[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20240820081920.6630a73f@kernel.org>
Date: Tue, 20 Aug 2024 08:19:20 -0700
From: Jakub Kicinski <kuba@...nel.org>
To: Mina Almasry <almasrymina@...gle.com>
Cc: Taehee Yoo <ap420073@...il.com>, netdev@...r.kernel.org,
linux-kernel@...r.kernel.org, linux-doc@...r.kernel.org,
linux-alpha@...r.kernel.org, linux-mips@...r.kernel.org,
linux-parisc@...r.kernel.org, sparclinux@...r.kernel.org,
linux-trace-kernel@...r.kernel.org, linux-arch@...r.kernel.org,
linux-kselftest@...r.kernel.org, bpf@...r.kernel.org,
linux-media@...r.kernel.org, dri-devel@...ts.freedesktop.org, "David S.
Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, Paolo
Abeni <pabeni@...hat.com>, Donald Hunter <donald.hunter@...il.com>,
Jonathan Corbet <corbet@....net>, Richard Henderson
<richard.henderson@...aro.org>, Ivan Kokshaysky <ink@...assic.park.msu.ru>,
Matt Turner <mattst88@...il.com>, Thomas Bogendoerfer
<tsbogend@...ha.franken.de>, "James E.J. Bottomley"
<James.Bottomley@...senpartnership.com>, Helge Deller <deller@....de>,
Andreas Larsson <andreas@...sler.com>, Jesper Dangaard Brouer
<hawk@...nel.org>, Ilias Apalodimas <ilias.apalodimas@...aro.org>, Steven
Rostedt <rostedt@...dmis.org>, Masami Hiramatsu <mhiramat@...nel.org>,
Mathieu Desnoyers <mathieu.desnoyers@...icios.com>, Arnd Bergmann
<arnd@...db.de>, Steffen Klassert <steffen.klassert@...unet.com>, Herbert
Xu <herbert@...dor.apana.org.au>, David Ahern <dsahern@...nel.org>, Willem
de Bruijn <willemdebruijn.kernel@...il.com>, Shuah Khan <shuah@...nel.org>,
Alexei Starovoitov <ast@...nel.org>, Daniel Borkmann
<daniel@...earbox.net>, John Fastabend <john.fastabend@...il.com>, Sumit
Semwal <sumit.semwal@...aro.org>, Christian König
<christian.koenig@....com>, Bagas Sanjaya <bagasdotme@...il.com>, Christoph
Hellwig <hch@...radead.org>, Nikolay Aleksandrov <razor@...ckwall.org>,
Pavel Begunkov <asml.silence@...il.com>, David Wei <dw@...idwei.uk>, Jason
Gunthorpe <jgg@...pe.ca>, Yunsheng Lin <linyunsheng@...wei.com>, Shailend
Chand <shailend@...gle.com>, Harshitha Ramamurthy <hramamurthy@...gle.com>,
Shakeel Butt <shakeel.butt@...ux.dev>, Jeroen de Borst
<jeroendb@...gle.com>, Praveen Kaligineedi <pkaligineedi@...gle.com>,
Willem de Bruijn <willemb@...gle.com>, Kaiyuan Zhang <kaiyuanz@...gle.com>,
Daniel Vetter <daniel.vetter@...ll.ch>
Subject: Re: [PATCH net-next v19 03/13] netdev: support binding dma-buf to
netdevice
On Tue, 20 Aug 2024 00:01:02 -0400 Mina Almasry wrote:
> Took a bit of a look here. Forgive me, I'm not that familiar with XDP
> and virtual interfaces, so I'm a bit unsure what to do here.
>
> For veth, it seems, the device behind the veth is stored in
> veth_priv->peer, so it seems maybe a dev_get_max_mp_channel() check on
> veth_priv->peer is the way to go to disable this for veth? I think we
> need to do this check on creation of the veth and on the ndo_bpf of
> veth.
veth is a SW device pair, it can't reasonably support netmem.
Given all the unreasonable features it grew over time we can't
rule out that someone will try, but that's not our problem now.
> For bonding, it seems we need to add mp channel check in bond_xdp_set,
> and bond_enslave?
Sort of, I'd factor out that logic into the core first, as some
sort of "xdp propagate" helper. Then we can add that check once.
I don't see anything bond specific in the logic.
> There are a few other drivers that define ndo_add_slave, seems a check
> in br_add_slave is needed as well.
I don't think it's that broad. Not many drivers propagate XDP:
$ git grep -C 200 '\.ndo_add_slave' | grep '\.ndo_bpf'
drivers/net/bonding/bond_main.c- .ndo_bpf = bond_xdp,
$ git grep --files-with-matches 'ops->ndo_bpf' -- drivers/
drivers/net/bonding/bond_main.c
drivers/net/hyperv/netvsc_bpf.c
> This seems like a potentially deep rabbit hole with a few checks to
> add all of the place. Is this blocking the series?
Protecting the stack from unreadable memory is *the* challenge
in this series. The rest is a fairly straightforward.
Powered by blists - more mailing lists