[v4 5/5] KVM: PPC: Book3S HV: migrate hot plugged memory

[Ram Pai <linuxram@us.ibm.com>]

From: Laurent Dufour <ldufour@linux.ibm.com>

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

Call kvmppc_uv_migrate_mem_slot() to accomplish this.
Disable page-merge for all pages in the memory slot.

Signed-off-by: Ram Pai <linuxram@us.ibm.com>
[rearranged the code, and modified the commit log]
Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
---
 arch/powerpc/include/asm/kvm_book3s_uvmem.h | 10 ++++++++++
 arch/powerpc/kvm/book3s_hv.c                | 10 ++--------
 arch/powerpc/kvm/book3s_hv_uvmem.c          | 22 ++++++++++++++++++++++
 3 files changed, 34 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_book3s_uvmem.h b/arch/powerpc/include/asm/kvm_book3s_uvmem.h
index f229ab5..6f7da00 100644
--- a/arch/powerpc/include/asm/kvm_book3s_uvmem.h
+++ b/arch/powerpc/include/asm/kvm_book3s_uvmem.h
@@ -25,6 +25,9 @@ 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);
+void kvmppc_memslot_create(struct kvm *kvm, const struct kvm_memory_slot *new);
+void kvmppc_memslot_delete(struct kvm *kvm, const struct kvm_memory_slot *old);
+
 #else
 static inline int kvmppc_uvmem_init(void)
 {
@@ -84,5 +87,12 @@ static inline int kvmppc_send_page_to_uv(struct kvm *kvm, unsigned long gfn)
 static inline void
 kvmppc_uvmem_drop_pages(const struct kvm_memory_slot *free,
 			struct kvm *kvm, bool skip_page_out) { }
+
+static inline void  kvmppc_memslot_create(struct kvm *kvm,
+		const struct kvm_memory_slot *new) { }
+
+static inline void  kvmppc_memslot_delete(struct kvm *kvm,
+		const struct kvm_memory_slot *old) { }
+
 #endif /* CONFIG_PPC_UV */
 #endif /* __ASM_KVM_BOOK3S_UVMEM_H__ */
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index d331b46..bf3be3b 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4515,16 +4515,10 @@ static void kvmppc_core_commit_memory_region_hv(struct kvm *kvm,
 
 	switch (change) {
 	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);
+		kvmppc_memslot_create(kvm, new);
 		break;
 	case KVM_MR_DELETE:
-		uv_unregister_mem_slot(kvm->arch.lpid, old->id);
-		kvmppc_uvmem_slot_free(kvm, old);
+		kvmppc_memslot_delete(kvm, old);
 		break;
 	default:
 		/* TODO: Handle KVM_MR_MOVE */
diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c
index a206984..a2b4d25 100644
--- a/arch/powerpc/kvm/book3s_hv_uvmem.c
+++ b/arch/powerpc/kvm/book3s_hv_uvmem.c
@@ -1089,6 +1089,28 @@ int kvmppc_send_page_to_uv(struct kvm *kvm, unsigned long gfn)
 	return (ret = U_SUCCESS) ? RESUME_GUEST : -EFAULT;
 }
 
+void kvmppc_memslot_create(struct kvm *kvm, const struct kvm_memory_slot *new)
+{
+	if (kvmppc_uvmem_slot_init(kvm, new))
+		return;
+
+	if (kvmppc_memslot_page_merge(kvm, new, false))
+		return;
+
+	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);
+}
+
+void kvmppc_memslot_delete(struct kvm *kvm, const struct kvm_memory_slot *old)
+{
+	uv_unregister_mem_slot(kvm->arch.lpid, old->id);
+	kvmppc_memslot_page_merge(kvm, old, true);
+	kvmppc_uvmem_slot_free(kvm, old);
+}
+
 static u64 kvmppc_get_secmem_size(void)
 {
 	struct device_node *np;
-- 
1.8.3.1