On 13/08/19 21:14, Bharath Vedartham wrote: > Hi all, > > I was looking at the function hva_to_pfn_fast(in virt/kvm/kvm_main) which is > executed in an atomic context(even in non-atomic context, since > hva_to_pfn_fast is much faster than hva_to_pfn_slow). > > My question is can this be executed in an interrupt context? No, it cannot for the reason you mention below. Paolo > The motivation for this question is that in an interrupt context, we cannot > assume "current" to be the task_struct of the process of interest. > __get_user_pages_fast assume current->mm when walking the process page > tables. > > So if this function hva_to_pfn_fast can be executed in an > interrupt context, it would not be safe to retrive the pfn with > __get_user_pages_fast. > > Thoughts on this? > > Thank you > Bharath >