guest_random_u32
u32 guest_random_u32(struct guest_random_state *state);
return (guest_random_u32(state) % 100) < percent;
return ((u64)guest_random_u32(state) << 32) | guest_random_u32(state);
page = guest_random_u32(&rand_state) % pages;
u8 pattern = guest_random_u32(&guest_rng);