kernel/include/net/xdp_sock.h, branch linux-5.2.y

xdp: fix race on generic receive path

2019-07-26T07:10:46Z

[ Upstream commit bf0bdd1343efbbf65b4d53aef1fce14acbd79d50 ] Unlike driver mode, generic xdp receive could be triggered by different threads on different CPU cores at the same time leading to the fill and rx queue breakage. For example, this could happen while sending packets from two processes to the first interface of veth pair while the second part of it is open with AF_XDP socket. Need to take a lock for each generic receive to avoid race. Fixes: c497176cb2e4 ("xsk: add Rx receive functions and poll support") Signed-off-by: Ilya Maximets Acked-by: Magnus Karlsson Tested-by: William Tu Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin

xsk: fix umem memory leak on cleanup

2019-03-16T00:27:51Z

When the umem is cleaned up, the task that created it might already be gone. If the task was gone, the xdp_umem_release function did not free the pages member of struct xdp_umem. It turned out that the task lookup was not needed at all; The code was a left-over when we moved from task accounting to user accounting [1]. This patch fixes the memory leak by removing the task lookup logic completely. [1] https://lore.kernel.org/netdev/20180131135356.19134-3-bjorn.topel@gmail.com/ Link: https://lore.kernel.org/netdev/c1cb2ca8-6a14-3980-8672-f3de0bb38dfd@suse.cz/ Fixes: c0c77d8fb787 ("xsk: add user memory registration support sockopt") Reported-by: Jiri Slaby Signed-off-by: Björn Töpel Signed-off-by: Daniel Borkmann

xsk: add id to umem

2019-01-25T00:50:03Z

This commit adds an id to the umem structure. The id uniquely identifies a umem instance, and will be exposed to user-space via the socket monitoring interface. Signed-off-by: Björn Töpel Signed-off-by: Daniel Borkmann

ethtool: don't allow disabling queues with umem installed

2018-10-05T07:31:01Z

We already check the RSS indirection table does not use queues which would be disabled by channel reconfiguration. Make sure user does not try to disable queues which have a UMEM and zero-copy AF_XDP socket installed. Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann

net: xsk: add a simple buffer reuse queue

2018-09-25T20:13:15Z

XSK UMEM is strongly single producer single consumer so reuse of frames is challenging. Add a simple "stash" of FILL packets to reuse for drivers to optionally make use of. This is useful when driver has to free (ndo_stop) or resize a ring with an active AF_XDP ZC socket. Signed-off-by: Jakub Kicinski Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher

xsk: i40e: get rid of useless struct xdp_umem_props

2018-08-31T23:38:16Z

This commit gets rid of the structure xdp_umem_props. It was there to be able to break a dependency at one point, but this is no longer needed. The values in the struct are instead stored directly in the xdp_umem structure. This simplifies the xsk code as well as af_xdp zero-copy drivers and as a bonus gets rid of one internal header file. The i40e driver is also adapted to the new interface in this commit. Signed-off-by: Magnus Karlsson Signed-off-by: Daniel Borkmann

xsk: expose xdp_umem_get_{data,dma} to drivers

2018-08-29T19:25:53Z

Move the xdp_umem_get_{data,dma} functions to include/net/xdp_sock.h, so that the upcoming zero-copy implementation in the Ethernet drivers can utilize them. Also, supply some dummy function implementations for CONFIG_XDP_SOCKETS=n configs. Signed-off-by: Björn Töpel Signed-off-by: Alexei Starovoitov

xsk: fix potential race in SKB TX completion code

2018-07-03T01:37:12Z

There is a potential race in the TX completion code for the SKB case. One process enters the sendmsg code of an AF_XDP socket in order to send a frame. The execution eventually trickles down to the driver that is told to send the packet. However, it decides to drop the packet due to some error condition (e.g., rings full) and frees the SKB. This will trigger the SKB destructor and a completion will be sent to the AF_XDP user space through its single-producer/single-consumer queues. At the same time a TX interrupt has fired on another core and it dispatches the TX completion code in the driver. It does its HW specific things and ends up freeing the SKB associated with the transmitted packet. This will trigger the SKB destructor and a completion will be sent to the AF_XDP user space through its single-producer/single-consumer queues. With a pseudo call stack, it would look like this: Core 1: sendmsg() being called in the application netdev_start_xmit() Driver entered through ndo_start_xmit Driver decides to free the SKB for some reason (e.g., rings full) Destructor of SKB called xskq_produce_addr() is called to signal completion to user space Core 2: TX completion irq NAPI loop Driver irq handler for TX completions Frees the SKB Destructor of SKB called xskq_produce_addr() is called to signal completion to user space We now have a violation of the single-producer/single-consumer principle for our queues as there are two threads trying to produce at the same time on the same queue. Fixed by introducing a spin_lock in the destructor. In regards to the performance, I get around 1.74 Mpps for txonly before and after the introduction of the spinlock. There is of course some impact due to the spin lock but it is in the less significant digits that are too noisy for me to measure. But let us say that the version without the spin lock got 1.745 Mpps in the best case and the version with 1.735 Mpps in the worst case, then that would mean a maximum drop in performance of 0.5%. Fixes: 35fcde7f8deb ("xsk: support for Tx") Signed-off-by: Magnus Karlsson Signed-off-by: Alexei Starovoitov

xsk: wire upp Tx zero-copy functions

2018-06-05T13:48:34Z

Here we add the functionality required to support zero-copy Tx, and also exposes various zero-copy related functions for the netdevs. Signed-off-by: Magnus Karlsson Signed-off-by: Daniel Borkmann

xsk: add zero-copy support for Rx

2018-06-05T13:46:55Z

Extend the xsk_rcv to support the new MEM_TYPE_ZERO_COPY memory, and wireup ndo_bpf call in bind. Signed-off-by: Björn Töpel Signed-off-by: Daniel Borkmann