MIPS_GCTL1_RID
guestctl1 = (guestctl1 & ~MIPS_GCTL1_RID) |
if (!(read_c0_guestctl1() & MIPS_GCTL1_RID))
(read_c0_guestctl1() ^ guestctl1) & MIPS_GCTL1_RID) {
clear_c0_guestctl1(MIPS_GCTL1_RID);
(guestctl1 & MIPS_GCTL1_RID)