diff options
Diffstat (limited to 'virt/kvm/kvm_main.c')
| -rw-r--r-- | virt/kvm/kvm_main.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 0021c2862140..27649fdaa007 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -449,8 +449,9 @@ static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot) if (!memslot->dirty_bitmap) return; - vfree(memslot->dirty_bitmap); + vfree(memslot->dirty_bitmap_head); memslot->dirty_bitmap = NULL; + memslot->dirty_bitmap_head = NULL; } /* @@ -537,15 +538,21 @@ static int kvm_vm_release(struct inode *inode, struct file *filp) return 0; } +/* + * Allocation size is twice as large as the actual dirty bitmap size. + * This makes it possible to do double buffering: see x86's + * kvm_vm_ioctl_get_dirty_log(). + */ static int kvm_create_dirty_bitmap(struct kvm_memory_slot *memslot) { - unsigned long dirty_bytes = kvm_dirty_bitmap_bytes(memslot); + unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot); memslot->dirty_bitmap = vmalloc(dirty_bytes); if (!memslot->dirty_bitmap) return -ENOMEM; memset(memslot->dirty_bitmap, 0, dirty_bytes); + memslot->dirty_bitmap_head = memslot->dirty_bitmap; return 0; } |