| Message ID | 20250415224756.152002-4-almasrymina@google.com |
|---|---|
| State | New |
| Headers | show |
| Series | None | expand |
On 04/15, Mina Almasry wrote: > 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 <sdf@fomichev.me>. 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 <sdf@fomichev.me> > Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> > Signed-off-by: Mina Almasry <almasrymina@google.com> > Acked-by: Stanislav Fomichev <sdf@fomichev.me> > > --- > > v8: > - move adding the binding to the net_devmem_dmabuf_bindings after it's > been fully initialized to eliminate potential for races with send path > (Stan). > - Use net_devmem_get_by_index_lock instead of rtnl_locking > > v6: > - Retain behavior that MSG_FASTOPEN succeeds even if cmsg is invalid > (Paolo). > - Rework the freeing of tx_vec slightly to improve readability. Now it > has its own err label (Paolo). > - Squash making unbinding scheduled work (Paolo). > - Add comment to clarify that net_iovs stuck in the transmit path hold > a ref on the underlying dmabuf binding (David). > - Fix the comment on how binding refcounting works on RX (the comment > was not matching the existing code behavior). > > v5: > - Return -EFAULT from zerocopy_fill_skb_from_devmem (Stan) > - don't null check before kvfree (stan). > > v4: > - Remove dmabuf_tx_cmsg definition and just use __u32 for the dma-buf id > (Willem). > - Check that iov_iter_type() is ITER_IOVEC in > zerocopy_fill_skb_from_iter() (Pavel). > - Fix binding->tx_vec not being freed on error paths (Paolo). > - Make devmem patch mutually exclusive with msg->ubuf_info path (Pavel). > - Check that MSG_ZEROCOPY and SOCK_ZEROCOPY are provided when > sockc.dmabuf_id is provided. > - Don't mm_account_pinned_pages() on devmem TX (Pavel). > > v3: > - Use kvmalloc_array instead of kcalloc (Stan). > - Fix unreachable code warning (Simon). > > v2: > - Remove dmabuf_offset from the dmabuf cmsg. > - Update zerocopy_fill_skb_from_devmem to interpret the > iov_base/iter_iov_addr as the offset into the dmabuf to send from > (Stan). > - Remove the confusing binding->tx_iter which is not needed if we > interpret the iov_base/iter_iov_addr as offset into the dmabuf (Stan). > - Remove check for binding->sgt and binding->sgt->nents in dmabuf > binding. > - Simplify the calculation of binding->tx_vec. > - Check in net_devmem_get_binding that the binding we're returning > has ifindex matching the sending socket (Willem). > --- > include/linux/skbuff.h | 17 +++- > include/net/sock.h | 1 + > net/core/datagram.c | 48 ++++++++- > net/core/devmem.c | 127 ++++++++++++++++++++---- > net/core/devmem.h | 61 ++++++++++-- > net/core/netdev-genl.c | 62 +++++++++++- > net/core/skbuff.c | 18 ++-- > net/core/sock.c | 6 ++ > net/ipv4/ip_output.c | 3 +- > net/ipv4/tcp.c | 50 ++++++++-- > net/ipv6/ip6_output.c | 3 +- > net/vmw_vsock/virtio_transport_common.c | 5 +- > 12 files changed, 338 insertions(+), 63 deletions(-) > > diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h > index f1381aff0f89..10dc0a439108 100644 > --- a/include/linux/skbuff.h > +++ b/include/linux/skbuff.h > @@ -1710,13 +1710,16 @@ static inline void skb_set_end_offset(struct sk_buff *skb, unsigned int offset) > extern const struct ubuf_info_ops msg_zerocopy_ubuf_ops; > > struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size, > - struct ubuf_info *uarg); > + struct ubuf_info *uarg, bool devmem); > > void msg_zerocopy_put_abort(struct ubuf_info *uarg, bool have_uref); > > +struct net_devmem_dmabuf_binding; > + > int __zerocopy_sg_from_iter(struct msghdr *msg, struct sock *sk, > struct sk_buff *skb, struct iov_iter *from, > - size_t length); > + size_t length, > + struct net_devmem_dmabuf_binding *binding); > > int zerocopy_fill_skb_from_iter(struct sk_buff *skb, > struct iov_iter *from, size_t length); > @@ -1724,12 +1727,14 @@ int zerocopy_fill_skb_from_iter(struct sk_buff *skb, > static inline int skb_zerocopy_iter_dgram(struct sk_buff *skb, > struct msghdr *msg, int len) > { > - return __zerocopy_sg_from_iter(msg, skb->sk, skb, &msg->msg_iter, len); > + return __zerocopy_sg_from_iter(msg, skb->sk, skb, &msg->msg_iter, len, > + NULL); > } > > int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb, > struct msghdr *msg, int len, > - struct ubuf_info *uarg); > + struct ubuf_info *uarg, > + struct net_devmem_dmabuf_binding *binding); > > /* Internal */ > #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB))) > @@ -3700,6 +3705,10 @@ static inline dma_addr_t __skb_frag_dma_map(struct device *dev, > size_t offset, size_t size, > enum dma_data_direction dir) > { > + if (skb_frag_is_net_iov(frag)) { > + return netmem_to_net_iov(frag->netmem)->dma_addr + offset + > + frag->offset; > + } > return dma_map_page(dev, skb_frag_page(frag), > skb_frag_off(frag) + offset, size, dir); > } > diff --git a/include/net/sock.h b/include/net/sock.h > index bb4d6189292f..5cb10cc0ca6e 100644 > --- a/include/net/sock.h > +++ b/include/net/sock.h > @@ -1851,6 +1851,7 @@ struct sockcm_cookie { > u32 tsflags; > u32 ts_opt_id; > u32 priority; > + u32 dmabuf_id; > }; > > static inline void sockcm_init(struct sockcm_cookie *sockc, > diff --git a/net/core/datagram.c b/net/core/datagram.c > index f0634f0cb834..042a7dceb85a 100644 > --- a/net/core/datagram.c > +++ b/net/core/datagram.c > @@ -63,6 +63,8 @@ > #include <net/busy_poll.h> > #include <crypto/hash.h> > > +#include "devmem.h" > + > /* > * Is a socket 'connection oriented' ? > */ > @@ -691,9 +693,49 @@ int zerocopy_fill_skb_from_iter(struct sk_buff *skb, > return 0; > } > > +static int > +zerocopy_fill_skb_from_devmem(struct sk_buff *skb, struct iov_iter *from, > + int length, > + struct net_devmem_dmabuf_binding *binding) > +{ > + int i = skb_shinfo(skb)->nr_frags; > + size_t virt_addr, size, off; > + struct net_iov *niov; > + > + /* Devmem filling works by taking an IOVEC from the user where the > + * iov_addrs are interpreted as an offset in bytes into the dma-buf to > + * send from. We do not support other iter types. > + */ > + if (iov_iter_type(from) != ITER_IOVEC) > + return -EFAULT; > + > + while (length && iov_iter_count(from)) { > + if (i == MAX_SKB_FRAGS) > + return -EMSGSIZE; > + > + virt_addr = (size_t)iter_iov_addr(from); > + niov = net_devmem_get_niov_at(binding, virt_addr, &off, &size); > + if (!niov) > + return -EFAULT; > + > + size = min_t(size_t, size, length); > + size = min_t(size_t, size, iter_iov_len(from)); > + > + get_netmem(net_iov_to_netmem(niov)); > + skb_add_rx_frag_netmem(skb, i, net_iov_to_netmem(niov), off, > + size, PAGE_SIZE); > + iov_iter_advance(from, size); > + length -= size; > + i++; > + } > + > + return 0; > +} > + > int __zerocopy_sg_from_iter(struct msghdr *msg, struct sock *sk, > struct sk_buff *skb, struct iov_iter *from, > - size_t length) > + size_t length, > + struct net_devmem_dmabuf_binding *binding) > { > unsigned long orig_size = skb->truesize; > unsigned long truesize; > @@ -701,6 +743,8 @@ int __zerocopy_sg_from_iter(struct msghdr *msg, struct sock *sk, > > if (msg && msg->msg_ubuf && msg->sg_from_iter) > ret = msg->sg_from_iter(skb, from, length); > + else if (unlikely(binding)) > + ret = zerocopy_fill_skb_from_devmem(skb, from, length, binding); > else > ret = zerocopy_fill_skb_from_iter(skb, from, length); > > @@ -734,7 +778,7 @@ int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *from) > if (skb_copy_datagram_from_iter(skb, 0, from, copy)) > return -EFAULT; > > - return __zerocopy_sg_from_iter(NULL, NULL, skb, from, ~0U); > + return __zerocopy_sg_from_iter(NULL, NULL, skb, from, ~0U, NULL); > } > EXPORT_SYMBOL(zerocopy_sg_from_iter); > > diff --git a/net/core/devmem.c b/net/core/devmem.c > index dca2ff7cf692..9599a82990e6 100644 > --- a/net/core/devmem.c > +++ b/net/core/devmem.c > @@ -16,6 +16,7 @@ > #include <net/netdev_rx_queue.h> > #include <net/page_pool/helpers.h> > #include <net/page_pool/memory_provider.h> > +#include <net/sock.h> > #include <trace/events/page_pool.h> > > #include "devmem.h" > @@ -52,8 +53,10 @@ static dma_addr_t net_devmem_get_dma_addr(const struct net_iov *niov) > ((dma_addr_t)net_iov_idx(niov) << PAGE_SHIFT); > } > > -void __net_devmem_dmabuf_binding_free(struct net_devmem_dmabuf_binding *binding) > +void __net_devmem_dmabuf_binding_free(struct work_struct *wq) > { > + struct net_devmem_dmabuf_binding *binding = container_of(wq, typeof(*binding), unbind_w); > + > size_t size, avail; > > gen_pool_for_each_chunk(binding->chunk_pool, > @@ -71,8 +74,10 @@ void __net_devmem_dmabuf_binding_free(struct net_devmem_dmabuf_binding *binding) > dma_buf_detach(binding->dmabuf, binding->attachment); > dma_buf_put(binding->dmabuf); > xa_destroy(&binding->bound_rxqs); > + kvfree(binding->tx_vec); > kfree(binding); > } > +EXPORT_SYMBOL(__net_devmem_dmabuf_binding_free); > > struct net_iov * > net_devmem_alloc_dmabuf(struct net_devmem_dmabuf_binding *binding) > @@ -117,6 +122,13 @@ void net_devmem_unbind_dmabuf(struct net_devmem_dmabuf_binding *binding) > unsigned long xa_idx; > unsigned int rxq_idx; > > + xa_erase(&net_devmem_dmabuf_bindings, binding->id); > + > + /* Ensure no tx net_devmem_lookup_dmabuf() are in flight after the > + * erase. > + */ > + synchronize_net(); > + > if (binding->list.next) > list_del(&binding->list); > > @@ -131,8 +143,6 @@ void net_devmem_unbind_dmabuf(struct net_devmem_dmabuf_binding *binding) > __net_mp_close_rxq(binding->dev, rxq_idx, &mp_params); > } > > - xa_erase(&net_devmem_dmabuf_bindings, binding->id); > - > net_devmem_dmabuf_binding_put(binding); > } > > @@ -166,8 +176,9 @@ int net_devmem_bind_dmabuf_to_queue(struct net_device *dev, u32 rxq_idx, > } > > struct net_devmem_dmabuf_binding * > -net_devmem_bind_dmabuf(struct net_device *dev, unsigned int dmabuf_fd, > - struct netlink_ext_ack *extack) > +net_devmem_bind_dmabuf(struct net_device *dev, > + enum dma_data_direction direction, > + unsigned int dmabuf_fd, struct netlink_ext_ack *extack) > { > struct net_devmem_dmabuf_binding *binding; > static u32 id_alloc_next; > @@ -189,43 +200,44 @@ net_devmem_bind_dmabuf(struct net_device *dev, unsigned int dmabuf_fd, > } > > binding->dev = dev; > - > - err = xa_alloc_cyclic(&net_devmem_dmabuf_bindings, &binding->id, > - binding, xa_limit_32b, &id_alloc_next, > - GFP_KERNEL); > - if (err < 0) > - goto err_free_binding; > - > xa_init_flags(&binding->bound_rxqs, XA_FLAGS_ALLOC); > - > refcount_set(&binding->ref, 1); > - > binding->dmabuf = dmabuf; > > binding->attachment = dma_buf_attach(binding->dmabuf, dev->dev.parent); > if (IS_ERR(binding->attachment)) { > err = PTR_ERR(binding->attachment); > NL_SET_ERR_MSG(extack, "Failed to bind dmabuf to device"); > - goto err_free_id; > + goto err_free_binding; > } > > binding->sgt = dma_buf_map_attachment_unlocked(binding->attachment, > - DMA_FROM_DEVICE); > + direction); > if (IS_ERR(binding->sgt)) { > err = PTR_ERR(binding->sgt); > NL_SET_ERR_MSG(extack, "Failed to map dmabuf attachment"); > goto err_detach; > } > > + if (direction == DMA_TO_DEVICE) { > + binding->tx_vec = kvmalloc_array(dmabuf->size / PAGE_SIZE, > + sizeof(struct net_iov *), > + GFP_KERNEL); > + if (!binding->tx_vec) { > + err = -ENOMEM; > + goto err_unmap; > + } > + } > + > /* For simplicity we expect to make PAGE_SIZE allocations, but the > * binding can be much more flexible than that. We may be able to > * allocate MTU sized chunks here. Leave that for future work... > */ > - binding->chunk_pool = > - gen_pool_create(PAGE_SHIFT, dev_to_node(&dev->dev)); > + binding->chunk_pool = gen_pool_create(PAGE_SHIFT, > + dev_to_node(&dev->dev)); > if (!binding->chunk_pool) { > err = -ENOMEM; > - goto err_unmap; > + goto err_tx_vec; > } > > virtual = 0; > @@ -270,24 +282,35 @@ net_devmem_bind_dmabuf(struct net_device *dev, unsigned int dmabuf_fd, > niov->owner = &owner->area; > page_pool_set_dma_addr_netmem(net_iov_to_netmem(niov), > net_devmem_get_dma_addr(niov)); > + if (direction == DMA_TO_DEVICE) > + binding->tx_vec[owner->area.base_virtual / PAGE_SIZE + i] = niov; > } > > virtual += len; > } > > + err = xa_alloc_cyclic(&net_devmem_dmabuf_bindings, &binding->id, > + binding, xa_limit_32b, &id_alloc_next, > + GFP_KERNEL); > + if (err < 0) > + goto err_free_id; > + > + > return binding; > > +err_free_id: > + xa_erase(&net_devmem_dmabuf_bindings, binding->id); > err_free_chunks: > gen_pool_for_each_chunk(binding->chunk_pool, > net_devmem_dmabuf_free_chunk_owner, NULL); > gen_pool_destroy(binding->chunk_pool); > +err_tx_vec: > + kvfree(binding->tx_vec); > err_unmap: > dma_buf_unmap_attachment_unlocked(binding->attachment, binding->sgt, > DMA_FROM_DEVICE); > err_detach: > dma_buf_detach(dmabuf, binding->attachment); > -err_free_id: > - xa_erase(&net_devmem_dmabuf_bindings, binding->id); > err_free_binding: > kfree(binding); > err_put_dmabuf: > @@ -295,6 +318,21 @@ net_devmem_bind_dmabuf(struct net_device *dev, unsigned int dmabuf_fd, > return ERR_PTR(err); > } > > +struct net_devmem_dmabuf_binding *net_devmem_lookup_dmabuf(u32 id) > +{ > + struct net_devmem_dmabuf_binding *binding; > + > + rcu_read_lock(); > + binding = xa_load(&net_devmem_dmabuf_bindings, id); > + if (binding) { > + if (!net_devmem_dmabuf_binding_get(binding)) > + binding = NULL; > + } > + rcu_read_unlock(); > + > + return binding; > +} > + > void net_devmem_get_net_iov(struct net_iov *niov) > { > net_devmem_dmabuf_binding_get(net_devmem_iov_binding(niov)); > @@ -305,6 +343,53 @@ void net_devmem_put_net_iov(struct net_iov *niov) > net_devmem_dmabuf_binding_put(net_devmem_iov_binding(niov)); > } > > +struct net_devmem_dmabuf_binding *net_devmem_get_binding(struct sock *sk, > + unsigned int dmabuf_id) > +{ > + struct net_devmem_dmabuf_binding *binding; > + struct dst_entry *dst = __sk_dst_get(sk); > + int err = 0; > + > + binding = net_devmem_lookup_dmabuf(dmabuf_id); > + if (!binding || !binding->tx_vec) { > + err = -EINVAL; > + goto out_err; > + } > + > + /* The dma-addrs in this binding are only reachable to the corresponding > + * net_device. > + */ > + if (!dst || !dst->dev || dst->dev->ifindex != binding->dev->ifindex) { > + err = -ENODEV; > + goto out_err; > + } > + > + return binding; > + > +out_err: > + if (binding) > + net_devmem_dmabuf_binding_put(binding); > + > + return ERR_PTR(err); > +} > + > +struct net_iov * > +net_devmem_get_niov_at(struct net_devmem_dmabuf_binding *binding, > + size_t virt_addr, size_t *off, size_t *size) > +{ > + size_t idx; > + > + if (virt_addr >= binding->dmabuf->size) > + return NULL; > + > + idx = virt_addr / PAGE_SIZE; > + > + *off = virt_addr % PAGE_SIZE; > + *size = PAGE_SIZE - *off; > + > + return binding->tx_vec[idx]; > +} > + > /*** "Dmabuf devmem memory provider" ***/ > > int mp_dmabuf_devmem_init(struct page_pool *pool) > diff --git a/net/core/devmem.h b/net/core/devmem.h > index 946f2e015746..67168aae5e5b 100644 > --- a/net/core/devmem.h > +++ b/net/core/devmem.h > @@ -23,8 +23,9 @@ struct net_devmem_dmabuf_binding { > > /* The user holds a ref (via the netlink API) for as long as they want > * the binding to remain alive. Each page pool using this binding holds > - * a ref to keep the binding alive. Each allocated net_iov holds a > - * ref. > + * a ref to keep the binding alive. The page_pool does not release the > + * ref until all the net_iovs allocated from this binding are released > + * back to the page_pool. > * > * The binding undos itself and unmaps the underlying dmabuf once all > * those refs are dropped and the binding is no longer desired or in > @@ -32,7 +33,10 @@ struct net_devmem_dmabuf_binding { > * > * net_devmem_get_net_iov() on dmabuf net_iovs will increment this > * reference, making sure that the binding remains alive until all the > - * net_iovs are no longer used. > + * net_iovs are no longer used. net_iovs allocated from this binding > + * that are stuck in the TX path for any reason (such as awaiting > + * retransmits) hold a reference to the binding until the skb holding > + * them is freed. > */ > refcount_t ref; > > @@ -48,6 +52,14 @@ struct net_devmem_dmabuf_binding { > * active. > */ > u32 id; > + > + /* Array of net_iov pointers for this binding, sorted by virtual > + * address. This array is convenient to map the virtual addresses to > + * net_iovs in the TX path. > + */ > + struct net_iov **tx_vec; > + > + struct work_struct unbind_w; > }; > > #if defined(CONFIG_NET_DEVMEM) > @@ -64,14 +76,17 @@ struct dmabuf_genpool_chunk_owner { > dma_addr_t base_dma_addr; > }; > > -void __net_devmem_dmabuf_binding_free(struct net_devmem_dmabuf_binding *binding); > +void __net_devmem_dmabuf_binding_free(struct work_struct *wq); > struct net_devmem_dmabuf_binding * > -net_devmem_bind_dmabuf(struct net_device *dev, unsigned int dmabuf_fd, > - struct netlink_ext_ack *extack); > +net_devmem_bind_dmabuf(struct net_device *dev, > + enum dma_data_direction direction, > + unsigned int dmabuf_fd, struct netlink_ext_ack *extack); > +struct net_devmem_dmabuf_binding *net_devmem_lookup_dmabuf(u32 id); > void net_devmem_unbind_dmabuf(struct net_devmem_dmabuf_binding *binding); > int net_devmem_bind_dmabuf_to_queue(struct net_device *dev, u32 rxq_idx, > struct net_devmem_dmabuf_binding *binding, > struct netlink_ext_ack *extack); > +void net_devmem_bind_tx_release(struct sock *sk); > > static inline struct dmabuf_genpool_chunk_owner * > net_devmem_iov_to_chunk_owner(const struct net_iov *niov) > @@ -100,10 +115,10 @@ static inline unsigned long net_iov_virtual_addr(const struct net_iov *niov) > ((unsigned long)net_iov_idx(niov) << PAGE_SHIFT); > } > > -static inline void > +static inline bool > net_devmem_dmabuf_binding_get(struct net_devmem_dmabuf_binding *binding) > { > - refcount_inc(&binding->ref); > + return refcount_inc_not_zero(&binding->ref); > } > > static inline void > @@ -112,7 +127,8 @@ net_devmem_dmabuf_binding_put(struct net_devmem_dmabuf_binding *binding) > if (!refcount_dec_and_test(&binding->ref)) > return; > > - __net_devmem_dmabuf_binding_free(binding); > + INIT_WORK(&binding->unbind_w, __net_devmem_dmabuf_binding_free); > + schedule_work(&binding->unbind_w); > } > > void net_devmem_get_net_iov(struct net_iov *niov); > @@ -123,6 +139,11 @@ net_devmem_alloc_dmabuf(struct net_devmem_dmabuf_binding *binding); > void net_devmem_free_dmabuf(struct net_iov *ppiov); > > bool net_is_devmem_iov(struct net_iov *niov); > +struct net_devmem_dmabuf_binding * > +net_devmem_get_binding(struct sock *sk, unsigned int dmabuf_id); > +struct net_iov * > +net_devmem_get_niov_at(struct net_devmem_dmabuf_binding *binding, size_t addr, > + size_t *off, size_t *size); > > #else > struct net_devmem_dmabuf_binding; > @@ -140,18 +161,23 @@ static inline void net_devmem_put_net_iov(struct net_iov *niov) > { > } > > -static inline void > -__net_devmem_dmabuf_binding_free(struct net_devmem_dmabuf_binding *binding) > +static inline void __net_devmem_dmabuf_binding_free(struct work_struct *wq) > { > } > > static inline struct net_devmem_dmabuf_binding * > net_devmem_bind_dmabuf(struct net_device *dev, unsigned int dmabuf_fd, > + enum dma_data_direction direction, > struct netlink_ext_ack *extack) > { > return ERR_PTR(-EOPNOTSUPP); > } > > +static inline struct net_devmem_dmabuf_binding *net_devmem_lookup_dmabuf(u32 id) > +{ > + return NULL; > +} > + > static inline void > net_devmem_unbind_dmabuf(struct net_devmem_dmabuf_binding *binding) > { > @@ -190,6 +216,19 @@ static inline bool net_is_devmem_iov(struct net_iov *niov) > { > return false; > } > + > +static inline struct net_devmem_dmabuf_binding * > +net_devmem_get_binding(struct sock *sk, unsigned int dmabuf_id) > +{ > + return ERR_PTR(-EOPNOTSUPP); > +} > + > +static inline struct net_iov * > +net_devmem_get_niov_at(struct net_devmem_dmabuf_binding *binding, size_t addr, > + size_t *off, size_t *size) > +{ > + return NULL; > +} > #endif > > #endif /* _NET_DEVMEM_H */ > diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c > index 5e42f800dfcf..56502923f885 100644 > --- a/net/core/netdev-genl.c > +++ b/net/core/netdev-genl.c > @@ -873,7 +873,8 @@ int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info) > goto err_unlock; > } > > - binding = net_devmem_bind_dmabuf(netdev, dmabuf_fd, info->extack); > + binding = net_devmem_bind_dmabuf(netdev, DMA_FROM_DEVICE, dmabuf_fd, > + info->extack); > if (IS_ERR(binding)) { > err = PTR_ERR(binding); > goto err_unlock; > @@ -934,10 +935,65 @@ int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info) > return err; > } > > -/* stub */ > int netdev_nl_bind_tx_doit(struct sk_buff *skb, struct genl_info *info) > { > - return 0; > + struct net_devmem_dmabuf_binding *binding; > + struct list_head *sock_binding_list; > + struct net_device *netdev; > + u32 ifindex, dmabuf_fd; > + struct sk_buff *rsp; > + int err = 0; > + void *hdr; > + > + if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_DEV_IFINDEX) || > + GENL_REQ_ATTR_CHECK(info, NETDEV_A_DMABUF_FD)) > + return -EINVAL; > + > + ifindex = nla_get_u32(info->attrs[NETDEV_A_DEV_IFINDEX]); > + dmabuf_fd = nla_get_u32(info->attrs[NETDEV_A_DMABUF_FD]); > + > + sock_binding_list = genl_sk_priv_get(&netdev_nl_family, > + NETLINK_CB(skb).sk); > + if (IS_ERR(sock_binding_list)) > + return PTR_ERR(sock_binding_list); > + > + rsp = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL); > + if (!rsp) > + return -ENOMEM; > + > + hdr = genlmsg_iput(rsp, info); > + if (!hdr) { > + err = -EMSGSIZE; > + goto err_genlmsg_free; > + } > + > + netdev = netdev_get_by_index_lock(genl_info_net(info), ifindex); > + if (!netdev || !netif_device_present(netdev)) { > + err = -ENODEV; > + goto err_unlock; > + } > + > + binding = net_devmem_bind_dmabuf(netdev, DMA_TO_DEVICE, dmabuf_fd, > + info->extack); > + if (IS_ERR(binding)) { > + err = PTR_ERR(binding); > + goto err_unlock; > + } > + > + list_add(&binding->list, sock_binding_list); > + > + nla_put_u32(rsp, NETDEV_A_DMABUF_ID, binding->id); > + genlmsg_end(rsp, hdr); > + > + netdev_unlock(netdev); > + > + return genlmsg_reply(rsp, info); > + > +err_unlock: > + netdev_unlock(netdev); > +err_genlmsg_free: > + nlmsg_free(rsp); > + return err; > } The above needs to be converted to netdev_nl_sock? Untested: diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c index 33cf5b21aeef..1c6b1dfa5742 100644 --- a/net/core/netdev-genl.c +++ b/net/core/netdev-genl.c @@ -938,7 +938,7 @@ int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info) int netdev_nl_bind_tx_doit(struct sk_buff *skb, struct genl_info *info) { struct net_devmem_dmabuf_binding *binding; - struct list_head *sock_binding_list; + struct netdev_nl_sock *priv; struct net_device *netdev; u32 ifindex, dmabuf_fd; struct sk_buff *rsp; @@ -952,10 +952,9 @@ int netdev_nl_bind_tx_doit(struct sk_buff *skb, struct genl_info *info) ifindex = nla_get_u32(info->attrs[NETDEV_A_DEV_IFINDEX]); dmabuf_fd = nla_get_u32(info->attrs[NETDEV_A_DMABUF_FD]); - sock_binding_list = genl_sk_priv_get(&netdev_nl_family, - NETLINK_CB(skb).sk); - if (IS_ERR(sock_binding_list)) - return PTR_ERR(sock_binding_list); + priv = genl_sk_priv_get(&netdev_nl_family, NETLINK_CB(skb).sk); + if (IS_ERR(priv)) + return PTR_ERR(priv); rsp = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL); if (!rsp) @@ -967,10 +966,12 @@ int netdev_nl_bind_tx_doit(struct sk_buff *skb, struct genl_info *info) goto err_genlmsg_free; } + mutex_lock(&priv->lock); + netdev = netdev_get_by_index_lock(genl_info_net(info), ifindex); if (!netdev || !netif_device_present(netdev)) { err = -ENODEV; - goto err_unlock; + goto err_unlock_sock; } #if 0 @@ -989,17 +990,21 @@ int netdev_nl_bind_tx_doit(struct sk_buff *skb, struct genl_info *info) goto err_unlock; } - list_add(&binding->list, sock_binding_list); + list_add(&binding->list, &priv->bindings); nla_put_u32(rsp, NETDEV_A_DMABUF_ID, binding->id); genlmsg_end(rsp, hdr); netdev_unlock(netdev); + mutex_unlock(&priv->lock); + return genlmsg_reply(rsp, info); err_unlock: netdev_unlock(netdev); +err_unlock_sock: + mutex_unlock(&priv->lock); err_genlmsg_free: nlmsg_free(rsp); return err;
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index f1381aff0f89..10dc0a439108 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1710,13 +1710,16 @@ static inline void skb_set_end_offset(struct sk_buff *skb, unsigned int offset) extern const struct ubuf_info_ops msg_zerocopy_ubuf_ops; struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size, - struct ubuf_info *uarg); + struct ubuf_info *uarg, bool devmem); void msg_zerocopy_put_abort(struct ubuf_info *uarg, bool have_uref); +struct net_devmem_dmabuf_binding; + int __zerocopy_sg_from_iter(struct msghdr *msg, struct sock *sk, struct sk_buff *skb, struct iov_iter *from, - size_t length); + size_t length, + struct net_devmem_dmabuf_binding *binding); int zerocopy_fill_skb_from_iter(struct sk_buff *skb, struct iov_iter *from, size_t length); @@ -1724,12 +1727,14 @@ int zerocopy_fill_skb_from_iter(struct sk_buff *skb, static inline int skb_zerocopy_iter_dgram(struct sk_buff *skb, struct msghdr *msg, int len) { - return __zerocopy_sg_from_iter(msg, skb->sk, skb, &msg->msg_iter, len); + return __zerocopy_sg_from_iter(msg, skb->sk, skb, &msg->msg_iter, len, + NULL); } int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb, struct msghdr *msg, int len, - struct ubuf_info *uarg); + struct ubuf_info *uarg, + struct net_devmem_dmabuf_binding *binding); /* Internal */ #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB))) @@ -3700,6 +3705,10 @@ static inline dma_addr_t __skb_frag_dma_map(struct device *dev, size_t offset, size_t size, enum dma_data_direction dir) { + if (skb_frag_is_net_iov(frag)) { + return netmem_to_net_iov(frag->netmem)->dma_addr + offset + + frag->offset; + } return dma_map_page(dev, skb_frag_page(frag), skb_frag_off(frag) + offset, size, dir); } diff --git a/include/net/sock.h b/include/net/sock.h index bb4d6189292f..5cb10cc0ca6e 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1851,6 +1851,7 @@ struct sockcm_cookie { u32 tsflags; u32 ts_opt_id; u32 priority; + u32 dmabuf_id; }; static inline void sockcm_init(struct sockcm_cookie *sockc, diff --git a/net/core/datagram.c b/net/core/datagram.c index f0634f0cb834..042a7dceb85a 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -63,6 +63,8 @@ #include <net/busy_poll.h> #include <crypto/hash.h> +#include "devmem.h" + /* * Is a socket 'connection oriented' ? */ @@ -691,9 +693,49 @@ int zerocopy_fill_skb_from_iter(struct sk_buff *skb, return 0; } +static int +zerocopy_fill_skb_from_devmem(struct sk_buff *skb, struct iov_iter *from, + int length, + struct net_devmem_dmabuf_binding *binding) +{ + int i = skb_shinfo(skb)->nr_frags; + size_t virt_addr, size, off; + struct net_iov *niov; + + /* Devmem filling works by taking an IOVEC from the user where the + * iov_addrs are interpreted as an offset in bytes into the dma-buf to + * send from. We do not support other iter types. + */ + if (iov_iter_type(from) != ITER_IOVEC) + return -EFAULT; + + while (length && iov_iter_count(from)) { + if (i == MAX_SKB_FRAGS) + return -EMSGSIZE; + + virt_addr = (size_t)iter_iov_addr(from); + niov = net_devmem_get_niov_at(binding, virt_addr, &off, &size); + if (!niov) + return -EFAULT; + + size = min_t(size_t, size, length); + size = min_t(size_t, size, iter_iov_len(from)); + + get_netmem(net_iov_to_netmem(niov)); + skb_add_rx_frag_netmem(skb, i, net_iov_to_netmem(niov), off, + size, PAGE_SIZE); + iov_iter_advance(from, size); + length -= size; + i++; + } + + return 0; +} + int __zerocopy_sg_from_iter(struct msghdr *msg, struct sock *sk, struct sk_buff *skb, struct iov_iter *from, - size_t length) + size_t length, + struct net_devmem_dmabuf_binding *binding) { unsigned long orig_size = skb->truesize; unsigned long truesize; @@ -701,6 +743,8 @@ int __zerocopy_sg_from_iter(struct msghdr *msg, struct sock *sk, if (msg && msg->msg_ubuf && msg->sg_from_iter) ret = msg->sg_from_iter(skb, from, length); + else if (unlikely(binding)) + ret = zerocopy_fill_skb_from_devmem(skb, from, length, binding); else ret = zerocopy_fill_skb_from_iter(skb, from, length); @@ -734,7 +778,7 @@ int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *from) if (skb_copy_datagram_from_iter(skb, 0, from, copy)) return -EFAULT; - return __zerocopy_sg_from_iter(NULL, NULL, skb, from, ~0U); + return __zerocopy_sg_from_iter(NULL, NULL, skb, from, ~0U, NULL); } EXPORT_SYMBOL(zerocopy_sg_from_iter); diff --git a/net/core/devmem.c b/net/core/devmem.c index dca2ff7cf692..9599a82990e6 100644 --- a/net/core/devmem.c +++ b/net/core/devmem.c @@ -16,6 +16,7 @@ #include <net/netdev_rx_queue.h> #include <net/page_pool/helpers.h> #include <net/page_pool/memory_provider.h> +#include <net/sock.h> #include <trace/events/page_pool.h> #include "devmem.h" @@ -52,8 +53,10 @@ static dma_addr_t net_devmem_get_dma_addr(const struct net_iov *niov) ((dma_addr_t)net_iov_idx(niov) << PAGE_SHIFT); } -void __net_devmem_dmabuf_binding_free(struct net_devmem_dmabuf_binding *binding) +void __net_devmem_dmabuf_binding_free(struct work_struct *wq) { + struct net_devmem_dmabuf_binding *binding = container_of(wq, typeof(*binding), unbind_w); + size_t size, avail; gen_pool_for_each_chunk(binding->chunk_pool, @@ -71,8 +74,10 @@ void __net_devmem_dmabuf_binding_free(struct net_devmem_dmabuf_binding *binding) dma_buf_detach(binding->dmabuf, binding->attachment); dma_buf_put(binding->dmabuf); xa_destroy(&binding->bound_rxqs); + kvfree(binding->tx_vec); kfree(binding); } +EXPORT_SYMBOL(__net_devmem_dmabuf_binding_free); struct net_iov * net_devmem_alloc_dmabuf(struct net_devmem_dmabuf_binding *binding) @@ -117,6 +122,13 @@ void net_devmem_unbind_dmabuf(struct net_devmem_dmabuf_binding *binding) unsigned long xa_idx; unsigned int rxq_idx; + xa_erase(&net_devmem_dmabuf_bindings, binding->id); + + /* Ensure no tx net_devmem_lookup_dmabuf() are in flight after the + * erase. + */ + synchronize_net(); + if (binding->list.next) list_del(&binding->list); @@ -131,8 +143,6 @@ void net_devmem_unbind_dmabuf(struct net_devmem_dmabuf_binding *binding) __net_mp_close_rxq(binding->dev, rxq_idx, &mp_params); } - xa_erase(&net_devmem_dmabuf_bindings, binding->id); - net_devmem_dmabuf_binding_put(binding); } @@ -166,8 +176,9 @@ int net_devmem_bind_dmabuf_to_queue(struct net_device *dev, u32 rxq_idx, } struct net_devmem_dmabuf_binding * -net_devmem_bind_dmabuf(struct net_device *dev, unsigned int dmabuf_fd, - struct netlink_ext_ack *extack) +net_devmem_bind_dmabuf(struct net_device *dev, + enum dma_data_direction direction, + unsigned int dmabuf_fd, struct netlink_ext_ack *extack) { struct net_devmem_dmabuf_binding *binding; static u32 id_alloc_next; @@ -189,43 +200,44 @@ net_devmem_bind_dmabuf(struct net_device *dev, unsigned int dmabuf_fd, } binding->dev = dev; - - err = xa_alloc_cyclic(&net_devmem_dmabuf_bindings, &binding->id, - binding, xa_limit_32b, &id_alloc_next, - GFP_KERNEL); - if (err < 0) - goto err_free_binding; - xa_init_flags(&binding->bound_rxqs, XA_FLAGS_ALLOC); - refcount_set(&binding->ref, 1); - binding->dmabuf = dmabuf; binding->attachment = dma_buf_attach(binding->dmabuf, dev->dev.parent); if (IS_ERR(binding->attachment)) { err = PTR_ERR(binding->attachment); NL_SET_ERR_MSG(extack, "Failed to bind dmabuf to device"); - goto err_free_id; + goto err_free_binding; } binding->sgt = dma_buf_map_attachment_unlocked(binding->attachment, - DMA_FROM_DEVICE); + direction); if (IS_ERR(binding->sgt)) { err = PTR_ERR(binding->sgt); NL_SET_ERR_MSG(extack, "Failed to map dmabuf attachment"); goto err_detach; } + if (direction == DMA_TO_DEVICE) { + binding->tx_vec = kvmalloc_array(dmabuf->size / PAGE_SIZE, + sizeof(struct net_iov *), + GFP_KERNEL); + if (!binding->tx_vec) { + err = -ENOMEM; + goto err_unmap; + } + } + /* For simplicity we expect to make PAGE_SIZE allocations, but the * binding can be much more flexible than that. We may be able to * allocate MTU sized chunks here. Leave that for future work... */ - binding->chunk_pool = - gen_pool_create(PAGE_SHIFT, dev_to_node(&dev->dev)); + binding->chunk_pool = gen_pool_create(PAGE_SHIFT, + dev_to_node(&dev->dev)); if (!binding->chunk_pool) { err = -ENOMEM; - goto err_unmap; + goto err_tx_vec; } virtual = 0; @@ -270,24 +282,35 @@ net_devmem_bind_dmabuf(struct net_device *dev, unsigned int dmabuf_fd, niov->owner = &owner->area; page_pool_set_dma_addr_netmem(net_iov_to_netmem(niov), net_devmem_get_dma_addr(niov)); + if (direction == DMA_TO_DEVICE) + binding->tx_vec[owner->area.base_virtual / PAGE_SIZE + i] = niov; } virtual += len; } + err = xa_alloc_cyclic(&net_devmem_dmabuf_bindings, &binding->id, + binding, xa_limit_32b, &id_alloc_next, + GFP_KERNEL); + if (err < 0) + goto err_free_id; + + return binding; +err_free_id: + xa_erase(&net_devmem_dmabuf_bindings, binding->id); err_free_chunks: gen_pool_for_each_chunk(binding->chunk_pool, net_devmem_dmabuf_free_chunk_owner, NULL); gen_pool_destroy(binding->chunk_pool); +err_tx_vec: + kvfree(binding->tx_vec); err_unmap: dma_buf_unmap_attachment_unlocked(binding->attachment, binding->sgt, DMA_FROM_DEVICE); err_detach: dma_buf_detach(dmabuf, binding->attachment); -err_free_id: - xa_erase(&net_devmem_dmabuf_bindings, binding->id); err_free_binding: kfree(binding); err_put_dmabuf: @@ -295,6 +318,21 @@ net_devmem_bind_dmabuf(struct net_device *dev, unsigned int dmabuf_fd, return ERR_PTR(err); } +struct net_devmem_dmabuf_binding *net_devmem_lookup_dmabuf(u32 id) +{ + struct net_devmem_dmabuf_binding *binding; + + rcu_read_lock(); + binding = xa_load(&net_devmem_dmabuf_bindings, id); + if (binding) { + if (!net_devmem_dmabuf_binding_get(binding)) + binding = NULL; + } + rcu_read_unlock(); + + return binding; +} + void net_devmem_get_net_iov(struct net_iov *niov) { net_devmem_dmabuf_binding_get(net_devmem_iov_binding(niov)); @@ -305,6 +343,53 @@ void net_devmem_put_net_iov(struct net_iov *niov) net_devmem_dmabuf_binding_put(net_devmem_iov_binding(niov)); } +struct net_devmem_dmabuf_binding *net_devmem_get_binding(struct sock *sk, + unsigned int dmabuf_id) +{ + struct net_devmem_dmabuf_binding *binding; + struct dst_entry *dst = __sk_dst_get(sk); + int err = 0; + + binding = net_devmem_lookup_dmabuf(dmabuf_id); + if (!binding || !binding->tx_vec) { + err = -EINVAL; + goto out_err; + } + + /* The dma-addrs in this binding are only reachable to the corresponding + * net_device. + */ + if (!dst || !dst->dev || dst->dev->ifindex != binding->dev->ifindex) { + err = -ENODEV; + goto out_err; + } + + return binding; + +out_err: + if (binding) + net_devmem_dmabuf_binding_put(binding); + + return ERR_PTR(err); +} + +struct net_iov * +net_devmem_get_niov_at(struct net_devmem_dmabuf_binding *binding, + size_t virt_addr, size_t *off, size_t *size) +{ + size_t idx; + + if (virt_addr >= binding->dmabuf->size) + return NULL; + + idx = virt_addr / PAGE_SIZE; + + *off = virt_addr % PAGE_SIZE; + *size = PAGE_SIZE - *off; + + return binding->tx_vec[idx]; +} + /*** "Dmabuf devmem memory provider" ***/ int mp_dmabuf_devmem_init(struct page_pool *pool) diff --git a/net/core/devmem.h b/net/core/devmem.h index 946f2e015746..67168aae5e5b 100644 --- a/net/core/devmem.h +++ b/net/core/devmem.h @@ -23,8 +23,9 @@ struct net_devmem_dmabuf_binding { /* The user holds a ref (via the netlink API) for as long as they want * the binding to remain alive. Each page pool using this binding holds - * a ref to keep the binding alive. Each allocated net_iov holds a - * ref. + * a ref to keep the binding alive. The page_pool does not release the + * ref until all the net_iovs allocated from this binding are released + * back to the page_pool. * * The binding undos itself and unmaps the underlying dmabuf once all * those refs are dropped and the binding is no longer desired or in @@ -32,7 +33,10 @@ struct net_devmem_dmabuf_binding { * * net_devmem_get_net_iov() on dmabuf net_iovs will increment this * reference, making sure that the binding remains alive until all the - * net_iovs are no longer used. + * net_iovs are no longer used. net_iovs allocated from this binding + * that are stuck in the TX path for any reason (such as awaiting + * retransmits) hold a reference to the binding until the skb holding + * them is freed. */ refcount_t ref; @@ -48,6 +52,14 @@ struct net_devmem_dmabuf_binding { * active. */ u32 id; + + /* Array of net_iov pointers for this binding, sorted by virtual + * address. This array is convenient to map the virtual addresses to + * net_iovs in the TX path. + */ + struct net_iov **tx_vec; + + struct work_struct unbind_w; }; #if defined(CONFIG_NET_DEVMEM) @@ -64,14 +76,17 @@ struct dmabuf_genpool_chunk_owner { dma_addr_t base_dma_addr; }; -void __net_devmem_dmabuf_binding_free(struct net_devmem_dmabuf_binding *binding); +void __net_devmem_dmabuf_binding_free(struct work_struct *wq); struct net_devmem_dmabuf_binding * -net_devmem_bind_dmabuf(struct net_device *dev, unsigned int dmabuf_fd, - struct netlink_ext_ack *extack); +net_devmem_bind_dmabuf(struct net_device *dev, + enum dma_data_direction direction, + unsigned int dmabuf_fd, struct netlink_ext_ack *extack); +struct net_devmem_dmabuf_binding *net_devmem_lookup_dmabuf(u32 id); void net_devmem_unbind_dmabuf(struct net_devmem_dmabuf_binding *binding); int net_devmem_bind_dmabuf_to_queue(struct net_device *dev, u32 rxq_idx, struct net_devmem_dmabuf_binding *binding, struct netlink_ext_ack *extack); +void net_devmem_bind_tx_release(struct sock *sk); static inline struct dmabuf_genpool_chunk_owner * net_devmem_iov_to_chunk_owner(const struct net_iov *niov) @@ -100,10 +115,10 @@ static inline unsigned long net_iov_virtual_addr(const struct net_iov *niov) ((unsigned long)net_iov_idx(niov) << PAGE_SHIFT); } -static inline void +static inline bool net_devmem_dmabuf_binding_get(struct net_devmem_dmabuf_binding *binding) { - refcount_inc(&binding->ref); + return refcount_inc_not_zero(&binding->ref); } static inline void @@ -112,7 +127,8 @@ net_devmem_dmabuf_binding_put(struct net_devmem_dmabuf_binding *binding) if (!refcount_dec_and_test(&binding->ref)) return; - __net_devmem_dmabuf_binding_free(binding); + INIT_WORK(&binding->unbind_w, __net_devmem_dmabuf_binding_free); + schedule_work(&binding->unbind_w); } void net_devmem_get_net_iov(struct net_iov *niov); @@ -123,6 +139,11 @@ net_devmem_alloc_dmabuf(struct net_devmem_dmabuf_binding *binding); void net_devmem_free_dmabuf(struct net_iov *ppiov); bool net_is_devmem_iov(struct net_iov *niov); +struct net_devmem_dmabuf_binding * +net_devmem_get_binding(struct sock *sk, unsigned int dmabuf_id); +struct net_iov * +net_devmem_get_niov_at(struct net_devmem_dmabuf_binding *binding, size_t addr, + size_t *off, size_t *size); #else struct net_devmem_dmabuf_binding; @@ -140,18 +161,23 @@ static inline void net_devmem_put_net_iov(struct net_iov *niov) { } -static inline void -__net_devmem_dmabuf_binding_free(struct net_devmem_dmabuf_binding *binding) +static inline void __net_devmem_dmabuf_binding_free(struct work_struct *wq) { } static inline struct net_devmem_dmabuf_binding * net_devmem_bind_dmabuf(struct net_device *dev, unsigned int dmabuf_fd, + enum dma_data_direction direction, struct netlink_ext_ack *extack) { return ERR_PTR(-EOPNOTSUPP); } +static inline struct net_devmem_dmabuf_binding *net_devmem_lookup_dmabuf(u32 id) +{ + return NULL; +} + static inline void net_devmem_unbind_dmabuf(struct net_devmem_dmabuf_binding *binding) { @@ -190,6 +216,19 @@ static inline bool net_is_devmem_iov(struct net_iov *niov) { return false; } + +static inline struct net_devmem_dmabuf_binding * +net_devmem_get_binding(struct sock *sk, unsigned int dmabuf_id) +{ + return ERR_PTR(-EOPNOTSUPP); +} + +static inline struct net_iov * +net_devmem_get_niov_at(struct net_devmem_dmabuf_binding *binding, size_t addr, + size_t *off, size_t *size) +{ + return NULL; +} #endif #endif /* _NET_DEVMEM_H */ diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c index 5e42f800dfcf..56502923f885 100644 --- a/net/core/netdev-genl.c +++ b/net/core/netdev-genl.c @@ -873,7 +873,8 @@ int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info) goto err_unlock; } - binding = net_devmem_bind_dmabuf(netdev, dmabuf_fd, info->extack); + binding = net_devmem_bind_dmabuf(netdev, DMA_FROM_DEVICE, dmabuf_fd, + info->extack); if (IS_ERR(binding)) { err = PTR_ERR(binding); goto err_unlock; @@ -934,10 +935,65 @@ int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info) return err; } -/* stub */ int netdev_nl_bind_tx_doit(struct sk_buff *skb, struct genl_info *info) { - return 0; + struct net_devmem_dmabuf_binding *binding; + struct list_head *sock_binding_list; + struct net_device *netdev; + u32 ifindex, dmabuf_fd; + struct sk_buff *rsp; + int err = 0; + void *hdr; + + if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_DEV_IFINDEX) || + GENL_REQ_ATTR_CHECK(info, NETDEV_A_DMABUF_FD)) + return -EINVAL; + + ifindex = nla_get_u32(info->attrs[NETDEV_A_DEV_IFINDEX]); + dmabuf_fd = nla_get_u32(info->attrs[NETDEV_A_DMABUF_FD]); + + sock_binding_list = genl_sk_priv_get(&netdev_nl_family, + NETLINK_CB(skb).sk); + if (IS_ERR(sock_binding_list)) + return PTR_ERR(sock_binding_list); + + rsp = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL); + if (!rsp) + return -ENOMEM; + + hdr = genlmsg_iput(rsp, info); + if (!hdr) { + err = -EMSGSIZE; + goto err_genlmsg_free; + } + + netdev = netdev_get_by_index_lock(genl_info_net(info), ifindex); + if (!netdev || !netif_device_present(netdev)) { + err = -ENODEV; + goto err_unlock; + } + + binding = net_devmem_bind_dmabuf(netdev, DMA_TO_DEVICE, dmabuf_fd, + info->extack); + if (IS_ERR(binding)) { + err = PTR_ERR(binding); + goto err_unlock; + } + + list_add(&binding->list, sock_binding_list); + + nla_put_u32(rsp, NETDEV_A_DMABUF_ID, binding->id); + genlmsg_end(rsp, hdr); + + netdev_unlock(netdev); + + return genlmsg_reply(rsp, info); + +err_unlock: + netdev_unlock(netdev); +err_genlmsg_free: + nlmsg_free(rsp); + return err; } void netdev_nl_sock_priv_init(struct netdev_nl_sock *priv) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 17ce5857b116..4f2734bf1cf6 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -1655,7 +1655,8 @@ void mm_unaccount_pinned_pages(struct mmpin *mmp) } EXPORT_SYMBOL_GPL(mm_unaccount_pinned_pages); -static struct ubuf_info *msg_zerocopy_alloc(struct sock *sk, size_t size) +static struct ubuf_info *msg_zerocopy_alloc(struct sock *sk, size_t size, + bool devmem) { struct ubuf_info_msgzc *uarg; struct sk_buff *skb; @@ -1670,7 +1671,7 @@ static struct ubuf_info *msg_zerocopy_alloc(struct sock *sk, size_t size) uarg = (void *)skb->cb; uarg->mmp.user = NULL; - if (mm_account_pinned_pages(&uarg->mmp, size)) { + if (likely(!devmem) && mm_account_pinned_pages(&uarg->mmp, size)) { kfree_skb(skb); return NULL; } @@ -1693,7 +1694,7 @@ static inline struct sk_buff *skb_from_uarg(struct ubuf_info_msgzc *uarg) } struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size, - struct ubuf_info *uarg) + struct ubuf_info *uarg, bool devmem) { if (uarg) { struct ubuf_info_msgzc *uarg_zc; @@ -1723,7 +1724,8 @@ struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size, next = (u32)atomic_read(&sk->sk_zckey); if ((u32)(uarg_zc->id + uarg_zc->len) == next) { - if (mm_account_pinned_pages(&uarg_zc->mmp, size)) + if (likely(!devmem) && + mm_account_pinned_pages(&uarg_zc->mmp, size)) return NULL; uarg_zc->len++; uarg_zc->bytelen = bytelen; @@ -1738,7 +1740,7 @@ struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size, } new_alloc: - return msg_zerocopy_alloc(sk, size); + return msg_zerocopy_alloc(sk, size, devmem); } EXPORT_SYMBOL_GPL(msg_zerocopy_realloc); @@ -1842,7 +1844,8 @@ EXPORT_SYMBOL_GPL(msg_zerocopy_ubuf_ops); int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb, struct msghdr *msg, int len, - struct ubuf_info *uarg) + struct ubuf_info *uarg, + struct net_devmem_dmabuf_binding *binding) { int err, orig_len = skb->len; @@ -1861,7 +1864,8 @@ int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb, return -EEXIST; } - err = __zerocopy_sg_from_iter(msg, sk, skb, &msg->msg_iter, len); + err = __zerocopy_sg_from_iter(msg, sk, skb, &msg->msg_iter, len, + binding); if (err == -EFAULT || (err == -EMSGSIZE && skb->len == orig_len)) { struct sock *save_sk = skb->sk; diff --git a/net/core/sock.c b/net/core/sock.c index b64df2463300..9dd298904035 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -3017,6 +3017,12 @@ int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg, if (!sk_set_prio_allowed(sk, *(u32 *)CMSG_DATA(cmsg))) return -EPERM; sockc->priority = *(u32 *)CMSG_DATA(cmsg); + break; + case SCM_DEVMEM_DMABUF: + if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32))) + return -EINVAL; + sockc->dmabuf_id = *(u32 *)CMSG_DATA(cmsg); + break; default: return -EINVAL; diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 6e18d7ec5062..a2705d454fd6 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -1014,7 +1014,8 @@ static int __ip_append_data(struct sock *sk, uarg = msg->msg_ubuf; } } else if (sock_flag(sk, SOCK_ZEROCOPY)) { - uarg = msg_zerocopy_realloc(sk, length, skb_zcopy(skb)); + uarg = msg_zerocopy_realloc(sk, length, skb_zcopy(skb), + false); if (!uarg) return -ENOBUFS; extra_uref = !skb_zcopy(skb); /* only ref on new uarg */ diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index e0e96f8fd47c..9f7cd3344496 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1059,6 +1059,7 @@ int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, int *copied, int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size) { + struct net_devmem_dmabuf_binding *binding = NULL; struct tcp_sock *tp = tcp_sk(sk); struct ubuf_info *uarg = NULL; struct sk_buff *skb; @@ -1066,11 +1067,24 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size) int flags, err, copied = 0; int mss_now = 0, size_goal, copied_syn = 0; int process_backlog = 0; + bool sockc_valid = true; int zc = 0; long timeo; flags = msg->msg_flags; + sockc = (struct sockcm_cookie){ .tsflags = READ_ONCE(sk->sk_tsflags), + .dmabuf_id = 0 }; + if (msg->msg_controllen) { + err = sock_cmsg_send(sk, msg, &sockc); + if (unlikely(err)) + /* Don't return error until MSG_FASTOPEN has been + * processed; that may succeed even if the cmsg is + * invalid. + */ + sockc_valid = false; + } + if ((flags & MSG_ZEROCOPY) && size) { if (msg->msg_ubuf) { uarg = msg->msg_ubuf; @@ -1078,7 +1092,8 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size) zc = MSG_ZEROCOPY; } else if (sock_flag(sk, SOCK_ZEROCOPY)) { skb = tcp_write_queue_tail(sk); - uarg = msg_zerocopy_realloc(sk, size, skb_zcopy(skb)); + uarg = msg_zerocopy_realloc(sk, size, skb_zcopy(skb), + sockc_valid && !!sockc.dmabuf_id); if (!uarg) { err = -ENOBUFS; goto out_err; @@ -1087,12 +1102,27 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size) zc = MSG_ZEROCOPY; else uarg_to_msgzc(uarg)->zerocopy = 0; + + if (sockc_valid && sockc.dmabuf_id) { + binding = net_devmem_get_binding(sk, sockc.dmabuf_id); + if (IS_ERR(binding)) { + err = PTR_ERR(binding); + binding = NULL; + goto out_err; + } + } } } else if (unlikely(msg->msg_flags & MSG_SPLICE_PAGES) && size) { if (sk->sk_route_caps & NETIF_F_SG) zc = MSG_SPLICE_PAGES; } + if (sockc_valid && sockc.dmabuf_id && + (!(flags & MSG_ZEROCOPY) || !sock_flag(sk, SOCK_ZEROCOPY))) { + err = -EINVAL; + goto out_err; + } + if (unlikely(flags & MSG_FASTOPEN || inet_test_bit(DEFER_CONNECT, sk)) && !tp->repair) { @@ -1131,14 +1161,8 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size) /* 'common' sending to sendq */ } - sockc = (struct sockcm_cookie) { .tsflags = READ_ONCE(sk->sk_tsflags)}; - if (msg->msg_controllen) { - err = sock_cmsg_send(sk, msg, &sockc); - if (unlikely(err)) { - err = -EINVAL; - goto out_err; - } - } + if (!sockc_valid) + goto out_err; /* This should be in poll */ sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); @@ -1258,7 +1282,8 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size) goto wait_for_space; } - err = skb_zerocopy_iter_stream(sk, skb, msg, copy, uarg); + err = skb_zerocopy_iter_stream(sk, skb, msg, copy, uarg, + binding); if (err == -EMSGSIZE || err == -EEXIST) { tcp_mark_push(tp, skb); goto new_segment; @@ -1339,6 +1364,8 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size) /* msg->msg_ubuf is pinned by the caller so we don't take extra refs */ if (uarg && !msg->msg_ubuf) net_zcopy_put(uarg); + if (binding) + net_devmem_dmabuf_binding_put(binding); return copied + copied_syn; do_error: @@ -1356,6 +1383,9 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size) sk->sk_write_space(sk); tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED); } + if (binding) + net_devmem_dmabuf_binding_put(binding); + return err; } EXPORT_SYMBOL_GPL(tcp_sendmsg_locked); diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index ef052ccd9380..7bd29a9ff0db 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -1524,7 +1524,8 @@ static int __ip6_append_data(struct sock *sk, uarg = msg->msg_ubuf; } } else if (sock_flag(sk, SOCK_ZEROCOPY)) { - uarg = msg_zerocopy_realloc(sk, length, skb_zcopy(skb)); + uarg = msg_zerocopy_realloc(sk, length, skb_zcopy(skb), + false); if (!uarg) return -ENOBUFS; extra_uref = !skb_zcopy(skb); /* only ref on new uarg */ diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index 7f7de6d88096..6e7b727c781c 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -87,7 +87,7 @@ static int virtio_transport_init_zcopy_skb(struct vsock_sock *vsk, uarg = msg_zerocopy_realloc(sk_vsock(vsk), iter->count, - NULL); + NULL, false); if (!uarg) return -1; @@ -107,8 +107,7 @@ static int virtio_transport_fill_skb(struct sk_buff *skb, { if (zcopy) return __zerocopy_sg_from_iter(info->msg, NULL, skb, - &info->msg->msg_iter, - len); + &info->msg->msg_iter, len, NULL); return memcpy_from_msg(skb_put(skb, len), info->msg, len); }