On 20.07.2018 10:44, Janosch Frank wrote: > General KVM huge page support on s390 has to be enabled via the > kvm.hpage module parameter. Either nested or hpage can be enabled, as > we currently do not support vSIE for huge backed guests. Once the vSIE > support is added we will either drop the parameter or enable it as > default. > > For a guest the feature has to be enabled through the new > KVM_CAP_S390_HPAGE_1M capability and the hpage module > parameter. Enabling it means that cmm can't be enabled for the vm and > disables pfmf and storage key interpretation. > > This is due to the fact that in some cases, in upcoming patches, we > have to split huge pages in the guest mapping to be able to set more > granular memory protection on 4k pages. These split pages have fake > page tables that are not visible to the Linux memory management which > subsequently will not manage its PGSTEs, while the SIE will. Disabling > these features lets us manage PGSTE data in a consistent matter and > solve that problem. > > Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx> Looks like you didn't take care of my review comments + r-b as response to the last version. -- Thanks, David / dhildenb
