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:

quoted

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