diff options
| -rw-r--r-- | virt/kvm/kvm_main.c | 47 |
1 files changed, 31 insertions, 16 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 9646bb9112c1..2104fc29cdd2 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1531,11 +1531,10 @@ static struct kvm_memslots *kvm_dup_memslots(struct kvm_memslots *old, static int kvm_set_memslot(struct kvm *kvm, const struct kvm_userspace_memory_region *mem, - struct kvm_memory_slot *old, struct kvm_memory_slot *new, int as_id, enum kvm_mr_change change) { - struct kvm_memory_slot *slot; + struct kvm_memory_slot *slot, old; struct kvm_memslots *slots; int r; @@ -1566,7 +1565,7 @@ static int kvm_set_memslot(struct kvm *kvm, * Note, the INVALID flag needs to be in the appropriate entry * in the freshly allocated memslots, not in @old or @new. */ - slot = id_to_memslot(slots, old->id); + slot = id_to_memslot(slots, new->id); slot->flags |= KVM_MEMSLOT_INVALID; /* @@ -1597,6 +1596,26 @@ static int kvm_set_memslot(struct kvm *kvm, kvm_copy_memslots(slots, __kvm_memslots(kvm, as_id)); } + /* + * Make a full copy of the old memslot, the pointer will become stale + * when the memslots are re-sorted by update_memslots(), and the old + * memslot needs to be referenced after calling update_memslots(), e.g. + * to free its resources and for arch specific behavior. This needs to + * happen *after* (re)acquiring slots_arch_lock. + */ + slot = id_to_memslot(slots, new->id); + if (slot) { + old = *slot; + } else { + WARN_ON_ONCE(change != KVM_MR_CREATE); + memset(&old, 0, sizeof(old)); + old.id = new->id; + old.as_id = as_id; + } + + /* Copy the arch-specific data, again after (re)acquiring slots_arch_lock. */ + memcpy(&new->arch, &old.arch, sizeof(old.arch)); + r = kvm_arch_prepare_memory_region(kvm, new, mem, change); if (r) goto out_slots; @@ -1604,14 +1623,18 @@ static int kvm_set_memslot(struct kvm *kvm, update_memslots(slots, new, change); slots = install_new_memslots(kvm, as_id, slots); - kvm_arch_commit_memory_region(kvm, mem, old, new, change); + kvm_arch_commit_memory_region(kvm, mem, &old, new, change); + + /* Free the old memslot's metadata. Note, this is the full copy!!! */ + if (change == KVM_MR_DELETE) + kvm_free_memslot(kvm, &old); kvfree(slots); return 0; out_slots: if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) { - slot = id_to_memslot(slots, old->id); + slot = id_to_memslot(slots, new->id); slot->flags &= ~KVM_MEMSLOT_INVALID; slots = install_new_memslots(kvm, as_id, slots); } else { @@ -1626,7 +1649,6 @@ static int kvm_delete_memslot(struct kvm *kvm, struct kvm_memory_slot *old, int as_id) { struct kvm_memory_slot new; - int r; if (!old->npages) return -EINVAL; @@ -1639,12 +1661,7 @@ static int kvm_delete_memslot(struct kvm *kvm, */ new.as_id = as_id; - r = kvm_set_memslot(kvm, mem, old, &new, as_id, KVM_MR_DELETE); - if (r) - return r; - - kvm_free_memslot(kvm, old); - return 0; + return kvm_set_memslot(kvm, mem, &new, as_id, KVM_MR_DELETE); } /* @@ -1718,7 +1735,6 @@ int __kvm_set_memory_region(struct kvm *kvm, if (!old.npages) { change = KVM_MR_CREATE; new.dirty_bitmap = NULL; - memset(&new.arch, 0, sizeof(new.arch)); } else { /* Modify an existing slot. */ if ((new.userspace_addr != old.userspace_addr) || (new.npages != old.npages) || @@ -1732,9 +1748,8 @@ int __kvm_set_memory_region(struct kvm *kvm, else /* Nothing to change. */ return 0; - /* Copy dirty_bitmap and arch from the current memslot. */ + /* Copy dirty_bitmap from the current memslot. */ new.dirty_bitmap = old.dirty_bitmap; - memcpy(&new.arch, &old.arch, sizeof(new.arch)); } if ((change == KVM_MR_CREATE) || (change == KVM_MR_MOVE)) { @@ -1760,7 +1775,7 @@ int __kvm_set_memory_region(struct kvm *kvm, bitmap_set(new.dirty_bitmap, 0, new.npages); } - r = kvm_set_memslot(kvm, mem, &old, &new, as_id, change); + r = kvm_set_memslot(kvm, mem, &new, as_id, change); if (r) goto out_bitmap; |