From: Gaurav Batra <gbatra@linux.vnet.ibm.com>
To: mpe@ellerman.id.au
Cc: brking@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org,
Gaurav Batra <gbatra@linux.vnet.ibm.com>,
gjoyce@linux.vnet.ibm.com
Subject: [PATCH] iommu/powerpc: Incorrect DDW Table is referenced for SR-IOV device
Date: Fri, 5 May 2023 13:47:01 -0500 [thread overview]
Message-ID: <20230505184701.91613-1-gbatra@linux.vnet.ibm.com> (raw)
For an SR-IOV device, while enabling DDW, a new table is created and added
at index 1 in the group. In the below 2 scenarios, the table is incorrectly
referenced at index 0 (which is where the table is for default DMA window).
1. When adding DDW
This issue is exposed with "slub_debug". Error thrown out from
dma_iommu_dma_supported()
Warning: IOMMU offset too big for device mask
mask: 0xffffffff, table offset: 0x800000000000000
2. During Dynamic removal of the PCI device.
Error is from iommu_tce_table_put() since a NULL table pointer is
passed in.
Fixes: 381ceda88c4c ("powerpc/pseries/iommu: Make use of DDW for indirect mapping")
Signed-off-by: Gaurav Batra <gbatra@linux.vnet.ibm.com>
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
---
arch/powerpc/kernel/dma-iommu.c | 4 +++-
arch/powerpc/platforms/pseries/iommu.c | 13 +++++++++----
2 files changed, 12 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/kernel/dma-iommu.c b/arch/powerpc/kernel/dma-iommu.c
index 038ce8d9061d..8920862ffd79 100644
--- a/arch/powerpc/kernel/dma-iommu.c
+++ b/arch/powerpc/kernel/dma-iommu.c
@@ -144,7 +144,7 @@ static bool dma_iommu_bypass_supported(struct device *dev, u64 mask)
/* We support DMA to/from any memory page via the iommu */
int dma_iommu_dma_supported(struct device *dev, u64 mask)
{
- struct iommu_table *tbl = get_iommu_table_base(dev);
+ struct iommu_table *tbl;
if (dev_is_pci(dev) && dma_iommu_bypass_supported(dev, mask)) {
/*
@@ -162,6 +162,8 @@ int dma_iommu_dma_supported(struct device *dev, u64 mask)
return 1;
}
+ tbl = get_iommu_table_base(dev);
+
if (!tbl) {
dev_err(dev, "Warning: IOMMU dma not supported: mask 0x%08llx, table unavailable\n", mask);
return 0;
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index c74b71d4733d..a8acd3b402d7 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -85,19 +85,24 @@ static struct iommu_table_group *iommu_pseries_alloc_group(int node)
static void iommu_pseries_free_group(struct iommu_table_group *table_group,
const char *node_name)
{
- struct iommu_table *tbl;
-
if (!table_group)
return;
- tbl = table_group->tables[0];
#ifdef CONFIG_IOMMU_API
if (table_group->group) {
iommu_group_put(table_group->group);
BUG_ON(table_group->group);
}
#endif
- iommu_tce_table_put(tbl);
+
+ /* Default DMA window table is at index 0, while DDW at 1. SR-IOV
+ * adapters only have table on index 1.
+ */
+ if (table_group->tables[0])
+ iommu_tce_table_put(table_group->tables[0]);
+
+ if (table_group->tables[1])
+ iommu_tce_table_put(table_group->tables[1]);
kfree(table_group);
}
--
next reply other threads:[~2023-05-05 18:48 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-05 18:47 Gaurav Batra [this message]
2023-07-03 5:21 ` [PATCH] iommu/powerpc: Incorrect DDW Table is referenced for SR-IOV device Michael Ellerman
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