On 03.02.15 01:12, Alex Williamson wrote:

On Thu, 2015-01-29 at 20:21 +1100, Alexey Kardashevskiy wrote:

quoted

Modern IBM POWERPC systems support multiple (currently two) TCE tables
per IOMMU group (a.k.a. PE). This adds a powerpc_iommu container
for TCE tables. Right now just one table is supported.

Signed-off-by: Alexey Kardashevskiy <redacted>
---
 arch/powerpc/include/asm/iommu.h            |  18 ++--
 arch/powerpc/kernel/eeh.c                   |   2 +-
 arch/powerpc/kernel/iommu.c                 |  34 ++++----
 arch/powerpc/platforms/powernv/pci-ioda.c   |  37 +++++---
 arch/powerpc/platforms/powernv/pci-p5ioc2.c |  16 ++--
 arch/powerpc/platforms/powernv/pci.c        |   2 +-
 arch/powerpc/platforms/powernv/pci.h        |   4 +-
 arch/powerpc/platforms/pseries/iommu.c      |   9 +-
 drivers/vfio/vfio_iommu_spapr_tce.c         | 131 ++++++++++++++++++++--------
 9 files changed, 170 insertions(+), 83 deletions(-)

[snip]

quoted

diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
index 29d5708..28909e1 100644
--- a/drivers/vfio/vfio_iommu_spapr_tce.c
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c

@@ -84,7 +84,7 @@ static void decrement_locked_vm(long npages)
  */
 struct tce_container {
 	struct mutex lock;
-	struct iommu_table *tbl;
+	struct iommu_group *grp;
 	bool enabled;
 };
 

@@ -104,16 +104,40 @@ static bool tce_check_page_size(struct page *page, unsigned page_shift)
 	return false;
 }
 
+static struct iommu_table *spapr_tce_find_table(
+		struct tce_container *container,
+		phys_addr_t ioba)
+{
+	long i;
+	struct iommu_table *ret = NULL;
+	struct powerpc_iommu *iommu = iommu_group_get_iommudata(container->grp);
+
+	mutex_lock(&container->lock);
+	for (i = 0; i < POWERPC_IOMMU_MAX_TABLES; ++i) {
+		struct iommu_table *tbl = &iommu->tables[i];
+		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)) {
+			ret = tbl;
+			break;
+		}
+	}
+	mutex_unlock(&container->lock);
+
+	return ret;
+}
+
 static int tce_iommu_enable(struct tce_container *container)
 {
 	int ret = 0;
+	struct powerpc_iommu *iommu;
+	struct iommu_table *tbl;
 
-	if (!container->tbl)
+	if (!container->grp)
 		return -ENXIO;
 
-	if (!current->mm)
-		return -ESRCH; /* process exited */
-
 	if (container->enabled)
 		return -EBUSY;
 

@@ -142,7 +166,12 @@ static int tce_iommu_enable(struct tce_container *container)
 	 * as this information is only available from KVM and VFIO is
 	 * KVM agnostic.
 	 */
-	ret = try_increment_locked_vm(IOMMU_TABLE_PAGES(container->tbl));
+	iommu = iommu_group_get_iommudata(container->grp);
+	if (!iommu)
+		return -EFAULT;
+
+	tbl = &iommu->tables[0];

There should probably be a comment somewhere documenting that tables[0]
is the small window and presumably [1] will be the DDW.

Rather than a comment, how about an enum?


Alex