudef]

@olivierlambert Thank you very much for the impeccable support and fast communication

I tested again today and the problem is always on the host side, regardless of the type of guest. This corrects some of my hasty information above.

[stormi]

@abudef said in "Hardware-assisted virtualization is not enabled on this host" even though platform:exp-nested-hvm=true is set:

I tested again today and the problem is always on the host side, regardless of the type of guest. This corrects some of my hasty information above.

What do you mean? Can you give examples?

[abudef]

@stormi If the host is on version 8.3 with Xen 4.17, nested virtualization does not work on any guest. If version 8.3 with Xen 4.17 is on a guest, but the host is running version 8.2.1 or an out-of-date 8.3 (Xen 4.13), it doesn't matter and nested guest virtualization works.

[stormi]

@abudef In the second case, do you mean there's:

8.2.1 host running a nested 8.3 (Xen 4.17) VM running itself a Nested XCP-ng? (so nested inside nested)

[abudef]

@stormi That's not quite what I meant. The point is that if the host is 8.3/4.17, then virtualization is not working on its guest and therefore no other nested guest can be started on this guest. And actually, yes, if 8.3/4.17 appears somewhere in the cascade of nested hosts, then nested virtualization will no longer work on its guest.

[olivierlambert]

@abudef Can you try this on a shutdown VM:

1. Disable nested from the VM/Advanced tab
2. xe vm-param-set platform:nested_virt=true uuid=<VM UUID>
3. Start the VM