[PATCH 1/9] KVM: introduce kvm_alloc/free_memslots

From: Paolo Bonzini
Date: Tue May 19 2015 - 13:28:49 EST


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.

Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
virt/kvm/kvm_main.c | 104 +++++++++++++++++++++++++++-------------------------
1 file 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;
}
--
1.8.3.1


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