| Message ID | 20230505184701.91613-1-gbatra@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 1f7aacc5eb9ed2cc17be7a90da5cd559effb9d59 |
| Headers | show |
| Series | iommu/powerpc: Incorrect DDW Table is referenced for SR-IOV device | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/github-powerpc_ppctests | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_selftests | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_sparse | success | Successfully ran 4 jobs. |
| snowpatch_ozlabs/github-powerpc_kernel_qemu | success | Successfully ran 24 jobs. |
| snowpatch_ozlabs/github-powerpc_clang | success | Successfully ran 6 jobs. |
On Fri, 05 May 2023 13:47:01 -0500, Gaurav Batra wrote: > 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() > > [...] Applied to powerpc/fixes. [1/1] iommu/powerpc: Incorrect DDW Table is referenced for SR-IOV device https://git.kernel.org/powerpc/c/1f7aacc5eb9ed2cc17be7a90da5cd559effb9d59 cheers
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); }
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(-) --