From: Jakub Kicinski <kuba@kernel.org>
To: Jason Wang <jasowang@redhat.com>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>,
Christoph Hellwig <hch@infradead.org>,
virtualization@lists.linux-foundation.org,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Paolo Abeni <pabeni@redhat.com>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Jesper Dangaard Brouer <hawk@kernel.org>,
John Fastabend <john.fastabend@gmail.com>,
netdev@vger.kernel.org, bpf@vger.kernel.org,
"Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [PATCH vhost v11 05/10] virtio_ring: introduce virtqueue_dma_dev()
Date: Mon, 31 Jul 2023 08:46:51 -0700 [thread overview]
Message-ID: <20230731084651.16ec0a96@kernel.org> (raw)
In-Reply-To: <CACGkMEs5uc=ct8BsJzV2SEJzAGXqCP__yxo-MBa6d6JzDG4YOg@mail.gmail.com>
On Mon, 31 Jul 2023 09:23:29 +0800 Jason Wang wrote:
> > I'd step back and ask you why do you want to use AF_XDP with virtio.
> > Instead of bifurcating one virtio instance into different queues why
> > not create a separate virtio instance?
>
> I'm not sure I get this, but do you mean a separate virtio device that
> owns AF_XDP queues only? If I understand it correctly, bifurcating is
> one of the key advantages of AF_XDP. What's more, current virtio
> doesn't support being split at queue (pair) level. And it may still
> suffer from the yes/no DMA API issue.
I guess we should step even further back and ask Xuan what the use case
is, because I'm not very sure. All we hear is "enable AF_XDP on virtio"
but AF_XDP is barely used on real HW, so why?
Bifurcating makes (used to make?) some sense in case of real HW when you
had only one PCI function and had to subdivide it. Virtio is either a SW
construct or offloaded to very capable HW, so either way cost of
creating an extra instance for DPDK or whatever else is very low.
next prev parent reply other threads:[~2023-07-31 15:46 UTC|newest]
Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-10 3:42 [PATCH vhost v11 00/10] virtio core prepares for AF_XDP Xuan Zhuo
2023-07-10 3:42 ` [PATCH vhost v11 01/10] virtio_ring: check use_dma_api before unmap desc for indirect Xuan Zhuo
2023-07-10 3:42 ` [PATCH vhost v11 02/10] virtio_ring: put mapping error check in vring_map_one_sg Xuan Zhuo
2023-07-10 3:42 ` [PATCH vhost v11 03/10] virtio_ring: introduce virtqueue_set_premapped() Xuan Zhuo
[not found] ` <CACGkMEumF73qbByV3K1+fdgnXBXqu-YS2yas+Vy_=Dn+yjy-cw@mail.gmail.com>
2023-07-12 8:35 ` Xuan Zhuo
2023-07-13 11:14 ` Christoph Hellwig
2023-07-13 14:47 ` Michael S. Tsirkin
2023-07-20 6:22 ` Christoph Hellwig
2023-07-13 14:52 ` Michael S. Tsirkin
2023-07-10 3:42 ` [PATCH vhost v11 04/10] virtio_ring: support add premapped buf Xuan Zhuo
2023-07-12 8:31 ` Jason Wang
2023-07-12 8:33 ` Xuan Zhuo
2023-07-10 3:42 ` [PATCH vhost v11 05/10] virtio_ring: introduce virtqueue_dma_dev() Xuan Zhuo
2023-07-12 8:33 ` Jason Wang
2023-07-13 11:15 ` Christoph Hellwig
2023-07-13 14:51 ` Michael S. Tsirkin
2023-07-20 6:22 ` Christoph Hellwig
2023-07-20 6:45 ` Xuan Zhuo
2023-07-20 6:57 ` Christoph Hellwig
2023-07-20 7:34 ` Xuan Zhuo
2023-07-24 20:05 ` Michael S. Tsirkin
2023-07-20 17:21 ` Michael S. Tsirkin
2023-07-24 16:43 ` Christoph Hellwig
2023-07-25 2:13 ` Xuan Zhuo
2023-07-25 7:34 ` Michael S. Tsirkin
2023-07-25 11:07 ` Xuan Zhuo
2023-07-28 6:02 ` Xuan Zhuo
2023-07-28 15:03 ` Jakub Kicinski
2023-07-31 1:23 ` Jason Wang
2023-07-31 15:46 ` Jakub Kicinski [this message]
2023-08-01 2:03 ` Xuan Zhuo
2023-08-01 2:36 ` Jakub Kicinski
2023-08-01 2:57 ` Xuan Zhuo
2023-08-01 15:45 ` Jakub Kicinski
2023-08-02 1:36 ` Xuan Zhuo
2023-08-02 11:12 ` Pavel Begunkov
2023-07-31 2:34 ` Xuan Zhuo
2023-08-01 16:17 ` Michael S. Tsirkin
2023-08-02 1:49 ` Xuan Zhuo
2023-08-07 6:14 ` Xuan Zhuo
2023-08-08 2:26 ` Jason Wang
2023-08-08 2:47 ` Xuan Zhuo
2023-08-08 3:08 ` Jason Wang
2023-08-08 3:09 ` Xuan Zhuo
2023-08-08 3:49 ` Jason Wang
[not found] ` <1691466855.2312648-3-xuanzhuo@linux.alibaba.com>
2023-08-08 3:59 ` Jason Wang
2023-08-10 1:56 ` Xuan Zhuo
2023-08-10 6:37 ` Jason Wang
2023-08-10 6:40 ` Michael S. Tsirkin
2023-08-10 6:39 ` Michael S. Tsirkin
2023-08-10 6:47 ` Xuan Zhuo
2023-07-10 3:42 ` [PATCH vhost v11 06/10] virtio_ring: skip unmap for premapped Xuan Zhuo
2023-07-13 3:50 ` Jason Wang
2023-07-13 4:02 ` Xuan Zhuo
2023-07-13 4:21 ` Jason Wang
2023-07-13 5:45 ` Xuan Zhuo
2023-07-10 3:42 ` [PATCH vhost v11 07/10] virtio_ring: correct the expression of the description of virtqueue_resize() Xuan Zhuo
2023-07-10 3:42 ` [PATCH vhost v11 08/10] virtio_ring: separate the logic of reset/enable from virtqueue_resize Xuan Zhuo
2023-07-10 3:42 ` [PATCH vhost v11 09/10] virtio_ring: introduce virtqueue_reset() Xuan Zhuo
2023-07-10 3:42 ` [PATCH vhost v11 10/10] virtio_net: merge dma operation for one page Xuan Zhuo
2023-07-10 9:40 ` Michael S. Tsirkin
2023-07-10 10:18 ` Xuan Zhuo
2023-07-10 11:59 ` Michael S. Tsirkin
2023-07-10 12:38 ` Xuan Zhuo
2023-07-11 2:36 ` Jason Wang
2023-07-11 2:40 ` Xuan Zhuo
2023-07-11 2:58 ` Jason Wang
2023-07-12 7:54 ` Xuan Zhuo
2023-07-12 8:32 ` Xuan Zhuo
2023-07-12 8:37 ` Jason Wang
2023-07-12 8:38 ` Xuan Zhuo
2023-07-14 10:37 ` Michael S. Tsirkin
2023-07-19 3:21 ` Xuan Zhuo
2023-07-19 8:55 ` Michael S. Tsirkin
2023-07-19 9:38 ` Jason Wang
2023-07-19 9:51 ` Michael S. Tsirkin
2023-07-20 2:26 ` Xuan Zhuo
2023-07-20 2:24 ` Xuan Zhuo
2023-07-13 4:20 ` Jason Wang
2023-07-13 5:53 ` Xuan Zhuo
2023-07-13 6:51 ` Xuan Zhuo
2023-07-14 3:56 ` Jason Wang
2023-07-20 6:23 ` Christoph Hellwig
2023-07-20 7:41 ` Jason Wang
2023-07-20 8:21 ` Christoph Hellwig
2023-07-13 7:00 ` Xuan Zhuo
2023-07-14 3:57 ` Jason Wang
2023-07-14 3:58 ` Xuan Zhuo
2023-07-14 5:45 ` Jason Wang
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