Subject: [PATCH v2 4/4] KVM: PPC: Book3S HV: migrate hot plugged memory

From: Ram Pai <[email-masked]>
Date: Thu, 18 Jun 2020 02:19:05 -0700

From: Laurent Dufour <[email-masked]>

When a memory slot is hot plugged to a SVM, PFNs associated with the
GFNs in that slot must be migrated to the secure-PFNs, aka device-PFNs.

kvmppc_uv_migrate_mem_slot() is called to accomplish this. UV_PAGE_IN
ucall is skipped, since the ultravisor does not trust the content of
those pages and hence ignores it.

Signed-off-by: Ram Pai <[email-masked]>
	[resolved conflicts, and modified the commit log]
Signed-off-by: Laurent Dufour <[email-masked]>
---
 arch/powerpc/include/asm/kvm_book3s_uvmem.h |  2 ++
 arch/powerpc/kvm/book3s_hv.c                | 10 ++++++----
 arch/powerpc/kvm/book3s_hv_uvmem.c          |  2 +-
 3 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_book3s_uvmem.h b/arch/powerpc/include/asm/kvm_book3s_uvmem.h
index f0c5708..05ae789 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,
 void kvmppc_uvmem_drop_pages(const struct kvm_memory_slot *free,
 			     struct kvm *kvm, bool skip_page_out,
 			     bool purge_gfn);
+int kvmppc_uv_migrate_mem_slot(struct kvm *kvm,
+				const struct kvm_memory_slot *memslot);
 #else
 static inline int kvmppc_uvmem_init(void)
 {
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 6cf80e5..bf7324d 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4531,10 +4531,12 @@ static void kvmppc_core_commit_memory_region_hv(struct kvm *kvm,
 	case KVM_MR_CREATE:
 		if (kvmppc_uvmem_slot_init(kvm, new))
 			return;
-		uv_register_mem_slot(kvm->arch.lpid,
-				     new->base_gfn << PAGE_SHIFT,
-				     new->npages * PAGE_SIZE,
-				     0, new->id);
+		if (uv_register_mem_slot(kvm->arch.lpid,
+					 new->base_gfn << PAGE_SHIFT,
+					 new->npages * PAGE_SIZE,
+					 0, new->id))
+			return;
+		kvmppc_uv_migrate_mem_slot(kvm, new);
 		break;
 	case KVM_MR_DELETE:
 		uv_unregister_mem_slot(kvm->arch.lpid, old->id);
diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c
index 78f8580..4d8f5bc 100644
--- a/arch/powerpc/kvm/book3s_hv_uvmem.c
+++ b/arch/powerpc/kvm/book3s_hv_uvmem.c
@@ -451,7 +451,7 @@ static int kvmppc_svm_migrate_page(struct vm_area_struct *vma,
 	return ret;
 }
 
-static int kvmppc_uv_migrate_mem_slot(struct kvm *kvm,
+int kvmppc_uv_migrate_mem_slot(struct kvm *kvm,
 		const struct kvm_memory_slot *memslot)
 {
 	unsigned long gfn = memslot->base_gfn;
-- 
1.8.3.1