=== DF-2426 baseline decisive run (serial console capture) ===
-- control: sysctl debug.df2426.control=1 --
DFH: ########## DF-2426 control BEGIN ##########
DFH: ==== DF-2426 control: block_size = 512 ====
DFH: ---- XPT_CALC_GEOMETRY block_size=512 volume_size=204800 (expecting sane geometry) ----
DFH: RESULT amd_action returned, xpt_done=1 status=0x01 heads=64 secs=32 cylinders=100
DFH:   PASS: nonzero block_size computes 64/32/100 geometry, CAM_REQ_CMP
DFH: ########## DF-2426 control END: 0 check(s) failed ##########

-- trigger0: sysctl debug.df2426.trigger0=1 -> Fatal trap 18 --
DFH: ==== DF-2426 trigger: block_size = 0 ====
DFH: calling amd_action: Fatal trap 18 imminent on the verbatim kernel (amd.c:683, (1024L*1024L)/ccg->block_size with block_size=0)
DFH: ---- XPT_CALC_GEOMETRY block_size=0 volume_size=204800 (expecting DIVIDE BY ZERO at amd.c:683) ----


Fatal trap 18: integer divide fault while in kernel mode
cpuid = 4; lapic id = 4
instruction pointer	= 0x8:0xffffffff80a7d62d
stack pointer	        = 0x10:0xfffff80116b4c728
frame pointer	        = 0x10:0xfffff80116b4c758
code segment		= base 0x0, limit 0xfffff, type 0x1b
			= DPL 0, pres 1, long 0, def32 0, gran 1
processor eflags	= interrupt enabled, resume, IOPL = 0
current process		= 862
current thread          = pri 6 
kernel: type 18 trap, code=0

CPU4 stopping CPUs: 0x0000002f
 stopped
Stopped at      amd_action+0x16d:       idivq   %rsi,%eax
db> 
-- trigger2 (block_size=2MiB): sysctl debug.df2426.trigger_big=1 -> Fatal trap 18 --
DFH: ==== DF-2426 trigger2: block_size = 2 MiB (passes the XPT garbage filter cam_xpt.c:3062; inner division yields 0) ====
DFH: calling amd_action: Fatal trap 18 imminent on the verbatim kernel (amd.c:683, volume_size/((1024L*1024L)/2097152) == volume_size/0)
DFH: ---- XPT_CALC_GEOMETRY block_size=2097152 volume_size=204800 (expecting inner div -> 0, OUTER DIVIDE BY ZERO at amd.c:683) ----


Fatal trap 18: integer divide fault while in kernel mode
cpuid = 3; lapic id = 3
instruction pointer	= 0x8:0xffffffff80a7d638
stack pointer	        = 0x10:0xfffff8011825d728
frame pointer	        = 0x10:0xfffff8011825d758
code segment		= base 0x0, limit 0xfffff, type 0x1b
			= DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags	= interrupt enabled, resume, IOPL = 0
current process		= 820
current thread          = pri 6 
kernel: type 18 trap, code=0