vbox6: Warning: unresolvable exception 16 (Windows 10 VM)

chelmuth commented 1 year ago

The error can be reproduced sporadically when running two VMs (e.g., Win10 and Ubuntu 20.04) in parallel. It seems an x87 FPU exception is pending when executing longjmp() (instruction fldcw).

Warning: unresolvable exception 16, pd 'init -> runtime -> upx_vbox6_win10 -> vbox', thread 'EMT-3', cpu 7, ip=0x10ee1d98 sp=0x416fe778 bp=0x416fe7a0 no signal handler

0x10ee1d98  0xc5d98  libc.lib.so  longjmp(W) +   0x68 = 0xc5d30  in file .../contrib/libc-dfcf0321f6f20fb8051954bc3fb4e661467a3434/src/lib/libc/lib/libc/amd64/gen/setjmp.S:108

   c5d88:       4c 8b 62 20             mov    0x20(%rdx),%r12
   c5d8c:       4c 8b 6a 28             mov    0x28(%rdx),%r13
   c5d90:       4c 8b 72 30             mov    0x30(%rdx),%r14
   c5d94:       4c 8b 7a 38             mov    0x38(%rdx),%r15
-> c5d98:       d9 6a 40                fldcw  0x40(%rdx)
   c5d9b:       48 85 c0                test   %rax,%rax
   c5d9e:       75 03                   jne    c5da3 <__longjmp+0x73>
   c5da0:       48 ff c0                inc    %rax

chelmuth commented 6 months ago

I could not reproduce this issue after the following commit was merged. Does anybody have different experiences?

5c279938848 nova: transfer guest fpu state via utcb

chelmuth commented 5 months ago

Closing this issue as it seems fixed (or nobody cares).

genodelabs / genode

vbox6: Warning: unresolvable exception 16 (Windows 10 VM) #5001