diff options
| -rw-r--r-- | arch/x86/kvm/x86.c | 49 |
1 files changed, 41 insertions, 8 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 43da65feed49..e7488350ca16 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2415,27 +2415,60 @@ static int kvm_vm_ioctl_reinject(struct kvm *kvm, int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log) { - int r; - int n; + int r, n, i; struct kvm_memory_slot *memslot; - int is_dirty = 0; + unsigned long is_dirty = 0; + unsigned long *dirty_bitmap = NULL; down_write(&kvm->slots_lock); - r = kvm_get_dirty_log(kvm, log, &is_dirty); - if (r) + r = -EINVAL; + if (log->slot >= KVM_MEMORY_SLOTS) + goto out; + + memslot = &kvm->memslots->memslots[log->slot]; + r = -ENOENT; + if (!memslot->dirty_bitmap) + goto out; + + n = ALIGN(memslot->npages, BITS_PER_LONG) / 8; + + r = -ENOMEM; + dirty_bitmap = vmalloc(n); + if (!dirty_bitmap) goto out; + memset(dirty_bitmap, 0, n); + + for (i = 0; !is_dirty && i < n/sizeof(long); i++) + is_dirty = memslot->dirty_bitmap[i]; /* If nothing is dirty, don't bother messing with page tables. */ if (is_dirty) { + struct kvm_memslots *slots, *old_slots; + spin_lock(&kvm->mmu_lock); kvm_mmu_slot_remove_write_access(kvm, log->slot); spin_unlock(&kvm->mmu_lock); - memslot = &kvm->memslots->memslots[log->slot]; - n = ALIGN(memslot->npages, BITS_PER_LONG) / 8; - memset(memslot->dirty_bitmap, 0, n); + + slots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL); + if (!slots) + goto out_free; + + memcpy(slots, kvm->memslots, sizeof(struct kvm_memslots)); + slots->memslots[log->slot].dirty_bitmap = dirty_bitmap; + + old_slots = kvm->memslots; + rcu_assign_pointer(kvm->memslots, slots); + synchronize_srcu_expedited(&kvm->srcu); + dirty_bitmap = old_slots->memslots[log->slot].dirty_bitmap; + kfree(old_slots); } + r = 0; + if (copy_to_user(log->dirty_bitmap, dirty_bitmap, n)) + r = -EFAULT; +out_free: + vfree(dirty_bitmap); out: up_write(&kvm->slots_lock); return r; |