[PATCH v9 0/8] KVM: PPC: Driver to manage pages of secure guest

[Jason Gunthorpe]

On Wed, Sep 25, 2019 at 10:36:41AM +0530, Bharata B Rao wrote:
> [The main change in this version is the introduction of new
> locking to prevent concurrent page-in and page-out calls. More
> details about this are present in patch 2/8]
> 
> 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 patches that are present
> in Michael Ellerman's tree
> (https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/log/?h=topic/ppc-kvm)
> 
> These patches along with Claudio's above patches are required to
> run secure pseries guests on KVM. This patchset is based on hmm.git
> because hmm.git has migrate_vma cleanup and not-device memremap_pages
> patchsets that are required by this patchset.

FWIW this is all merged to Linus now and will be in rc1

Jason