[PATCH kernel v12 28/34] vfio: powerpc/spapr: powerpc/powernv/ioda: Define and implement DMA windows API

From: Alexey Kardashevskiy
Date: Fri Jun 05 2015 - 02:39:37 EST


This extends iommu_table_group_ops by a set of callbacks to support
dynamic DMA windows management.

create_table() creates a TCE table with specific parameters.
it receives iommu_table_group to know nodeid in order to allocate
TCE table memory closer to the PHB. The exact format of allocated
multi-level table might be also specific to the PHB model (not
the case now though).
This callback calculated the DMA window offset on a PCI bus from @num
and stores it in a just created table.

set_window() sets the window at specified TVT index + @num on PHB.

unset_window() unsets the window from specified TVT.

This adds a free() callback to iommu_table_ops to free the memory
(potentially a tree of tables) allocated for the TCE table.

create_table() and free() are supposed to be called once per
VFIO container and set_window()/unset_window() are supposed to be
called for every group in a container.

This adds IOMMU capabilities to iommu_table_group such as default
32bit window parameters and others. This makes use of new values in
vfio_iommu_spapr_tce. IODA1/P5IOC2 do not support DDW so they do not
advertise pagemasks to the userspace.

Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx>
Acked-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
Reviewed-by: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>
---
Changes:
v10:
* squashed "vfio: powerpc/spapr: Use 32bit DMA window properties from table_group"
into this
* shortened the subject

v9:
* new in the series - to make the next patch simpler
---
arch/powerpc/include/asm/iommu.h | 19 ++++++
arch/powerpc/platforms/powernv/pci-ioda.c | 96 ++++++++++++++++++++++++++---
arch/powerpc/platforms/powernv/pci-p5ioc2.c | 7 ++-
drivers/vfio/vfio_iommu_spapr_tce.c | 19 +++---
4 files changed, 124 insertions(+), 17 deletions(-)

diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
index 706cfc0..e554175 100644
--- a/arch/powerpc/include/asm/iommu.h
+++ b/arch/powerpc/include/asm/iommu.h
@@ -70,6 +70,7 @@ struct iommu_table_ops {
/* get() returns a physical address */
unsigned long (*get)(struct iommu_table *tbl, long index);
void (*flush)(struct iommu_table *tbl);
+ void (*free)(struct iommu_table *tbl);
};

/* These are used by VIO */
@@ -146,6 +147,17 @@ extern struct iommu_table *iommu_init_table(struct iommu_table * tbl,
struct iommu_table_group;

struct iommu_table_group_ops {
+ long (*create_table)(struct iommu_table_group *table_group,
+ int num,
+ __u32 page_shift,
+ __u64 window_size,
+ __u32 levels,
+ struct iommu_table **ptbl);
+ long (*set_window)(struct iommu_table_group *table_group,
+ int num,
+ struct iommu_table *tblnew);
+ long (*unset_window)(struct iommu_table_group *table_group,
+ int num);
/* Switch ownership from platform code to external user (e.g. VFIO) */
void (*take_ownership)(struct iommu_table_group *table_group);
/* Switch ownership from external user (e.g. VFIO) back to core */
@@ -159,6 +171,13 @@ struct iommu_table_group_link {
};

struct iommu_table_group {
+ /* IOMMU properties */
+ __u32 tce32_start;
+ __u32 tce32_size;
+ __u64 pgsizes; /* Bitmap of supported page sizes */
+ __u32 max_dynamic_windows_supported;
+ __u32 max_levels;
+
struct iommu_group *group;
struct iommu_table *tables[IOMMU_TABLE_GROUP_MAX_TABLES];
struct iommu_table_group_ops *ops;
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index a253dda..ace0302 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -25,6 +25,7 @@
#include <linux/memblock.h>
#include <linux/iommu.h>
#include <linux/rculist.h>
+#include <linux/sizes.h>

#include <asm/sections.h>
#include <asm/io.h>
@@ -1869,6 +1870,12 @@ static void pnv_ioda2_tce_free(struct iommu_table *tbl, long index,
pnv_pci_ioda2_tce_invalidate(tbl, index, npages, false);
}

+static void pnv_ioda2_table_free(struct iommu_table *tbl)
+{
+ pnv_pci_ioda2_table_free_pages(tbl);
+ iommu_free_table(tbl, "pnv");
+}
+
static struct iommu_table_ops pnv_ioda2_iommu_ops = {
.set = pnv_ioda2_tce_build,
#ifdef CONFIG_IOMMU_API
@@ -1876,6 +1883,7 @@ static struct iommu_table_ops pnv_ioda2_iommu_ops = {
#endif
.clear = pnv_ioda2_tce_free,
.get = pnv_tce_get,
+ .free = pnv_ioda2_table_free,
};

static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb,
@@ -1946,6 +1954,8 @@ static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb,
TCE_PCI_SWINV_PAIR);

tbl->it_ops = &pnv_ioda1_iommu_ops;
+ pe->table_group.tce32_start = tbl->it_offset << tbl->it_page_shift;
+ pe->table_group.tce32_size = tbl->it_size << tbl->it_page_shift;
iommu_init_table(tbl, phb->hose->node);

if (pe->flags & PNV_IODA_PE_DEV) {
@@ -1984,7 +1994,7 @@ static long pnv_pci_ioda2_set_window(struct iommu_table_group *table_group,
const __u64 start_addr = tbl->it_offset << tbl->it_page_shift;
const __u64 win_size = tbl->it_size << tbl->it_page_shift;

- pe_info(pe, "Setting up window %llx..%llx pg=%x\n",
+ pe_info(pe, "Setting up window#%d %llx..%llx pg=%x\n", num,
start_addr, start_addr + win_size - 1,
IOMMU_PAGE_SIZE(tbl));

@@ -1994,7 +2004,7 @@ static long pnv_pci_ioda2_set_window(struct iommu_table_group *table_group,
*/
rc = opal_pci_map_pe_dma_window(phb->opal_id,
pe->pe_number,
- pe->pe_number << 1,
+ (pe->pe_number << 1) + num,
tbl->it_indirect_levels + 1,
__pa(tbl->it_base),
size << 3,
@@ -2039,7 +2049,67 @@ static void pnv_pci_ioda2_set_bypass(struct pnv_ioda_pe *pe, bool enable)
pe->tce_bypass_enabled = enable;
}

+static long pnv_pci_ioda2_table_alloc_pages(int nid, __u64 bus_offset,
+ __u32 page_shift, __u64 window_size, __u32 levels,
+ struct iommu_table *tbl);
+
+static long pnv_pci_ioda2_create_table(struct iommu_table_group *table_group,
+ int num, __u32 page_shift, __u64 window_size, __u32 levels,
+ struct iommu_table **ptbl)
+{
+ struct pnv_ioda_pe *pe = container_of(table_group, struct pnv_ioda_pe,
+ table_group);
+ int nid = pe->phb->hose->node;
+ __u64 bus_offset = num ? pe->tce_bypass_base : table_group->tce32_start;
+ long ret;
+ struct iommu_table *tbl;
+
+ tbl = pnv_pci_table_alloc(nid);
+ if (!tbl)
+ return -ENOMEM;
+
+ ret = pnv_pci_ioda2_table_alloc_pages(nid,
+ bus_offset, page_shift, window_size,
+ levels, tbl);
+ if (ret) {
+ iommu_free_table(tbl, "pnv");
+ return ret;
+ }
+
+ tbl->it_ops = &pnv_ioda2_iommu_ops;
+ if (pe->phb->ioda.tce_inval_reg)
+ tbl->it_type |= (TCE_PCI_SWINV_CREATE | TCE_PCI_SWINV_FREE);
+
+ *ptbl = tbl;
+
+ return 0;
+}
+
#ifdef CONFIG_IOMMU_API
+static long pnv_pci_ioda2_unset_window(struct iommu_table_group *table_group,
+ int num)
+{
+ struct pnv_ioda_pe *pe = container_of(table_group, struct pnv_ioda_pe,
+ table_group);
+ struct pnv_phb *phb = pe->phb;
+ long ret;
+
+ pe_info(pe, "Removing DMA window #%d\n", num);
+
+ ret = opal_pci_map_pe_dma_window(phb->opal_id, pe->pe_number,
+ (pe->pe_number << 1) + num,
+ 0/* levels */, 0/* table address */,
+ 0/* table size */, 0/* page size */);
+ if (ret)
+ pe_warn(pe, "Unmapping failed, ret = %ld\n", ret);
+ else
+ pnv_pci_ioda2_tce_invalidate_entire(pe);
+
+ pnv_pci_unlink_table_and_group(table_group->tables[num], table_group);
+
+ return ret;
+}
+
static void pnv_ioda2_take_ownership(struct iommu_table_group *table_group)
{
struct pnv_ioda_pe *pe = container_of(table_group, struct pnv_ioda_pe,
@@ -2059,6 +2129,9 @@ static void pnv_ioda2_release_ownership(struct iommu_table_group *table_group)
}

static struct iommu_table_group_ops pnv_pci_ioda2_ops = {
+ .create_table = pnv_pci_ioda2_create_table,
+ .set_window = pnv_pci_ioda2_set_window,
+ .unset_window = pnv_pci_ioda2_unset_window,
.take_ownership = pnv_ioda2_take_ownership,
.release_ownership = pnv_ioda2_release_ownership,
};
@@ -2213,7 +2286,7 @@ static void pnv_pci_ioda2_table_free_pages(struct iommu_table *tbl)
static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
struct pnv_ioda_pe *pe)
{
- struct iommu_table *tbl;
+ struct iommu_table *tbl = NULL;
int64_t rc;

/* We shouldn't already have a 32-bit DMA associated */
@@ -2223,10 +2296,8 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
/* TVE #1 is selected by PCI address bit 59 */
pe->tce_bypass_base = 1ull << 59;

- 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;
@@ -2234,13 +2305,22 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
phb->ioda.m32_pci_base);

/* Setup linux iommu table */
- rc = pnv_pci_ioda2_table_alloc_pages(pe->phb->hose->node,
- 0, IOMMU_PAGE_SHIFT_4K, phb->ioda.m32_pci_base,
- POWERNV_IOMMU_DEFAULT_LEVELS, tbl);
+ pe->table_group.tce32_start = 0;
+ pe->table_group.tce32_size = phb->ioda.m32_pci_base;
+ pe->table_group.max_dynamic_windows_supported =
+ IOMMU_TABLE_GROUP_MAX_TABLES;
+ pe->table_group.max_levels = POWERNV_IOMMU_MAX_LEVELS;
+ pe->table_group.pgsizes = SZ_4K | SZ_64K | SZ_16M;
+
+ rc = pnv_pci_ioda2_create_table(&pe->table_group, 0,
+ IOMMU_PAGE_SHIFT_4K,
+ pe->table_group.tce32_size,
+ POWERNV_IOMMU_DEFAULT_LEVELS, &tbl);
if (rc) {
pe_err(pe, "Failed to create 32-bit TCE table, err %ld", rc);
goto fail;
}
+ pnv_pci_link_table_and_group(phb->hose->node, 0, tbl, &pe->table_group);

tbl->it_ops = &pnv_ioda2_iommu_ops;
iommu_init_table(tbl, phb->hose->node);
diff --git a/arch/powerpc/platforms/powernv/pci-p5ioc2.c b/arch/powerpc/platforms/powernv/pci-p5ioc2.c
index 94c880c..a295660 100644
--- a/arch/powerpc/platforms/powernv/pci-p5ioc2.c
+++ b/arch/powerpc/platforms/powernv/pci-p5ioc2.c
@@ -119,6 +119,8 @@ static void __init pnv_pci_init_p5ioc2_phb(struct device_node *np, u64 hub_id,
u64 phb_id;
int64_t rc;
static int primary = 1;
+ struct iommu_table_group *table_group;
+ struct iommu_table *tbl;

pr_info(" Initializing p5ioc2 PHB %s\n", np->full_name);

@@ -193,7 +195,10 @@ static void __init pnv_pci_init_p5ioc2_phb(struct device_node *np, u64 hub_id,
* hotplug or SRIOV on P5IOC2 and therefore iommu_free_table()
* should not be called for phb->p5ioc2.table_group.tables[0] ever.
*/
- phb->p5ioc2.table_group.tables[0] = &phb->p5ioc2.iommu_table;
+ tbl = phb->p5ioc2.table_group.tables[0] = &phb->p5ioc2.iommu_table;
+ table_group = &phb->p5ioc2.table_group;
+ table_group->tce32_start = tbl->it_offset << tbl->it_page_shift;
+ table_group->tce32_size = tbl->it_size << tbl->it_page_shift;
}

void __init pnv_pci_init_p5ioc2_hub(struct device_node *np)
diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
index a9e2d13..6d919eb 100644
--- a/drivers/vfio/vfio_iommu_spapr_tce.c
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -135,7 +135,6 @@ static int tce_iommu_enable(struct tce_container *container)
{
int ret = 0;
unsigned long locked;
- struct iommu_table *tbl;
struct iommu_table_group *table_group;

if (!container->grp)
@@ -171,13 +170,19 @@ static int tce_iommu_enable(struct tce_container *container)
* 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.
*/
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;
+ if (!table_group->tce32_size)
+ return -EPERM;
+
+ locked = table_group->tce32_size >> PAGE_SHIFT;
ret = try_increment_locked_vm(locked);
if (ret)
return ret;
@@ -350,7 +355,6 @@ 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;
struct iommu_table_group *table_group;

if (WARN_ON(!container->grp))
@@ -358,8 +362,7 @@ static long tce_iommu_ioctl(void *iommu_data,

table_group = iommu_group_get_iommudata(container->grp);

- tbl = table_group->tables[0];
- if (WARN_ON_ONCE(!tbl))
+ if (!table_group)
return -ENXIO;

minsz = offsetofend(struct vfio_iommu_spapr_tce_info,
@@ -371,8 +374,8 @@ static long tce_iommu_ioctl(void *iommu_data,
if (info.argsz < minsz)
return -EINVAL;

- info.dma32_window_start = tbl->it_offset << tbl->it_page_shift;
- info.dma32_window_size = tbl->it_size << tbl->it_page_shift;
+ info.dma32_window_start = table_group->tce32_start;
+ info.dma32_window_size = table_group->tce32_size;
info.flags = 0;

if (copy_to_user((void __user *)arg, &info, minsz))
--
2.4.0.rc3.8.gfb3e7d5

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