Using vmalloc in device driver code

Hi All, From what i have learnt vmalloc requires a minor page fault to sync the process page tables with the reference page tables. So, is it safe to use memory already allocated by vmalloc in io context/device driver code (especially when the io call has returned back to the device driver after finishing io on the device). I know that in general it is better to use kmalloc (for better efficiency and so on....) but, i want to know if it is inaccurate to use vmalloc in this particular case and why (in terms of cannot service page faults in interrupt context etc)? Thanks in advance for your help. Regards, Neha