Xiaomi has own user interface that called as MIUI, that’s the nice suer interface but now, the third party Android ROM, CyanogenMOd has been adapttation for Xiaomi smartphone.
CyanogenMod has been adopt by OPPO and OnePlus One smartphone, and now CyanogenMod has also ready to support Xiaomi smartphone, since the Xiaomi has several flagship smartphone that popular in domestic market and also global market recently.
CyanogenMod has drop to the three model of Xiaomi smartphone. And now after CyanogenMod release their new CyanogenMod 11 version based on Android 4.4.2 KitKat operating system. But both version is available as the nightly update. And this version is still update until CyanogenMod release the stable version.
Here is the CyanogenMod 11 for Xiaomi download
Note: Xiaomi two native support for dual system, you can open the “True Dual Boot” (TDB) in Recovery, the data can be divided into partitions, and then install MIUI, CM11, and share SD card partition, but note that this option will switch for Reset the phone.