Subject: Re: [PATCH kernel v10 17/34] powerpc/spapr: vfio: Switch from iommu_table to new iommu_table_group

From: Gavin Shan <[email-masked]>
Date: Thu, 14 May 2015 11:52:42 +1000

On Tue, May 12, 2015 at 01:39:06AM +1000, Alexey Kardashevskiy wrote:
>Modern IBM POWERPC systems support multiple (currently two) TCE tables
>per IOMMU group (a.k.a. PE). This adds a iommu_table_group container
>for TCE tables. Right now just one table is supported.
>
>For IODA, instead of embedding iommu_table, the new iommu_table_group
>keeps pointers to those. The iommu_table structs are allocated
>dynamically now by a pnv_pci_table_alloc() helper as PCI hotplug
>code (for EEH recovery) and SRIOV are supported there.
>
>For P5IOC2, both iommu_table_group and iommu_table are embedded into
>PE struct. As there is no EEH and SRIOV support for P5IOC2,
>iommu_free_table() should not be called on iommu_table struct pointers
>so we can keep it embedded in pnv_phb::p5ioc2.
>
>For pSeries, this replaces multiple calls of kzalloc_node() with a new
>iommu_pseries_group_alloc() helper and stores the table group struct
>pointer into the pci_dn struct. For release, a iommu_table_group_free()
>helper is added.
>
>This moves iommu_table struct allocation from SR-IOV code to
>the generic DMA initialization code in pnv_pci_ioda2_setup_dma_pe.
>
>This replaces a single pointer to iommu_group with a list of
>iommu_table_group structs. For now it is just a single iommu_table_group
>in this list but later with TCE table sharing enabled, the list will
>keep all the IOMMU groups which use the particular table. The list
>uses iommu_table_group_link structs rather than iommu_table_group::next
>as a VFIO container may have 2 IOMMU tables, each will have its own list
>head pointer as it is mainly for TCE invalidation code which should
>walk through all attached groups and invalidate TCE cache so
>the table has to keep the list head pointer. The other option would
>be storing list head in a VFIO container but it would not work as
>the platform code (which does TCE table update and invalidation) has
>no idea about VFIO.
>
>This should cause no behavioural change.
>
>Signed-off-by: Alexey Kardashevskiy <[email-masked]>
>[aw: for the vfio related changes]
>Acked-by: Alex Williamson <[email-masked]>
>Reviewed-by: David Gibson <[email-masked]>

Reviewed-by: Gavin Shan <[email-masked]>

Thanks,
Gavin

>---
>Changes:
>v10:
>* iommu_table is not embedded into iommu_table_group but allocated
>dynamically
>* iommu_table allocation is moved to a single place for IODA2's
>pnv_pci_ioda_setup_dma_pe where it belongs to
>* added list of groups into iommu_table; most of the code just looks at
>the first item to keep the patch simpler
>
>v9:
>* s/it_group/it_table_group/
>* added and used iommu_table_group_free(), from now iommu_free_table()
>is only used for VIO
>* added iommu_pseries_group_alloc()
>* squashed "powerpc/iommu: Introduce iommu_table_alloc() helper" into this
>---
> arch/powerpc/include/asm/iommu.h            |   8 +-
> arch/powerpc/kernel/iommu.c                 |   9 +-
> arch/powerpc/platforms/powernv/pci-ioda.c   |  45 ++++++----
> arch/powerpc/platforms/powernv/pci-p5ioc2.c |   3 +
> arch/powerpc/platforms/powernv/pci.c        |  73 +++++++++++++++++
> arch/powerpc/platforms/powernv/pci.h        |   7 ++
> arch/powerpc/platforms/pseries/iommu.c      |  36 ++++++--
> drivers/vfio/vfio_iommu_spapr_tce.c         | 122 ++++++++++++++++++++--------
> 8 files changed, 241 insertions(+), 62 deletions(-)
>
>diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
>index 61bde1a..664beeb 100644
>--- a/arch/powerpc/include/asm/iommu.h
>+++ b/arch/powerpc/include/asm/iommu.h
>@@ -92,7 +92,7 @@ struct iommu_table {
> 	unsigned long *it_map;       /* A simple allocation bitmap for now */
> 	unsigned long  it_page_shift;/* table iommu page size */
> #ifdef CONFIG_IOMMU_API
>-	struct iommu_table_group *it_table_group;
>+	struct list_head it_group_list;/* List of iommu_table_group_link */
> #endif
> 	struct iommu_table_ops *it_ops;
> 	void (*set_bypass)(struct iommu_table *tbl, bool enable);
>@@ -130,6 +130,12 @@ extern struct iommu_table *iommu_init_table(struct iommu_table * tbl,
>
> #define IOMMU_TABLE_GROUP_MAX_TABLES	1
>
>+struct iommu_table_group_link {
>+	struct list_head next;
>+	struct rcu_head rcu;
>+	struct iommu_table_group *table_group;
>+};
>+
> struct iommu_table_group {
> 	struct iommu_group *group;
> 	struct iommu_table *tables[IOMMU_TABLE_GROUP_MAX_TABLES];
>diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
>index 79e8b43..bdf19c6 100644
>--- a/arch/powerpc/kernel/iommu.c
>+++ b/arch/powerpc/kernel/iommu.c
>@@ -1075,6 +1075,7 @@ EXPORT_SYMBOL_GPL(iommu_release_ownership);
> int iommu_add_device(struct device *dev)
> {
> 	struct iommu_table *tbl;
>+	struct iommu_table_group_link *tgl;
>
> 	/*
> 	 * The sysfs entries should be populated before
>@@ -1092,15 +1093,17 @@ int iommu_add_device(struct device *dev)
> 	}
>
> 	tbl = get_iommu_table_base(dev);
>-	if (!tbl || !tbl->it_table_group || !tbl->it_table_group->group) {
>+	if (!tbl || list_empty(&tbl->it_group_list)) {
> 		pr_debug("%s: Skipping device %s with no tbl\n",
> 			 __func__, dev_name(dev));
> 		return 0;
> 	}
>
>+	tgl = list_first_entry_or_null(&tbl->it_group_list,
>+			struct iommu_table_group_link, next);
> 	pr_debug("%s: Adding %s to iommu group %d\n",
> 		 __func__, dev_name(dev),
>-		 iommu_group_id(tbl->it_table_group->group));
>+		 iommu_group_id(tgl->table_group->group));
>
> 	if (PAGE_SIZE < IOMMU_PAGE_SIZE(tbl)) {
> 		pr_err("%s: Invalid IOMMU page size %lx (%lx) on %s\n",
>@@ -1109,7 +1112,7 @@ int iommu_add_device(struct device *dev)
> 		return -EINVAL;
> 	}
>
>-	return iommu_group_add_device(tbl->it_table_group->group, dev);
>+	return iommu_group_add_device(tgl->table_group->group, dev);
> }
> EXPORT_SYMBOL_GPL(iommu_add_device);
>
>diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>index 02ed448..53bf242b 100644
>--- a/arch/powerpc/platforms/powernv/pci-ioda.c
>+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>@@ -1288,7 +1288,6 @@ static void pnv_pci_ioda2_release_dma_pe(struct pci_dev *dev, struct pnv_ioda_pe
> 	struct iommu_table    *tbl;
> 	unsigned long         addr;
> 	int64_t               rc;
>-	struct iommu_table_group *table_group;
>
> 	bus = dev->bus;
> 	hose = pci_bus_to_host(bus);
>@@ -1308,14 +1307,13 @@ static void pnv_pci_ioda2_release_dma_pe(struct pci_dev *dev, struct pnv_ioda_pe
> 	if (rc)
> 		pe_warn(pe, "OPAL error %ld release DMA window\n", rc);
>
>-	table_group = tbl->it_table_group;
>-	if (table_group->group) {
>-		iommu_group_put(table_group->group);
>-		BUG_ON(table_group->group);
>+	pnv_pci_unlink_table_and_group(tbl, &pe->table_group);
>+	if (pe->table_group.group) {
>+		iommu_group_put(pe->table_group.group);
>+		BUG_ON(pe->table_group.group);
> 	}
> 	iommu_free_table(tbl, of_node_full_name(dev->dev.of_node));
> 	free_pages(addr, get_order(TCE32_TABLE_SIZE));
>-	pe->table_group.tables[0] = NULL;
> }
>
> static void pnv_ioda_release_vf_PE(struct pci_dev *pdev, u16 num_vfs)
>@@ -1675,7 +1673,10 @@ static void pnv_ioda_setup_bus_dma(struct pnv_ioda_pe *pe,
> static void pnv_pci_ioda1_tce_invalidate(struct iommu_table *tbl,
> 		unsigned long index, unsigned long npages, bool rm)
> {
>-	struct pnv_ioda_pe *pe = container_of(tbl->it_table_group,
>+	struct iommu_table_group_link *tgl = list_first_entry_or_null(
>+			&tbl->it_group_list, struct iommu_table_group_link,
>+			next);
>+	struct pnv_ioda_pe *pe = container_of(tgl->table_group,
> 			struct pnv_ioda_pe, table_group);
> 	__be64 __iomem *invalidate = rm ?
> 		(__be64 __iomem *)pe->tce_inval_reg_phys :
>@@ -1753,7 +1754,10 @@ static struct iommu_table_ops pnv_ioda1_iommu_ops = {
> static void pnv_pci_ioda2_tce_invalidate(struct iommu_table *tbl,
> 		unsigned long index, unsigned long npages, bool rm)
> {
>-	struct pnv_ioda_pe *pe = container_of(tbl->it_table_group,
>+	struct iommu_table_group_link *tgl = list_first_entry_or_null(
>+			&tbl->it_group_list, struct iommu_table_group_link,
>+			next);
>+	struct pnv_ioda_pe *pe = container_of(tgl->table_group,
> 			struct pnv_ioda_pe, table_group);
> 	unsigned long start, end, inc;
> 	__be64 __iomem *invalidate = rm ?
>@@ -1830,12 +1834,10 @@ static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb,
> 	if (WARN_ON(pe->tce32_seg >= 0))
> 		return;
>
>-	tbl = kzalloc_node(sizeof(struct iommu_table), GFP_KERNEL,
>-			phb->hose->node);
>-	tbl->it_table_group = &pe->table_group;
>-	pe->table_group.tables[0] = tbl;
>+	tbl = pnv_pci_table_alloc(phb->hose->node);
> 	iommu_register_group(&pe->table_group, phb->hose->global_number,
> 			pe->pe_number);
>+	pnv_pci_link_table_and_group(phb->hose->node, 0, tbl, &pe->table_group);
>
> 	/* Grab a 32-bit TCE table */
> 	pe->tce32_seg = base;
>@@ -1910,11 +1912,18 @@ static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb,
> 		pe->tce32_seg = -1;
> 	if (tce_mem)
> 		__free_pages(tce_mem, get_order(TCE32_TABLE_SIZE * segs));
>+	if (tbl) {
>+		pnv_pci_unlink_table_and_group(tbl, &pe->table_group);
>+		iommu_free_table(tbl, "pnv");
>+	}
> }
>
> static void pnv_pci_ioda2_set_bypass(struct iommu_table *tbl, bool enable)
> {
>-	struct pnv_ioda_pe *pe = container_of(tbl->it_table_group,
>+	struct iommu_table_group_link *tgl = list_first_entry_or_null(
>+			&tbl->it_group_list, struct iommu_table_group_link,
>+			next);
>+	struct pnv_ioda_pe *pe = container_of(tgl->table_group,
> 			struct pnv_ioda_pe, table_group);
> 	uint16_t window_id = (pe->pe_number << 1 ) + 1;
> 	int64_t rc;
>@@ -1969,12 +1978,10 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
> 	if (WARN_ON(pe->tce32_seg >= 0))
> 		return;
>
>-	tbl = kzalloc_node(sizeof(struct iommu_table), GFP_KERNEL,
>-			phb->hose->node);
>-	tbl->it_table_group = &pe->table_group;
>-	pe->table_group.tables[0] = tbl;
>+	tbl = pnv_pci_table_alloc(phb->hose->node);
> 	iommu_register_group(&pe->table_group, phb->hose->global_number,
> 			pe->pe_number);
>+	pnv_pci_link_table_and_group(phb->hose->node, 0, tbl, &pe->table_group);
>
> 	/* The PE will reserve all possible 32-bits space */
> 	pe->tce32_seg = 0;
>@@ -2047,6 +2054,10 @@ fail:
> 		pe->tce32_seg = -1;
> 	if (tce_mem)
> 		__free_pages(tce_mem, get_order(tce_table_size));
>+	if (tbl) {
>+		pnv_pci_unlink_table_and_group(tbl, &pe->table_group);
>+		iommu_free_table(tbl, "pnv");
>+	}
> }
>
> static void pnv_ioda_setup_dma(struct pnv_phb *phb)
>diff --git a/arch/powerpc/platforms/powernv/pci-p5ioc2.c b/arch/powerpc/platforms/powernv/pci-p5ioc2.c
>index 4ea9def..b524b17 100644
>--- a/arch/powerpc/platforms/powernv/pci-p5ioc2.c
>+++ b/arch/powerpc/platforms/powernv/pci-p5ioc2.c
>@@ -99,6 +99,9 @@ static void pnv_pci_p5ioc2_dma_dev_setup(struct pnv_phb *phb,
> 		iommu_init_table(tbl, phb->hose->node);
> 		iommu_register_group(&phb->p5ioc2.table_group,
> 				pci_domain_nr(phb->hose->bus), phb->opal_id);
>+		INIT_LIST_HEAD_RCU(&tbl->it_group_list);
>+		pnv_pci_link_table_and_group(phb->hose->node, 0,
>+				tbl, &phb->p5ioc2.table_group);
> 	}
>
> 	set_iommu_table_base(&pdev->dev, tbl);
>diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
>index 84b4ea4..ed7de7b 100644
>--- a/arch/powerpc/platforms/powernv/pci.c
>+++ b/arch/powerpc/platforms/powernv/pci.c
>@@ -606,6 +606,79 @@ unsigned long pnv_tce_get(struct iommu_table *tbl, long index)
> 	return ((u64 *)tbl->it_base)[index - tbl->it_offset];
> }
>
>+struct iommu_table *pnv_pci_table_alloc(int nid)
>+{
>+	struct iommu_table *tbl;
>+
>+	tbl = kzalloc_node(sizeof(struct iommu_table), GFP_KERNEL, nid);
>+	INIT_LIST_HEAD_RCU(&tbl->it_group_list);
>+
>+	return tbl;
>+}
>+
>+long pnv_pci_link_table_and_group(int node, int num,
>+		struct iommu_table *tbl,
>+		struct iommu_table_group *table_group)
>+{
>+	struct iommu_table_group_link *tgl = NULL;
>+
>+	BUG_ON(!tbl);
>+	BUG_ON(!table_group);
>+	BUG_ON(!table_group->group);
>+
>+	tgl = kzalloc_node(sizeof(struct iommu_table_group_link), GFP_KERNEL,
>+			node);
>+	if (!tgl)
>+		return -ENOMEM;
>+
>+	tgl->table_group = table_group;
>+	list_add_rcu(&tgl->next, &tbl->it_group_list);
>+
>+	table_group->tables[num] = tbl;
>+
>+	return 0;
>+}
>+
>+static void pnv_iommu_table_group_link_free(struct rcu_head *head)
>+{
>+	struct iommu_table_group_link *tgl = container_of(head,
>+			struct iommu_table_group_link, rcu);
>+
>+	kfree(tgl);
>+}
>+
>+void pnv_pci_unlink_table_and_group(struct iommu_table *tbl,
>+		struct iommu_table_group *table_group)
>+{
>+	long i;
>+	bool found;
>+	struct iommu_table_group_link *tgl;
>+
>+	/* Remove link to a group from table's list of attached groups */
>+	found = false;
>+	list_for_each_entry_rcu(tgl, &tbl->it_group_list, next) {
>+		if (tgl->table_group == table_group) {
>+			list_del_rcu(&tgl->next);
>+			call_rcu(&tgl->rcu, pnv_iommu_table_group_link_free);
>+			found = true;
>+			break;
>+		}
>+	}
>+	if (WARN_ON(!found))
>+		return;
>+
>+	/* Clean a pointer to iommu_table in iommu_table_group::tables[] */
>+	found = false;
>+	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
>+		if (table_group->tables[i] == tbl) {
>+			table_group->tables[i] = NULL;
>+			found = true;
>+			break;
>+		}
>+	}
>+	WARN_ON(!found);
>+}
>+
> void pnv_pci_setup_iommu_table(struct iommu_table *tbl,
> 			       void *tce_mem, u64 tce_size,
> 			       u64 dma_offset, unsigned page_shift)
>diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
>index 720cc99..87bdd4f 100644
>--- a/arch/powerpc/platforms/powernv/pci.h
>+++ b/arch/powerpc/platforms/powernv/pci.h
>@@ -213,6 +213,13 @@ int pnv_pci_cfg_read(struct pci_dn *pdn,
> 		     int where, int size, u32 *val);
> int pnv_pci_cfg_write(struct pci_dn *pdn,
> 		      int where, int size, u32 val);
>+extern struct iommu_table *pnv_pci_table_alloc(int nid);
>+
>+extern long pnv_pci_link_table_and_group(int node, int num,
>+		struct iommu_table *tbl,
>+		struct iommu_table_group *table_group);
>+extern void pnv_pci_unlink_table_and_group(struct iommu_table *tbl,
>+		struct iommu_table_group *table_group);
> extern void pnv_pci_setup_iommu_table(struct iommu_table *tbl,
> 				      void *tce_mem, u64 tce_size,
> 				      u64 dma_offset, unsigned page_shift);
>diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
>index ad5ac6d..040fd45 100644
>--- a/arch/powerpc/platforms/pseries/iommu.c
>+++ b/arch/powerpc/platforms/pseries/iommu.c
>@@ -37,6 +37,7 @@
> #include <linux/memory.h>
> #include <linux/of.h>
> #include <linux/iommu.h>
>+#include <linux/rculist.h>
> #include <asm/io.h>
> #include <asm/prom.h>
> #include <asm/rtas.h>
>@@ -56,6 +57,7 @@ static struct iommu_table_group *iommu_pseries_alloc_group(int node)
> {
> 	struct iommu_table_group *table_group = NULL;
> 	struct iommu_table *tbl = NULL;
>+	struct iommu_table_group_link *tgl = NULL;
>
> 	table_group = kzalloc_node(sizeof(struct iommu_table_group), GFP_KERNEL,
> 			   node);
>@@ -66,12 +68,21 @@ static struct iommu_table_group *iommu_pseries_alloc_group(int node)
> 	if (!tbl)
> 		goto fail_exit;
>
>-	tbl->it_table_group = table_group;
>+	tgl = kzalloc_node(sizeof(struct iommu_table_group_link), GFP_KERNEL,
>+			node);
>+	if (!tgl)
>+		goto fail_exit;
>+
>+	INIT_LIST_HEAD_RCU(&tbl->it_group_list);
>+	tgl->table_group = table_group;
>+	list_add_rcu(&tgl->next, &tbl->it_group_list);
>+
> 	table_group->tables[0] = tbl;
>
> 	return table_group;
>
> fail_exit:
>+	kfree(tgl);
> 	kfree(table_group);
> 	kfree(tbl);
>
>@@ -82,18 +93,33 @@ static void iommu_pseries_free_group(struct iommu_table_group *table_group,
> 		const char *node_name)
> {
> 	struct iommu_table *tbl;
>+	long i;
>
> 	if (!table_group)
> 		return;
>
>+	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
>+		tbl = table_group->tables[i];
>+
>+		if (tbl) {
>+#ifdef CONFIG_IOMMU_API
>+			struct iommu_table_group_link *tgl, *tmp;
>+
>+			list_for_each_entry_safe(tgl, tmp, &tbl->it_group_list,
>+					next) {
>+				list_del_rcu(&tgl->next);
>+				kfree(tgl);
>+			}
>+#endif
>+			iommu_free_table(tbl, node_name);
>+		}
>+	}
>+#ifdef CONFIG_IOMMU_API
> 	if (table_group->group) {
> 		iommu_group_put(table_group->group);
> 		BUG_ON(table_group->group);
> 	}
>-
>-	tbl = table_group->tables[0];
>-	iommu_free_table(tbl, node_name);
>-
>+#endif
> 	kfree(table_group);
> }
>
>diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
>index bd87e46..ed3310b 100644
>--- a/drivers/vfio/vfio_iommu_spapr_tce.c
>+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
>@@ -88,7 +88,7 @@ static void decrement_locked_vm(long npages)
>  */
> struct tce_container {
> 	struct mutex lock;
>-	struct iommu_table *tbl;
>+	struct iommu_group *grp;
> 	bool enabled;
> 	unsigned long locked_pages;
> };
>@@ -103,13 +103,42 @@ static bool tce_page_is_contained(struct page *page, unsigned page_shift)
> 	return (PAGE_SHIFT + compound_order(compound_head(page))) >= page_shift;
> }
>
>+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];
>+
>+		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_enable(struct tce_container *container)
> {
> 	int ret = 0;
> 	unsigned long locked;
>-	struct iommu_table *tbl = container->tbl;
>+	struct iommu_table *tbl;
>+	struct iommu_table_group *table_group;
>
>-	if (!container->tbl)
>+	if (!container->grp)
> 		return -ENXIO;
>
> 	if (!current->mm)
>@@ -143,6 +172,11 @@ static int tce_iommu_enable(struct tce_container *container)
> 	 * as this information is only available from KVM and VFIO is
> 	 * KVM agnostic.
> 	 */
>+	table_group = iommu_group_get_iommudata(container->grp);
>+	if (!table_group)
>+		return -ENODEV;
>+
>+	tbl = table_group->tables[0];
> 	locked = (tbl->it_size << tbl->it_page_shift) >> PAGE_SHIFT;
> 	ret = try_increment_locked_vm(locked);
> 	if (ret)
>@@ -190,11 +224,10 @@ static void tce_iommu_release(void *iommu_data)
> {
> 	struct tce_container *container = iommu_data;
>
>-	WARN_ON(container->tbl && !container->tbl->it_table_group->group);
>+	WARN_ON(container->grp);
>
>-	if (container->tbl && container->tbl->it_table_group->group)
>-		tce_iommu_detach_group(iommu_data,
>-				container->tbl->it_table_group->group);
>+	if (container->grp)
>+		tce_iommu_detach_group(iommu_data, container->grp);
>
> 	tce_iommu_disable(container);
> 	mutex_destroy(&container->lock);
>@@ -312,9 +345,16 @@ static long tce_iommu_ioctl(void *iommu_data,
>
> 	case VFIO_IOMMU_SPAPR_TCE_GET_INFO: {
> 		struct vfio_iommu_spapr_tce_info info;
>-		struct iommu_table *tbl = container->tbl;
>+		struct iommu_table *tbl;
>+		struct iommu_table_group *table_group;
>
>-		if (WARN_ON(!tbl))
>+		if (WARN_ON(!container->grp))
>+			return -ENXIO;
>+
>+		table_group = iommu_group_get_iommudata(container->grp);
>+
>+		tbl = table_group->tables[0];
>+		if (WARN_ON_ONCE(!tbl))
> 			return -ENXIO;
>
> 		minsz = offsetofend(struct vfio_iommu_spapr_tce_info,
>@@ -337,17 +377,13 @@ static long tce_iommu_ioctl(void *iommu_data,
> 	}
> 	case VFIO_IOMMU_MAP_DMA: {
> 		struct vfio_iommu_type1_dma_map param;
>-		struct iommu_table *tbl = container->tbl;
>+		struct iommu_table *tbl = NULL;
> 		unsigned long tce;
>+		long num;
>
> 		if (!container->enabled)
> 			return -EPERM;
>
>-		if (!tbl)
>-			return -ENXIO;
>-
>-		BUG_ON(!tbl->it_table_group->group);
>-
> 		minsz = offsetofend(struct vfio_iommu_type1_dma_map, size);
>
> 		if (copy_from_user(&param, (void __user *)arg, minsz))
>@@ -360,6 +396,10 @@ static long tce_iommu_ioctl(void *iommu_data,
> 				VFIO_DMA_MAP_FLAG_WRITE))
> 			return -EINVAL;
>
>+		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;
>@@ -385,14 +425,12 @@ static long tce_iommu_ioctl(void *iommu_data,
> 	}
> 	case VFIO_IOMMU_UNMAP_DMA: {
> 		struct vfio_iommu_type1_dma_unmap param;
>-		struct iommu_table *tbl = container->tbl;
>+		struct iommu_table *tbl = NULL;
>+		long num;
>
> 		if (!container->enabled)
> 			return -EPERM;
>
>-		if (WARN_ON(!tbl))
>-			return -ENXIO;
>-
> 		minsz = offsetofend(struct vfio_iommu_type1_dma_unmap,
> 				size);
>
>@@ -406,6 +444,10 @@ static long tce_iommu_ioctl(void *iommu_data,
> 		if (param.flags)
> 			return -EINVAL;
>
>+		num = tce_iommu_find_table(container, param.iova, &tbl);
>+		if (num < 0)
>+			return -ENXIO;
>+
> 		if (param.size & ~IOMMU_PAGE_MASK(tbl))
> 			return -EINVAL;
>
>@@ -434,12 +476,11 @@ static long tce_iommu_ioctl(void *iommu_data,
> 		mutex_unlock(&container->lock);
> 		return 0;
> 	case VFIO_EEH_PE_OP:
>-		if (!container->tbl || !container->tbl->it_table_group->group)
>+		if (!container->grp)
> 			return -ENODEV;
>
>-		return vfio_spapr_iommu_eeh_ioctl(
>-				container->tbl->it_table_group->group,
>-				cmd, arg);
>+		return vfio_spapr_iommu_eeh_ioctl(container->grp,
>+						  cmd, arg);
> 	}
>
> 	return -ENOTTY;
>@@ -450,17 +491,15 @@ static int tce_iommu_attach_group(void *iommu_data,
> {
> 	int ret;
> 	struct tce_container *container = iommu_data;
>-	struct iommu_table *tbl = iommu_group_get_iommudata(iommu_group);
>+	struct iommu_table_group *table_group;
>
>-	BUG_ON(!tbl);
> 	mutex_lock(&container->lock);
>
> 	/* pr_debug("tce_vfio: Attaching group #%u to iommu %p\n",
> 			iommu_group_id(iommu_group), iommu_group); */
>-	if (container->tbl) {
>+	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->tbl->
>-						it_table_group->group),
>+				iommu_group_id(container->grp),
> 				iommu_group_id(iommu_group));
> 		ret = -EBUSY;
> 		goto unlock_exit;
>@@ -473,9 +512,15 @@ static int tce_iommu_attach_group(void *iommu_data,
> 		goto unlock_exit;
> 	}
>
>-	ret = iommu_take_ownership(tbl);
>+	table_group = iommu_group_get_iommudata(iommu_group);
>+	if (!table_group) {
>+		ret = -ENXIO;
>+		goto unlock_exit;
>+	}
>+
>+	ret = iommu_take_ownership(table_group->tables[0]);
> 	if (!ret)
>-		container->tbl = tbl;
>+		container->grp = iommu_group;
>
> unlock_exit:
> 	mutex_unlock(&container->lock);
>@@ -487,26 +532,31 @@ static void tce_iommu_detach_group(void *iommu_data,
> 		struct iommu_group *iommu_group)
> {
> 	struct tce_container *container = iommu_data;
>-	struct iommu_table *tbl = iommu_group_get_iommudata(iommu_group);
>+	struct iommu_table_group *table_group;
>+	struct iommu_table *tbl;
>
>-	BUG_ON(!tbl);
> 	mutex_lock(&container->lock);
>-	if (tbl != container->tbl) {
>+	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(tbl->it_table_group->group));
>+				iommu_group_id(container->grp));
> 		goto unlock_exit;
> 	}
>
> 	if (container->enabled) {
> 		pr_warn("tce_vfio: detaching group #%u from enabled container, forcing disable\n",
>-				iommu_group_id(tbl->it_table_group->group));
>+				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->tbl = NULL;
>+	container->grp = NULL;
>+
>+	table_group = iommu_group_get_iommudata(iommu_group);
>+	BUG_ON(!table_group);
>+
>+	tbl = table_group->tables[0];
> 	tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
> 	iommu_release_ownership(tbl);
>
>-- 
>2.4.0.rc3.8.gfb3e7d5
>