DF-5073 — boot A (sanity control), leak-guest transcript
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Boot command:
  cd dfbsd-qemu && QEMU_EXTRA="-acpitable file=ssdt_acad_sane.aml" ./vm.sh up 300

SSDT: ACPI0003 device PWRS whose _PSR *does* return One (well-formed firmware).

root reads:
  # sysctl hw.acpi.acline
  hw.acpi.acline: 1
  # dmesg | grep -i "line\|acad" | tail -5
  ACPI: SSDT 0x00000000BFFE1CAC 000050 (v02 DFACAD ACADSANE 00000001 INTL 20251212)
  acpi_acad0: <AC Adapter> on acpi0
  (no "Off Line"; the initial read transitions -1 -> 1 and prints "On Line"
   earlier in dmesg)

unprivileged user (ssh dfbsd-maxx, uid 1001):
  $ sysctl hw.acpi.acline
  hw.acpi.acline: 1

=> The injected SSDT drives acpi_acad attach, _PSR evaluation, and the
   world-readable hw.acpi.acline sysctl end-to-end. The sysctl is readable
   without any privilege.