Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1395 insertions, 0 deletions

diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
new file mode 100644
index 000000000..169f07ac1
--- /dev/null
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -0,0 +1,1395 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * VFIO: IOMMU DMA mapping support for TCE on POWER
+ *
+ * Copyright (C) 2013 IBM Corp.  All rights reserved.
+ *     Author: Alexey Kardashevskiy <aik@ozlabs.ru>
+ *
+ * Derived from original vfio_iommu_type1.c:
+ * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
+ *     Author: Alex Williamson <alex.williamson@redhat.com>
+ */
+
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/err.h>
+#include <linux/vfio.h>
+#include <linux/vmalloc.h>
+#include <linux/sched/mm.h>
+#include <linux/sched/signal.h>
+#include <linux/mm.h>
+#include "vfio.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"
+#define DRIVER_DESC     "VFIO IOMMU SPAPR TCE"
+
+static void tce_iommu_detach_group(void *iommu_data,
+		struct iommu_group *iommu_group);
+
+/*
+ * VFIO IOMMU fd for SPAPR_TCE IOMMU implementation
+ *
+ * This code handles mapping and unmapping of user data buffers
+ * into DMA'ble space using the IOMMU
+ */
+
+struct tce_iommu_group {
+	struct list_head next;
+	struct iommu_group *grp;
+};
+
+/*
+ * A container needs to remember which preregistered region  it has
+ * referenced to do proper cleanup at the userspace process exit.
+ */
+struct tce_iommu_prereg {
+	struct list_head next;
+	struct mm_iommu_table_group_mem_t *mem;
+};
+
+/*
+ * The container descriptor supports only a single group per container.
+ * Required by the API as the container is not supplied with the IOMMU group
+ * at the moment of initialization.
+ */
+struct tce_container {
+	struct mutex lock;
+	bool enabled;
+	bool v2;
+	bool def_window_pending;
+	unsigned long locked_pages;
+	struct mm_struct *mm;
+	struct iommu_table *tables[IOMMU_TABLE_GROUP_MAX_TABLES];
+	struct list_head group_list;
+	struct list_head prereg_list;
+};
+
+static long tce_iommu_mm_set(struct tce_container *container)
+{
+	if (container->mm) {
+		if (container->mm == current->mm)
+			return 0;
+		return -EPERM;
+	}
+	BUG_ON(!current->mm);
+	container->mm = current->mm;
+	mmgrab(container->mm);
+
+	return 0;
+}
+
+static long tce_iommu_prereg_free(struct tce_container *container,
+		struct tce_iommu_prereg *tcemem)
+{
+	long ret;
+
+	ret = mm_iommu_put(container->mm, tcemem->mem);
+	if (ret)
+		return ret;
+
+	list_del(&tcemem->next);
+	kfree(tcemem);
+
+	return 0;
+}
+
+static long tce_iommu_unregister_pages(struct tce_container *container,
+		__u64 vaddr, __u64 size)
+{
+	struct mm_iommu_table_group_mem_t *mem;
+	struct tce_iommu_prereg *tcemem;
+	bool found = false;
+	long ret;
+
+	if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK))
+		return -EINVAL;
+
+	mem = mm_iommu_get(container->mm, vaddr, size >> PAGE_SHIFT);
+	if (!mem)
+		return -ENOENT;
+
+	list_for_each_entry(tcemem, &container->prereg_list, next) {
+		if (tcemem->mem == mem) {
+			found = true;
+			break;
+		}
+	}
+
+	if (!found)
+		ret = -ENOENT;
+	else
+		ret = tce_iommu_prereg_free(container, tcemem);
+
+	mm_iommu_put(container->mm, mem);
+
+	return ret;
+}
+
+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;
+	struct tce_iommu_prereg *tcemem;
+	unsigned long entries = size >> PAGE_SHIFT;
+
+	if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK) ||
+			((vaddr + size) < vaddr))
+		return -EINVAL;
+
+	mem = mm_iommu_get(container->mm, vaddr, entries);
+	if (mem) {
+		list_for_each_entry(tcemem, &container->prereg_list, next) {
+			if (tcemem->mem == mem) {
+				ret = -EBUSY;
+				goto put_exit;
+			}
+		}
+	} else {
+		ret = mm_iommu_new(container->mm, vaddr, entries, &mem);
+		if (ret)
+			return ret;
+	}
+
+	tcemem = kzalloc(sizeof(*tcemem), GFP_KERNEL);
+	if (!tcemem) {
+		ret = -ENOMEM;
+		goto put_exit;
+	}
+
+	tcemem->mem = mem;
+	list_add(&tcemem->next, &container->prereg_list);
+
+	container->enabled = true;
+
+	return 0;
+
+put_exit:
+	mm_iommu_put(container->mm, mem);
+	return ret;
+}
+
+static bool tce_page_is_contained(struct mm_struct *mm, unsigned long hpa,
+		unsigned int it_page_shift)
+{
+	struct page *page;
+	unsigned long size = 0;
+
+	if (mm_iommu_is_devmem(mm, hpa, it_page_shift, &size))
+		return size == (1UL << it_page_shift);
+
+	page = pfn_to_page(hpa >> PAGE_SHIFT);
+	/*
+	 * Check that the TCE table granularity is not bigger than the size of
+	 * a page we just found. Otherwise the hardware can get access to
+	 * a bigger memory chunk that it should.
+	 */
+	return page_shift(compound_head(page)) >= it_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;
+
+	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
+		struct iommu_table *tbl = container->tables[i];
+
+		if (tbl) {
+			unsigned long entry = ioba >> tbl->it_page_shift;
+			unsigned long start = tbl->it_offset;
+			unsigned long end = start + tbl->it_size;
+
+			if ((start <= entry) && (entry < end)) {
+				*ptbl = tbl;
+				return i;
+			}
+		}
+	}
+
+	return -1;
+}
+
+static int tce_iommu_find_free_table(struct tce_container *container)
+{
+	int i;
+
+	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
+		if (!container->tables[i])
+			return i;
+	}
+
+	return -ENOSPC;
+}
+
+static int tce_iommu_enable(struct tce_container *container)
+{
+	int ret = 0;
+	unsigned long locked;
+	struct iommu_table_group *table_group;
+	struct tce_iommu_group *tcegrp;
+
+	if (container->enabled)
+		return -EBUSY;
+
+	/*
+	 * When userspace pages are mapped into the IOMMU, they are effectively
+	 * locked memory, so, theoretically, we need to update the accounting
+	 * of locked pages on each map and unmap.  For powerpc, the map unmap
+	 * paths can be very hot, though, and the accounting would kill
+	 * performance, especially since it would be difficult to impossible
+	 * to handle the accounting in real mode only.
+	 *
+	 * To address that, rather than precisely accounting every page, we
+	 * instead account for a worst case on locked memory when the iommu is
+	 * enabled and disabled.  The worst case upper bound on locked memory
+	 * is the size of the whole iommu window, which is usually relatively
+	 * small (compared to total memory sizes) on POWER hardware.
+	 *
+	 * Also we don't have a nice way to fail on H_PUT_TCE due to ulimits,
+	 * that would effectively kill the guest at random points, much better
+	 * enforcing the limit based on the max that the guest can map.
+	 *
+	 * Unfortunately at the moment it counts whole tables, no matter how
+	 * much memory the guest has. I.e. for 4GB guest and 4 IOMMU groups
+	 * each with 2GB DMA window, 8GB will be counted here. The reason for
+	 * this is that we cannot tell here the amount of RAM used by the guest
+	 * as this information is only available from KVM and VFIO is
+	 * KVM agnostic.
+	 *
+	 * So we do not allow enabling a container without a group attached
+	 * as there is no way to know how much we should increment
+	 * the locked_vm counter.
+	 */
+	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;
+
+	if (!table_group->tce32_size)
+		return -EPERM;
+
+	ret = tce_iommu_mm_set(container);
+	if (ret)
+		return ret;
+
+	locked = table_group->tce32_size >> PAGE_SHIFT;
+	ret = account_locked_vm(container->mm, locked, true);
+	if (ret)
+		return ret;
+
+	container->locked_pages = locked;
+
+	container->enabled = true;
+
+	return ret;
+}
+
+static void tce_iommu_disable(struct tce_container *container)
+{
+	if (!container->enabled)
+		return;
+
+	container->enabled = false;
+
+	BUG_ON(!container->mm);
+	account_locked_vm(container->mm, container->locked_pages, false);
+}
+
+static void *tce_iommu_open(unsigned long arg)
+{
+	struct tce_container *container;
+
+	if ((arg != VFIO_SPAPR_TCE_IOMMU) && (arg != VFIO_SPAPR_TCE_v2_IOMMU)) {
+		pr_err("tce_vfio: Wrong IOMMU type\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	container = kzalloc(sizeof(*container), GFP_KERNEL);
+	if (!container)
+		return ERR_PTR(-ENOMEM);
+
+	mutex_init(&container->lock);
+	INIT_LIST_HEAD_RCU(&container->group_list);
+	INIT_LIST_HEAD_RCU(&container->prereg_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 tce_container *container,
+		struct iommu_table *tbl);
+
+static void tce_iommu_release(void *iommu_data)
+{
+	struct tce_container *container = iommu_data;
+	struct tce_iommu_group *tcegrp;
+	struct tce_iommu_prereg *tcemem, *tmtmp;
+	long i;
+
+	while (tce_groups_attached(container)) {
+		tcegrp = list_first_entry(&container->group_list,
+				struct tce_iommu_group, next);
+		tce_iommu_detach_group(iommu_data, tcegrp->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(container, tbl);
+	}
+
+	list_for_each_entry_safe(tcemem, tmtmp, &container->prereg_list, next)
+		WARN_ON(tce_iommu_prereg_free(container, tcemem));
+
+	tce_iommu_disable(container);
+	if (container->mm)
+		mmdrop(container->mm);
+	mutex_destroy(&container->lock);
+
+	kfree(container);
+}
+
+static void tce_iommu_unuse_page(unsigned long hpa)
+{
+	struct page *page;
+
+	page = pfn_to_page(hpa >> PAGE_SHIFT);
+	unpin_user_page(page);
+}
+
+static int tce_iommu_prereg_ua_to_hpa(struct tce_container *container,
+		unsigned long tce, unsigned long shift,
+		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(container->mm, tce, 1ULL << shift);
+	if (!mem)
+		return -EINVAL;
+
+	ret = mm_iommu_ua_to_hpa(mem, tce, shift, phpa);
+	if (ret)
+		return -EINVAL;
+
+	*pmem = mem;
+
+	return 0;
+}
+
+static void tce_iommu_unuse_page_v2(struct tce_container *container,
+		struct iommu_table *tbl, unsigned long entry)
+{
+	struct mm_iommu_table_group_mem_t *mem = NULL;
+	int ret;
+	unsigned long hpa = 0;
+	__be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY_RO(tbl, entry);
+
+	if (!pua)
+		return;
+
+	ret = tce_iommu_prereg_ua_to_hpa(container, be64_to_cpu(*pua),
+			tbl->it_page_shift, &hpa, &mem);
+	if (ret)
+		pr_debug("%s: tce %llx at #%lx was not cached, ret=%d\n",
+				__func__, be64_to_cpu(*pua), entry, ret);
+	if (mem)
+		mm_iommu_mapped_dec(mem);
+
+	*pua = cpu_to_be64(0);
+}
+
+static int tce_iommu_clear(struct tce_container *container,
+		struct iommu_table *tbl,
+		unsigned long entry, unsigned long pages)
+{
+	unsigned long oldhpa;
+	long ret;
+	enum dma_data_direction direction;
+	unsigned long lastentry = entry + pages, firstentry = entry;
+
+	for ( ; entry < lastentry; ++entry) {
+		if (tbl->it_indirect_levels && tbl->it_userspace) {
+			/*
+			 * For multilevel tables, we can take a shortcut here
+			 * and skip some TCEs as we know that the userspace
+			 * addresses cache is a mirror of the real TCE table
+			 * and if it is missing some indirect levels, then
+			 * the hardware table does not have them allocated
+			 * either and therefore does not require updating.
+			 */
+			__be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY_RO(tbl,
+					entry);
+			if (!pua) {
+				/* align to level_size which is power of two */
+				entry |= tbl->it_level_size - 1;
+				continue;
+			}
+		}
+
+		cond_resched();
+
+		direction = DMA_NONE;
+		oldhpa = 0;
+		ret = iommu_tce_xchg_no_kill(container->mm, tbl, entry, &oldhpa,
+				&direction);
+		if (ret)
+			continue;
+
+		if (direction == DMA_NONE)
+			continue;
+
+		if (container->v2) {
+			tce_iommu_unuse_page_v2(container, tbl, entry);
+			continue;
+		}
+
+		tce_iommu_unuse_page(oldhpa);
+	}
+
+	iommu_tce_kill(tbl, firstentry, pages);
+
+	return 0;
+}
+
+static int tce_iommu_use_page(unsigned long tce, unsigned long *hpa)
+{
+	struct page *page = NULL;
+	enum dma_data_direction direction = iommu_tce_direction(tce);
+
+	if (pin_user_pages_fast(tce & PAGE_MASK, 1,
+			direction != DMA_TO_DEVICE ? FOLL_WRITE : 0,
+			&page) != 1)
+		return -EFAULT;
+
+	*hpa = __pa((unsigned long) page_address(page));
+
+	return 0;
+}
+
+static long tce_iommu_build(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;
+	unsigned long hpa;
+	enum dma_data_direction dirtmp;
+
+	for (i = 0; i < pages; ++i) {
+		unsigned long offset = tce & IOMMU_PAGE_MASK(tbl) & ~PAGE_MASK;
+
+		ret = tce_iommu_use_page(tce, &hpa);
+		if (ret)
+			break;
+
+		if (!tce_page_is_contained(container->mm, hpa,
+				tbl->it_page_shift)) {
+			ret = -EPERM;
+			break;
+		}
+
+		hpa |= offset;
+		dirtmp = direction;
+		ret = iommu_tce_xchg_no_kill(container->mm, tbl, entry + i,
+				&hpa, &dirtmp);
+		if (ret) {
+			tce_iommu_unuse_page(hpa);
+			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(hpa);
+
+		tce += IOMMU_PAGE_SIZE(tbl);
+	}
+
+	if (ret)
+		tce_iommu_clear(container, tbl, entry, i);
+	else
+		iommu_tce_kill(tbl, entry, pages);
+
+	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;
+	unsigned long hpa;
+	enum dma_data_direction dirtmp;
+
+	for (i = 0; i < pages; ++i) {
+		struct mm_iommu_table_group_mem_t *mem = NULL;
+		__be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry + i);
+
+		ret = tce_iommu_prereg_ua_to_hpa(container,
+				tce, tbl->it_page_shift, &hpa, &mem);
+		if (ret)
+			break;
+
+		if (!tce_page_is_contained(container->mm, hpa,
+				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_no_kill(container->mm, tbl, entry + i,
+				&hpa, &dirtmp);
+		if (ret) {
+			/* dirtmp cannot be DMA_NONE here */
+			tce_iommu_unuse_page_v2(container, 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(container, tbl, entry + i);
+
+		*pua = cpu_to_be64(tce);
+
+		tce += IOMMU_PAGE_SIZE(tbl);
+	}
+
+	if (ret)
+		tce_iommu_clear(container, tbl, entry, i);
+	else
+		iommu_tce_kill(tbl, entry, pages);
+
+	return ret;
+}
+
+static long tce_iommu_create_table(struct tce_container *container,
+			struct iommu_table_group *table_group,
+			int num,
+			__u32 page_shift,
+			__u64 window_size,
+			__u32 levels,
+			struct iommu_table **ptbl)
+{
+	long ret, table_size;
+
+	table_size = table_group->ops->get_table_size(page_shift, window_size,
+			levels);
+	if (!table_size)
+		return -EINVAL;
+
+	ret = account_locked_vm(container->mm, table_size >> PAGE_SHIFT, true);
+	if (ret)
+		return ret;
+
+	ret = table_group->ops->create_table(table_group, num,
+			page_shift, window_size, levels, ptbl);
+
+	WARN_ON(!ret && !(*ptbl)->it_ops->free);
+	WARN_ON(!ret && ((*ptbl)->it_allocated_size > table_size));
+
+	return ret;
+}
+
+static void tce_iommu_free_table(struct tce_container *container,
+		struct iommu_table *tbl)
+{
+	unsigned long pages = tbl->it_allocated_size >> PAGE_SHIFT;
+
+	iommu_tce_table_put(tbl);
+	account_locked_vm(container->mm, pages, false);
+}
+
+static long tce_iommu_create_window(struct tce_container *container,
+		__u32 page_shift, __u64 window_size, __u32 levels,
+		__u64 *start_addr)
+{
+	struct tce_iommu_group *tcegrp;
+	struct iommu_table_group *table_group;
+	struct iommu_table *tbl = NULL;
+	long ret, num;
+
+	num = tce_iommu_find_free_table(container);
+	if (num < 0)
+		return num;
+
+	/* Get the first group for ops::create_table */
+	tcegrp = list_first_entry(&container->group_list,
+			struct tce_iommu_group, next);
+	table_group = iommu_group_get_iommudata(tcegrp->grp);
+	if (!table_group)
+		return -EFAULT;
+
+	if (!(table_group->pgsizes & (1ULL << page_shift)))
+		return -EINVAL;
+
+	if (!table_group->ops->set_window || !table_group->ops->unset_window ||
+			!table_group->ops->get_table_size ||
+			!table_group->ops->create_table)
+		return -EPERM;
+
+	/* Create TCE table */
+	ret = tce_iommu_create_table(container, table_group, num,
+			page_shift, window_size, levels, &tbl);
+	if (ret)
+		return ret;
+
+	BUG_ON(!tbl->it_ops->free);
+
+	/*
+	 * Program the table to every group.
+	 * Groups have been tested for compatibility at the attach time.
+	 */
+	list_for_each_entry(tcegrp, &container->group_list, next) {
+		table_group = iommu_group_get_iommudata(tcegrp->grp);
+
+		ret = table_group->ops->set_window(table_group, num, tbl);
+		if (ret)
+			goto unset_exit;
+	}
+
+	container->tables[num] = tbl;
+
+	/* Return start address assigned by platform in create_table() */
+	*start_addr = tbl->it_offset << tbl->it_page_shift;
+
+	return 0;
+
+unset_exit:
+	list_for_each_entry(tcegrp, &container->group_list, next) {
+		table_group = iommu_group_get_iommudata(tcegrp->grp);
+		table_group->ops->unset_window(table_group, num);
+	}
+	tce_iommu_free_table(container, tbl);
+
+	return ret;
+}
+
+static long tce_iommu_remove_window(struct tce_container *container,
+		__u64 start_addr)
+{
+	struct iommu_table_group *table_group = NULL;
+	struct iommu_table *tbl;
+	struct tce_iommu_group *tcegrp;
+	int num;
+
+	num = tce_iommu_find_table(container, start_addr, &tbl);
+	if (num < 0)
+		return -EINVAL;
+
+	BUG_ON(!tbl->it_size);
+
+	/* Detach groups from IOMMUs */
+	list_for_each_entry(tcegrp, &container->group_list, next) {
+		table_group = iommu_group_get_iommudata(tcegrp->grp);
+
+		/*
+		 * SPAPR TCE IOMMU exposes the default DMA window to
+		 * the guest via dma32_window_start/size of
+		 * VFIO_IOMMU_SPAPR_TCE_GET_INFO. Some platforms allow
+		 * the userspace to remove this window, some do not so
+		 * here we check for the platform capability.
+		 */
+		if (!table_group->ops || !table_group->ops->unset_window)
+			return -EPERM;
+
+		table_group->ops->unset_window(table_group, num);
+	}
+
+	/* Free table */
+	tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
+	tce_iommu_free_table(container, tbl);
+	container->tables[num] = NULL;
+
+	return 0;
+}
+
+static long tce_iommu_create_default_window(struct tce_container *container)
+{
+	long ret;
+	__u64 start_addr = 0;
+	struct tce_iommu_group *tcegrp;
+	struct iommu_table_group *table_group;
+
+	if (!container->def_window_pending)
+		return 0;
+
+	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;
+
+	ret = tce_iommu_create_window(container, IOMMU_PAGE_SHIFT_4K,
+			table_group->tce32_size, 1, &start_addr);
+	WARN_ON_ONCE(!ret && start_addr);
+
+	if (!ret)
+		container->def_window_pending = false;
+
+	return ret;
+}
+
+static long tce_iommu_ioctl(void *iommu_data,
+				 unsigned int cmd, unsigned long arg)
+{
+	struct tce_container *container = iommu_data;
+	unsigned long minsz, ddwsz;
+	long ret;
+
+	switch (cmd) {
+	case VFIO_CHECK_EXTENSION:
+		switch (arg) {
+		case VFIO_SPAPR_TCE_IOMMU:
+		case VFIO_SPAPR_TCE_v2_IOMMU:
+			ret = 1;
+			break;
+		default:
+			ret = vfio_spapr_iommu_eeh_ioctl(NULL, cmd, arg);
+			break;
+		}
+
+		return (ret < 0) ? 0 : ret;
+	}
+
+	/*
+	 * Sanity check to prevent one userspace from manipulating
+	 * another userspace mm.
+	 */
+	BUG_ON(!container);
+	if (container->mm && container->mm != current->mm)
+		return -EPERM;
+
+	switch (cmd) {
+	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 (!tce_groups_attached(container))
+			return -ENXIO;
+
+		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;
+
+		minsz = offsetofend(struct vfio_iommu_spapr_tce_info,
+				dma32_window_size);
+
+		if (copy_from_user(&info, (void __user *)arg, minsz))
+			return -EFAULT;
+
+		if (info.argsz < minsz)
+			return -EINVAL;
+
+		info.dma32_window_start = table_group->tce32_start;
+		info.dma32_window_size = table_group->tce32_size;
+		info.flags = 0;
+		memset(&info.ddw, 0, sizeof(info.ddw));
+
+		if (table_group->max_dynamic_windows_supported &&
+				container->v2) {
+			info.flags |= VFIO_IOMMU_SPAPR_INFO_DDW;
+			info.ddw.pgsizes = table_group->pgsizes;
+			info.ddw.max_dynamic_windows_supported =
+				table_group->max_dynamic_windows_supported;
+			info.ddw.levels = table_group->max_levels;
+		}
+
+		ddwsz = offsetofend(struct vfio_iommu_spapr_tce_info, ddw);
+
+		if (info.argsz >= ddwsz)
+			minsz = ddwsz;
+
+		if (copy_to_user((void __user *)arg, &info, minsz))
+			return -EFAULT;
+
+		return 0;
+	}
+	case VFIO_IOMMU_MAP_DMA: {
+		struct vfio_iommu_type1_dma_map param;
+		struct iommu_table *tbl = NULL;
+		long num;
+		enum dma_data_direction direction;
+
+		if (!container->enabled)
+			return -EPERM;
+
+		minsz = offsetofend(struct vfio_iommu_type1_dma_map, size);
+
+		if (copy_from_user(&param, (void __user *)arg, minsz))
+			return -EFAULT;
+
+		if (param.argsz < minsz)
+			return -EINVAL;
+
+		if (param.flags & ~(VFIO_DMA_MAP_FLAG_READ |
+				VFIO_DMA_MAP_FLAG_WRITE))
+			return -EINVAL;
+
+		ret = tce_iommu_create_default_window(container);
+		if (ret)
+			return ret;
+
+		num = tce_iommu_find_table(container, param.iova, &tbl);
+		if (num < 0)
+			return -ENXIO;
+
+		if ((param.size & ~IOMMU_PAGE_MASK(tbl)) ||
+				(param.vaddr & ~IOMMU_PAGE_MASK(tbl)))
+			return -EINVAL;
+
+		/* iova is checked by the IOMMU API */
+		if (param.flags & VFIO_DMA_MAP_FLAG_READ) {
+			if (param.flags & VFIO_DMA_MAP_FLAG_WRITE)
+				direction = DMA_BIDIRECTIONAL;
+			else
+				direction = DMA_TO_DEVICE;
+		} else {
+			if (param.flags & VFIO_DMA_MAP_FLAG_WRITE)
+				direction = DMA_FROM_DEVICE;
+			else
+				return -EINVAL;
+		}
+
+		ret = iommu_tce_put_param_check(tbl, param.iova, param.vaddr);
+		if (ret)
+			return ret;
+
+		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);
+
+		return ret;
+	}
+	case VFIO_IOMMU_UNMAP_DMA: {
+		struct vfio_iommu_type1_dma_unmap param;
+		struct iommu_table *tbl = NULL;
+		long num;
+
+		if (!container->enabled)
+			return -EPERM;
+
+		minsz = offsetofend(struct vfio_iommu_type1_dma_unmap,
+				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;
+
+		ret = tce_iommu_create_default_window(container);
+		if (ret)
+			return ret;
+
+		num = tce_iommu_find_table(container, param.iova, &tbl);
+		if (num < 0)
+			return -ENXIO;
+
+		if (param.size & ~IOMMU_PAGE_MASK(tbl))
+			return -EINVAL;
+
+		ret = iommu_tce_clear_param_check(tbl, param.iova, 0,
+				param.size >> tbl->it_page_shift);
+		if (ret)
+			return ret;
+
+		ret = tce_iommu_clear(container, tbl,
+				param.iova >> tbl->it_page_shift,
+				param.size >> tbl->it_page_shift);
+		iommu_flush_tce(tbl);
+
+		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);
+
+		ret = tce_iommu_mm_set(container);
+		if (ret)
+			return ret;
+
+		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;
+
+		if (!container->mm)
+			return -EPERM;
+
+		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);
+		return ret;
+
+
+	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: {
+		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;
+	}
+
+	case VFIO_IOMMU_SPAPR_TCE_CREATE: {
+		struct vfio_iommu_spapr_tce_create create;
+
+		if (!container->v2)
+			break;
+
+		ret = tce_iommu_mm_set(container);
+		if (ret)
+			return ret;
+
+		if (!tce_groups_attached(container))
+			return -ENXIO;
+
+		minsz = offsetofend(struct vfio_iommu_spapr_tce_create,
+				start_addr);
+
+		if (copy_from_user(&create, (void __user *)arg, minsz))
+			return -EFAULT;
+
+		if (create.argsz < minsz)
+			return -EINVAL;
+
+		if (create.flags)
+			return -EINVAL;
+
+		mutex_lock(&container->lock);
+
+		ret = tce_iommu_create_default_window(container);
+		if (!ret)
+			ret = tce_iommu_create_window(container,
+					create.page_shift,
+					create.window_size, create.levels,
+					&create.start_addr);
+
+		mutex_unlock(&container->lock);
+
+		if (!ret && copy_to_user((void __user *)arg, &create, minsz))
+			ret = -EFAULT;
+
+		return ret;
+	}
+	case VFIO_IOMMU_SPAPR_TCE_REMOVE: {
+		struct vfio_iommu_spapr_tce_remove remove;
+
+		if (!container->v2)
+			break;
+
+		ret = tce_iommu_mm_set(container);
+		if (ret)
+			return ret;
+
+		if (!tce_groups_attached(container))
+			return -ENXIO;
+
+		minsz = offsetofend(struct vfio_iommu_spapr_tce_remove,
+				start_addr);
+
+		if (copy_from_user(&remove, (void __user *)arg, minsz))
+			return -EFAULT;
+
+		if (remove.argsz < minsz)
+			return -EINVAL;
+
+		if (remove.flags)
+			return -EINVAL;
+
+		if (container->def_window_pending && !remove.start_addr) {
+			container->def_window_pending = false;
+			return 0;
+		}
+
+		mutex_lock(&container->lock);
+
+		ret = tce_iommu_remove_window(container, remove.start_addr);
+
+		mutex_unlock(&container->lock);
+
+		return ret;
+	}
+	}
+
+	return -ENOTTY;
+}
+
+static void tce_iommu_release_ownership(struct tce_container *container,
+		struct iommu_table_group *table_group)
+{
+	int i;
+
+	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);
+		if (tbl->it_map)
+			iommu_release_ownership(tbl);
+
+		container->tables[i] = NULL;
+	}
+}
+
+static int tce_iommu_take_ownership(struct tce_container *container,
+		struct iommu_table_group *table_group)
+{
+	int i, j, rc = 0;
+
+	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
+		struct iommu_table *tbl = table_group->tables[i];
+
+		if (!tbl || !tbl->it_map)
+			continue;
+
+		rc = iommu_take_ownership(tbl);
+		if (rc) {
+			for (j = 0; j < i; ++j)
+				iommu_release_ownership(
+						table_group->tables[j]);
+
+			return rc;
+		}
+	}
+
+	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
+		container->tables[i] = table_group->tables[i];
+
+	return 0;
+}
+
+static void tce_iommu_release_ownership_ddw(struct tce_container *container,
+		struct iommu_table_group *table_group)
+{
+	long i;
+
+	if (!table_group->ops->unset_window) {
+		WARN_ON_ONCE(1);
+		return;
+	}
+
+	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
+		if (container->tables[i])
+			table_group->ops->unset_window(table_group, i);
+
+	table_group->ops->release_ownership(table_group);
+}
+
+static long tce_iommu_take_ownership_ddw(struct tce_container *container,
+		struct iommu_table_group *table_group)
+{
+	long i, ret = 0;
+
+	if (!table_group->ops->create_table || !table_group->ops->set_window ||
+			!table_group->ops->release_ownership) {
+		WARN_ON_ONCE(1);
+		return -EFAULT;
+	}
+
+	table_group->ops->take_ownership(table_group);
+
+	/* Set all windows to the new group */
+	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
+		struct iommu_table *tbl = container->tables[i];
+
+		if (!tbl)
+			continue;
+
+		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;
+}
+
+static int tce_iommu_attach_group(void *iommu_data,
+		struct iommu_group *iommu_group, enum vfio_group_type type)
+{
+	int ret = 0;
+	struct tce_container *container = iommu_data;
+	struct iommu_table_group *table_group;
+	struct tce_iommu_group *tcegrp = NULL;
+
+	if (type == VFIO_EMULATED_IOMMU)
+		return -EINVAL;
+
+	mutex_lock(&container->lock);
+
+	/* pr_debug("tce_vfio: Attaching group #%u to iommu %p\n",
+			iommu_group_id(iommu_group), iommu_group); */
+	table_group = iommu_group_get_iommudata(iommu_group);
+	if (!table_group) {
+		ret = -ENODEV;
+		goto unlock_exit;
+	}
+
+	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_table_group_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->create_table !=
+				table_group->ops->create_table) {
+			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;
+	}
+
+	if (!table_group->ops || !table_group->ops->take_ownership ||
+			!table_group->ops->release_ownership) {
+		if (container->v2) {
+			ret = -EPERM;
+			goto free_exit;
+		}
+		ret = tce_iommu_take_ownership(container, table_group);
+	} else {
+		if (!container->v2) {
+			ret = -EPERM;
+			goto free_exit;
+		}
+		ret = tce_iommu_take_ownership_ddw(container, table_group);
+		if (!tce_groups_attached(container) && !container->tables[0])
+			container->def_window_pending = true;
+	}
+
+	if (!ret) {
+		tcegrp->grp = iommu_group;
+		list_add(&tcegrp->next, &container->group_list);
+	}
+
+free_exit:
+	if (ret && tcegrp)
+		kfree(tcegrp);
+
+unlock_exit:
+	mutex_unlock(&container->lock);
+
+	return ret;
+}
+
+static void tce_iommu_detach_group(void *iommu_data,
+		struct iommu_group *iommu_group)
+{
+	struct tce_container *container = iommu_data;
+	struct iommu_table_group *table_group;
+	bool found = false;
+	struct tce_iommu_group *tcegrp;
+
+	mutex_lock(&container->lock);
+
+	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;
+	}
+
+	list_del(&tcegrp->next);
+	kfree(tcegrp);
+
+	table_group = iommu_group_get_iommudata(iommu_group);
+	BUG_ON(!table_group);
+
+	if (!table_group->ops || !table_group->ops->release_ownership)
+		tce_iommu_release_ownership(container, table_group);
+	else
+		tce_iommu_release_ownership_ddw(container, table_group);
+
+unlock_exit:
+	mutex_unlock(&container->lock);
+}
+
+static const struct vfio_iommu_driver_ops tce_iommu_driver_ops = {
+	.name		= "iommu-vfio-powerpc",
+	.owner		= THIS_MODULE,
+	.open		= tce_iommu_open,
+	.release	= tce_iommu_release,
+	.ioctl		= tce_iommu_ioctl,
+	.attach_group	= tce_iommu_attach_group,
+	.detach_group	= tce_iommu_detach_group,
+};
+
+static int __init tce_iommu_init(void)
+{
+	return vfio_register_iommu_driver(&tce_iommu_driver_ops);
+}
+
+static void __exit tce_iommu_cleanup(void)
+{
+	vfio_unregister_iommu_driver(&tce_iommu_driver_ops);
+}
+
+module_init(tce_iommu_init);
+module_exit(tce_iommu_cleanup);
+
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+