VIES_PENDING_INOUT
vie->status |= VIES_PENDING_INOUT;
ASSERT(vie->status & VIES_PENDING_INOUT);
VIES_PENDING_MMIO | VIES_PENDING_INOUT | VIES_USER_FALLBACK;
(vie->status & VIES_PENDING_INOUT) == 0) {
vie->status &= ~(VIES_PENDING_INOUT);