On Fri, Mar 10, 2023 at 02:20:32PM +0100, Christian Borntraeger wrote: > > Are you sure? Quickly checked ppc64, x86 and arm64 - they do not > > seem adhere virt_to_phys(0) == 0, nor the VR kernel (so far). > > Isnt that the prefix page? I think we did say that the prefix page must be 0 in virt and phys otherwise we will have performance issues due to cache synonyms. As far as I am concerned we should keep virt_to_phys() semantics in sync with other archs and one should not rely on s390 implementation- specifics. Please, see also my other reply to Nico in v2.
