KVM: introduce kvm_alloc/free_memslots

kvm_alloc_memslots is extracted out of previously scattered code
that was in kvm_init_memslots_id and kvm_create_vm.

kvm_free_memslot and kvm_free_memslots are new names of
kvm_free_physmem and kvm_free_physmem_slot, but they also take
an explicit pointer to struct kvm_memslots.

This will simplify the transition to multiple address spaces,
each represented by one pointer to struct kvm_memslots.

Reviewed-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Reviewed-by: Radim Krcmar <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 55 insertions, 49 deletions

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index bd3c08a7c6c2..e299763ef744 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -440,13 +440,60 @@ static int kvm_init_mmu_notifier(struct kvm *kvm)
 
 #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */
 
-static void kvm_init_memslots_id(struct kvm *kvm)
+static struct kvm_memslots *kvm_alloc_memslots(void)
 {
         int i;
-        struct kvm_memslots *slots = kvm->memslots;
+        struct kvm_memslots *slots;
 
+        slots = kvm_kvzalloc(sizeof(struct kvm_memslots));
+        if (!slots)
+                return NULL;
+
+        /*
+         * Init kvm generation close to the maximum to easily test the
+         * code of handling generation number wrap-around.
+         */
+        slots->generation = -150;
         for (i = 0; i < KVM_MEM_SLOTS_NUM; i++)
                 slots->id_to_index[i] = slots->memslots[i].id = i;
+
+        return slots;
+}
+
+static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot)
+{
+        if (!memslot->dirty_bitmap)
+                return;
+
+        kvfree(memslot->dirty_bitmap);
+        memslot->dirty_bitmap = NULL;
+}
+
+/*
+ * Free any memory in @free but not in @dont.
+ */
+static void kvm_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
+                              struct kvm_memory_slot *dont)
+{
+        if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
+                kvm_destroy_dirty_bitmap(free);
+
+        kvm_arch_free_memslot(kvm, free, dont);
+
+        free->npages = 0;
+}
+
+static void kvm_free_memslots(struct kvm *kvm, struct kvm_memslots *slots)
+{
+        struct kvm_memory_slot *memslot;
+
+        if (!slots)
+                return;
+
+        kvm_for_each_memslot(memslot, slots)
+                kvm_free_memslot(kvm, memslot, NULL);
+
+        kvfree(slots);
 }
 
 static struct kvm *kvm_create_vm(unsigned long type)
@@ -472,17 +519,10 @@ static struct kvm *kvm_create_vm(unsigned long type)
         BUILD_BUG_ON(KVM_MEM_SLOTS_NUM > SHRT_MAX);
 
         r = -ENOMEM;
-        kvm->memslots = kvm_kvzalloc(sizeof(struct kvm_memslots));
+        kvm->memslots = kvm_alloc_memslots();
         if (!kvm->memslots)
                 goto out_err_no_srcu;
 
-        /*
-         * Init kvm generation close to the maximum to easily test the
-         * code of handling generation number wrap-around.
-         */
-        kvm->memslots->generation = -150;
-
-        kvm_init_memslots_id(kvm);
         if (init_srcu_struct(&kvm->srcu))
                 goto out_err_no_srcu;
         if (init_srcu_struct(&kvm->irq_srcu))
@@ -523,7 +563,7 @@ out_err_no_srcu:
 out_err_no_disable:
         for (i = 0; i < KVM_NR_BUSES; i++)
                 kfree(kvm->buses[i]);
-        kvfree(kvm->memslots);
+        kvm_free_memslots(kvm, kvm->memslots);
         kvm_arch_free_vm(kvm);
         return ERR_PTR(r);
 }
@@ -540,40 +580,6 @@ void *kvm_kvzalloc(unsigned long size)
                 return kzalloc(size, GFP_KERNEL);
 }
 
-static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot)
-{
-        if (!memslot->dirty_bitmap)
-                return;
-
-        kvfree(memslot->dirty_bitmap);
-        memslot->dirty_bitmap = NULL;
-}
-
-/*
- * Free any memory in @free but not in @dont.
- */
-static void kvm_free_physmem_slot(struct kvm *kvm, struct kvm_memory_slot *free,
-                                  struct kvm_memory_slot *dont)
-{
-        if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
-                kvm_destroy_dirty_bitmap(free);
-
-        kvm_arch_free_memslot(kvm, free, dont);
-
-        free->npages = 0;
-}
-
-static void kvm_free_physmem(struct kvm *kvm)
-{
-        struct kvm_memslots *slots = kvm->memslots;
-        struct kvm_memory_slot *memslot;
-
-        kvm_for_each_memslot(memslot, slots)
-                kvm_free_physmem_slot(kvm, memslot, NULL);
-
-        kvfree(kvm->memslots);
-}
-
 static void kvm_destroy_devices(struct kvm *kvm)
 {
         struct list_head *node, *tmp;
@@ -607,7 +613,7 @@ static void kvm_destroy_vm(struct kvm *kvm)
 #endif
         kvm_arch_destroy_vm(kvm);
         kvm_destroy_devices(kvm);
-        kvm_free_physmem(kvm);
+        kvm_free_memslots(kvm, kvm->memslots);
         cleanup_srcu_struct(&kvm->irq_srcu);
         cleanup_srcu_struct(&kvm->srcu);
         kvm_arch_free_vm(kvm);
@@ -898,7 +904,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
         if (r)
                 goto out_slots;
 
-        /* actual memory is freed via old in kvm_free_physmem_slot below */
+        /* actual memory is freed via old in kvm_free_memslot below */
         if (change == KVM_MR_DELETE) {
                 new.dirty_bitmap = NULL;
                 memset(&new.arch, 0, sizeof(new.arch));
@@ -909,7 +915,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
 
         kvm_arch_commit_memory_region(kvm, mem, &old, change);
 
-        kvm_free_physmem_slot(kvm, &old, &new);
+        kvm_free_memslot(kvm, &old, &new);
         kvfree(old_memslots);
 
         /*
@@ -931,7 +937,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
 out_slots:
         kvfree(slots);
 out_free:
-        kvm_free_physmem_slot(kvm, &new, &old);
+        kvm_free_memslot(kvm, &new, &old);
 out:
         return r;
 }