On Wed, May 12, 2021 at 11:32:35AM +0200, Joerg Roedel wrote: > On Wed, May 12, 2021 at 10:58:20AM +0200, Juergen Gross wrote: > > No, those were used before, but commit 9da3f2b7405440 broke Xen's use > > case. That is why I did commit 1457d8cf7664f. > > [...] > > Having the distinction between user and kernel memory accesses > explicitly in the code seems to be the most robust solution. On the other hand, as I found out today, 9da3f2b7405440 had a short life-time and got reverted upstream. So using __get_user()/__put_user() should be fine in this code path. It just deserves a comment explaining its use here and why pagefault_enable()/disable() is not needed. Even the get_kernel* helpers use __get_user_size() internally. Regards, Joerg