-gfn_t unalias_gfn_instantiation(struct kvm *kvm, gfn_t gfn)
-{
- int i;
- struct kvm_mem_alias *alias;
- struct kvm_mem_aliases *aliases;
-
- aliases = kvm_aliases(kvm);
-
- for (i = 0; i < aliases->naliases; ++i) {
- alias = &aliases->aliases[i];
- if (alias->flags & KVM_ALIAS_INVALID)
- continue;
- if (gfn >= alias->base_gfn
- && gfn < alias->base_gfn + alias->npages)
- return alias->target_gfn + gfn - alias->base_gfn;
- }
- return gfn;
-}
-
-gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn)
-{
- int i;
- struct kvm_mem_alias *alias;
- struct kvm_mem_aliases *aliases;
-
- aliases = kvm_aliases(kvm);
-
- for (i = 0; i < aliases->naliases; ++i) {
- alias = &aliases->aliases[i];
- if (gfn >= alias->base_gfn
- && gfn < alias->base_gfn + alias->npages)
- return alias->target_gfn + gfn - alias->base_gfn;
- }
- return gfn;
-}
-
-/*
- * Set a new alias region. Aliases map a portion of physical memory into
- * another portion. This is useful for memory windows, for example the PC
- * VGA region.
- */
-static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm,
- struct kvm_memory_alias *alias)
-{
- int r, n;
- struct kvm_mem_alias *p;
- struct kvm_mem_aliases *aliases, *old_aliases;
-
- r = -EINVAL;
- /* General sanity checks */
- if (alias->memory_size & (PAGE_SIZE - 1))
- goto out;
- if (alias->guest_phys_addr & (PAGE_SIZE - 1))
- goto out;
- if (alias->slot >= KVM_ALIAS_SLOTS)
- goto out;
- if (alias->guest_phys_addr + alias->memory_size
- < alias->guest_phys_addr)
- goto out;
- if (alias->target_phys_addr + alias->memory_size
- < alias->target_phys_addr)
- goto out;
-
- r = -ENOMEM;
- aliases = kzalloc(sizeof(struct kvm_mem_aliases), GFP_KERNEL);
- if (!aliases)
- goto out;
-
- mutex_lock(&kvm->slots_lock);
-
- /* invalidate any gfn reference in case of deletion/shrinking */
- memcpy(aliases, kvm->arch.aliases, sizeof(struct kvm_mem_aliases));
- aliases->aliases[alias->slot].flags |= KVM_ALIAS_INVALID;
- old_aliases = kvm->arch.aliases;
- rcu_assign_pointer(kvm->arch.aliases, aliases);
- synchronize_srcu_expedited(&kvm->srcu);
- kvm_mmu_zap_all(kvm);
- kfree(old_aliases);
-
- r = -ENOMEM;
- aliases = kzalloc(sizeof(struct kvm_mem_aliases), GFP_KERNEL);
- if (!aliases)
- goto out_unlock;
-
- memcpy(aliases, kvm->arch.aliases, sizeof(struct kvm_mem_aliases));
-
- p = &aliases->aliases[alias->slot];
- p->base_gfn = alias->guest_phys_addr >> PAGE_SHIFT;
- p->npages = alias->memory_size >> PAGE_SHIFT;
- p->target_gfn = alias->target_phys_addr >> PAGE_SHIFT;
- p->flags &= ~(KVM_ALIAS_INVALID);
-
- for (n = KVM_ALIAS_SLOTS; n > 0; --n)
- if (aliases->aliases[n - 1].npages)
- break;
- aliases->naliases = n;
-
- old_aliases = kvm->arch.aliases;
- rcu_assign_pointer(kvm->arch.aliases, aliases);
- synchronize_srcu_expedited(&kvm->srcu);
- kfree(old_aliases);
- r = 0;
-
-out_unlock:
- mutex_unlock(&kvm->slots_lock);
-out:
- return r;
-}
-