On Wed, Apr 03, 2019 at 07:59:13PM +0200, Boris Bobrov wrote: > Hello, > > I am working on implementing SEV support in OpenStack. There are some > questions that came up in the discussion of the spec [0] > > [0] https://review.openstack.org/#/c/641994/ > > As far as i understand, the memory for SEV machines need to be pinned so > that it doesn't migrate to swap and page migration. ROMS, UEFI pflash and > video RAM should be pinned too. > > Initially we planned to use hard_limit of <memtune> element to pin the > memory. However, from the discussion in the spec it seems that there is no > way to determine a good enough value and that hard_limit should not be used > at all. > > What should be used then? > > There is a suggestion to use something like this: > > <memoryBacking> > <hugepages> > <page size="2" unit="M" nodeset="1"/> > </hugepages> > <nosharepages/> > <locked/> > <source type="file"/> > <access mode="shared"/> > <allocation mode="immediate"/> > </memoryBacking> > > Will it work? Are there any caveats we should remember about with this > config? If we can use it, is there anything that would be redundant or not > necessary for our case? AFAIK from the SEV pov only the <locked/> element is required. This extra things where just suggested on the openstack review becasue it was suggested to make it dependant on use of huge pages in Nova. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :| _______________________________________________ libvirt-users mailing list libvirt-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvirt-users
