From: Christoph Hellwig <hch@infradead.org>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>,
Xuan Zhuo <xuanzhuo@linux.alibaba.com>,
virtualization@lists.linux-foundation.org,
Jason Wang <jasowang@redhat.com>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, 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
Subject: Re: [PATCH vhost v11 03/10] virtio_ring: introduce virtqueue_set_premapped()
Date: Wed, 19 Jul 2023 23:22:07 -0700 [thread overview]
Message-ID: <ZLjSj4uSr+pIKSui@infradead.org> (raw)
In-Reply-To: <20230713104542-mutt-send-email-mst@kernel.org>
On Thu, Jul 13, 2023 at 10:47:23AM -0400, Michael S. Tsirkin wrote:
> There are a gazillion virtio drivers and most of them just use the
> virtio API, without bothering with these micro-optimizations. virtio
> already tracks addresses so mapping/unmapping them for DMA is easier
> done in the core. It's only networking and only with XDP where the
> difference becomes measureable.
Yes, but now you two differing code paths (which then branch into
another two with the fake DMA mappings). I'm really worried about
the madness that follows like the USB dma mapping code that is a
constant soure of trouble.
next prev parent reply other threads:[~2023-07-20 6:22 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 [this message]
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
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=ZLjSj4uSr+pIKSui@infradead.org \
--to=hch@infradead.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=hawk@kernel.org \
--cc=jasowang@redhat.com \
--cc=john.fastabend@gmail.com \
--cc=kuba@kernel.org \
--cc=mst@redhat.com \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=virtualization@lists.linux-foundation.org \
--cc=xuanzhuo@linux.alibaba.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).