August 2024 - Linux-kselftest-mirror

[PATCH net-next v19 11/13] net: add devmem TCP documentation

by Mina Almasry

Add documentation outlining the usage and details of devmem TCP. Signed-off-by: Mina Almasry <almasrymina(a)google.com> Reviewed-by: Bagas Sanjaya <bagasdotme(a)gmail.com> Reviewed-by: Donald Hunter <donald.hunter(a)gmail.com> --- v16: - Add documentation on unbinding the NIC from dmabuf (Donald). - Add note that any dmabuf should work (Donald). v9: https://lore.kernel.org/netdev/20240403002053.2376017-14-almasrymina@google… - Bagas doc suggestions. v8: - Applied docs suggestions (Randy). Thanks! v7: - Applied docs suggestions (Jakub). v2: - Missing spdx (simon) - add to index.rst (simon) --- Documentation/networking/devmem.rst | 269 ++++++++++++++++++++++++++++ Documentation/networking/index.rst | 1 + 2 files changed, 270 insertions(+) create mode 100644 Documentation/networking/devmem.rst diff --git a/Documentation/networking/devmem.rst b/Documentation/networking/devmem.rst new file mode 100644 index 000000000000..417fc977844e --- /dev/null +++ b/Documentation/networking/devmem.rst @@ -0,0 +1,269 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================= +Device Memory TCP +================= + + +Intro +===== + +Device memory TCP (devmem TCP) enables receiving data directly into device +memory (dmabuf). The feature is currently implemented for TCP sockets. + + +Opportunity +----------- + +A large number of data transfers have device memory as the source and/or +destination. Accelerators drastically increased the prevalence of such +transfers. Some examples include: + +- Distributed training, where ML accelerators, such as GPUs on different hosts, + exchange data. + +- Distributed raw block storage applications transfer large amounts of data with + remote SSDs. Much of this data does not require host processing. + +Typically the Device-to-Device data transfers in the network are implemented as +the following low-level operations: Device-to-Host copy, Host-to-Host network +transfer, and Host-to-Device copy. + +The flow involving host copies is suboptimal, especially for bulk data transfers, +and can put significant strains on system resources such as host memory +bandwidth and PCIe bandwidth. + +Devmem TCP optimizes this use case by implementing socket APIs that enable +the user to receive incoming network packets directly into device memory. + +Packet payloads go directly from the NIC to device memory. + +Packet headers go to host memory and are processed by the TCP/IP stack +normally. The NIC must support header split to achieve this. + +Advantages: + +- Alleviate host memory bandwidth pressure, compared to existing + network-transfer + device-copy semantics. + +- Alleviate PCIe bandwidth pressure, by limiting data transfer to the lowest + level of the PCIe tree, compared to the traditional path which sends data + through the root complex. + + +More Info +--------- + + slides, video + https://netdevconf.org/0x17/sessions/talk/device-memory-tcp.html + + patchset + [RFC PATCH v6 00/12] Device Memory TCP + https://lore.kernel.org/netdev/20240305020153.2787423-1-almasrymina@google.… + + +Interface +========= + + +Example +------- + +tools/testing/selftests/net/ncdevmem.c:do_server shows an example of setting up +the RX path of this API. + + +NIC Setup +--------- + +Header split, flow steering, & RSS are required features for devmem TCP. + +Header split is used to split incoming packets into a header buffer in host +memory, and a payload buffer in device memory. + +Flow steering & RSS are used to ensure that only flows targeting devmem land on +an RX queue bound to devmem. + +Enable header split & flow steering:: + + # enable header split + ethtool -G eth1 tcp-data-split on + + + # enable flow steering + ethtool -K eth1 ntuple on + +Configure RSS to steer all traffic away from the target RX queue (queue 15 in +this example):: + + ethtool --set-rxfh-indir eth1 equal 15 + + +The user must bind a dmabuf to any number of RX queues on a given NIC using +the netlink API:: + + /* Bind dmabuf to NIC RX queue 15 */ + struct netdev_queue *queues; + queues = malloc(sizeof(*queues) * 1); + + queues[0]._present.type = 1; + queues[0]._present.idx = 1; + queues[0].type = NETDEV_RX_QUEUE_TYPE_RX; + queues[0].idx = 15; + + *ys = ynl_sock_create(&ynl_netdev_family, &yerr); + + req = netdev_bind_rx_req_alloc(); + netdev_bind_rx_req_set_ifindex(req, 1 /* ifindex */); + netdev_bind_rx_req_set_dmabuf_fd(req, dmabuf_fd); + __netdev_bind_rx_req_set_queues(req, queues, n_queue_index); + + rsp = netdev_bind_rx(*ys, req); + + dmabuf_id = rsp->dmabuf_id; + + +The netlink API returns a dmabuf_id: a unique ID that refers to this dmabuf +that has been bound. + +The user can unbind the dmabuf from the netdevice by closing the netlink socket +that established the binding. We do this so that the binding is automatically +unbound even if the userspace process crashes. + +Note that any reasonably well-behaved dmabuf from any exporter should work with +devmem TCP, even if the dmabuf is not actually backed by devmem. An example of +this is udmabuf, which wraps user memory (non-devmem) in a dmabuf. + + +Socket Setup +------------ + +The socket must be flow steered to the dmabuf bound RX queue:: + + ethtool -N eth1 flow-type tcp4 ... queue 15, + + +Receiving data +-------------- + +The user application must signal to the kernel that it is capable of receiving +devmem data by passing the MSG_SOCK_DEVMEM flag to recvmsg:: + + ret = recvmsg(fd, &msg, MSG_SOCK_DEVMEM); + +Applications that do not specify the MSG_SOCK_DEVMEM flag will receive an EFAULT +on devmem data. + +Devmem data is received directly into the dmabuf bound to the NIC in 'NIC +Setup', and the kernel signals such to the user via the SCM_DEVMEM_* cmsgs:: + + for (cm = CMSG_FIRSTHDR(&msg); cm; cm = CMSG_NXTHDR(&msg, cm)) { + if (cm->cmsg_level != SOL_SOCKET || + (cm->cmsg_type != SCM_DEVMEM_DMABUF && + cm->cmsg_type != SCM_DEVMEM_LINEAR)) + continue; + + dmabuf_cmsg = (struct dmabuf_cmsg *)CMSG_DATA(cm); + + if (cm->cmsg_type == SCM_DEVMEM_DMABUF) { + /* Frag landed in dmabuf. + * + * dmabuf_cmsg->dmabuf_id is the dmabuf the + * frag landed on. + * + * dmabuf_cmsg->frag_offset is the offset into + * the dmabuf where the frag starts. + * + * dmabuf_cmsg->frag_size is the size of the + * frag. + * + * dmabuf_cmsg->frag_token is a token used to + * refer to this frag for later freeing. + */ + + struct dmabuf_token token; + token.token_start = dmabuf_cmsg->frag_token; + token.token_count = 1; + continue; + } + + if (cm->cmsg_type == SCM_DEVMEM_LINEAR) + /* Frag landed in linear buffer. + * + * dmabuf_cmsg->frag_size is the size of the + * frag. + */ + continue; + + } + +Applications may receive 2 cmsgs: + +- SCM_DEVMEM_DMABUF: this indicates the fragment landed in the dmabuf indicated + by dmabuf_id. + +- SCM_DEVMEM_LINEAR: this indicates the fragment landed in the linear buffer. + This typically happens when the NIC is unable to split the packet at the + header boundary, such that part (or all) of the payload landed in host + memory. + +Applications may receive no SO_DEVMEM_* cmsgs. That indicates non-devmem, +regular TCP data that landed on an RX queue not bound to a dmabuf. + + +Freeing frags +------------- + +Frags received via SCM_DEVMEM_DMABUF are pinned by the kernel while the user +processes the frag. The user must return the frag to the kernel via +SO_DEVMEM_DONTNEED:: + + ret = setsockopt(client_fd, SOL_SOCKET, SO_DEVMEM_DONTNEED, &token, + sizeof(token)); + +The user must ensure the tokens are returned to the kernel in a timely manner. +Failure to do so will exhaust the limited dmabuf that is bound to the RX queue +and will lead to packet drops. + + +Implementation & Caveats +======================== + +Unreadable skbs +--------------- + +Devmem payloads are inaccessible to the kernel processing the packets. This +results in a few quirks for payloads of devmem skbs: + +- Loopback is not functional. Loopback relies on copying the payload, which is + not possible with devmem skbs. + +- Software checksum calculation fails. + +- TCP Dump and bpf can't access devmem packet payloads. + + +Testing +======= + +More realistic example code can be found in the kernel source under +tools/testing/selftests/net/ncdevmem.c + +ncdevmem is a devmem TCP netcat. It works very similarly to netcat, but +receives data directly into a udmabuf. + +To run ncdevmem, you need to run it on a server on the machine under test, and +you need to run netcat on a peer to provide the TX data. + +ncdevmem has a validation mode as well that expects a repeating pattern of +incoming data and validates it as such. For example, you can launch +ncdevmem on the server by:: + + ncdevmem -s <server IP> -c <client IP> -f eth1 -d 3 -n 0000:06:00.0 -l \ + -p 5201 -v 7 + +On client side, use regular netcat to send TX data to ncdevmem process +on the server:: + + yes $(echo -e \\x01\\x02\\x03\\x04\\x05\\x06) | \ + tr \\n \\0 | head -c 5G | nc <server IP> 5201 -p 5201 diff --git a/Documentation/networking/index.rst b/Documentation/networking/index.rst index d1af04b952f8..0be9924db642 100644 --- a/Documentation/networking/index.rst +++ b/Documentation/networking/index.rst @@ -49,6 +49,7 @@ Contents: cdc_mbim dccp dctcp + devmem dns_resolver driver eql -- 2.46.0.76.ge559c4bf1a-goog

1 year, 2 months

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[PATCH net-next v19 10/13] net: add SO_DEVMEM_DONTNEED setsockopt to release RX frags

by Mina Almasry

Add an interface for the user to notify the kernel that it is done reading the devmem dmabuf frags returned as cmsg. The kernel will drop the reference on the frags to make them available for reuse. Signed-off-by: Willem de Bruijn <willemb(a)google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz(a)google.com> Signed-off-by: Mina Almasry <almasrymina(a)google.com> Reviewed-by: Pavel Begunkov <asml.silence(a)gmail.com> Reviewed-by: Eric Dumazet <edumazet(a)google.com> --- v16: - Use sk_is_tcp(). - Fix unnamed 128 DONTNEED limit (David). - Fix kernel allocating for 128 tokens even if the user didn't ask for that much (Eric). - Fix number assignement (Arnd). v10: - Fix leak of tokens (Nikolay). v7: - Updated SO_DEVMEM_* uapi to use the next available entry (Arnd). v6: - Squash in locking optimizations from edumazet(a)google.com. With his changes we lock the xarray once per sock_devmem_dontneed operation rather than once per frag. Changes in v1: - devmemtoken -> dmabuf_token (David). - Use napi_pp_put_page() for refcounting (Yunsheng). - Fix build error with missing socket options on other asms. --- arch/alpha/include/uapi/asm/socket.h | 1 + arch/mips/include/uapi/asm/socket.h | 1 + arch/parisc/include/uapi/asm/socket.h | 1 + arch/sparc/include/uapi/asm/socket.h | 1 + include/uapi/asm-generic/socket.h | 1 + include/uapi/linux/uio.h | 4 ++ net/core/sock.c | 68 +++++++++++++++++++++++++++ 7 files changed, 77 insertions(+) diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h index ef4656a41058..251b73c5481e 100644 --- a/arch/alpha/include/uapi/asm/socket.h +++ b/arch/alpha/include/uapi/asm/socket.h @@ -144,6 +144,7 @@ #define SCM_DEVMEM_LINEAR SO_DEVMEM_LINEAR #define SO_DEVMEM_DMABUF 79 #define SCM_DEVMEM_DMABUF SO_DEVMEM_DMABUF +#define SO_DEVMEM_DONTNEED 80 #if !defined(__KERNEL__) diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h index 414807d55e33..8ab7582291ab 100644 --- a/arch/mips/include/uapi/asm/socket.h +++ b/arch/mips/include/uapi/asm/socket.h @@ -155,6 +155,7 @@ #define SCM_DEVMEM_LINEAR SO_DEVMEM_LINEAR #define SO_DEVMEM_DMABUF 79 #define SCM_DEVMEM_DMABUF SO_DEVMEM_DMABUF +#define SO_DEVMEM_DONTNEED 80 #if !defined(__KERNEL__) diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h index 2b817efd4544..38fc0b188e08 100644 --- a/arch/parisc/include/uapi/asm/socket.h +++ b/arch/parisc/include/uapi/asm/socket.h @@ -136,6 +136,7 @@ #define SCM_DEVMEM_LINEAR SO_DEVMEM_LINEAR #define SO_DEVMEM_DMABUF 79 #define SCM_DEVMEM_DMABUF SO_DEVMEM_DMABUF +#define SO_DEVMEM_DONTNEED 80 #if !defined(__KERNEL__) diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h index 00248fc68977..57084ed2f3c4 100644 --- a/arch/sparc/include/uapi/asm/socket.h +++ b/arch/sparc/include/uapi/asm/socket.h @@ -137,6 +137,7 @@ #define SCM_DEVMEM_LINEAR SO_DEVMEM_LINEAR #define SO_DEVMEM_DMABUF 0x0058 #define SCM_DEVMEM_DMABUF SO_DEVMEM_DMABUF +#define SO_DEVMEM_DONTNEED 0x0059 #if !defined(__KERNEL__) diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h index e993edc9c0ee..3b4e3e815602 100644 --- a/include/uapi/asm-generic/socket.h +++ b/include/uapi/asm-generic/socket.h @@ -139,6 +139,7 @@ #define SCM_DEVMEM_LINEAR SO_DEVMEM_LINEAR #define SO_DEVMEM_DMABUF 79 #define SCM_DEVMEM_DMABUF SO_DEVMEM_DMABUF +#define SO_DEVMEM_DONTNEED 80 #if !defined(__KERNEL__) diff --git a/include/uapi/linux/uio.h b/include/uapi/linux/uio.h index 3a22ddae376a..d17f8fcd93ec 100644 --- a/include/uapi/linux/uio.h +++ b/include/uapi/linux/uio.h @@ -33,6 +33,10 @@ struct dmabuf_cmsg { */ }; +struct dmabuf_token { + __u32 token_start; + __u32 token_count; +}; /* * UIO_MAXIOV shall be at least 16 1003.1g (5.4.1.1) */ diff --git a/net/core/sock.c b/net/core/sock.c index 9abc4fe25953..df2a2dd6409d 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -124,6 +124,7 @@ #include <linux/netdevice.h> #include <net/protocol.h> #include <linux/skbuff.h> +#include <linux/skbuff_ref.h> #include <net/net_namespace.h> #include <net/request_sock.h> #include <net/sock.h> @@ -1049,6 +1050,69 @@ static int sock_reserve_memory(struct sock *sk, int bytes) return 0; } +#ifdef CONFIG_PAGE_POOL + +/* This is the number of tokens that the user can SO_DEVMEM_DONTNEED in + * 1 syscall. The limit exists to limit the amount of memory the kernel + * allocates to copy these tokens. + */ +#define MAX_DONTNEED_TOKENS 128 + +static noinline_for_stack int +sock_devmem_dontneed(struct sock *sk, sockptr_t optval, unsigned int optlen) +{ + unsigned int num_tokens, i, j, k, netmem_num = 0; + struct dmabuf_token *tokens; + netmem_ref netmems[16]; + int ret = 0; + + if (!sk_is_tcp(sk)) + return -EBADF; + + if (optlen % sizeof(struct dmabuf_token) || + optlen > sizeof(*tokens) * MAX_DONTNEED_TOKENS) + return -EINVAL; + + tokens = kvmalloc_array(optlen, sizeof(*tokens), GFP_KERNEL); + if (!tokens) + return -ENOMEM; + + num_tokens = optlen / sizeof(struct dmabuf_token); + if (copy_from_sockptr(tokens, optval, optlen)) { + kvfree(tokens); + return -EFAULT; + } + + xa_lock_bh(&sk->sk_user_frags); + for (i = 0; i < num_tokens; i++) { + for (j = 0; j < tokens[i].token_count; j++) { + netmem_ref netmem = (__force netmem_ref)__xa_erase( + &sk->sk_user_frags, tokens[i].token_start + j); + + if (netmem && + !WARN_ON_ONCE(!netmem_is_net_iov(netmem))) { + netmems[netmem_num++] = netmem; + if (netmem_num == ARRAY_SIZE(netmems)) { + xa_unlock_bh(&sk->sk_user_frags); + for (k = 0; k < netmem_num; k++) + WARN_ON_ONCE(!napi_pp_put_page(netmems[k])); + netmem_num = 0; + xa_lock_bh(&sk->sk_user_frags); + } + ret++; + } + } + } + + xa_unlock_bh(&sk->sk_user_frags); + for (k = 0; k < netmem_num; k++) + WARN_ON_ONCE(!napi_pp_put_page(netmems[k])); + + kvfree(tokens); + return ret; +} +#endif + void sockopt_lock_sock(struct sock *sk) { /* When current->bpf_ctx is set, the setsockopt is called from @@ -1211,6 +1275,10 @@ int sk_setsockopt(struct sock *sk, int level, int optname, ret = -EOPNOTSUPP; return ret; } +#ifdef CONFIG_PAGE_POOL + case SO_DEVMEM_DONTNEED: + return sock_devmem_dontneed(sk, optval, optlen); +#endif } sockopt_lock_sock(sk); -- 2.46.0.76.ge559c4bf1a-goog

1 year, 2 months

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[PATCH net-next v19 08/13] net: add support for skbs with unreadable frags

by Mina Almasry

For device memory TCP, we expect the skb headers to be available in host memory for access, and we expect the skb frags to be in device memory and unaccessible to the host. We expect there to be no mixing and matching of device memory frags (unaccessible) with host memory frags (accessible) in the same skb. Add a skb->devmem flag which indicates whether the frags in this skb are device memory frags or not. __skb_fill_netmem_desc() now checks frags added to skbs for net_iov, and marks the skb as skb->devmem accordingly. Add checks through the network stack to avoid accessing the frags of devmem skbs and avoid coalescing devmem skbs with non devmem skbs. Signed-off-by: Willem de Bruijn <willemb(a)google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz(a)google.com> Signed-off-by: Mina Almasry <almasrymina(a)google.com> Reviewed-by: Eric Dumazet <edumazet(a)google.com> --- v16: - Fix unreadable handling in skb_split_no_header() (Eric). v11: - drop excessive checks for frag 0 pull (Paolo) v9: https://lore.kernel.org/netdev/20240403002053.2376017-11-almasrymina@google… - change skb->readable to skb->unreadable (Pavel/David). skb->readable was very complicated, because by default skbs are readable so the flag needed to be set to true in all code paths where new skbs were created or cloned. Forgetting to set skb->readable=true in some paths caused crashes. Flip it to skb->unreadable so that the default 0 value works well, and we only need to set it to true when we add unreadable frags. v6 - skb->dmabuf -> skb->readable (Pavel). Pavel's original suggestion was to remove the skb->dmabuf flag entirely, but when I looked into it closely, I found the issue that if we remove the flag we have to dereference the shinfo(skb) pointer to obtain the first frag, which can cause a performance regression if it dirties the cache line when the shinfo(skb) was not really needed. Instead, I converted the skb->dmabuf flag into a generic skb->readable flag which can be re-used by io_uring. Changes in v1: - Rename devmem -> dmabuf (David). - Flip skb_frags_not_readable (Jakub). --- include/linux/skbuff.h | 19 +++++++++++++++++-- include/net/tcp.h | 5 +++-- net/core/datagram.c | 6 ++++++ net/core/skbuff.c | 43 ++++++++++++++++++++++++++++++++++++++++-- net/ipv4/tcp.c | 3 +++ net/ipv4/tcp_input.c | 13 ++++++++++--- net/ipv4/tcp_output.c | 5 ++++- net/packet/af_packet.c | 4 ++-- 8 files changed, 86 insertions(+), 12 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index dbadf2dd6b35..d02a88bad953 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -827,6 +827,8 @@ enum skb_tstamp_type { * @csum_level: indicates the number of consecutive checksums found in * the packet minus one that have been verified as * CHECKSUM_UNNECESSARY (max 3) + * @unreadable: indicates that at least 1 of the fragments in this skb is + * unreadable. * @dst_pending_confirm: need to confirm neighbour * @decrypted: Decrypted SKB * @slow_gro: state present at GRO time, slower prepare step required @@ -1008,7 +1010,7 @@ struct sk_buff { #if IS_ENABLED(CONFIG_IP_SCTP) __u8 csum_not_inet:1; #endif - + __u8 unreadable:1; #if defined(CONFIG_NET_SCHED) || defined(CONFIG_NET_XGRESS) __u16 tc_index; /* traffic control index */ #endif @@ -1823,6 +1825,12 @@ static inline void skb_zcopy_downgrade_managed(struct sk_buff *skb) __skb_zcopy_downgrade_managed(skb); } +/* Return true if frags in this skb are readable by the host. */ +static inline bool skb_frags_readable(const struct sk_buff *skb) +{ + return !skb->unreadable; +} + static inline void skb_mark_not_on_list(struct sk_buff *skb) { skb->next = NULL; @@ -2539,10 +2547,17 @@ static inline void skb_len_add(struct sk_buff *skb, int delta) static inline void __skb_fill_netmem_desc(struct sk_buff *skb, int i, netmem_ref netmem, int off, int size) { - struct page *page = netmem_to_page(netmem); + struct page *page; __skb_fill_netmem_desc_noacc(skb_shinfo(skb), i, netmem, off, size); + if (netmem_is_net_iov(netmem)) { + skb->unreadable = true; + return; + } + + page = netmem_to_page(netmem); + /* Propagate page pfmemalloc to the skb if we can. The problem is * that not all callers have unique ownership of the page but rely * on page_is_pfmemalloc doing the right thing(tm). diff --git a/include/net/tcp.h b/include/net/tcp.h index 2aac11e7e1cc..e8f6e602c2ad 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1060,7 +1060,7 @@ static inline int tcp_skb_mss(const struct sk_buff *skb) static inline bool tcp_skb_can_collapse_to(const struct sk_buff *skb) { - return likely(!TCP_SKB_CB(skb)->eor); + return likely(!TCP_SKB_CB(skb)->eor && skb_frags_readable(skb)); } static inline bool tcp_skb_can_collapse(const struct sk_buff *to, @@ -1069,7 +1069,8 @@ static inline bool tcp_skb_can_collapse(const struct sk_buff *to, /* skb_cmp_decrypted() not needed, use tcp_write_collapse_fence() */ return likely(tcp_skb_can_collapse_to(to) && mptcp_skb_can_collapse(to, from) && - skb_pure_zcopy_same(to, from)); + skb_pure_zcopy_same(to, from) && + skb_frags_readable(to) == skb_frags_readable(from)); } static inline bool tcp_skb_can_collapse_rx(const struct sk_buff *to, diff --git a/net/core/datagram.c b/net/core/datagram.c index a40f733b37d7..f0693707aece 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -407,6 +407,9 @@ static int __skb_datagram_iter(const struct sk_buff *skb, int offset, return 0; } + if (!skb_frags_readable(skb)) + goto short_copy; + /* Copy paged appendix. Hmm... why does this look so complicated? */ for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { int end; @@ -623,6 +626,9 @@ int zerocopy_fill_skb_from_iter(struct sk_buff *skb, { int frag = skb_shinfo(skb)->nr_frags; + if (!skb_frags_readable(skb)) + return -EFAULT; + while (length && iov_iter_count(from)) { struct page *head, *last_head = NULL; struct page *pages[MAX_SKB_FRAGS]; diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 91c7def73700..ea60dae05168 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -1972,6 +1972,9 @@ int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask) if (skb_shared(skb) || skb_unclone(skb, gfp_mask)) return -EINVAL; + if (!skb_frags_readable(skb)) + return -EFAULT; + if (!num_frags) goto release; @@ -2145,6 +2148,9 @@ struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t gfp_mask) unsigned int size; int headerlen; + if (!skb_frags_readable(skb)) + return NULL; + if (WARN_ON_ONCE(skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST)) return NULL; @@ -2483,6 +2489,9 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb, struct sk_buff *n; int oldheadroom; + if (!skb_frags_readable(skb)) + return NULL; + if (WARN_ON_ONCE(skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST)) return NULL; @@ -2827,6 +2836,9 @@ void *__pskb_pull_tail(struct sk_buff *skb, int delta) */ int i, k, eat = (skb->tail + delta) - skb->end; + if (!skb_frags_readable(skb)) + return NULL; + if (eat > 0 || skb_cloned(skb)) { if (pskb_expand_head(skb, 0, eat > 0 ? eat + 128 : 0, GFP_ATOMIC)) @@ -2980,6 +2992,9 @@ int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len) to += copy; } + if (!skb_frags_readable(skb)) + goto fault; + for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { int end; skb_frag_t *f = &skb_shinfo(skb)->frags[i]; @@ -3168,6 +3183,9 @@ static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe, /* * then map the fragments */ + if (!skb_frags_readable(skb)) + return false; + for (seg = 0; seg < skb_shinfo(skb)->nr_frags; seg++) { const skb_frag_t *f = &skb_shinfo(skb)->frags[seg]; @@ -3391,6 +3409,9 @@ int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len) from += copy; } + if (!skb_frags_readable(skb)) + goto fault; + for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; int end; @@ -3470,6 +3491,9 @@ __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len, pos = copy; } + if (!skb_frags_readable(skb)) + return 0; + for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { int end; skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; @@ -3570,6 +3594,9 @@ __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, pos = copy; } + if (!skb_frags_readable(skb)) + return 0; + for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { int end; @@ -4061,6 +4088,7 @@ static inline void skb_split_inside_header(struct sk_buff *skb, skb_shinfo(skb1)->frags[i] = skb_shinfo(skb)->frags[i]; skb_shinfo(skb1)->nr_frags = skb_shinfo(skb)->nr_frags; + skb1->unreadable = skb->unreadable; skb_shinfo(skb)->nr_frags = 0; skb1->data_len = skb->data_len; skb1->len += skb1->data_len; @@ -4108,6 +4136,8 @@ static inline void skb_split_no_header(struct sk_buff *skb, pos += size; } skb_shinfo(skb1)->nr_frags = k; + + skb1->unreadable = skb->unreadable; } /** @@ -4346,6 +4376,9 @@ unsigned int skb_seq_read(unsigned int consumed, const u8 **data, return block_limit - abs_offset; } + if (!skb_frags_readable(st->cur_skb)) + return 0; + if (st->frag_idx == 0 && !st->frag_data) st->stepped_offset += skb_headlen(st->cur_skb); @@ -5958,7 +5991,10 @@ bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from, if (to->pp_recycle != from->pp_recycle) return false; - if (len <= skb_tailroom(to)) { + if (skb_frags_readable(from) != skb_frags_readable(to)) + return false; + + if (len <= skb_tailroom(to) && skb_frags_readable(from)) { if (len) BUG_ON(skb_copy_bits(from, 0, skb_put(to, len), len)); *delta_truesize = 0; @@ -6135,6 +6171,9 @@ int skb_ensure_writable(struct sk_buff *skb, unsigned int write_len) if (!pskb_may_pull(skb, write_len)) return -ENOMEM; + if (!skb_frags_readable(skb)) + return -EFAULT; + if (!skb_cloned(skb) || skb_clone_writable(skb, write_len)) return 0; @@ -6814,7 +6853,7 @@ void skb_condense(struct sk_buff *skb) { if (skb->data_len) { if (skb->data_len > skb->end - skb->tail || - skb_cloned(skb)) + skb_cloned(skb) || !skb_frags_readable(skb)) return; /* Nice, we can free page frag(s) right now */ diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 20a1b0333017..30e0aa38ba9b 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2160,6 +2160,9 @@ static int tcp_zerocopy_receive(struct sock *sk, skb = tcp_recv_skb(sk, seq, &offset); } + if (!skb_frags_readable(skb)) + break; + if (TCP_SKB_CB(skb)->has_rxtstamp) { tcp_update_recv_tstamps(skb, tss); zc->msg_flags |= TCP_CMSG_TS; diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index e2b9583ed96a..01cbc317fd71 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5395,6 +5395,9 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *list, struct rb_root *root, for (end_of_skbs = true; skb != NULL && skb != tail; skb = n) { n = tcp_skb_next(skb, list); + if (!skb_frags_readable(skb)) + goto skip_this; + /* No new bits? It is possible on ofo queue. */ if (!before(start, TCP_SKB_CB(skb)->end_seq)) { skb = tcp_collapse_one(sk, skb, list, root); @@ -5415,17 +5418,20 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *list, struct rb_root *root, break; } - if (n && n != tail && tcp_skb_can_collapse_rx(skb, n) && + if (n && n != tail && skb_frags_readable(n) && + tcp_skb_can_collapse_rx(skb, n) && TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(n)->seq) { end_of_skbs = false; break; } +skip_this: /* Decided to skip this, advance start seq. */ start = TCP_SKB_CB(skb)->end_seq; } if (end_of_skbs || - (TCP_SKB_CB(skb)->tcp_flags & (TCPHDR_SYN | TCPHDR_FIN))) + (TCP_SKB_CB(skb)->tcp_flags & (TCPHDR_SYN | TCPHDR_FIN)) || + !skb_frags_readable(skb)) return; __skb_queue_head_init(&tmp); @@ -5467,7 +5473,8 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *list, struct rb_root *root, if (!skb || skb == tail || !tcp_skb_can_collapse_rx(nskb, skb) || - (TCP_SKB_CB(skb)->tcp_flags & (TCPHDR_SYN | TCPHDR_FIN))) + (TCP_SKB_CB(skb)->tcp_flags & (TCPHDR_SYN | TCPHDR_FIN)) || + !skb_frags_readable(skb)) goto end; } } diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index cdd0def14427..4fd746bd4d54 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2344,7 +2344,8 @@ static bool tcp_can_coalesce_send_queue_head(struct sock *sk, int len) if (unlikely(TCP_SKB_CB(skb)->eor) || tcp_has_tx_tstamp(skb) || - !skb_pure_zcopy_same(skb, next)) + !skb_pure_zcopy_same(skb, next) || + skb_frags_readable(skb) != skb_frags_readable(next)) return false; len -= skb->len; @@ -3264,6 +3265,8 @@ static bool tcp_can_collapse(const struct sock *sk, const struct sk_buff *skb) return false; if (skb_cloned(skb)) return false; + if (!skb_frags_readable(skb)) + return false; /* Some heuristics for collapsing over SACK'd could be invented */ if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED) return false; diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 4a364cdd445e..a705ec214254 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2216,7 +2216,7 @@ static int packet_rcv(struct sk_buff *skb, struct net_device *dev, } } - snaplen = skb->len; + snaplen = skb_frags_readable(skb) ? skb->len : skb_headlen(skb); res = run_filter(skb, sk, snaplen); if (!res) @@ -2336,7 +2336,7 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, } } - snaplen = skb->len; + snaplen = skb_frags_readable(skb) ? skb->len : skb_headlen(skb); res = run_filter(skb, sk, snaplen); if (!res) -- 2.46.0.76.ge559c4bf1a-goog

1 year, 2 months

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[PATCH net-next v19 07/13] net: support non paged skb frags

by Mina Almasry

Make skb_frag_page() fail in the case where the frag is not backed by a page, and fix its relevant callers to handle this case. Signed-off-by: Mina Almasry <almasrymina(a)google.com> Reviewed-by: Eric Dumazet <edumazet(a)google.com> --- v10: - Fixed newly generated kdoc warnings found by patchwork. While we're at it, fix the Return section of the functions I touched. v6: - Rebased on top of the merged netmem changes. Changes in v1: - Fix illegal_highdma() (Yunsheng). - Rework napi_pp_put_page() slightly to reduce code churn (Willem). --- include/linux/skbuff.h | 42 +++++++++++++++++++++++++++++++++++++- include/linux/skbuff_ref.h | 9 ++++---- net/core/dev.c | 3 ++- net/core/gro.c | 3 ++- net/core/skbuff.c | 11 ++++++++++ net/ipv4/esp4.c | 3 ++- net/ipv4/tcp.c | 3 +++ net/ipv6/esp6.c | 3 ++- 8 files changed, 67 insertions(+), 10 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index cf8f6ce06742..dbadf2dd6b35 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -3523,21 +3523,58 @@ static inline void skb_frag_off_copy(skb_frag_t *fragto, fragto->offset = fragfrom->offset; } +/* Return: true if the skb_frag contains a net_iov. */ +static inline bool skb_frag_is_net_iov(const skb_frag_t *frag) +{ + return netmem_is_net_iov(frag->netmem); +} + +/** + * skb_frag_net_iov - retrieve the net_iov referred to by fragment + * @frag: the fragment + * + * Return: the &struct net_iov associated with @frag. Returns NULL if this + * frag has no associated net_iov. + */ +static inline struct net_iov *skb_frag_net_iov(const skb_frag_t *frag) +{ + if (!skb_frag_is_net_iov(frag)) + return NULL; + + return netmem_to_net_iov(frag->netmem); +} + /** * skb_frag_page - retrieve the page referred to by a paged fragment * @frag: the paged fragment * - * Returns the &struct page associated with @frag. + * Return: the &struct page associated with @frag. Returns NULL if this frag + * has no associated page. */ static inline struct page *skb_frag_page(const skb_frag_t *frag) { + if (skb_frag_is_net_iov(frag)) + return NULL; + return netmem_to_page(frag->netmem); } +/** + * skb_frag_netmem - retrieve the netmem referred to by a fragment + * @frag: the fragment + * + * Return: the &netmem_ref associated with @frag. + */ +static inline netmem_ref skb_frag_netmem(const skb_frag_t *frag) +{ + return frag->netmem; +} + int skb_pp_cow_data(struct page_pool *pool, struct sk_buff **pskb, unsigned int headroom); int skb_cow_data_for_xdp(struct page_pool *pool, struct sk_buff **pskb, struct bpf_prog *prog); + /** * skb_frag_address - gets the address of the data contained in a paged fragment * @frag: the paged fragment buffer @@ -3547,6 +3584,9 @@ int skb_cow_data_for_xdp(struct page_pool *pool, struct sk_buff **pskb, */ static inline void *skb_frag_address(const skb_frag_t *frag) { + if (!skb_frag_page(frag)) + return NULL; + return page_address(skb_frag_page(frag)) + skb_frag_off(frag); } diff --git a/include/linux/skbuff_ref.h b/include/linux/skbuff_ref.h index 16c241a23472..0f3c58007488 100644 --- a/include/linux/skbuff_ref.h +++ b/include/linux/skbuff_ref.h @@ -34,14 +34,13 @@ static inline void skb_frag_ref(struct sk_buff *skb, int f) bool napi_pp_put_page(netmem_ref netmem); -static inline void -skb_page_unref(struct page *page, bool recycle) +static inline void skb_page_unref(netmem_ref netmem, bool recycle) { #ifdef CONFIG_PAGE_POOL - if (recycle && napi_pp_put_page(page_to_netmem(page))) + if (recycle && napi_pp_put_page(netmem)) return; #endif - put_page(page); + put_page(netmem_to_page(netmem)); } /** @@ -54,7 +53,7 @@ skb_page_unref(struct page *page, bool recycle) */ static inline void __skb_frag_unref(skb_frag_t *frag, bool recycle) { - skb_page_unref(skb_frag_page(frag), recycle); + skb_page_unref(skb_frag_netmem(frag), recycle); } /** diff --git a/net/core/dev.c b/net/core/dev.c index 0a8caf0e4c77..87a43c6997f4 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3434,8 +3434,9 @@ static int illegal_highdma(struct net_device *dev, struct sk_buff *skb) if (!(dev->features & NETIF_F_HIGHDMA)) { for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; + struct page *page = skb_frag_page(frag); - if (PageHighMem(skb_frag_page(frag))) + if (page && PageHighMem(page)) return 1; } } diff --git a/net/core/gro.c b/net/core/gro.c index b3b43de1a650..26f09c3e830b 100644 --- a/net/core/gro.c +++ b/net/core/gro.c @@ -408,7 +408,8 @@ static inline void skb_gro_reset_offset(struct sk_buff *skb, u32 nhoff) pinfo = skb_shinfo(skb); frag0 = &pinfo->frags[0]; - if (pinfo->nr_frags && !PageHighMem(skb_frag_page(frag0)) && + if (pinfo->nr_frags && skb_frag_page(frag0) && + !PageHighMem(skb_frag_page(frag0)) && (!NET_IP_ALIGN || !((skb_frag_off(frag0) + nhoff) & 3))) { NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0); NAPI_GRO_CB(skb)->frag0_len = min_t(unsigned int, diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 9e2b28342793..91c7def73700 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -1371,6 +1371,14 @@ void skb_dump(const char *level, const struct sk_buff *skb, bool full_pkt) struct page *p; u8 *vaddr; + if (skb_frag_is_net_iov(frag)) { + printk("%sskb frag %d: not readable\n", level, i); + len -= skb_frag_size(frag); + if (!len) + break; + continue; + } + skb_frag_foreach_page(frag, skb_frag_off(frag), skb_frag_size(frag), p, p_off, p_len, copied) { @@ -3163,6 +3171,9 @@ static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe, for (seg = 0; seg < skb_shinfo(skb)->nr_frags; seg++) { const skb_frag_t *f = &skb_shinfo(skb)->frags[seg]; + if (WARN_ON_ONCE(!skb_frag_page(f))) + return false; + if (__splice_segment(skb_frag_page(f), skb_frag_off(f), skb_frag_size(f), offset, len, spd, false, sk, pipe)) diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c index 47378ca41904..f3281312eb5e 100644 --- a/net/ipv4/esp4.c +++ b/net/ipv4/esp4.c @@ -115,7 +115,8 @@ static void esp_ssg_unref(struct xfrm_state *x, void *tmp, struct sk_buff *skb) */ if (req->src != req->dst) for (sg = sg_next(req->src); sg; sg = sg_next(sg)) - skb_page_unref(sg_page(sg), skb->pp_recycle); + skb_page_unref(page_to_netmem(sg_page(sg)), + skb->pp_recycle); } #ifdef CONFIG_INET_ESPINTCP diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 8514257f4ecd..20a1b0333017 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2177,6 +2177,9 @@ static int tcp_zerocopy_receive(struct sock *sk, break; } page = skb_frag_page(frags); + if (WARN_ON_ONCE(!page)) + break; + prefetchw(page); pages[pages_to_map++] = page; length += PAGE_SIZE; diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c index 3920e8aa1031..b2400c226a32 100644 --- a/net/ipv6/esp6.c +++ b/net/ipv6/esp6.c @@ -132,7 +132,8 @@ static void esp_ssg_unref(struct xfrm_state *x, void *tmp, struct sk_buff *skb) */ if (req->src != req->dst) for (sg = sg_next(req->src); sg; sg = sg_next(sg)) - skb_page_unref(sg_page(sg), skb->pp_recycle); + skb_page_unref(page_to_netmem(sg_page(sg)), + skb->pp_recycle); } #ifdef CONFIG_INET6_ESPINTCP -- 2.46.0.76.ge559c4bf1a-goog

1 year, 2 months

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[PATCH net-next v19 05/13] page_pool: devmem support

by Mina Almasry

Convert netmem to be a union of struct page and struct netmem. Overload the LSB of struct netmem* to indicate that it's a net_iov, otherwise it's a page. Currently these entries in struct page are rented by the page_pool and used exclusively by the net stack: struct { unsigned long pp_magic; struct page_pool *pp; unsigned long _pp_mapping_pad; unsigned long dma_addr; atomic_long_t pp_ref_count; }; Mirror these (and only these) entries into struct net_iov and implement netmem helpers that can access these common fields regardless of whether the underlying type is page or net_iov. Implement checks for net_iov in netmem helpers which delegate to mm APIs, to ensure net_iov are never passed to the mm stack. Signed-off-by: Mina Almasry <almasrymina(a)google.com> Reviewed-by: Pavel Begunkov <asml.silence(a)gmail.com> --- v19: - Move page_pool_set_dma_addr(_netmem) to page_pool_priv.h - Don't reset niov dma_addr on allocation/free. Instead, it's set once when the binding happens and it never changes (Jakub) v17: - Rename netmem_to_pfn to netmem_pfn_trace (Jakub) - Move some low level netmem helpers to netmem_priv.h (Jakub). v13: - Move NET_IOV dependent changes to this patch. - Fixed comment (Pavel) - Applied Reviewed-by from Pavel. v9: https://lore.kernel.org/netdev/20240403002053.2376017-8-almasrymina@google.… - Remove CONFIG checks in netmem_is_net_iov() (Pavel/David/Jens) v7: - Remove static_branch_unlikely from netmem_to_net_iov(). We're getting better results from the fast path in bench_page_pool_simple tests without the static_branch_unlikely, and the addition of static_branch_unlikely doesn't improve performance of devmem TCP. Additionally only check netmem_to_net_iov() if CONFIG_DMA_SHARED_BUFFER is enabled, otherwise dmabuf net_iovs cannot exist anyway. net-next base: 8 cycle fast path. with static_branch_unlikely: 10 cycle fast path. without static_branch_unlikely: 9 cycle fast path. CONFIG_DMA_SHARED_BUFFER disabled: 8 cycle fast path as baseline. Performance of devmem TCP is at 95% line rate is regardless of static_branch_unlikely or not. v6: - Rebased on top of the merged netmem_ref type. - Rebased on top of the merged skb_pp_frag_ref() changes. v5: - Use netmem instead of page* with LSB set. - Use pp_ref_count for refcounting net_iov. - Removed many of the custom checks for netmem. v1: - Disable fragmentation support for iov properly. - fix napi_pp_put_page() path (Yunsheng). - Use pp_frag_count for devmem refcounting. Cc: linux-mm(a)kvack.org Cc: Matthew Wilcox <willy(a)infradead.org> --- include/net/netmem.h | 128 +++++++++++++++++++++++++++++-- include/net/page_pool/helpers.h | 39 ++-------- include/trace/events/page_pool.h | 12 +-- net/core/devmem.c | 8 ++ net/core/netmem_priv.h | 31 ++++++++ net/core/page_pool.c | 25 +++--- net/core/page_pool_priv.h | 24 ++++++ net/core/skbuff.c | 23 +++--- 8 files changed, 221 insertions(+), 69 deletions(-) create mode 100644 net/core/netmem_priv.h diff --git a/include/net/netmem.h b/include/net/netmem.h index 664df8325ece..284f84a312c2 100644 --- a/include/net/netmem.h +++ b/include/net/netmem.h @@ -9,14 +9,51 @@ #define _NET_NETMEM_H #include <net/devmem.h> +#include <net/net_debug.h> /* net_iov */ +DECLARE_STATIC_KEY_FALSE(page_pool_mem_providers); + +/* We overload the LSB of the struct page pointer to indicate whether it's + * a page or net_iov. + */ +#define NET_IOV 0x01UL + struct net_iov { + unsigned long __unused_padding; + unsigned long pp_magic; + struct page_pool *pp; struct dmabuf_genpool_chunk_owner *owner; unsigned long dma_addr; + atomic_long_t pp_ref_count; }; +/* These fields in struct page are used by the page_pool and net stack: + * + * struct { + * unsigned long pp_magic; + * struct page_pool *pp; + * unsigned long _pp_mapping_pad; + * unsigned long dma_addr; + * atomic_long_t pp_ref_count; + * }; + * + * We mirror the page_pool fields here so the page_pool can access these fields + * without worrying whether the underlying fields belong to a page or net_iov. + * + * The non-net stack fields of struct page are private to the mm stack and must + * never be mirrored to net_iov. + */ +#define NET_IOV_ASSERT_OFFSET(pg, iov) \ + static_assert(offsetof(struct page, pg) == \ + offsetof(struct net_iov, iov)) +NET_IOV_ASSERT_OFFSET(pp_magic, pp_magic); +NET_IOV_ASSERT_OFFSET(pp, pp); +NET_IOV_ASSERT_OFFSET(dma_addr, dma_addr); +NET_IOV_ASSERT_OFFSET(pp_ref_count, pp_ref_count); +#undef NET_IOV_ASSERT_OFFSET + static inline struct dmabuf_genpool_chunk_owner * net_iov_owner(const struct net_iov *niov) { @@ -47,20 +84,37 @@ net_iov_binding(const struct net_iov *niov) */ typedef unsigned long __bitwise netmem_ref; +static inline bool netmem_is_net_iov(const netmem_ref netmem) +{ + return (__force unsigned long)netmem & NET_IOV; +} + /* This conversion fails (returns NULL) if the netmem_ref is not struct page * backed. - * - * Currently struct page is the only possible netmem, and this helper never - * fails. */ static inline struct page *netmem_to_page(netmem_ref netmem) { + if (WARN_ON_ONCE(netmem_is_net_iov(netmem))) + return NULL; + return (__force struct page *)netmem; } -/* Converting from page to netmem is always safe, because a page can always be - * a netmem. - */ +static inline struct net_iov *netmem_to_net_iov(netmem_ref netmem) +{ + if (netmem_is_net_iov(netmem)) + return (struct net_iov *)((__force unsigned long)netmem & + ~NET_IOV); + + DEBUG_NET_WARN_ON_ONCE(true); + return NULL; +} + +static inline netmem_ref net_iov_to_netmem(struct net_iov *niov) +{ + return (__force netmem_ref)((unsigned long)niov | NET_IOV); +} + static inline netmem_ref page_to_netmem(struct page *page) { return (__force netmem_ref)page; @@ -68,17 +122,77 @@ static inline netmem_ref page_to_netmem(struct page *page) static inline int netmem_ref_count(netmem_ref netmem) { + /* The non-pp refcount of net_iov is always 1. On net_iov, we only + * support pp refcounting which uses the pp_ref_count field. + */ + if (netmem_is_net_iov(netmem)) + return 1; + return page_ref_count(netmem_to_page(netmem)); } -static inline unsigned long netmem_to_pfn(netmem_ref netmem) +static inline unsigned long netmem_pfn_trace(netmem_ref netmem) { + if (netmem_is_net_iov(netmem)) + return 0; + return page_to_pfn(netmem_to_page(netmem)); } +static inline struct net_iov *__netmem_clear_lsb(netmem_ref netmem) +{ + return (struct net_iov *)((__force unsigned long)netmem & ~NET_IOV); +} + +static inline struct page_pool *netmem_get_pp(netmem_ref netmem) +{ + return __netmem_clear_lsb(netmem)->pp; +} + +static inline atomic_long_t *netmem_get_pp_ref_count_ref(netmem_ref netmem) +{ + return &__netmem_clear_lsb(netmem)->pp_ref_count; +} + +static inline bool netmem_is_pref_nid(netmem_ref netmem, int pref_nid) +{ + /* Assume net_iov are on the preferred node without actually + * checking... + * + * This check is only used to check for recycling memory in the page + * pool's fast paths. Currently the only implementation of net_iov + * is dmabuf device memory. It's a deliberate decision by the user to + * bind a certain dmabuf to a certain netdev, and the netdev rx queue + * would not be able to reallocate memory from another dmabuf that + * exists on the preferred node, so, this check doesn't make much sense + * in this case. Assume all net_iovs can be recycled for now. + */ + if (netmem_is_net_iov(netmem)) + return true; + + return page_to_nid(netmem_to_page(netmem)) == pref_nid; +} + static inline netmem_ref netmem_compound_head(netmem_ref netmem) { + /* niov are never compounded */ + if (netmem_is_net_iov(netmem)) + return netmem; + return page_to_netmem(compound_head(netmem_to_page(netmem))); } +static inline void *netmem_address(netmem_ref netmem) +{ + if (netmem_is_net_iov(netmem)) + return NULL; + + return page_address(netmem_to_page(netmem)); +} + +static inline unsigned long netmem_get_dma_addr(netmem_ref netmem) +{ + return __netmem_clear_lsb(netmem)->dma_addr; +} + #endif /* _NET_NETMEM_H */ diff --git a/include/net/page_pool/helpers.h b/include/net/page_pool/helpers.h index 2b43a893c619..793e6fd78bc5 100644 --- a/include/net/page_pool/helpers.h +++ b/include/net/page_pool/helpers.h @@ -216,7 +216,7 @@ page_pool_get_dma_dir(const struct page_pool *pool) static inline void page_pool_fragment_netmem(netmem_ref netmem, long nr) { - atomic_long_set(&netmem_to_page(netmem)->pp_ref_count, nr); + atomic_long_set(netmem_get_pp_ref_count_ref(netmem), nr); } /** @@ -244,7 +244,7 @@ static inline void page_pool_fragment_page(struct page *page, long nr) static inline long page_pool_unref_netmem(netmem_ref netmem, long nr) { - struct page *page = netmem_to_page(netmem); + atomic_long_t *pp_ref_count = netmem_get_pp_ref_count_ref(netmem); long ret; /* If nr == pp_ref_count then we have cleared all remaining @@ -261,19 +261,19 @@ static inline long page_pool_unref_netmem(netmem_ref netmem, long nr) * initially, and only overwrite it when the page is partitioned into * more than one piece. */ - if (atomic_long_read(&page->pp_ref_count) == nr) { + if (atomic_long_read(pp_ref_count) == nr) { /* As we have ensured nr is always one for constant case using * the BUILD_BUG_ON(), only need to handle the non-constant case * here for pp_ref_count draining, which is a rare case. */ BUILD_BUG_ON(__builtin_constant_p(nr) && nr != 1); if (!__builtin_constant_p(nr)) - atomic_long_set(&page->pp_ref_count, 1); + atomic_long_set(pp_ref_count, 1); return 0; } - ret = atomic_long_sub_return(nr, &page->pp_ref_count); + ret = atomic_long_sub_return(nr, pp_ref_count); WARN_ON(ret < 0); /* We are the last user here too, reset pp_ref_count back to 1 to @@ -282,7 +282,7 @@ static inline long page_pool_unref_netmem(netmem_ref netmem, long nr) * page_pool_unref_page() currently. */ if (unlikely(!ret)) - atomic_long_set(&page->pp_ref_count, 1); + atomic_long_set(pp_ref_count, 1); return ret; } @@ -401,9 +401,7 @@ static inline void page_pool_free_va(struct page_pool *pool, void *va, static inline dma_addr_t page_pool_get_dma_addr_netmem(netmem_ref netmem) { - struct page *page = netmem_to_page(netmem); - - dma_addr_t ret = page->dma_addr; + dma_addr_t ret = netmem_get_dma_addr(netmem); if (PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA) ret <<= PAGE_SHIFT; @@ -423,24 +421,6 @@ static inline dma_addr_t page_pool_get_dma_addr(const struct page *page) return page_pool_get_dma_addr_netmem(page_to_netmem((struct page *)page)); } -static inline bool page_pool_set_dma_addr_netmem(netmem_ref netmem, - dma_addr_t addr) -{ - struct page *page = netmem_to_page(netmem); - - if (PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA) { - page->dma_addr = addr >> PAGE_SHIFT; - - /* We assume page alignment to shave off bottom bits, - * if this "compression" doesn't work we need to drop. - */ - return addr != (dma_addr_t)page->dma_addr << PAGE_SHIFT; - } - - page->dma_addr = addr; - return false; -} - /** * page_pool_dma_sync_for_cpu - sync Rx page for CPU after it's written by HW * @pool: &page_pool the @page belongs to @@ -463,11 +443,6 @@ static inline void page_pool_dma_sync_for_cpu(const struct page_pool *pool, page_pool_get_dma_dir(pool)); } -static inline bool page_pool_set_dma_addr(struct page *page, dma_addr_t addr) -{ - return page_pool_set_dma_addr_netmem(page_to_netmem(page), addr); -} - static inline bool page_pool_put(struct page_pool *pool) { return refcount_dec_and_test(&pool->user_cnt); diff --git a/include/trace/events/page_pool.h b/include/trace/events/page_pool.h index 543e54e432a1..31825ed30032 100644 --- a/include/trace/events/page_pool.h +++ b/include/trace/events/page_pool.h @@ -57,12 +57,12 @@ TRACE_EVENT(page_pool_state_release, __entry->pool = pool; __entry->netmem = (__force unsigned long)netmem; __entry->release = release; - __entry->pfn = netmem_to_pfn(netmem); + __entry->pfn = netmem_pfn_trace(netmem); ), - TP_printk("page_pool=%p netmem=%p pfn=0x%lx release=%u", + TP_printk("page_pool=%p netmem=%p is_net_iov=%lu pfn=0x%lx release=%u", __entry->pool, (void *)__entry->netmem, - __entry->pfn, __entry->release) + __entry->netmem & NET_IOV, __entry->pfn, __entry->release) ); TRACE_EVENT(page_pool_state_hold, @@ -83,12 +83,12 @@ TRACE_EVENT(page_pool_state_hold, __entry->pool = pool; __entry->netmem = (__force unsigned long)netmem; __entry->hold = hold; - __entry->pfn = netmem_to_pfn(netmem); + __entry->pfn = netmem_pfn_trace(netmem); ), - TP_printk("page_pool=%p netmem=%p pfn=0x%lx hold=%u", + TP_printk("page_pool=%p netmem=%p is_net_iov=%lu, pfn=0x%lx hold=%u", __entry->pool, (void *)__entry->netmem, - __entry->pfn, __entry->hold) + __entry->netmem & NET_IOV, __entry->pfn, __entry->hold) ); TRACE_EVENT(page_pool_update_nid, diff --git a/net/core/devmem.c b/net/core/devmem.c index 88d188149148..301f4250ca82 100644 --- a/net/core/devmem.c +++ b/net/core/devmem.c @@ -19,6 +19,8 @@ #include <net/devmem.h> #include <net/netdev_queues.h> +#include "page_pool_priv.h" + /* Device memory support */ /* Protected by rtnl_lock() */ @@ -83,6 +85,10 @@ net_devmem_alloc_dmabuf(struct net_devmem_dmabuf_binding *binding) index = offset / PAGE_SIZE; niov = &owner->niovs[index]; + niov->pp_magic = 0; + niov->pp = NULL; + atomic_long_set(&niov->pp_ref_count, 0); + return niov; } @@ -255,6 +261,8 @@ struct net_devmem_dmabuf_binding *net_devmem_bind_dmabuf(struct net_device *dev, for (i = 0; i < owner->num_niovs; i++) { niov = &owner->niovs[i]; niov->owner = owner; + page_pool_set_dma_addr_netmem(net_iov_to_netmem(niov), + net_devmem_get_dma_addr(niov)); } virtual += len; diff --git a/net/core/netmem_priv.h b/net/core/netmem_priv.h new file mode 100644 index 000000000000..7eadb8393e00 --- /dev/null +++ b/net/core/netmem_priv.h @@ -0,0 +1,31 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __NETMEM_PRIV_H +#define __NETMEM_PRIV_H + +static inline unsigned long netmem_get_pp_magic(netmem_ref netmem) +{ + return __netmem_clear_lsb(netmem)->pp_magic; +} + +static inline void netmem_or_pp_magic(netmem_ref netmem, unsigned long pp_magic) +{ + __netmem_clear_lsb(netmem)->pp_magic |= pp_magic; +} + +static inline void netmem_clear_pp_magic(netmem_ref netmem) +{ + __netmem_clear_lsb(netmem)->pp_magic = 0; +} + +static inline void netmem_set_pp(netmem_ref netmem, struct page_pool *pool) +{ + __netmem_clear_lsb(netmem)->pp = pool; +} + +static inline void netmem_set_dma_addr(netmem_ref netmem, + unsigned long dma_addr) +{ + __netmem_clear_lsb(netmem)->dma_addr = dma_addr; +} +#endif diff --git a/net/core/page_pool.c b/net/core/page_pool.c index 2abe6e919224..13277f05aebd 100644 --- a/net/core/page_pool.c +++ b/net/core/page_pool.c @@ -25,6 +25,9 @@ #include <trace/events/page_pool.h> #include "page_pool_priv.h" +#include "netmem_priv.h" + +DEFINE_STATIC_KEY_FALSE(page_pool_mem_providers); #define DEFER_TIME (msecs_to_jiffies(1000)) #define DEFER_WARN_INTERVAL (60 * HZ) @@ -358,7 +361,7 @@ static noinline netmem_ref page_pool_refill_alloc_cache(struct page_pool *pool) if (unlikely(!netmem)) break; - if (likely(page_to_nid(netmem_to_page(netmem)) == pref_nid)) { + if (likely(netmem_is_pref_nid(netmem, pref_nid))) { pool->alloc.cache[pool->alloc.count++] = netmem; } else { /* NUMA mismatch; @@ -454,10 +457,8 @@ static bool page_pool_dma_map(struct page_pool *pool, netmem_ref netmem) static void page_pool_set_pp_info(struct page_pool *pool, netmem_ref netmem) { - struct page *page = netmem_to_page(netmem); - - page->pp = pool; - page->pp_magic |= PP_SIGNATURE; + netmem_set_pp(netmem, pool); + netmem_or_pp_magic(netmem, PP_SIGNATURE); /* Ensuring all pages have been split into one fragment initially: * page_pool_set_pp_info() is only called once for every page when it @@ -472,10 +473,8 @@ static void page_pool_set_pp_info(struct page_pool *pool, netmem_ref netmem) static void page_pool_clear_pp_info(netmem_ref netmem) { - struct page *page = netmem_to_page(netmem); - - page->pp_magic = 0; - page->pp = NULL; + netmem_clear_pp_magic(netmem); + netmem_set_pp(netmem, NULL); } static struct page *__page_pool_alloc_page_order(struct page_pool *pool, @@ -692,8 +691,9 @@ static bool page_pool_recycle_in_cache(netmem_ref netmem, static bool __page_pool_page_can_be_recycled(netmem_ref netmem) { - return page_ref_count(netmem_to_page(netmem)) == 1 && - !page_is_pfmemalloc(netmem_to_page(netmem)); + return netmem_is_net_iov(netmem) || + (page_ref_count(netmem_to_page(netmem)) == 1 && + !page_is_pfmemalloc(netmem_to_page(netmem))); } /* If the page refcnt == 1, this will try to recycle the page. @@ -728,6 +728,7 @@ __page_pool_put_page(struct page_pool *pool, netmem_ref netmem, /* Page found as candidate for recycling */ return netmem; } + /* Fallback/non-XDP mode: API user have elevated refcnt. * * Many drivers split up the page into fragments, and some @@ -949,7 +950,7 @@ static void page_pool_empty_ring(struct page_pool *pool) /* Empty recycle ring */ while ((netmem = (__force netmem_ref)ptr_ring_consume_bh(&pool->ring))) { /* Verify the refcnt invariant of cached pages */ - if (!(page_ref_count(netmem_to_page(netmem)) == 1)) + if (!(netmem_ref_count(netmem) == 1)) pr_crit("%s() page_pool refcnt %d violation\n", __func__, netmem_ref_count(netmem)); diff --git a/net/core/page_pool_priv.h b/net/core/page_pool_priv.h index 90665d40f1eb..581501b5cd8c 100644 --- a/net/core/page_pool_priv.h +++ b/net/core/page_pool_priv.h @@ -3,10 +3,34 @@ #ifndef __PAGE_POOL_PRIV_H #define __PAGE_POOL_PRIV_H +#include "netmem_priv.h" + s32 page_pool_inflight(const struct page_pool *pool, bool strict); int page_pool_list(struct page_pool *pool); void page_pool_detached(struct page_pool *pool); void page_pool_unlist(struct page_pool *pool); +static inline bool page_pool_set_dma_addr_netmem(netmem_ref netmem, + dma_addr_t addr) +{ + if (PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA) { + netmem_set_dma_addr(netmem, addr >> PAGE_SHIFT); + + /* We assume page alignment to shave off bottom bits, + * if this "compression" doesn't work we need to drop. + */ + return addr != (dma_addr_t)netmem_get_dma_addr(netmem) + << PAGE_SHIFT; + } + + netmem_set_dma_addr(netmem, addr); + return false; +} + +static inline bool page_pool_set_dma_addr(struct page *page, dma_addr_t addr) +{ + return page_pool_set_dma_addr_netmem(page_to_netmem(page), addr); +} + #endif diff --git a/net/core/skbuff.c b/net/core/skbuff.c index de2a044cc665..9e2b28342793 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -89,6 +89,7 @@ #include "dev.h" #include "sock_destructor.h" +#include "netmem_priv.h" #ifdef CONFIG_SKB_EXTENSIONS static struct kmem_cache *skbuff_ext_cache __ro_after_init; @@ -920,9 +921,9 @@ static void skb_clone_fraglist(struct sk_buff *skb) skb_get(list); } -static bool is_pp_page(struct page *page) +static bool is_pp_netmem(netmem_ref netmem) { - return (page->pp_magic & ~0x3UL) == PP_SIGNATURE; + return (netmem_get_pp_magic(netmem) & ~0x3UL) == PP_SIGNATURE; } int skb_pp_cow_data(struct page_pool *pool, struct sk_buff **pskb, @@ -1020,9 +1021,7 @@ EXPORT_SYMBOL(skb_cow_data_for_xdp); #if IS_ENABLED(CONFIG_PAGE_POOL) bool napi_pp_put_page(netmem_ref netmem) { - struct page *page = netmem_to_page(netmem); - - page = compound_head(page); + netmem = netmem_compound_head(netmem); /* page->pp_magic is OR'ed with PP_SIGNATURE after the allocation * in order to preserve any existing bits, such as bit 0 for the @@ -1031,10 +1030,10 @@ bool napi_pp_put_page(netmem_ref netmem) * and page_is_pfmemalloc() is checked in __page_pool_put_page() * to avoid recycling the pfmemalloc page. */ - if (unlikely(!is_pp_page(page))) + if (unlikely(!is_pp_netmem(netmem))) return false; - page_pool_put_full_netmem(page->pp, page_to_netmem(page), false); + page_pool_put_full_netmem(netmem_get_pp(netmem), netmem, false); return true; } @@ -1061,7 +1060,7 @@ static bool skb_pp_recycle(struct sk_buff *skb, void *data) static int skb_pp_frag_ref(struct sk_buff *skb) { struct skb_shared_info *shinfo; - struct page *head_page; + netmem_ref head_netmem; int i; if (!skb->pp_recycle) @@ -1070,11 +1069,11 @@ static int skb_pp_frag_ref(struct sk_buff *skb) shinfo = skb_shinfo(skb); for (i = 0; i < shinfo->nr_frags; i++) { - head_page = compound_head(skb_frag_page(&shinfo->frags[i])); - if (likely(is_pp_page(head_page))) - page_pool_ref_page(head_page); + head_netmem = netmem_compound_head(shinfo->frags[i].netmem); + if (likely(is_pp_netmem(head_netmem))) + page_pool_ref_netmem(head_netmem); else - page_ref_inc(head_page); + page_ref_inc(netmem_to_page(head_netmem)); } return 0; } -- 2.46.0.76.ge559c4bf1a-goog

1 year, 2 months

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[PATCH net-next v19 04/13] netdev: netdevice devmem allocator

by Mina Almasry

Implement netdev devmem allocator. The allocator takes a given struct netdev_dmabuf_binding as input and allocates net_iov from that binding. The allocation simply delegates to the binding's genpool for the allocation logic and wraps the returned memory region in a net_iov struct. Signed-off-by: Willem de Bruijn <willemb(a)google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz(a)google.com> Signed-off-by: Mina Almasry <almasrymina(a)google.com> Reviewed-by: Pavel Begunkov <asml.silence(a)gmail.com> --- v19: - Don't reset dma_addr on allocation/free (Jakub) v17: - Don't acquire a binding ref for every allocation (Jakub). v11: - Fix extraneous inline directive (Paolo) v8: - Rename netdev_dmabuf_binding -> net_devmem_dmabuf_binding to avoid patch-by-patch build error. - Move niov->pp_magic/pp/pp_ref_counter usage to later patch to avoid patch-by-patch build error. v7: - netdev_ -> net_devmem_* naming (Yunsheng). v6: - Add comment on net_iov_dma_addr to explain why we don't use niov->dma_addr (Pavel) - Refactor new functions into net/core/devmem.c (Pavel) v1: - Rename devmem -> dmabuf (David). --- include/net/devmem.h | 13 +++++++++++++ include/net/netmem.h | 18 ++++++++++++++++++ net/core/devmem.c | 38 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 69 insertions(+) diff --git a/include/net/devmem.h b/include/net/devmem.h index c7bd6a0a6b9e..2e7cc46d4d3c 100644 --- a/include/net/devmem.h +++ b/include/net/devmem.h @@ -69,7 +69,20 @@ 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); void dev_dmabuf_uninstall(struct net_device *dev); +struct net_iov * +net_devmem_alloc_dmabuf(struct net_devmem_dmabuf_binding *binding); +void net_devmem_free_dmabuf(struct net_iov *ppiov); #else +static inline struct net_iov * +net_devmem_alloc_dmabuf(struct net_devmem_dmabuf_binding *binding) +{ + return NULL; +} + +static inline void net_devmem_free_dmabuf(struct net_iov *ppiov) +{ +} + static inline void __net_devmem_dmabuf_binding_free(struct net_devmem_dmabuf_binding *binding) { diff --git a/include/net/netmem.h b/include/net/netmem.h index 41e96c2f94b5..664df8325ece 100644 --- a/include/net/netmem.h +++ b/include/net/netmem.h @@ -14,8 +14,26 @@ struct net_iov { struct dmabuf_genpool_chunk_owner *owner; + unsigned long dma_addr; }; +static inline struct dmabuf_genpool_chunk_owner * +net_iov_owner(const struct net_iov *niov) +{ + return niov->owner; +} + +static inline unsigned int net_iov_idx(const struct net_iov *niov) +{ + return niov - net_iov_owner(niov)->niovs; +} + +static inline struct net_devmem_dmabuf_binding * +net_iov_binding(const struct net_iov *niov) +{ + return net_iov_owner(niov)->binding; +} + /* netmem */ /** diff --git a/net/core/devmem.c b/net/core/devmem.c index 1b693424c17d..88d188149148 100644 --- a/net/core/devmem.c +++ b/net/core/devmem.c @@ -35,6 +35,14 @@ static void net_devmem_dmabuf_free_chunk_owner(struct gen_pool *genpool, kfree(owner); } +static dma_addr_t net_devmem_get_dma_addr(const struct net_iov *niov) +{ + struct dmabuf_genpool_chunk_owner *owner = net_iov_owner(niov); + + return owner->base_dma_addr + + ((dma_addr_t)net_iov_idx(niov) << PAGE_SHIFT); +} + void __net_devmem_dmabuf_binding_free(struct net_devmem_dmabuf_binding *binding) { size_t size, avail; @@ -57,6 +65,36 @@ void __net_devmem_dmabuf_binding_free(struct net_devmem_dmabuf_binding *binding) kfree(binding); } +struct net_iov * +net_devmem_alloc_dmabuf(struct net_devmem_dmabuf_binding *binding) +{ + struct dmabuf_genpool_chunk_owner *owner; + unsigned long dma_addr; + struct net_iov *niov; + ssize_t offset; + ssize_t index; + + dma_addr = gen_pool_alloc_owner(binding->chunk_pool, PAGE_SIZE, + (void **)&owner); + if (!dma_addr) + return NULL; + + offset = dma_addr - owner->base_dma_addr; + index = offset / PAGE_SIZE; + niov = &owner->niovs[index]; + + return niov; +} + +void net_devmem_free_dmabuf(struct net_iov *niov) +{ + struct net_devmem_dmabuf_binding *binding = net_iov_binding(niov); + unsigned long dma_addr = net_devmem_get_dma_addr(niov); + + if (gen_pool_has_addr(binding->chunk_pool, dma_addr, PAGE_SIZE)) + gen_pool_free(binding->chunk_pool, dma_addr, PAGE_SIZE); +} + void net_devmem_unbind_dmabuf(struct net_devmem_dmabuf_binding *binding) { struct netdev_rx_queue *rxq; -- 2.46.0.76.ge559c4bf1a-goog

1 year, 2 months

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[PATCH net-next v19 02/13] net: netdev netlink api to bind dma-buf to a net device

by Mina Almasry

API takes the dma-buf fd as input, and binds it to the netdevice. The user can specify the rx queues to bind the dma-buf to. Suggested-by: Stanislav Fomichev <sdf(a)google.com> Signed-off-by: Mina Almasry <almasrymina(a)google.com> Reviewed-by: Donald Hunter <donald.hunter(a)gmail.com> Reviewed-by: Jakub Kicinski <kuba(a)kernel.org> --- v16: - Use subset-of: queue queue-id instead of queue-dmabuf (Jakub). - Rename attribute 'bind-dmabuf' to more generic 'dmabuf' (Jakub). - Use 'dmabuf' everywhere instead of mix of 'dma-buf' and 'dmabuf' (Donald). - Remove repetitive 'dmabuf' naming that appeared in some places (Jakub). - Reordered where the new operations went so I don't break the enum UAPI (Jakub). v7: - Use flags: [ admin-perm ] instead of a CAP_NET_ADMIN check. Changes in v1: - Add rx-queue-type to distingish rx from tx (Jakub) - Return dma-buf ID from netlink API (David, Stan) Changes in RFC-v3: - Support binding multiple rx rx-queues --- Documentation/netlink/specs/netdev.yaml | 47 +++++++++++++++++++++++++ include/uapi/linux/netdev.h | 11 ++++++ net/core/netdev-genl-gen.c | 19 ++++++++++ net/core/netdev-genl-gen.h | 2 ++ net/core/netdev-genl.c | 6 ++++ tools/include/uapi/linux/netdev.h | 11 ++++++ 6 files changed, 96 insertions(+) diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml index 959755be4d7f..4930e8142aa6 100644 --- a/Documentation/netlink/specs/netdev.yaml +++ b/Documentation/netlink/specs/netdev.yaml @@ -457,6 +457,39 @@ attribute-sets: Number of times driver re-started accepting send requests to this queue from the stack. type: uint + - + name: queue-id + subset-of: queue + attributes: + - + name: id + - + name: type + - + name: dmabuf + attributes: + - + name: ifindex + doc: netdev ifindex to bind the dmabuf to. + type: u32 + checks: + min: 1 + - + name: queues + doc: receive queues to bind the dmabuf to. + type: nest + nested-attributes: queue-id + multi-attr: true + - + name: fd + doc: dmabuf file descriptor to bind. + type: u32 + - + name: id + doc: id of the dmabuf binding + type: u32 + checks: + min: 1 operations: list: @@ -619,6 +652,20 @@ operations: - rx-bytes - tx-packets - tx-bytes + - + name: bind-rx + doc: Bind dmabuf to netdev + attribute-set: dmabuf + flags: [ admin-perm ] + do: + request: + attributes: + - ifindex + - fd + - queues + reply: + attributes: + - id mcast-groups: list: diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h index 43742ac5b00d..91bf3ecc5f1d 100644 --- a/include/uapi/linux/netdev.h +++ b/include/uapi/linux/netdev.h @@ -173,6 +173,16 @@ enum { NETDEV_A_QSTATS_MAX = (__NETDEV_A_QSTATS_MAX - 1) }; +enum { + NETDEV_A_DMABUF_IFINDEX = 1, + NETDEV_A_DMABUF_QUEUES, + NETDEV_A_DMABUF_FD, + NETDEV_A_DMABUF_ID, + + __NETDEV_A_DMABUF_MAX, + NETDEV_A_DMABUF_MAX = (__NETDEV_A_DMABUF_MAX - 1) +}; + enum { NETDEV_CMD_DEV_GET = 1, NETDEV_CMD_DEV_ADD_NTF, @@ -186,6 +196,7 @@ enum { NETDEV_CMD_QUEUE_GET, NETDEV_CMD_NAPI_GET, NETDEV_CMD_QSTATS_GET, + NETDEV_CMD_BIND_RX, __NETDEV_CMD_MAX, NETDEV_CMD_MAX = (__NETDEV_CMD_MAX - 1) diff --git a/net/core/netdev-genl-gen.c b/net/core/netdev-genl-gen.c index 8350a0afa9ec..6b7fe6035067 100644 --- a/net/core/netdev-genl-gen.c +++ b/net/core/netdev-genl-gen.c @@ -27,6 +27,11 @@ const struct nla_policy netdev_page_pool_info_nl_policy[NETDEV_A_PAGE_POOL_IFIND [NETDEV_A_PAGE_POOL_IFINDEX] = NLA_POLICY_FULL_RANGE(NLA_U32, &netdev_a_page_pool_ifindex_range), }; +const struct nla_policy netdev_queue_id_nl_policy[NETDEV_A_QUEUE_TYPE + 1] = { + [NETDEV_A_QUEUE_ID] = { .type = NLA_U32, }, + [NETDEV_A_QUEUE_TYPE] = NLA_POLICY_MAX(NLA_U32, 1), +}; + /* NETDEV_CMD_DEV_GET - do */ static const struct nla_policy netdev_dev_get_nl_policy[NETDEV_A_DEV_IFINDEX + 1] = { [NETDEV_A_DEV_IFINDEX] = NLA_POLICY_MIN(NLA_U32, 1), @@ -74,6 +79,13 @@ static const struct nla_policy netdev_qstats_get_nl_policy[NETDEV_A_QSTATS_SCOPE [NETDEV_A_QSTATS_SCOPE] = NLA_POLICY_MASK(NLA_UINT, 0x1), }; +/* NETDEV_CMD_BIND_RX - do */ +static const struct nla_policy netdev_bind_rx_nl_policy[NETDEV_A_DMABUF_FD + 1] = { + [NETDEV_A_DMABUF_IFINDEX] = NLA_POLICY_MIN(NLA_U32, 1), + [NETDEV_A_DMABUF_FD] = { .type = NLA_U32, }, + [NETDEV_A_DMABUF_QUEUES] = NLA_POLICY_NESTED(netdev_queue_id_nl_policy), +}; + /* Ops table for netdev */ static const struct genl_split_ops netdev_nl_ops[] = { { @@ -151,6 +163,13 @@ static const struct genl_split_ops netdev_nl_ops[] = { .maxattr = NETDEV_A_QSTATS_SCOPE, .flags = GENL_CMD_CAP_DUMP, }, + { + .cmd = NETDEV_CMD_BIND_RX, + .doit = netdev_nl_bind_rx_doit, + .policy = netdev_bind_rx_nl_policy, + .maxattr = NETDEV_A_DMABUF_FD, + .flags = GENL_ADMIN_PERM | GENL_CMD_CAP_DO, + }, }; static const struct genl_multicast_group netdev_nl_mcgrps[] = { diff --git a/net/core/netdev-genl-gen.h b/net/core/netdev-genl-gen.h index 4db40fd5b4a9..67c34005750c 100644 --- a/net/core/netdev-genl-gen.h +++ b/net/core/netdev-genl-gen.h @@ -13,6 +13,7 @@ /* Common nested types */ extern const struct nla_policy netdev_page_pool_info_nl_policy[NETDEV_A_PAGE_POOL_IFINDEX + 1]; +extern const struct nla_policy netdev_queue_id_nl_policy[NETDEV_A_QUEUE_TYPE + 1]; int netdev_nl_dev_get_doit(struct sk_buff *skb, struct genl_info *info); int netdev_nl_dev_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb); @@ -30,6 +31,7 @@ int netdev_nl_napi_get_doit(struct sk_buff *skb, struct genl_info *info); int netdev_nl_napi_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb); int netdev_nl_qstats_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb); +int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info); enum { NETDEV_NLGRP_MGMT, diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c index 05f9515d2c05..2d726e65211d 100644 --- a/net/core/netdev-genl.c +++ b/net/core/netdev-genl.c @@ -721,6 +721,12 @@ int netdev_nl_qstats_get_dumpit(struct sk_buff *skb, return err; } +/* Stub */ +int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info) +{ + return 0; +} + static int netdev_genl_netdevice_event(struct notifier_block *nb, unsigned long event, void *ptr) { diff --git a/tools/include/uapi/linux/netdev.h b/tools/include/uapi/linux/netdev.h index 43742ac5b00d..91bf3ecc5f1d 100644 --- a/tools/include/uapi/linux/netdev.h +++ b/tools/include/uapi/linux/netdev.h @@ -173,6 +173,16 @@ enum { NETDEV_A_QSTATS_MAX = (__NETDEV_A_QSTATS_MAX - 1) }; +enum { + NETDEV_A_DMABUF_IFINDEX = 1, + NETDEV_A_DMABUF_QUEUES, + NETDEV_A_DMABUF_FD, + NETDEV_A_DMABUF_ID, + + __NETDEV_A_DMABUF_MAX, + NETDEV_A_DMABUF_MAX = (__NETDEV_A_DMABUF_MAX - 1) +}; + enum { NETDEV_CMD_DEV_GET = 1, NETDEV_CMD_DEV_ADD_NTF, @@ -186,6 +196,7 @@ enum { NETDEV_CMD_QUEUE_GET, NETDEV_CMD_NAPI_GET, NETDEV_CMD_QSTATS_GET, + NETDEV_CMD_BIND_RX, __NETDEV_CMD_MAX, NETDEV_CMD_MAX = (__NETDEV_CMD_MAX - 1) -- 2.46.0.76.ge559c4bf1a-goog

1 year, 2 months

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[PATCH net-next v19 01/13] netdev: add netdev_rx_queue_restart()

by Mina Almasry

Add netdev_rx_queue_restart(), which resets an rx queue using the queue API recently merged[1]. The queue API was merged to enable the core net stack to reset individual rx queues to actuate changes in the rx queue's configuration. In later patches in this series, we will use netdev_rx_queue_restart() to reset rx queues after binding or unbinding dmabuf configuration, which will cause reallocation of the page_pool to repopulate its memory using the new configuration. [1] https://lore.kernel.org/netdev/20240430231420.699177-1-shailend@google.com/… Signed-off-by: David Wei <dw(a)davidwei.uk> Signed-off-by: Mina Almasry <almasrymina(a)google.com> Reviewed-by: Pavel Begunkov <asml.silence(a)gmail.com> Reviewed-by: Jakub Kicinski <kuba(a)kernel.org> --- v18: - Add more color to commit message (Xuan Zhuo). v17: - Use ASSERT_RTNL() (Jakub). v13: - Add reviewed-by from Pavel (thanks!) - Fixed comment (Pavel) v11: - Fix not checking dev->queue_mgmt_ops (Pavel). - Fix ndo_queue_mem_free call that passed the wrong pointer (David). v9: https://lore.kernel.org/all/20240502045410.3524155-4-dw@davidwei.uk/ (submitted by David). - fixed SPDX license identifier (Simon). - Rebased on top of merged queue API definition, and changed implementation to match that. - Replace rtnl_lock() with rtnl_is_locked() to make it useable from my netlink code where rtnl is already locked. --- include/net/netdev_rx_queue.h | 3 ++ net/core/Makefile | 1 + net/core/netdev_rx_queue.c | 74 +++++++++++++++++++++++++++++++++++ 3 files changed, 78 insertions(+) create mode 100644 net/core/netdev_rx_queue.c diff --git a/include/net/netdev_rx_queue.h b/include/net/netdev_rx_queue.h index aa1716fb0e53..e78ca52d67fb 100644 --- a/include/net/netdev_rx_queue.h +++ b/include/net/netdev_rx_queue.h @@ -54,4 +54,7 @@ get_netdev_rx_queue_index(struct netdev_rx_queue *queue) return index; } #endif + +int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq); + #endif diff --git a/net/core/Makefile b/net/core/Makefile index 62be9aef2528..f82232b358a2 100644 --- a/net/core/Makefile +++ b/net/core/Makefile @@ -19,6 +19,7 @@ obj-$(CONFIG_NETDEV_ADDR_LIST_TEST) += dev_addr_lists_test.o obj-y += net-sysfs.o obj-y += hotdata.o +obj-y += netdev_rx_queue.o obj-$(CONFIG_PAGE_POOL) += page_pool.o page_pool_user.o obj-$(CONFIG_PROC_FS) += net-procfs.o obj-$(CONFIG_NET_PKTGEN) += pktgen.o diff --git a/net/core/netdev_rx_queue.c b/net/core/netdev_rx_queue.c new file mode 100644 index 000000000000..da11720a5983 --- /dev/null +++ b/net/core/netdev_rx_queue.c @@ -0,0 +1,74 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +#include <linux/netdevice.h> +#include <net/netdev_queues.h> +#include <net/netdev_rx_queue.h> + +int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq_idx) +{ + void *new_mem, *old_mem; + int err; + + if (!dev->queue_mgmt_ops || !dev->queue_mgmt_ops->ndo_queue_stop || + !dev->queue_mgmt_ops->ndo_queue_mem_free || + !dev->queue_mgmt_ops->ndo_queue_mem_alloc || + !dev->queue_mgmt_ops->ndo_queue_start) + return -EOPNOTSUPP; + + ASSERT_RTNL(); + + new_mem = kvzalloc(dev->queue_mgmt_ops->ndo_queue_mem_size, GFP_KERNEL); + if (!new_mem) + return -ENOMEM; + + old_mem = kvzalloc(dev->queue_mgmt_ops->ndo_queue_mem_size, GFP_KERNEL); + if (!old_mem) { + err = -ENOMEM; + goto err_free_new_mem; + } + + err = dev->queue_mgmt_ops->ndo_queue_mem_alloc(dev, new_mem, rxq_idx); + if (err) + goto err_free_old_mem; + + err = dev->queue_mgmt_ops->ndo_queue_stop(dev, old_mem, rxq_idx); + if (err) + goto err_free_new_queue_mem; + + err = dev->queue_mgmt_ops->ndo_queue_start(dev, new_mem, rxq_idx); + if (err) + goto err_start_queue; + + dev->queue_mgmt_ops->ndo_queue_mem_free(dev, old_mem); + + kvfree(old_mem); + kvfree(new_mem); + + return 0; + +err_start_queue: + /* Restarting the queue with old_mem should be successful as we haven't + * changed any of the queue configuration, and there is not much we can + * do to recover from a failure here. + * + * WARN if we fail to recover the old rx queue, and at least free + * old_mem so we don't also leak that. + */ + if (dev->queue_mgmt_ops->ndo_queue_start(dev, old_mem, rxq_idx)) { + WARN(1, + "Failed to restart old queue in error path. RX queue %d may be unhealthy.", + rxq_idx); + dev->queue_mgmt_ops->ndo_queue_mem_free(dev, old_mem); + } + +err_free_new_queue_mem: + dev->queue_mgmt_ops->ndo_queue_mem_free(dev, new_mem); + +err_free_old_mem: + kvfree(old_mem); + +err_free_new_mem: + kvfree(new_mem); + + return err; +} -- 2.46.0.76.ge559c4bf1a-goog

1 year, 2 months

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[PATCH] Kselftest: msg_oob.c: Fix warning for Incorrect Specifier

by David Hunter

Change specifier to %p to correctly substitute type 'const void *'. A specifer involved with a macro is causing a misleading warning to occur: In file included from msg_oob.c:14: msg_oob.c: In function ��__recvpair��: ../../kselftest_harness.h:106:40: warning: format ��%s�� expects argument of type ��char *��, but argument 6 has type ��const void *�� [-Wformat=] 106 | fprintf(TH_LOG_STREAM, "# %s:%d:%s:" fmt "\n", \ | ^~~~~~~~~~~~~ ../../kselftest_harness.h:101:17: note: in expansion of macro ��__TH_LOG�� 101 | __TH_LOG(fmt, ##__VA_ARGS__); \ | ^~~~~~~~ msg_oob.c:235:17: note: in expansion of macro ��TH_LOG�� 235 | TH_LOG("Expected:%s", expected_errno ? strerror(expected_errno) : expected_buf); | ^~~~~~ A second set of these three warnings occur later for the incorrect specifier at msg_oob.c:256. By tracing the various macros involved, the correct specifier (in msg_oob.c) can be spotted and changed. Signed-off-by: David Hunter <david.hunter.linux(a)gmail.com> --- tools/testing/selftests/net/af_unix/msg_oob.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/net/af_unix/msg_oob.c b/tools/testing/selftests/net/af_unix/msg_oob.c index 16d0c172eaeb..87090ebda2a7 100644 --- a/tools/testing/selftests/net/af_unix/msg_oob.c +++ b/tools/testing/selftests/net/af_unix/msg_oob.c @@ -232,7 +232,7 @@ static void __recvpair(struct __test_metadata *_metadata, if (ret[0] != expected_len || recv_errno[0] != expected_errno) { TH_LOG("AF_UNIX :%s", ret[0] < 0 ? strerror(recv_errno[0]) : recv_buf[0]); - TH_LOG("Expected:%s", expected_errno ? strerror(expected_errno) : expected_buf); + TH_LOG("Expected:%p", expected_errno ? strerror(expected_errno) : expected_buf); ASSERT_EQ(ret[0], expected_len); ASSERT_EQ(recv_errno[0], expected_errno); @@ -256,7 +256,7 @@ static void __recvpair(struct __test_metadata *_metadata, cmp = strncmp(expected_buf, recv_buf[0], expected_len); if (cmp) { TH_LOG("AF_UNIX :%s", ret[0] < 0 ? strerror(recv_errno[0]) : recv_buf[0]); - TH_LOG("Expected:%s", expected_errno ? strerror(expected_errno) : expected_buf); + TH_LOG("Expected:%p", expected_errno ? strerror(expected_errno) : expected_buf); ASSERT_EQ(cmp, 0); } -- 2.43.0

1 year, 2 months

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[PATCH v2 1/1] selftests: net: af_unix: convert param to const char* in __recvpair() to fix warning

by Mirsad Todorovac

GCC 13.2.0 reported warning about (void *) being used as a param where (char *) is expected: In file included from msg_oob.c:14: msg_oob.c: In function ‘__recvpair’: ../../kselftest_harness.h:106:40: warning: format ‘%s’ expects argument of type ‘char *’, \ but argument 6 has type ‘const void *’ [-Wformat=] 106 | fprintf(TH_LOG_STREAM, "# %s:%d:%s:" fmt "\n", \ | ^~~~~~~~~~~~~ ../../kselftest_harness.h:101:17: note: in expansion of macro ‘__TH_LOG’ 101 | __TH_LOG(fmt, ##__VA_ARGS__); \ | ^~~~~~~~ msg_oob.c:235:17: note: in expansion of macro ‘TH_LOG’ 235 | TH_LOG("Expected:%s", expected_errno ? strerror(expected_errno) : expected_buf); | ^~~~~~ ../../kselftest_harness.h:106:40: warning: format ‘%s’ expects argument of type ‘char *’, \ but argument 6 has type ‘const void *’ [-Wformat=] 106 | fprintf(TH_LOG_STREAM, "# %s:%d:%s:" fmt "\n", \ | ^~~~~~~~~~~~~ ../../kselftest_harness.h:101:17: note: in expansion of macro ‘__TH_LOG’ 101 | __TH_LOG(fmt, ##__VA_ARGS__); \ | ^~~~~~~~ msg_oob.c:259:25: note: in expansion of macro ‘TH_LOG’ 259 | TH_LOG("Expected:%s", expected_errno ? strerror(expected_errno) : expected_buf); | ^~~~~~ As Simon suggested, all calls to __recvpair() have char * as expected_buf param, so it is safe to change param type from (const void *) to (const char *), which silences the warning. Fixes: d098d77232c37 ("selftest: af_unix: Add msg_oob.c.") Reported-by: Mirsad Todorovac <mtodorovac69(a)gmail.com> Cc: "David S. Miller" <davem(a)davemloft.net> Cc: Eric Dumazet <edumazet(a)google.com> Cc: Jakub Kicinski <kuba(a)kernel.org> Cc: Paolo Abeni <pabeni(a)redhat.com> Cc: Shuah Khan <shuah(a)kernel.org> Cc: Kuniyuki Iwashima <kuniyu(a)amazon.com> Cc: netdev(a)vger.kernel.org Cc: linux-kselftest(a)vger.kernel.org Suggested-by: Simon Horman <horms(a)kernel.org> Signed-off-by: Mirsad Todorovac <mtodorovac69(a)gmail.com> --- v1 -> v2: fixed a typo. change funct param type rather than making two casts, as Simon suggested. changed Subject: line to reflect the modification. minor formatting changes. v1: initial version to fix the compiler warning. tools/testing/selftests/net/af_unix/msg_oob.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/net/af_unix/msg_oob.c b/tools/testing/selftests/net/af_unix/msg_oob.c index 16d0c172eaeb..535eb2c3d7d1 100644 --- a/tools/testing/selftests/net/af_unix/msg_oob.c +++ b/tools/testing/selftests/net/af_unix/msg_oob.c @@ -209,7 +209,7 @@ static void __sendpair(struct __test_metadata *_metadata, static void __recvpair(struct __test_metadata *_metadata, FIXTURE_DATA(msg_oob) *self, - const void *expected_buf, int expected_len, + const char *expected_buf, int expected_len, int buf_len, int flags) { int i, ret[2], recv_errno[2], expected_errno = 0; -- 2.43.0

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Linux-kselftest-mirror August 2024