On 11/3/23 10:29, Nico Boehr wrote:
This is to prepare for running guests without MSO/MSL, which is currently not possible. We already have code in sie64a to setup a guest primary ASCE before entering SIE, so we can in theory switch to the page tables which translate gpa to hpa. But the host is running in primary space mode already, so changing the primary ASCE before entering SIE will also affect the host's code and data. To make this switch useful, the host should run in a different address space mode. Hence, set up and change to home address space mode before installing the guest ASCE. The home space ASCE is just copied over from the primary space ASCE, so no functional change is intended, also for tests that want to use MSO/MSL. If a test intends to use a different primary space ASCE, it can now just set the guest.asce in the save_area. Signed-off-by: Nico Boehr <nrb@xxxxxxxxxxxxx> Reviewed-by: Thomas Huth <thuth@xxxxxxxxxx>
Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxx>