From 03e96b8c11d140fb4ead0b30c2d6e1a294b501ef Mon Sep 17 00:00:00 2001 From: Mina Almasry Date: Thu, 8 May 2025 00:48:21 +0000 Subject: netmem: add niov->type attribute to distinguish different net_iov types Later patches in the series adds TX net_iovs where there is no pp associated, so we can't rely on niov->pp->mp_ops to tell what is the type of the net_iov. Add a type enum to the net_iov which tells us the net_iov type. Signed-off-by: Mina Almasry Link: https://patch.msgid.link/20250508004830.4100853-2-almasrymina@google.com Signed-off-by: Paolo Abeni --- io_uring/zcrx.c | 1 + 1 file changed, 1 insertion(+) (limited to 'io_uring') diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c index fe86606b9f30..a07ad38935c8 100644 --- a/io_uring/zcrx.c +++ b/io_uring/zcrx.c @@ -259,6 +259,7 @@ static int io_zcrx_create_area(struct io_zcrx_ifq *ifq, niov->owner = &area->nia; area->freelist[i] = i; atomic_set(&area->user_refs[i], 0); + niov->type = NET_IOV_IOURING; } area->free_count = nr_iovs; -- cgit v1.2.3 From bd61848900bff597764238f3a8ec67c815cd316e Mon Sep 17 00:00:00 2001 From: Mina Almasry Date: Thu, 8 May 2025 00:48:24 +0000 Subject: net: devmem: Implement TX path Augment dmabuf binding to be able to handle TX. Additional to all the RX binding, we also create tx_vec needed for the TX path. Provide API for sendmsg to be able to send dmabufs bound to this device: - Provide a new dmabuf_tx_cmsg which includes the dmabuf to send from. - MSG_ZEROCOPY with SCM_DEVMEM_DMABUF cmsg indicates send from dma-buf. Devmem is uncopyable, so piggyback off the existing MSG_ZEROCOPY implementation, while disabling instances where MSG_ZEROCOPY falls back to copying. We additionally pipe the binding down to the new zerocopy_fill_skb_from_devmem which fills a TX skb with net_iov netmems instead of the traditional page netmems. We also special case skb_frag_dma_map to return the dma-address of these dmabuf net_iovs instead of attempting to map pages. The TX path may release the dmabuf in a context where we cannot wait. This happens when the user unbinds a TX dmabuf while there are still references to its netmems in the TX path. In that case, the netmems will be put_netmem'd from a context where we can't unmap the dmabuf, Resolve this by making __net_devmem_dmabuf_binding_free schedule_work'd. Based on work by Stanislav Fomichev . A lot of the meat of the implementation came from devmem TCP RFC v1[1], which included the TX path, but Stan did all the rebasing on top of netmem/net_iov. Cc: Stanislav Fomichev Signed-off-by: Kaiyuan Zhang Signed-off-by: Mina Almasry Acked-by: Stanislav Fomichev Link: https://patch.msgid.link/20250508004830.4100853-5-almasrymina@google.com Signed-off-by: Paolo Abeni --- io_uring/zcrx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'io_uring') diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c index a07ad38935c8..0c64129f5d50 100644 --- a/io_uring/zcrx.c +++ b/io_uring/zcrx.c @@ -810,7 +810,7 @@ static int io_zcrx_recv_frag(struct io_kiocb *req, struct io_zcrx_ifq *ifq, return io_zcrx_copy_frag(req, ifq, frag, off, len); niov = netmem_to_net_iov(frag->netmem); - if (niov->pp->mp_ops != &io_uring_pp_zc_ops || + if (!niov->pp || niov->pp->mp_ops != &io_uring_pp_zc_ops || io_pp_to_ifq(niov->pp) != ifq) return -EFAULT; -- cgit v1.2.3