The register file for the x86 MMU is not fully zero'd when creating the thread0
context. This leaves garbage in several of the registers. For the X87 FPU
registers, they are properly tagged as empty, but the register file still
contains garbage. For the XMM registers, only register 0 is actually zero'd
(not the whole file). The diff attached, fully zero's the X87 registers and
ALL 16 of the XMM registers.
The contents of the fxsave area look something like the stuff below w/out the
diff. With the diff, all of the registers are zero'd. Diff is against 10.2-R.