KVM: PPC: Add skip_page_out parameter to uvmem functions

Add 'skip_page_out' parameter to kvmppc_uvmem_drop_pages() so the
callers can specify whetheter or not to skip paging out pages. This
will be needed in a follow-on patch that implements H_SVM_INIT_ABORT
hcall.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

arch/powerpc/include/asm/kvm_book3s_uvmem.h

@@ -20,7 +20,7 @@ unsigned long kvmppc_h_svm_init_start(struct kvm *kvm);
 unsigned long kvmppc_h_svm_init_done(struct kvm *kvm);
 int kvmppc_send_page_to_uv(struct kvm *kvm, unsigned long gfn);
 void kvmppc_uvmem_drop_pages(const struct kvm_memory_slot *free,
-			     struct kvm *kvm);
+			     struct kvm *kvm, bool skip_page_out);
 #else
 static inline int kvmppc_uvmem_init(void)
 {
@@ -69,6 +69,6 @@ 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) { }
+			struct kvm *kvm, bool skip_page_out) { }
 #endif /* CONFIG_PPC_UV */
 #endif /* __ASM_KVM_BOOK3S_UVMEM_H__ */

arch/powerpc/kvm/book3s_64_mmu_radix.c

@@ -1102,7 +1102,7 @@ void kvmppc_radix_flush_memslot(struct kvm *kvm,
 	unsigned int shift;
 
 	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_START)
-		kvmppc_uvmem_drop_pages(memslot, kvm);
+		kvmppc_uvmem_drop_pages(memslot, kvm, true);
 
 	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
 		return;

arch/powerpc/kvm/book3s_hv.c

@@ -5477,7 +5477,7 @@ static int kvmhv_svm_off(struct kvm *kvm)
 			continue;
 
 		kvm_for_each_memslot(memslot, slots) {
-			kvmppc_uvmem_drop_pages(memslot, kvm);
+			kvmppc_uvmem_drop_pages(memslot, kvm, true);
 			uv_unregister_mem_slot(kvm->arch.lpid, memslot->id);
 		}
 	}

arch/powerpc/kvm/book3s_hv_uvmem.c

@@ -258,7 +258,7 @@ unsigned long kvmppc_h_svm_init_done(struct kvm *kvm)
  * QEMU page table with normal PTEs from newly allocated pages.
  */
 void kvmppc_uvmem_drop_pages(const struct kvm_memory_slot *free,
-			     struct kvm *kvm)
+			     struct kvm *kvm, bool skip_page_out)
 {
 	int i;
 	struct kvmppc_uvmem_page_pvt *pvt;
@@ -276,7 +276,7 @@ void kvmppc_uvmem_drop_pages(const struct kvm_memory_slot *free,
 
 		uvmem_page = pfn_to_page(uvmem_pfn);
 		pvt = uvmem_page->zone_device_data;
-		pvt->skip_page_out = true;
+		pvt->skip_page_out = skip_page_out;
 		mutex_unlock(&kvm->arch.uvmem_lock);
 
 		pfn = gfn_to_pfn(kvm, gfn);