Re: [PATCH v5 4/7] KVM: PPC: Book3S HV: in H_SVM_INIT_DONE, migrate remaining normal-GFNs to secure-GFNs.

The Ultravisor is expected to explicitly call H_SVM_PAGE_IN for all the
pages of the SVM before calling H_SVM_INIT_DONE. This causes a huge
delay in tranistioning the VM to SVM. The Ultravisor is only interested
in the pages that contain the kernel, initrd and other important data
structures. The rest contain throw-away content.

However if not all pages are requested by the Ultravisor, the Hypervisor
continues to consider the GFNs corresponding to the non-requested pages
as normal GFNs. This can lead to data-corruption and undefined behavior.

In H_SVM_INIT_DONE handler, move all the PFNs associated with the SVM's
GFNs to secure-PFNs. Skip the GFNs that are already Paged-in or Shared
or Paged-in followed by a Paged-out.

Cc: Paul Mackerras <redacted>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Bharata B Rao <redacted>
Cc: Aneesh Kumar K.V <redacted>
Cc: Sukadev Bhattiprolu <redacted>
Cc: Laurent Dufour <redacted>
Cc: Thiago Jung Bauermann <redacted>
Cc: David Gibson <redacted>
Cc: Claudio Carvalho <redacted>
Cc: kvm-ppc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Ram Pai <redacted>
---
 Documentation/powerpc/ultravisor.rst        |   2 +
 arch/powerpc/include/asm/kvm_book3s_uvmem.h |   2 +
 arch/powerpc/kvm/book3s_hv_uvmem.c          | 136 +++++++++++++++++++++++++---
 3 files changed, 127 insertions(+), 13 deletions(-)

diff --git a/Documentation/powerpc/ultravisor.rst b/Documentation/powerpc/ultravisor.rst
index a1c8c37..ba6b1bf 100644
--- a/Documentation/powerpc/ultravisor.rst
+++ b/Documentation/powerpc/ultravisor.rst

@@ -934,6 +934,8 @@ Return values
 	* H_UNSUPPORTED		if called from the wrong context (e.g.
 				from an SVM or before an H_SVM_INIT_START
 				hypercall).
+	* H_STATE		if the hypervisor could not successfully
+                                transition the VM to Secure VM.
 
 Description
 ~~~~~~~~~~~

diff --git a/arch/powerpc/include/asm/kvm_book3s_uvmem.h b/arch/powerpc/include/asm/kvm_book3s_uvmem.h
index 9cb7d8b..f229ab5 100644
--- a/arch/powerpc/include/asm/kvm_book3s_uvmem.h
+++ b/arch/powerpc/include/asm/kvm_book3s_uvmem.h

@@ -23,6 +23,8 @@ unsigned long kvmppc_h_svm_page_out(struct kvm *kvm,
 unsigned long kvmppc_h_svm_init_abort(struct kvm *kvm);
 void kvmppc_uvmem_drop_pages(const struct kvm_memory_slot *free,
 			     struct kvm *kvm, bool skip_page_out);
+int kvmppc_uv_migrate_mem_slot(struct kvm *kvm,
+			const struct kvm_memory_slot *memslot);