SPEC_CTRL_MDS_ENABLE
testl $SPEC_CTRL_DUMMY_ENABLE|SPEC_CTRL_MDS_ENABLE, PCPU(trampoline)+TR_PCB_SPEC_CTRL+4 ; \
testq $SPEC_CTRL_MDS_ENABLE, %rax ; \
ASSYM(SPEC_CTRL_MDS_ENABLE, SPEC_CTRL_MDS_ENABLE);
spec_mask = SPEC_CTRL_MDS_ENABLE;
spec_ctrl |= SPEC_CTRL_MDS_ENABLE;