netdev - Re: [PATCH vhost v11 05/10] virtio_ring: introduce virtqueue_dma

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <ZLja73TJ1Ow19xdr@infradead.org>
Date: Wed, 19 Jul 2023 23:57:51 -0700
From: Christoph Hellwig <hch@...radead.org>
To: Xuan Zhuo <xuanzhuo@...ux.alibaba.com>
Cc: Christoph Hellwig <hch@...radead.org>,
	virtualization@...ts.linux-foundation.org,
	Jason Wang <jasowang@...hat.com>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
	Alexei Starovoitov <ast@...nel.org>,
	Daniel Borkmann <daniel@...earbox.net>,
	Jesper Dangaard Brouer <hawk@...nel.org>,
	John Fastabend <john.fastabend@...il.com>, netdev@...r.kernel.org,
	bpf@...r.kernel.org, "Michael S. Tsirkin" <mst@...hat.com>
Subject: Re: [PATCH vhost v11 05/10] virtio_ring: introduce
 virtqueue_dma_dev()

On Thu, Jul 20, 2023 at 02:45:14PM +0800, Xuan Zhuo wrote:
>  virtqueue_dma_dev() return the device that working with the DMA APIs.
>  Then that can be used like other devices. So what is the problem.
> 
>  I always think the code path without the DMA APIs is the trouble for you.

Because we now have an API where the upper level drivers sometimes
see the dma device and sometimes not.  This will be abused and cause
trouble sooner than you can say "layering".