[*] patched kernel check
DragonFly dfbsd 6.5-DEVELOPMENT DragonFly 6.5-DEVELOPMENT #1: Tue Oct  6 03:20:15 UTC 2026     root@dfbsd:/usr/obj/usr/src/sys/X86_64_GENERIC  x86_64

[*] triggering: sysctl debug.enter_debugger=gdb (expect clean return)
TRIGGER_RC=124
[*] post-check: guest alive?
Connection timed out during banner exchange
[*] clearing flag back for cleanliness
Connection timed out during banner exchange
DONE

=== SMP1 CONTROL (patched kernel, QEMU -smp 1, identical trigger) ===
[*] triggering: sysctl debug.enter_debugger=gdb (expect clean return)
debug.enter_debugger:  ->
SYSCTL_RETURNED_RC=0
STILL_ALIVE_OK
TRIGGER_EXIT=0
serial (serial.patched.txt): CPU0 stopping CPUs: 0x00000000 / stopped /
CPU0 restarting CPUs: 0x0000000000000000 / restarted   <- full clean kdb cycle