| Message ID | 20221018191602.2112515-1-jonathan.lemon@gmail.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | zero-copy RX for io_uring | expand |
On 2022/10/19 03:15, Jonathan Lemon wrote: > This series is a RFC for io_uring/zctap. This is an evolution of > the earlier zctap work, re-targeted to use io_uring as the userspace > API. The current code is intended to provide a zero-copy RX path for > upper-level networking protocols (aka TCP and UDP). The current draft > focuses on host-provided memory (not GPU memory). > > This RFC contains the upper-level core code required for operation, > with the intent of soliciting feedback on the general API. This does > not contain the network driver side changes required for complete > operation. Also please note that as an RFC, there are some things > which are incomplete or in need of rework. > > The intent is to use a network driver which provides header/data > splitting, so the frame header (which is processed by the networking > stack) does not reside in user memory. > > The code is successfully receiving a zero-copy TCP stream from a > remote sender. An RFC, the intent is to solicit feedback on the > API and overall design. The current code will also work with > system pages, copying the data out to the application - this is > intended as a fallback/testing path. > > Performance numbers are coming soon! > > High level description: > > The application allocates a frame backing store, and provides this > to the kernel for use. An interface queue is requested from the > networking device, and incoming frames are deposited into the provided > memory region. > > Responsibility for correctly steering incoming frames to the queue > is outside the scope of this work - it is assumed that the user > has set steering rules up separately. > > Incoming frames are sent up the stack as skb's and eventually > land in the application's socket receive queue. This differs > from AF_XDP, which receives raw frames directly to userspace, > without protocol processing. > > The RECV_ZC opcode then returns an iov[] style vector which points > to the data in userspace memory. When the application has completed > processing of the data, the buffer is returned back to the kernel > through a fill ring for reuse. > > Changelog: > v1: initial version > v2: Remove separate PROVIDE_REGION opcode, fold this functionality > into REGISTER_IFQ. Remove page_pool hooks, as it appears the > page pool is currently incompatible with user-mapped memory. > Add io_zctap_buffers and network driver API. > . > > Jonathan Lemon (13): > io_uring: add zctap ifq definition > netdevice: add SETUP_ZCTAP to the netdev_bpf structure > io_uring: add register ifq opcode > io_uring: create a zctap region for a mapped buffer > io_uring: create page freelist for the ifq region > io_uring: Provide driver API for zctap packet buffers. > io_uring: Allocate the zctap buffers for the device > io_uring: Add zctap buffer get/put functions and refcounting. > skbuff: Introduce SKBFL_FIXED_FRAG and skb_fixed() > io_uring: Allocate a uarg for use by the ifq RX > io_uring: Define the zctap iov[] returned to the user. > io_uring: add OP_RECV_ZC command. > io_uring: Make remove_ifq_region a delayed work call > > include/linux/io_uring.h | 35 ++ > include/linux/io_uring_types.h | 11 + > include/linux/netdevice.h | 6 + > include/linux/skbuff.h | 10 +- > include/uapi/linux/io_uring.h | 24 + > io_uring/Makefile | 3 +- > io_uring/io_uring.c | 8 + > io_uring/kbuf.c | 13 + > io_uring/kbuf.h | 2 + > io_uring/net.c | 123 +++++ > io_uring/opdef.c | 15 + > io_uring/zctap.c | 842 +++++++++++++++++++++++++++++++++ > io_uring/zctap.h | 16 + > 13 files changed, 1106 insertions(+), 2 deletions(-) > create mode 100644 io_uring/zctap.c > create mode 100644 io_uring/zctap.h > Hi, Jonathan We are interested in your work, too. I think the API is better than V1. I have a question: Is this patchset still incomplete? We'd like to know how to split msg header and body by XDP with io_uring ZC_RECV. Or could you please share one runnable demo which could run with your previous liburing patch. Regards, Zhang.
On Thu, Oct 20, 2022 at 11:35:14AM +0800, Ziyang Zhang wrote: > Hi, Jonathan > > We are interested in your work, too. I think the API is better than V1. > I have a question: Is this patchset still incomplete? We'd like to know how to > split msg header and body by XDP with io_uring ZC_RECV. Or could you please > share one runnable demo which could run with your previous liburing patch. It seems my earlier reply to this didn't go to the list, so retrying. I just posted RFC v3, which is just about complete. The cover letter also has the location of a github repo which has a simple example showing the operation. I'm in the process of updating iperf3 as another sample application. The packet splitting is done by the NIC hardware. There are Broadcom and nVidia NICs which have these feature sets. One of my testbeds is set up and working with Broadcom.
This series is a RFC for io_uring/zctap. This is an evolution of the earlier zctap work, re-targeted to use io_uring as the userspace API. The current code is intended to provide a zero-copy RX path for upper-level networking protocols (aka TCP and UDP). The current draft focuses on host-provided memory (not GPU memory). This RFC contains the upper-level core code required for operation, with the intent of soliciting feedback on the general API. This does not contain the network driver side changes required for complete operation. Also please note that as an RFC, there are some things which are incomplete or in need of rework. The intent is to use a network driver which provides header/data splitting, so the frame header (which is processed by the networking stack) does not reside in user memory. The code is successfully receiving a zero-copy TCP stream from a remote sender. An RFC, the intent is to solicit feedback on the API and overall design. The current code will also work with system pages, copying the data out to the application - this is intended as a fallback/testing path. Performance numbers are coming soon! High level description: The application allocates a frame backing store, and provides this to the kernel for use. An interface queue is requested from the networking device, and incoming frames are deposited into the provided memory region. Responsibility for correctly steering incoming frames to the queue is outside the scope of this work - it is assumed that the user has set steering rules up separately. Incoming frames are sent up the stack as skb's and eventually land in the application's socket receive queue. This differs from AF_XDP, which receives raw frames directly to userspace, without protocol processing. The RECV_ZC opcode then returns an iov[] style vector which points to the data in userspace memory. When the application has completed processing of the data, the buffer is returned back to the kernel through a fill ring for reuse. Changelog: v1: initial version v2: Remove separate PROVIDE_REGION opcode, fold this functionality into REGISTER_IFQ. Remove page_pool hooks, as it appears the page pool is currently incompatible with user-mapped memory. Add io_zctap_buffers and network driver API. . Jonathan Lemon (13): io_uring: add zctap ifq definition netdevice: add SETUP_ZCTAP to the netdev_bpf structure io_uring: add register ifq opcode io_uring: create a zctap region for a mapped buffer io_uring: create page freelist for the ifq region io_uring: Provide driver API for zctap packet buffers. io_uring: Allocate the zctap buffers for the device io_uring: Add zctap buffer get/put functions and refcounting. skbuff: Introduce SKBFL_FIXED_FRAG and skb_fixed() io_uring: Allocate a uarg for use by the ifq RX io_uring: Define the zctap iov[] returned to the user. io_uring: add OP_RECV_ZC command. io_uring: Make remove_ifq_region a delayed work call include/linux/io_uring.h | 35 ++ include/linux/io_uring_types.h | 11 + include/linux/netdevice.h | 6 + include/linux/skbuff.h | 10 +- include/uapi/linux/io_uring.h | 24 + io_uring/Makefile | 3 +- io_uring/io_uring.c | 8 + io_uring/kbuf.c | 13 + io_uring/kbuf.h | 2 + io_uring/net.c | 123 +++++ io_uring/opdef.c | 15 + io_uring/zctap.c | 842 +++++++++++++++++++++++++++++++++ io_uring/zctap.h | 16 + 13 files changed, 1106 insertions(+), 2 deletions(-) create mode 100644 io_uring/zctap.c create mode 100644 io_uring/zctap.h