bhyve memory leak in stable/11

[Eugene Grosbein]

After 2 days of uptime there is a guest that should have only 2GB of RAM but uses nearly 22G "extra":

# ps -o vsz,rss,command | grep sfile01
29234040 24851428 bhyve: sfile01 (bhyve)

# bhyvectl --vm=sfile01 --get-all | grep -B1 -A1 mem
ID  Length      Name
0   2048MB      sysmem
1   2048KB      bootrom
Address     Length      Segment     Offset      Prot  Flags
0           2048MB      sysmem      0           RWX
FFE00000    2048KB      bootrom     0           R-X
--
number of ExtINTs delivered to vcpu             0
Resident memory                                 2085765120
Wired memory                                    0
vcpu total runtime                              5701638719326

Also, there is another guest vm using 23696M despite of limit 2048M,
and another one using 25238M despite of limit 4096M,
and another one using 52867M despite of limit 40960M.

Please point me to right direction for debugging this.