diff --git a/Documentation/vfio.txt b/Documentation/vfio.txt
index 96978ec..7dcf2b5 100644
--- a/Documentation/vfio.txt
+++ b/Documentation/vfio.txt
@@ -289,10 +289,12 @@ PPC64 sPAPR implementation note
 
 This implementation has some specifics:
 
-1) Only one IOMMU group per container is supported as an IOMMU group
-represents the minimal entity which isolation can be guaranteed for and
-groups are allocated statically, one per a Partitionable Endpoint (PE)
+1) On older systems (POWER7 with P5IOC2/IODA1) only one IOMMU group per
+container is supported as an IOMMU table is allocated at the boot time,
+one table per a IOMMU group which is a Partitionable Endpoint (PE)
 (PE is often a PCI domain but not always).
+Newer systems (POWER8 with IODA2) have improved hardware design which allows
+to remove this limitation and have multiple IOMMU groups per a VFIO container.
 
 2) The hardware supports so called DMA windows - the PCI address range
 within which DMA transfer is allowed, any attempt to access address space
@@ -427,6 +429,29 @@ The code flow from the example above should be slightly changed:
 
 	....
 
+5) There is v2 of SPAPR TCE IOMMU. It deprecates VFIO_IOMMU_ENABLE/
+VFIO_IOMMU_DISABLE and implements 2 new ioctls:
+VFIO_IOMMU_SPAPR_REGISTER_MEMORY and VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY
+(which are unsupported in v1 IOMMU).
+
+PPC64 paravirtualized guests generate a lot of map/unmap requests,
+and the handling of those includes pinning/unpinning pages and updating
+mm::locked_vm counter to make sure we do not exceed the rlimit.
+The v2 IOMMU splits accounting and pinning into separate operations:
+
+- VFIO_IOMMU_SPAPR_REGISTER_MEMORY/VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY ioctls
+receive a user space address and size of the block to be pinned.
+Bisecting is not supported and VFIO_IOMMU_UNREGISTER_MEMORY is expected to
+be called with the exact address and size used for registering
+the memory block. The userspace is not expected to call these often.
+The ranges are stored in a linked list in a VFIO container.
+
+- VFIO_IOMMU_MAP_DMA/VFIO_IOMMU_UNMAP_DMA ioctls only update the actual
+IOMMU table and do not do pinning; instead these check that the userspace
+address is from pre-registered range.
+
+This separation helps in optimizing DMA for guests.
+
 -------------------------------------------------------------------------------
 
 [1] VFIO was originally an acronym for "Virtual Function I/O" in its
diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
index 9d37492..f9957eb 100644
--- a/arch/powerpc/include/asm/iommu.h
+++ b/arch/powerpc/include/asm/iommu.h
@@ -112,9 +112,15 @@ struct iommu_table {
 	unsigned long *it_map;       /* A simple allocation bitmap for now */
 	unsigned long  it_page_shift;/* table iommu page size */
 	struct list_head it_group_list;/* List of iommu_table_group_link */
+	unsigned long *it_userspace; /* userspace view of the table */
 	struct iommu_table_ops *it_ops;
 };
 
+#define IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry) \
+		((tbl)->it_userspace ? \
+			&((tbl)->it_userspace[(entry) - (tbl)->it_offset]) : \
+			NULL)
+
 /* Pure 2^n version of get_order */
 static inline __attribute_const__
 int get_iommu_order(unsigned long size, struct iommu_table *tbl)
diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
index 203caac..91a3223 100644
--- a/drivers/vfio/vfio_iommu_spapr_tce.c
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -19,8 +19,10 @@
 #include <linux/uaccess.h>
 #include <linux/err.h>
 #include <linux/vfio.h>
+#include <linux/vmalloc.h>
 #include <asm/iommu.h>
 #include <asm/tce.h>
+#include <asm/mmu_context.h>
 
 #define DRIVER_VERSION  "0.1"
 #define DRIVER_AUTHOR   "aik@ozlabs.ru"
@@ -81,6 +83,11 @@ static void decrement_locked_vm(long npages)
  * into DMA'ble space using the IOMMU
  */
 
+struct tce_iommu_group {
+	struct list_head next;
+	struct iommu_group *grp;
+};
+
 /*
  * The container descriptor supports only a single group per container.
  * Required by the API as the container is not supplied with the IOMMU group
@@ -88,11 +95,84 @@ static void decrement_locked_vm(long npages)
  */
 struct tce_container {
 	struct mutex lock;
-	struct iommu_group *grp;
 	bool enabled;
+	bool v2;
 	unsigned long locked_pages;
+	struct iommu_table *tables[IOMMU_TABLE_GROUP_MAX_TABLES];
+	struct list_head group_list;
 };
 
+static long tce_iommu_unregister_pages(struct tce_container *container,
+		__u64 vaddr, __u64 size)
+{
+	struct mm_iommu_table_group_mem_t *mem;
+
+	if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK))
+		return -EINVAL;
+
+	mem = mm_iommu_find(vaddr, size >> PAGE_SHIFT);
+	if (!mem)
+		return -ENOENT;
+
+	return mm_iommu_put(mem);
+}
+
+static long tce_iommu_register_pages(struct tce_container *container,
+		__u64 vaddr, __u64 size)
+{
+	long ret = 0;
+	struct mm_iommu_table_group_mem_t *mem = NULL;
+	unsigned long entries = size >> PAGE_SHIFT;
+
+	if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK) ||
+			((vaddr + size) < vaddr))
+		return -EINVAL;
+
+	ret = mm_iommu_get(vaddr, entries, &mem);
+	if (ret)
+		return ret;
+
+	container->enabled = true;
+
+	return 0;
+}
+
+static long tce_iommu_userspace_view_alloc(struct iommu_table *tbl)
+{
+	unsigned long cb = _ALIGN_UP(sizeof(tbl->it_userspace[0]) *
+			tbl->it_size, PAGE_SIZE);
+	unsigned long *uas;
+	long ret;
+
+	BUG_ON(tbl->it_userspace);
+
+	ret = try_increment_locked_vm(cb >> PAGE_SHIFT);
+	if (ret)
+		return ret;
+
+	uas = vzalloc(cb);
+	if (!uas) {
+		decrement_locked_vm(cb >> PAGE_SHIFT);
+		return -ENOMEM;
+	}
+	tbl->it_userspace = uas;
+
+	return 0;
+}
+
+static void tce_iommu_userspace_view_free(struct iommu_table *tbl)
+{
+	unsigned long cb = _ALIGN_UP(sizeof(tbl->it_userspace[0]) *
+			tbl->it_size, PAGE_SIZE);
+
+	if (!tbl->it_userspace)
+		return;
+
+	vfree(tbl->it_userspace);
+	tbl->it_userspace = NULL;
+	decrement_locked_vm(cb >> PAGE_SHIFT);
+}
+
 static bool tce_page_is_contained(struct page *page, unsigned page_shift)
 {
 	/*
@@ -103,18 +183,18 @@ static bool tce_page_is_contained(struct page *page, unsigned page_shift)
 	return (PAGE_SHIFT + compound_order(compound_head(page))) >= page_shift;
 }
 
+static inline bool tce_groups_attached(struct tce_container *container)
+{
+	return !list_empty(&container->group_list);
+}
+
 static long tce_iommu_find_table(struct tce_container *container,
 		phys_addr_t ioba, struct iommu_table **ptbl)
 {
 	long i;
-	struct iommu_table_group *table_group;
-
-	table_group = iommu_group_get_iommudata(container->grp);
-	if (!table_group)
-		return -1;
 
 	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
-		struct iommu_table *tbl = table_group->tables[i];
+		struct iommu_table *tbl = container->tables[i];
 
 		if (tbl) {
 			unsigned long entry = ioba >> tbl->it_page_shift;
@@ -136,9 +216,7 @@ static int tce_iommu_enable(struct tce_container *container)
 	int ret = 0;
 	unsigned long locked;
 	struct iommu_table_group *table_group;
-
-	if (!container->grp)
-		return -ENXIO;
+	struct tce_iommu_group *tcegrp;
 
 	if (!current->mm)
 		return -ESRCH; /* process exited */
@@ -175,7 +253,12 @@ static int tce_iommu_enable(struct tce_container *container)
 	 * as there is no way to know how much we should increment
 	 * the locked_vm counter.
 	 */
-	table_group = iommu_group_get_iommudata(container->grp);
+	if (!tce_groups_attached(container))
+		return -ENODEV;
+
+	tcegrp = list_first_entry(&container->group_list,
+			struct tce_iommu_group, next);
+	table_group = iommu_group_get_iommudata(tcegrp->grp);
 	if (!table_group)
 		return -ENODEV;
 
@@ -211,7 +294,7 @@ static void *tce_iommu_open(unsigned long arg)
 {
 	struct tce_container *container;
 
-	if (arg != VFIO_SPAPR_TCE_IOMMU) {
+	if ((arg != VFIO_SPAPR_TCE_IOMMU) && (arg != VFIO_SPAPR_TCE_v2_IOMMU)) {
 		pr_err("tce_vfio: Wrong IOMMU type\n");
 		return ERR_PTR(-EINVAL);
 	}
@@ -221,18 +304,45 @@ static void *tce_iommu_open(unsigned long arg)
 		return ERR_PTR(-ENOMEM);
 
 	mutex_init(&container->lock);
+	INIT_LIST_HEAD_RCU(&container->group_list);
+
+	container->v2 = arg == VFIO_SPAPR_TCE_v2_IOMMU;
 
 	return container;
 }
 
+static int tce_iommu_clear(struct tce_container *container,
+		struct iommu_table *tbl,
+		unsigned long entry, unsigned long pages);
+static void tce_iommu_free_table(struct iommu_table *tbl);
+
 static void tce_iommu_release(void *iommu_data)
 {
 	struct tce_container *container = iommu_data;
+	struct iommu_table_group *table_group;
+	struct tce_iommu_group *tcegrp;
+	long i;
 
-	WARN_ON(container->grp);
+	while (tce_groups_attached(container)) {
+		tcegrp = list_first_entry(&container->group_list,
+				struct tce_iommu_group, next);
+		table_group = iommu_group_get_iommudata(tcegrp->grp);
+		tce_iommu_detach_group(iommu_data, tcegrp->grp);
+	}
 
-	if (container->grp)
-		tce_iommu_detach_group(iommu_data, container->grp);
+	/*
+	 * If VFIO created a table, it was not disposed
+	 * by tce_iommu_detach_group() so do it now.
+	 */
+	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
+		struct iommu_table *tbl = container->tables[i];
+
+		if (!tbl)
+			continue;
+
+		tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
+		tce_iommu_free_table(tbl);
+	}
 
 	tce_iommu_disable(container);
 	mutex_destroy(&container->lock);
@@ -249,6 +359,47 @@ static void tce_iommu_unuse_page(struct tce_container *container,
 	put_page(page);
 }
 
+static int tce_iommu_prereg_ua_to_hpa(unsigned long tce, unsigned long size,
+		unsigned long *phpa, struct mm_iommu_table_group_mem_t **pmem)
+{
+	long ret = 0;
+	struct mm_iommu_table_group_mem_t *mem;
+
+	mem = mm_iommu_lookup(tce, size);
+	if (!mem)
+		return -EINVAL;
+
+	ret = mm_iommu_ua_to_hpa(mem, tce, phpa);
+	if (ret)
+		return -EINVAL;
+
+	*pmem = mem;
+
+	return 0;
+}
+
+static void tce_iommu_unuse_page_v2(struct iommu_table *tbl,
+		unsigned long entry)
+{
+	struct mm_iommu_table_group_mem_t *mem = NULL;
+	int ret;
+	unsigned long hpa = 0;
+	unsigned long *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry);
+
+	if (!pua || !current || !current->mm)
+		return;
+
+	ret = tce_iommu_prereg_ua_to_hpa(*pua, IOMMU_PAGE_SIZE(tbl),
+			&hpa, &mem);
+	if (ret)
+		pr_debug("%s: tce %lx at #%lx was not cached, ret=%d\n",
+				__func__, *pua, entry, ret);
+	if (mem)
+		mm_iommu_mapped_dec(mem);
+
+	*pua = 0;
+}
+
 static int tce_iommu_clear(struct tce_container *container,
 		struct iommu_table *tbl,
 		unsigned long entry, unsigned long pages)
@@ -267,6 +418,11 @@ static int tce_iommu_clear(struct tce_container *container,
 		if (direction == DMA_NONE)
 			continue;
 
+		if (container->v2) {
+			tce_iommu_unuse_page_v2(tbl, entry);
+			continue;
+		}
+
 		tce_iommu_unuse_page(container, oldhpa);
 	}
 
@@ -333,6 +489,64 @@ static long tce_iommu_build(struct tce_container *container,
 	return ret;
 }
 
+static long tce_iommu_build_v2(struct tce_container *container,
+		struct iommu_table *tbl,
+		unsigned long entry, unsigned long tce, unsigned long pages,
+		enum dma_data_direction direction)
+{
+	long i, ret = 0;
+	struct page *page;
+	unsigned long hpa;
+	enum dma_data_direction dirtmp;
+
+	for (i = 0; i < pages; ++i) {
+		struct mm_iommu_table_group_mem_t *mem = NULL;
+		unsigned long *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl,
+				entry + i);
+
+		ret = tce_iommu_prereg_ua_to_hpa(tce, IOMMU_PAGE_SIZE(tbl),
+				&hpa, &mem);
+		if (ret)
+			break;
+
+		page = pfn_to_page(hpa >> PAGE_SHIFT);
+		if (!tce_page_is_contained(page, tbl->it_page_shift)) {
+			ret = -EPERM;
+			break;
+		}
+
+		/* Preserve offset within IOMMU page */
+		hpa |= tce & IOMMU_PAGE_MASK(tbl) & ~PAGE_MASK;
+		dirtmp = direction;
+
+		/* The registered region is being unregistered */
+		if (mm_iommu_mapped_inc(mem))
+			break;
+
+		ret = iommu_tce_xchg(tbl, entry + i, &hpa, &dirtmp);
+		if (ret) {
+			/* dirtmp cannot be DMA_NONE here */
+			tce_iommu_unuse_page_v2(tbl, entry + i);
+			pr_err("iommu_tce: %s failed ioba=%lx, tce=%lx, ret=%ld\n",
+					__func__, entry << tbl->it_page_shift,
+					tce, ret);
+			break;
+		}
+
+		if (dirtmp != DMA_NONE)
+			tce_iommu_unuse_page_v2(tbl, entry + i);
+
+		*pua = tce;
+
+		tce += IOMMU_PAGE_SIZE(tbl);
+	}
+
+	if (ret)
+		tce_iommu_clear(container, tbl, entry, i);
+
+	return ret;
+}
+
 static long tce_iommu_create_table(struct tce_container *container,
 			struct iommu_table_group *table_group,
 			int num,
@@ -358,6 +572,12 @@ static long tce_iommu_create_table(struct tce_container *container,
 	WARN_ON(!ret && !(*ptbl)->it_ops->free);
 	WARN_ON(!ret && ((*ptbl)->it_allocated_size != table_size));
 
+	if (!ret && container->v2) {
+		ret = tce_iommu_userspace_view_alloc(*ptbl);
+		if (ret)
+			(*ptbl)->it_ops->free(*ptbl);
+	}
+
 	if (ret)
 		decrement_locked_vm(table_size >> PAGE_SHIFT);
 
@@ -368,6 +588,7 @@ static void tce_iommu_free_table(struct iommu_table *tbl)
 {
 	unsigned long pages = tbl->it_allocated_size >> PAGE_SHIFT;
 
+	tce_iommu_userspace_view_free(tbl);
 	tbl->it_ops->free(tbl);
 	decrement_locked_vm(pages);
 }
@@ -383,6 +604,7 @@ static long tce_iommu_ioctl(void *iommu_data,
 	case VFIO_CHECK_EXTENSION:
 		switch (arg) {
 		case VFIO_SPAPR_TCE_IOMMU:
+		case VFIO_SPAPR_TCE_v2_IOMMU:
 			ret = 1;
 			break;
 		default:
@@ -394,12 +616,15 @@ static long tce_iommu_ioctl(void *iommu_data,
 
 	case VFIO_IOMMU_SPAPR_TCE_GET_INFO: {
 		struct vfio_iommu_spapr_tce_info info;
+		struct tce_iommu_group *tcegrp;
 		struct iommu_table_group *table_group;
 
-		if (WARN_ON(!container->grp))
+		if (!tce_groups_attached(container))
 			return -ENXIO;
 
-		table_group = iommu_group_get_iommudata(container->grp);
+		tcegrp = list_first_entry(&container->group_list,
+				struct tce_iommu_group, next);
+		table_group = iommu_group_get_iommudata(tcegrp->grp);
 
 		if (!table_group)
 			return -ENXIO;
@@ -468,11 +693,18 @@ static long tce_iommu_ioctl(void *iommu_data,
 		if (ret)
 			return ret;
 
-		ret = tce_iommu_build(container, tbl,
-				param.iova >> tbl->it_page_shift,
-				param.vaddr,
-				param.size >> tbl->it_page_shift,
-				direction);
+		if (container->v2)
+			ret = tce_iommu_build_v2(container, tbl,
+					param.iova >> tbl->it_page_shift,
+					param.vaddr,
+					param.size >> tbl->it_page_shift,
+					direction);
+		else
+			ret = tce_iommu_build(container, tbl,
+					param.iova >> tbl->it_page_shift,
+					param.vaddr,
+					param.size >> tbl->it_page_shift,
+					direction);
 
 		iommu_flush_tce(tbl);
 
@@ -518,7 +750,62 @@ static long tce_iommu_ioctl(void *iommu_data,
 
 		return ret;
 	}
+	case VFIO_IOMMU_SPAPR_REGISTER_MEMORY: {
+		struct vfio_iommu_spapr_register_memory param;
+
+		if (!container->v2)
+			break;
+
+		minsz = offsetofend(struct vfio_iommu_spapr_register_memory,
+				size);
+
+		if (copy_from_user(&param, (void __user *)arg, minsz))
+			return -EFAULT;
+
+		if (param.argsz < minsz)
+			return -EINVAL;
+
+		/* No flag is supported now */
+		if (param.flags)
+			return -EINVAL;
+
+		mutex_lock(&container->lock);
+		ret = tce_iommu_register_pages(container, param.vaddr,
+				param.size);
+		mutex_unlock(&container->lock);
+
+		return ret;
+	}
+	case VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY: {
+		struct vfio_iommu_spapr_register_memory param;
+
+		if (!container->v2)
+			break;
+
+		minsz = offsetofend(struct vfio_iommu_spapr_register_memory,
+				size);
+
+		if (copy_from_user(&param, (void __user *)arg, minsz))
+			return -EFAULT;
+
+		if (param.argsz < minsz)
+			return -EINVAL;
+
+		/* No flag is supported now */
+		if (param.flags)
+			return -EINVAL;
+
+		mutex_lock(&container->lock);
+		ret = tce_iommu_unregister_pages(container, param.vaddr,
+				param.size);
+		mutex_unlock(&container->lock);
+
+		return ret;
+	}
 	case VFIO_IOMMU_ENABLE:
+		if (container->v2)
+			break;
+
 		mutex_lock(&container->lock);
 		ret = tce_iommu_enable(container);
 		mutex_unlock(&container->lock);
@@ -526,16 +813,27 @@ static long tce_iommu_ioctl(void *iommu_data,
 
 
 	case VFIO_IOMMU_DISABLE:
+		if (container->v2)
+			break;
+
 		mutex_lock(&container->lock);
 		tce_iommu_disable(container);
 		mutex_unlock(&container->lock);
 		return 0;
-	case VFIO_EEH_PE_OP:
-		if (!container->grp)
-			return -ENODEV;
 
-		return vfio_spapr_iommu_eeh_ioctl(container->grp,
-						  cmd, arg);
+	case VFIO_EEH_PE_OP: {
+		struct tce_iommu_group *tcegrp;
+
+		ret = 0;
+		list_for_each_entry(tcegrp, &container->group_list, next) {
+			ret = vfio_spapr_iommu_eeh_ioctl(tcegrp->grp,
+					cmd, arg);
+			if (ret)
+				return ret;
+		}
+		return ret;
+	}
+
 	}
 
 	return -ENOTTY;
@@ -547,14 +845,17 @@ static void tce_iommu_release_ownership(struct tce_container *container,
 	int i;
 
 	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
-		struct iommu_table *tbl = table_group->tables[i];
+		struct iommu_table *tbl = container->tables[i];
 
 		if (!tbl)
 			continue;
 
 		tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
+		tce_iommu_userspace_view_free(tbl);
 		if (tbl->it_map)
 			iommu_release_ownership(tbl);
+
+		container->tables[i] = NULL;
 	}
 }
 
@@ -569,7 +870,10 @@ static int tce_iommu_take_ownership(struct tce_container *container,
 		if (!tbl || !tbl->it_map)
 			continue;
 
-		rc = iommu_take_ownership(tbl);
+		rc = tce_iommu_userspace_view_alloc(tbl);
+		if (!rc)
+			rc = iommu_take_ownership(tbl);
+
 		if (rc) {
 			for (j = 0; j < i; ++j)
 				iommu_release_ownership(
@@ -579,6 +883,9 @@ static int tce_iommu_take_ownership(struct tce_container *container,
 		}
 	}
 
+	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
+		container->tables[i] = table_group->tables[i];
+
 	return 0;
 }
 
@@ -592,18 +899,8 @@ static void tce_iommu_release_ownership_ddw(struct tce_container *container,
 		return;
 	}
 
-	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
-		/* Store table pointer as unset_window resets it */
-		struct iommu_table *tbl = table_group->tables[i];
-
-		if (!tbl)
-			continue;
-
+	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
 		table_group->ops->unset_window(table_group, i);
-		tce_iommu_clear(container, tbl,
-				tbl->it_offset, tbl->it_size);
-		tce_iommu_free_table(tbl);
-	}
 
 	table_group->ops->release_ownership(table_group);
 }
@@ -611,7 +908,7 @@ static void tce_iommu_release_ownership_ddw(struct tce_container *container,
 static long tce_iommu_take_ownership_ddw(struct tce_container *container,
 		struct iommu_table_group *table_group)
 {
-	long ret;
+	long i, ret = 0;
 	struct iommu_table *tbl = NULL;
 
 	if (!table_group->ops->create_table || !table_group->ops->set_window ||
@@ -622,23 +919,45 @@ static long tce_iommu_take_ownership_ddw(struct tce_container *container,
 
 	table_group->ops->take_ownership(table_group);
 
-	ret = tce_iommu_create_table(container,
-			table_group,
-			0, /* window number */
-			IOMMU_PAGE_SHIFT_4K,
-			table_group->tce32_size,
-			1, /* default levels */
-			&tbl);
-	if (!ret) {
-		ret = table_group->ops->set_window(table_group, 0, tbl);
+	/*
+	 * If it the first group attached, check if there is
+	 * a default DMA window and create one if none as
+	 * the userspace expects it to exist.
+	 */
+	if (!tce_groups_attached(container) && !container->tables[0]) {
+		ret = tce_iommu_create_table(container,
+				table_group,
+				0, /* window number */
+				IOMMU_PAGE_SHIFT_4K,
+				table_group->tce32_size,
+				1, /* default levels */
+				&tbl);
 		if (ret)
-			tce_iommu_free_table(tbl);
+			goto release_exit;
 		else
-			table_group->tables[0] = tbl;
+			container->tables[0] = tbl;
 	}
 
-	if (ret)
-		table_group->ops->release_ownership(table_group);
+	/* Set all windows to the new group */
+	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
+		tbl = container->tables[i];
+
+		if (!tbl)
+			continue;
+
+		/* Set the default window to a new group */
+		ret = table_group->ops->set_window(table_group, i, tbl);
+		if (ret)
+			goto release_exit;
+	}
+
+	return 0;
+
+release_exit:
+	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
+		table_group->ops->unset_window(table_group, i);
+
+	table_group->ops->release_ownership(table_group);
 
 	return ret;
 }
@@ -649,29 +968,44 @@ static int tce_iommu_attach_group(void *iommu_data,
 	int ret;
 	struct tce_container *container = iommu_data;
 	struct iommu_table_group *table_group;
+	struct tce_iommu_group *tcegrp = NULL;
 
 	mutex_lock(&container->lock);
 
 	/* pr_debug("tce_vfio: Attaching group #%u to iommu %p\n",
 			iommu_group_id(iommu_group), iommu_group); */
-	if (container->grp) {
-		pr_warn("tce_vfio: Only one group per IOMMU container is allowed, existing id=%d, attaching id=%d\n",
-				iommu_group_id(container->grp),
-				iommu_group_id(iommu_group));
-		ret = -EBUSY;
-		goto unlock_exit;
-	}
-
-	if (container->enabled) {
-		pr_err("tce_vfio: attaching group #%u to enabled container\n",
-				iommu_group_id(iommu_group));
-		ret = -EBUSY;
-		goto unlock_exit;
-	}
-
 	table_group = iommu_group_get_iommudata(iommu_group);
-	if (!table_group) {
-		ret = -ENXIO;
+
+	if (tce_groups_attached(container) && (!table_group->ops ||
+			!table_group->ops->take_ownership ||
+			!table_group->ops->release_ownership)) {
+		ret = -EBUSY;
+		goto unlock_exit;
+	}
+
+	/* Check if new group has the same iommu_ops (i.e. compatible) */
+	list_for_each_entry(tcegrp, &container->group_list, next) {
+		struct iommu_table_group *table_group_tmp;
+
+		if (tcegrp->grp == iommu_group) {
+			pr_warn("tce_vfio: Group %d is already attached\n",
+					iommu_group_id(iommu_group));
+			ret = -EBUSY;
+			goto unlock_exit;
+		}
+		table_group_tmp = iommu_group_get_iommudata(tcegrp->grp);
+		if (table_group_tmp->ops != table_group->ops) {
+			pr_warn("tce_vfio: Group %d is incompatible with group %d\n",
+					iommu_group_id(iommu_group),
+					iommu_group_id(tcegrp->grp));
+			ret = -EPERM;
+			goto unlock_exit;
+		}
+	}
+
+	tcegrp = kzalloc(sizeof(*tcegrp), GFP_KERNEL);
+	if (!tcegrp) {
+		ret = -ENOMEM;
 		goto unlock_exit;
 	}
 
@@ -681,10 +1015,15 @@ static int tce_iommu_attach_group(void *iommu_data,
 	else
 		ret = tce_iommu_take_ownership_ddw(container, table_group);
 
-	if (!ret)
-		container->grp = iommu_group;
+	if (!ret) {
+		tcegrp->grp = iommu_group;
+		list_add(&tcegrp->next, &container->group_list);
+	}
 
 unlock_exit:
+	if (ret && tcegrp)
+		kfree(tcegrp);
+
 	mutex_unlock(&container->lock);
 
 	return ret;
@@ -695,24 +1034,26 @@ static void tce_iommu_detach_group(void *iommu_data,
 {
 	struct tce_container *container = iommu_data;
 	struct iommu_table_group *table_group;
+	bool found = false;
+	struct tce_iommu_group *tcegrp;
 
 	mutex_lock(&container->lock);
-	if (iommu_group != container->grp) {
-		pr_warn("tce_vfio: detaching group #%u, expected group is #%u\n",
-				iommu_group_id(iommu_group),
-				iommu_group_id(container->grp));
+
+	list_for_each_entry(tcegrp, &container->group_list, next) {
+		if (tcegrp->grp == iommu_group) {
+			found = true;
+			break;
+		}
+	}
+
+	if (!found) {
+		pr_warn("tce_vfio: detaching unattached group #%u\n",
+				iommu_group_id(iommu_group));
 		goto unlock_exit;
 	}
 
-	if (container->enabled) {
-		pr_warn("tce_vfio: detaching group #%u from enabled container, forcing disable\n",
-				iommu_group_id(container->grp));
-		tce_iommu_disable(container);
-	}
-
-	/* pr_debug("tce_vfio: detaching group #%u from iommu %p\n",
-	   iommu_group_id(iommu_group), iommu_group); */
-	container->grp = NULL;
+	list_del(&tcegrp->next);
+	kfree(tcegrp);
 
 	table_group = iommu_group_get_iommudata(iommu_group);
 	BUG_ON(!table_group);
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index b57b750..8fdcfb9 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -36,6 +36,8 @@
 /* Two-stage IOMMU */
 #define VFIO_TYPE1_NESTING_IOMMU	6	/* Implies v2 */
 
+#define VFIO_SPAPR_TCE_v2_IOMMU		7
+
 /*
  * The IOCTL interface is designed for extensibility by embedding the
  * structure length (argsz) and flags into structures passed between
@@ -495,6 +497,31 @@ struct vfio_eeh_pe_op {
 
 #define VFIO_EEH_PE_OP			_IO(VFIO_TYPE, VFIO_BASE + 21)
 
+/**
+ * VFIO_IOMMU_SPAPR_REGISTER_MEMORY - _IOW(VFIO_TYPE, VFIO_BASE + 17, struct vfio_iommu_spapr_register_memory)
+ *
+ * Registers user space memory where DMA is allowed. It pins
+ * user pages and does the locked memory accounting so
+ * subsequent VFIO_IOMMU_MAP_DMA/VFIO_IOMMU_UNMAP_DMA calls
+ * get faster.
+ */
+struct vfio_iommu_spapr_register_memory {
+	__u32	argsz;
+	__u32	flags;
+	__u64	vaddr;				/* Process virtual address */
+	__u64	size;				/* Size of mapping (bytes) */
+};
+#define VFIO_IOMMU_SPAPR_REGISTER_MEMORY	_IO(VFIO_TYPE, VFIO_BASE + 17)
+
+/**
+ * VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY - _IOW(VFIO_TYPE, VFIO_BASE + 18, struct vfio_iommu_spapr_register_memory)
+ *
+ * Unregisters user space memory registered with
+ * VFIO_IOMMU_SPAPR_REGISTER_MEMORY.
+ * Uses vfio_iommu_spapr_register_memory for parameters.
+ */
+#define VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY	_IO(VFIO_TYPE, VFIO_BASE + 18)
+
 /* ***************************************************************** */
 
 #endif /* _UAPIVFIO_H */
