Magnus Karlsson wrote: > On Wed, 5 Jun 2024 at 01:03, Willem de Bruijn > <willemdebruijn.kernel@xxxxxxxxx> wrote: > > > > Magnus Karlsson wrote: > > > Revert "xsk: support redirect to any socket bound to the same umem" > > > > > > This patch introduced a potential kernel crash when multiple napi > > > instances redirect to the same AF_XDP socket. By removing the > > > queue_index check, it is possible for multiple napi instances to > > > access the Rx ring at the same time, which will result in a corrupted > > > ring state which can lead to a crash when flushing the rings in > > > __xsk_flush(). This can happen when the linked list of sockets to > > > flush gets corrupted by concurrent accesses. A quick and small fix is > > > unfortunately not possible, so let us revert this for now. > > > > This is a very useful feature, to be able to use AF_XDP sockets with > > a standard RSS nic configuration. > > I completely agree. > > > Not all AF_XDP use cases require the absolute highest packet rate. > > > > Can this be addressed with an optional spinlock on the RxQ, only for > > this case? > > Yes, or with a MPSC ring implementation. > > > If there is no simple enough fix in the short term, do you plan to > > reintroduce this in another form later? > > Yuval and I are looking into a solution based around an optional > spinlock since it is easier to pull off than an MPSC ring. The > discussion is on-going on the xdp-newbies list [0], but as soon as we > have a first patch, we will post it here for review and debate. > > [0] https://lore.kernel.org/xdp-newbies/8100DBDC-0B7C-49DB-9995-6027F6E63147@xxxxxxxxxxx/ Glad to hear that it's intended to be supported, and even being worked on, thanks! I'll follow the conversation there.
