10.2-RELEASE guest in Hyper-V boot failed.

[hshh]

After upgrade to 10.2-RELEASE from 10.1, my FreeBSD guest hang on boot.
Kernel can not find out rootfs.
All daX devices size is 0MB !!
Someone has this issue too,
https://forums.freebsd.org/threads/10-2-cant-see-hdd-on-hyper-v-2k8r2.52797/

Hyper-V host is win2008.

As 10.1, HDD mounted in freebsd is da0p2.
# gpart show
=>      34  41942973  da0  GPT  (20G)
        34      1024    1  freebsd-boot  (512K)
      1058   4194304    2  freebsd-swap  (2.0G)
   4195362         6       - free -  (3.0K)
   4195368  37747632    3  freebsd-ufs  (18G)
  41943000         7       - free -  (3.5K)

# df -h
Filesystem    Size    Used   Avail Capacity  Mounted on
/dev/da0p3     17G    5.0G     11G    31%    /
devfs         1.0K    1.0K      0B   100%    /dev

# swapinfo
Device          1K-blocks     Used    Avail Capacity
/dev/da0p2        2097152     2116  2095036     0%

-- 
@hshh