On Thu, Aug 22, 2019 at 03:56:13PM +0530, Bharata B Rao wrote:

Hi,

A pseries guest can be run as a secure guest on Ultravisor-enabled
POWER platforms. On such platforms, this driver will be used to manage
the movement of guest pages between the normal memory managed by
hypervisor(HV) and secure memory managed by Ultravisor(UV).

Private ZONE_DEVICE memory equal to the amount of secure memory
available in the platform for running secure guests is created.
Whenever a page belonging to the guest becomes secure, a page from
this private device memory is used to represent and track that secure
page on the HV side. The movement of pages between normal and secure
memory is done via migrate_vma_pages(). The reverse movement is driven
via pagemap_ops.migrate_to_ram().

The page-in or page-out requests from UV will come to HV as hcalls and
HV will call back into UV via uvcalls to satisfy these page requests.

These patches are against hmm.git
(https://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma.git/log/?h=hmm)

plus

Claudio Carvalho's base ultravisor enablement patchset v6
(https://lore.kernel.org/linuxppc-dev/20190822034838.27876-1-cclaudio@linux.ibm.com/T/#t (local))

How are you thinking these patches will go upstream?  Are you going to
send them via the hmm tree?

I assume you need Claudio's patchset as a prerequisite for your series
to compile, which means the hmm maintainers would need to pull in a
topic branch from Michael Ellerman's powerpc tree, or something like
that.

Paul.