From: Ivan Malov ivan.malov@oktetlabs.ru
[ Upstream commit 512d1999b8e94a5d43fba3afc73e774849674742 ]
When a XSK pool gets mapped, xp_check_dma_contiguity() adds bit 0x1 to pages' DMA addresses that go in ascending order and at 4K stride.
The problem is that the bit does not get cleared before doing unmap. As a result, a lot of warnings from iommu_dma_unmap_page() are seen in dmesg, which indicates that lookups by iommu_iova_to_phys() fail.
Fixes: 2b43470add8c ("xsk: Introduce AF_XDP buffer allocation API") Signed-off-by: Ivan Malov ivan.malov@oktetlabs.ru Signed-off-by: Daniel Borkmann daniel@iogearbox.net Acked-by: Magnus Karlsson magnus.karlsson@intel.com Link: https://lore.kernel.org/bpf/20220628091848.534803-1-ivan.malov@oktetlabs.ru Signed-off-by: Sasha Levin sashal@kernel.org --- net/xdp/xsk_buff_pool.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c index fc7fbfc1e586..ccedbbd27692 100644 --- a/net/xdp/xsk_buff_pool.c +++ b/net/xdp/xsk_buff_pool.c @@ -326,6 +326,7 @@ static void __xp_dma_unmap(struct xsk_dma_map *dma_map, unsigned long attrs) for (i = 0; i < dma_map->dma_pages_cnt; i++) { dma = &dma_map->dma_pages[i]; if (*dma) { + *dma &= ~XSK_NEXT_PG_CONTIG_MASK; dma_unmap_page_attrs(dma_map->dev, *dma, PAGE_SIZE, DMA_BIDIRECTIONAL, attrs); *dma = 0;