no VM console output on FreeBSD 12.1 host

[cgull]

I've been experimenting with vm for a little while. It was working for me with 12.0, and I think 12.1-BETAs and -RCs, but is working less well for me now with 12.1-RELEASE. With either nmdm or tmux console, I get console output from bhyveload, but none from the kernel once it starts. If i set debug=yes in the config file, I see the output there, and from that I can see that console input works. I think the VM is running normally otherwise, but I'm doing install/boot testing and I haven't exhaustively checked. The same VM produces normal console output if I start bhyve manually in tmux. IIRC I saw similar behavior with a Linux guest yesterday (output from grub-bhyve, none from guest). I see this with both vm-1.3 from packages, or tag v1.4.0 from github.

I suspect I might be doing something wrong somewhere but I haven't found it yet.

[razzfazz]

console=nmdm seems to work for me on 12.1, but console=tmux produces no output at all.

Someone filed a FreeBSD bug report about this here.

[drozdowsky]

flag -f does not work for me
workaround:

vm start guest
vm console guest 

[scornet256]

Im definitely not qualified to suggest a fix of some sort, but this helped me (for now).

/usr/local/lib/vm-bhyve/vm-run (from line 266) :

        # actually run bhyve!
        # we're already in the background so we just wait for it to exit
        bhyve ${_opts} \
              ${_devices} \
              ${_iso_dev} \
              ${_comstring} \
              # ${_name} >>"${_logpath}" 2>&1
              ${_name}

[anteract]

this all fails also without vm-bhyve, so its not really an issue for this project... Not to say it wouldn't be nice of someone comes up with a fix.

[bsdxbsdx]

I think the cause is https://svnweb.freebsd.org/changeset/base/352720. I've been reverting it to fix vm-bhyve. If the change stays then I suspect vm-bhyve or whatever it uses internally will need to detect and compensate.

[anteract]

This change worked for me. Thanks