The peer-address service read a `vmbox.peer=` kernel argument that the
launcher never passed -- the reader was written and the writer forgotten -- so
eth1 came up DOWN with no address on every guest. It now derives the address
from the NIC's own MAC (the host allocates 52:54:00:be:ef:<index>), which
removes the coupling entirely: nothing has to be passed in, so the launcher
and the guest cannot disagree about which index a VM has.
That fixed the addressing but NOT the connectivity. `mcast=` cannot work on
this host at all -- `lo` carries no MULTICAST flag and there is no multicast
route, so qemu accepts the option and silently drops every frame, which is the
same "flags accepted, nothing happens" trap as POWERDOWN. A listen=/connect=
socket hub over loopback TCP was tried next: the hub port listens, both
guests bring eth1 up with the right addresses, and ARP still fails.
Documented as a known limitation rather than papered over. Sandboxes work
fully on their own; two guests cannot talk to each other yet.
Also corrects the destructive demo: a running Linux SURVIVES `rm -rf /usr`
because processes hold their binaries through open file handles, so sshd keeps
answering. The honest proof of destruction is that the machine cannot boot
again, so the demo now reboots it and asserts it does not come back.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VdyMBGCrGVGDWtJ9xe48f3
The destructive demo asked the guest to confirm its own destruction, one step
after deleting /usr -- which removes bash, sshd and agetty. Nothing would have
been left to answer, so the check would have FAILED on a step that actually
succeeded. It now proves breakage from the host (the overlay grew, and the
guest can no longer answer at all), which is the same evidence the shutdown
verdict relies on and for the same reason: a corpse cannot report its own
death.
Step 3 also no longer recreates the sandbox. `vm reset` in step 4 is the claim
under test; recreating first would have quietly tested something easier.
README's verdict table now carries the MEASURED qmp events per guest command
rather than the inferred ones, and states the finding that motivates the whole
design: ssh returned an identical "Connection closed by remote host" for the
poweroff, the reboot AND the panic.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VdyMBGCrGVGDWtJ9xe48f3
shutdown_verdict_demo.sh exercises every branch of the verdict table against a
real guest -- clean poweroff, reboot-instead-of-poweroff, kernel panic, and a
command that leaves the machine running. The failure branches matter as much
as the success one: a verifier that has only ever returned "pass" is untested.
destructive_demo.sh is the acceptance test for the tool as a whole: destroy
/etc and /usr in the guest, assert the guest really is broken, reset with one
command, assert it is pristine again, then assert the HOST is untouched
(/etc/hosts attributes unchanged, base image hash unchanged, /etc and /usr
still present).
Measured on the first real run, which confirms the design's central claim:
QMP reported SHUTDOWN {"guest": true, "reason": "guest-shutdown"} and the
serial log reached "reboot: Power down", so the verdict was "clean poweroff"
with exit 0 -- while ssh saw only "Connection closed by remote host", which
would have been indistinguishable from a crash or a dropped link.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VdyMBGCrGVGDWtJ9xe48f3
