=== F3v: DONTWAIT + busy -> immediate EWOULDBLOCK ===
hw.df5563.busy: 0 -> 1
[park 1826] ioctl 0xc0046403 on /dev/df5563...
[park 1826] ioctl: returned -1 (errno=35: Resource temporarily unavailable)
rc=0
hw.df5563.busy: 1 -> 0

=== F2v: WAIT-only park (sliced) -> SIGKILL must terminate ===
hw.df5563.busy: 0 -> 1
--- ps while parked ---
   PID STAT   WCHAN
  1829 S1     iicreq  
   PID STAT   COMMAND
F2V_PASS: SIGKILL terminated the WAIT-only sleeper
[park 1829] ioctl 0xc0046402 on /dev/df5563...

=== F1v: park IIC_WAIT|IIC_INTR, unload everything underneath, then SIGKILL ===
--- ps while parked ---
   PID STAT   WCHAN
  1835 S1     iicreq  
rc(iic)=0
rc(rig)=0
rc(reg)=0
rc(iicbb)=0
rc(iicbus)=0
=== guest alive? ===
 7:25PM  up 5 mins, 0 users, load averages: 0.00, 0.01, 0.00
   PID STAT   COMMAND
F1V_PASS: no panic; park process gone; guest healthy
[park 1835] ioctl 0xc0046401 on /dev/df5563...
[park 1835] ioctl: returned -1 (errno=6: Device not configured)

=== reload once more to prove the stack still works ===
[df5563] sanity request_bus error=0
[df5563] SANITY: write_ok=1 read_ok=1 starts=2 stops=2
rdrand0: No RdRand support.