KVM: Separate out dirty_bitmap allocation code as kvm_kvzalloc()

Will be used for lpage_info allocation later.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 7e140683ff14d503a9714058cadd9dde7e4ffaf9..1148c96a48178b71488448c5234645090b1a01db 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -516,16 +516,32 @@ out_err_nodisable:
        return ERR_PTR(r);
 }
 
+/*
+ * Avoid using vmalloc for a small buffer.
+ * Should not be used when the size is statically known.
+ */
+static void *kvm_kvzalloc(unsigned long size)
+{
+       if (size > PAGE_SIZE)
+               return vzalloc(size);
+       else
+               return kzalloc(size, GFP_KERNEL);
+}
+
+static void kvm_kvfree(const void *addr)
+{
+       if (is_vmalloc_addr(addr))
+               vfree(addr);
+       else
+               kfree(addr);
+}
+
 static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot)
 {
        if (!memslot->dirty_bitmap)
                return;
 
-       if (2 * kvm_dirty_bitmap_bytes(memslot) > PAGE_SIZE)
-               vfree(memslot->dirty_bitmap);
-       else
-               kfree(memslot->dirty_bitmap);
-
+       kvm_kvfree(memslot->dirty_bitmap);
        memslot->dirty_bitmap = NULL;
 }
 
@@ -617,11 +633,7 @@ static int kvm_create_dirty_bitmap(struct kvm_memory_slot *memslot)
 #ifndef CONFIG_S390
        unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot);
 
-       if (dirty_bytes > PAGE_SIZE)
-               memslot->dirty_bitmap = vzalloc(dirty_bytes);
-       else
-               memslot->dirty_bitmap = kzalloc(dirty_bytes, GFP_KERNEL);
-
+       memslot->dirty_bitmap = kvm_kvzalloc(dirty_bytes);
        if (!memslot->dirty_bitmap)
                return -ENOMEM;