On Wed, Apr 17, 2019 at 01:39:19AM +0800, Kairui Song wrote: > And I also think the "fake"/"real" reg is fragile, could we abuse > another eflag (just like PERF_EFLAGS_EXACT) to indicate the regs are > partially dumped fake registers?
Sure, the SDM seems to suggest bits 1,3,5,15 are 'available'. We've already used 3 and 5, and I think we can use !X86_EFLAGS_FIXED to indicate a fake regs set. Any real regs set will always have that set.
