Re: [PATCH v5 5/7] KVM: PPC: Book3S HV: migrate hot plugged memory

From: Laurent Dufour <redacted>

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.

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

Signed-off-by: Ram Pai <redacted>
[rearranged the code, and modified the commit log]
Signed-off-by: Laurent Dufour <redacted>
---
 arch/powerpc/include/asm/kvm_book3s_uvmem.h | 14 ++++++++++++++
 arch/powerpc/kvm/book3s_hv.c                | 10 ++--------
 arch/powerpc/kvm/book3s_hv_uvmem.c          | 23 +++++++++++++++++++----
 3 files changed, 35 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_book3s_uvmem.h b/arch/powerpc/include/asm/kvm_book3s_uvmem.h
index f229ab5..59c17ca 100644
--- a/arch/powerpc/include/asm/kvm_book3s_uvmem.h
+++ b/arch/powerpc/include/asm/kvm_book3s_uvmem.h

@@ -25,6 +25,10 @@ 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);
+int kvmppc_uvmem_memslot_create(struct kvm *kvm,
+		const struct kvm_memory_slot *new);
+void kvmppc_uvmem_memslot_delete(struct kvm *kvm,
+		const struct kvm_memory_slot *old);
 #else
 static inline int kvmppc_uvmem_init(void)
 {

@@ -84,5 +88,15 @@ 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 int  kvmppc_uvmem_memslot_create(struct kvm *kvm,
+		const struct kvm_memory_slot *new)
+{
+	return H_UNSUPPORTED;
+}
+
+static inline void  kvmppc_uvmem_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..b1485ca 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_uvmem_memslot_create(kvm, new);