6.8-stable review patch. If anyone has any objections, please let me know.
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From: Nicolin Chen nicolinc@nvidia.com
[ Upstream commit afc5aa46ed560f01ceda897c053c6a40c77ce5c4 ]
The swiotlb does not support a mapping size > swiotlb_max_mapping_size(). On the other hand, with a 64KB PAGE_SIZE configuration, it's observed that an NVME device can map a size between 300KB~512KB, which certainly failed the swiotlb mappings, though the default pool of swiotlb has many slots: systemd[1]: Started Journal Service. => nvme 0000:00:01.0: swiotlb buffer is full (sz: 327680 bytes), total 32768 (slots), used 32 (slots) note: journal-offline[392] exited with irqs disabled note: journal-offline[392] exited with preempt_count 1
Call trace: [ 3.099918] swiotlb_tbl_map_single+0x214/0x240 [ 3.099921] iommu_dma_map_page+0x218/0x328 [ 3.099928] dma_map_page_attrs+0x2e8/0x3a0 [ 3.101985] nvme_prep_rq.part.0+0x408/0x878 [nvme] [ 3.102308] nvme_queue_rqs+0xc0/0x300 [nvme] [ 3.102313] blk_mq_flush_plug_list.part.0+0x57c/0x600 [ 3.102321] blk_add_rq_to_plug+0x180/0x2a0 [ 3.102323] blk_mq_submit_bio+0x4c8/0x6b8 [ 3.103463] __submit_bio+0x44/0x220 [ 3.103468] submit_bio_noacct_nocheck+0x2b8/0x360 [ 3.103470] submit_bio_noacct+0x180/0x6c8 [ 3.103471] submit_bio+0x34/0x130 [ 3.103473] ext4_bio_write_folio+0x5a4/0x8c8 [ 3.104766] mpage_submit_folio+0xa0/0x100 [ 3.104769] mpage_map_and_submit_buffers+0x1a4/0x400 [ 3.104771] ext4_do_writepages+0x6a0/0xd78 [ 3.105615] ext4_writepages+0x80/0x118 [ 3.105616] do_writepages+0x90/0x1e8 [ 3.105619] filemap_fdatawrite_wbc+0x94/0xe0 [ 3.105622] __filemap_fdatawrite_range+0x68/0xb8 [ 3.106656] file_write_and_wait_range+0x84/0x120 [ 3.106658] ext4_sync_file+0x7c/0x4c0 [ 3.106660] vfs_fsync_range+0x3c/0xa8 [ 3.106663] do_fsync+0x44/0xc0
Since untrusted devices might go down the swiotlb pathway with dma-iommu, these devices should not map a size larger than swiotlb_max_mapping_size.
To fix this bug, add iommu_dma_max_mapping_size() for untrusted devices to take into account swiotlb_max_mapping_size() v.s. iova_rcache_range() from the iommu_dma_opt_mapping_size().
Fixes: 82612d66d51d ("iommu: Allow the dma-iommu api to use bounce buffers") Link: https://lore.kernel.org/r/ee51a3a5c32cf885b18f6416171802669f4a718a.170785146... Signed-off-by: Nicolin Chen nicolinc@nvidia.com [will: Drop redundant is_swiotlb_active(dev) check] Signed-off-by: Will Deacon will@kernel.org Reviewed-by: Michael Kelley mhklinux@outlook.com Acked-by: Robin Murphy robin.murphy@arm.com Tested-by: Nicolin Chen nicolinc@nvidia.com Tested-by: Michael Kelley mhklinux@outlook.com Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/iommu/dma-iommu.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 50ccc4f1ef81c..639efa0c40721 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -1706,6 +1706,14 @@ static size_t iommu_dma_opt_mapping_size(void) return iova_rcache_range(); }
+static size_t iommu_dma_max_mapping_size(struct device *dev) +{ + if (dev_is_untrusted(dev)) + return swiotlb_max_mapping_size(dev); + + return SIZE_MAX; +} + static const struct dma_map_ops iommu_dma_ops = { .flags = DMA_F_PCI_P2PDMA_SUPPORTED, .alloc = iommu_dma_alloc, @@ -1728,6 +1736,7 @@ static const struct dma_map_ops iommu_dma_ops = { .unmap_resource = iommu_dma_unmap_resource, .get_merge_boundary = iommu_dma_get_merge_boundary, .opt_mapping_size = iommu_dma_opt_mapping_size, + .max_mapping_size = iommu_dma_max_mapping_size, };
/*