If your iPhone is running iOS 8 or iOS 8.1 and already jailbroken, there is nothing to worry about in case you have to restore it. Semi Restore iOS 8 tool is finally available to all users who have jailbroken with Pangu app.
SemiRestore8 is designed to help users restore jailbroken iPhone on iOS 8.1 and iOS 8. This is a safe method which won’t let you lose your jailbreak status. You know that Apple released iOS 8.1.1 which cannot be jailbroken using Pangu or any other program. But if you decide to restore via iTunes the usual way, you will have to install iOS 8.1.1 and lose the jailbreak. Use Semi Restore iOS 8.1 / 8 tool called SemiRestore8 and avoid such an issue.
CoolStar is the dev who created SemiRestore and updated it to support iOS 8 firmware versions. You also have to use OpenSSH to safely restore jailbroken iPhone iOS 8 or iOS 8.1 device but this should make you smile with a relief. You can get a great condition and preserve the jailbreak which is really awesome.
Right now you can still downgrade your iOS 8.1.1 iDevice to iOS 8.1 but Apple will soon stop signing this version and this is when SemiRestore8 will be even more useful. You can now download tweaks and different jailbreak apps as you can always restore even if you get the reboot loop problem because of a buggy program.
You can get your program at http://semi-restore.com/ but note that is supports Windows and Linux platforms at the moment though devs promise to release Mac version as well. The program works on all iPhones and other Apple iOS devices that are compatible with iOS 8. Remember to backup before you restore.