static void domain_exit(struct dmar_domain *domain);
+static void vm_domain_exit(struct dmar_domain *domain);
 
 void free_dmar_iommu(struct intel_iommu *iommu)
 {
                clear_bit(i, iommu->domain_ids);
 
                spin_lock_irqsave(&domain->iommu_lock, flags);
-               if (--domain->iommu_count == 0)
-                       domain_exit(domain);
+               if (--domain->iommu_count == 0) {
+                       if (domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE)
+                               vm_domain_exit(domain);
+                       else
+                               domain_exit(domain);
+               }
                spin_unlock_irqrestore(&domain->iommu_lock, flags);
 
                i = find_next_bit(iommu->domain_ids,
        spin_unlock_irqrestore(&device_domain_lock, flags1);
 }
 
+/* domain id for virtual machine, it won't be set in context */
+static unsigned long vm_domid;
+
+static struct dmar_domain *iommu_alloc_vm_domain(void)
+{
+       struct dmar_domain *domain;
+
+       domain = alloc_domain_mem();
+       if (!domain)
+               return NULL;
+
+       domain->id = vm_domid++;
+       memset(&domain->iommu_bmp, 0, sizeof(unsigned long));
+       domain->flags = DOMAIN_FLAG_VIRTUAL_MACHINE;
+
+       return domain;
+}
+
+static int vm_domain_init(struct dmar_domain *domain, int guest_width)
+{
+       int adjust_width;
+
+       init_iova_domain(&domain->iovad, DMA_32BIT_PFN);
+       spin_lock_init(&domain->mapping_lock);
+       spin_lock_init(&domain->iommu_lock);
+
+       domain_reserve_special_ranges(domain);
+
+       /* calculate AGAW */
+       domain->gaw = guest_width;
+       adjust_width = guestwidth_to_adjustwidth(guest_width);
+       domain->agaw = width_to_agaw(adjust_width);
+
+       INIT_LIST_HEAD(&domain->devices);
+
+       domain->iommu_count = 0;
+       domain->iommu_coherency = 0;
+
+       /* always allocate the top pgd */
+       domain->pgd = (struct dma_pte *)alloc_pgtable_page();
+       if (!domain->pgd)
+               return -ENOMEM;
+       domain_flush_cache(domain, domain->pgd, PAGE_SIZE);
+       return 0;
+}
+
+static void iommu_free_vm_domain(struct dmar_domain *domain)
+{
+       unsigned long flags;
+       struct dmar_drhd_unit *drhd;
+       struct intel_iommu *iommu;
+       unsigned long i;
+       unsigned long ndomains;
+
+       for_each_drhd_unit(drhd) {
+               if (drhd->ignored)
+                       continue;
+               iommu = drhd->iommu;
+
+               ndomains = cap_ndoms(iommu->cap);
+               i = find_first_bit(iommu->domain_ids, ndomains);
+               for (; i < ndomains; ) {
+                       if (iommu->domains[i] == domain) {
+                               spin_lock_irqsave(&iommu->lock, flags);
+                               clear_bit(i, iommu->domain_ids);
+                               iommu->domains[i] = NULL;
+                               spin_unlock_irqrestore(&iommu->lock, flags);
+                               break;
+                       }
+                       i = find_next_bit(iommu->domain_ids, ndomains, i+1);
+               }
+       }
+}
+
+static void vm_domain_exit(struct dmar_domain *domain)
+{
+       u64 end;
+
+       /* Domain 0 is reserved, so dont process it */
+       if (!domain)
+               return;
+
+       vm_domain_remove_all_dev_info(domain);
+       /* destroy iovas */
+       put_iova_domain(&domain->iovad);
+       end = DOMAIN_MAX_ADDR(domain->gaw);
+       end = end & (~VTD_PAGE_MASK);
+
+       /* clear ptes */
+       dma_pte_clear_range(domain, 0, end);
+
+       /* free page tables */
+       dma_pte_free_pagetable(domain, 0, end);
+
+       iommu_free_vm_domain(domain);
+       free_domain_mem(domain);
+}
+
 void intel_iommu_domain_exit(struct dmar_domain *domain)
 {
        u64 end;