Re: [EXT] [RFC PATCH 0/4] PCI: endpoint: Introduce a virtio-net EP function

From: Shunsuke Mie
Date: Mon Feb 13 2023 - 22:27:13 EST



On 2023/02/08 1:02, Frank Li wrote:
We project extending this module to support RDMA. The plan is based on
virtio-rdma[1].
It extends the virtio-net and we are plan to implement the proposed
spec based on this patch.
[1] virtio-rdma
- proposal:
https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.k
ernel.org%2Fall%2F20220511095900.343-1-
xieyongji%40bytedance.com%2FT%2F&data=05%7C01%7Cfrank.li%40nxp.co
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2qbxL9USph9o%3D&reserved=0
- presentation on kvm forum:
https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fyout
u.be%2FQrhv6hC_YK4&data=05%7C01%7Cfrank.li%40nxp.com%7C0ef2bd62
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erved=0

Sorry for our outlook client always change link. This previous discussion.
https://lore.kernel.org/imx/d098a631-9930-26d3-48f3-8f95386c8e50@xxxxxx/T/#t

Look like Endpoint maintainer Kishon like endpoint side work as vhost.
Previous Haotian Wang submit similar patches, which just not use eDMA, just use memcpy.
But overall idea is the same.

I think your and haotian's method is more reasonable for PCI-RC EP connection.

Kishon is not active recently. Maybe need Lorenzo Pieralisi and Bjorn helgass's comments
for overall directions.
I think so too. Thank you for your summarization. I've commented on the e-mail.
Frank Li

Please feel free to comment and suggest.
Frank Li

To realize the function, this patchset has few changes and introduces a
new APIs to PCI EP framework related to virtio. Furthermore, it device
depends on the some patchtes that is discussing. Those depended
patchset
are following:
- [PATCH 1/2] dmaengine: dw-edma: Fix to change for continuous
transfer
link:

https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.k
%2F&data=05%7C01%7Cfrank.li%40nxp.com%7C0ef2bd62eda945c413be08db
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ernel.org%2Fdmaengine%2F20221223022608.550697-1-

mie%40igel.co.jp%2F&data=05%7C01%7CFrank.Li%40nxp.com%7Cac57a62d4
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reserved=0
- [RFC PATCH 0/3] Deal with alignment restriction on EP side
link:

https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.k
%2F&data=05%7C01%7Cfrank.li%40nxp.com%7C0ef2bd62eda945c413be08db
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ernel.org%2Flinux-pci%2F20230113090350.1103494-1-

mie%40igel.co.jp%2F&data=05%7C01%7CFrank.Li%40nxp.com%7Cac57a62d4
10b458a5ba408db05ce0a4e%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%

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D&reserved=0
- [RFC PATCH v2 0/7] Introduce a vringh accessor for IO memory
link:

https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.k
%2F&data=05%7C01%7Cfrank.li%40nxp.com%7C0ef2bd62eda945c413be08db
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ernel.org%2Fvirtualization%2F20230202090934.549556-1-

mie%40igel.co.jp%2F&data=05%7C01%7CFrank.Li%40nxp.com%7Cac57a62d4
10b458a5ba408db05ce0a4e%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%

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About this patchset has 4 patches. The first of two patch is little changes
to virtio. The third patch add APIs to easily access virtio data structure
on PCIe Host side memory. The last one introduce a virtio-net EP device
function. Details are in commit respectively.

Currently those network devices are testd using ping only. I'll add a
result of performance evaluation using iperf and etc to the future version
of this patchset.

Shunsuke Mie (4):
virtio_pci: add a definition of queue flag in ISR
virtio_ring: remove const from vring getter
PCI: endpoint: Introduce virtio library for EP functions
PCI: endpoint: function: Add EP function driver to provide virtio net
device

drivers/pci/endpoint/Kconfig | 7 +
drivers/pci/endpoint/Makefile | 1 +
drivers/pci/endpoint/functions/Kconfig | 12 +
drivers/pci/endpoint/functions/Makefile | 1 +
.../pci/endpoint/functions/pci-epf-vnet-ep.c | 343 ++++++++++
.../pci/endpoint/functions/pci-epf-vnet-rc.c | 635
++++++++++++++++++
drivers/pci/endpoint/functions/pci-epf-vnet.c | 387 +++++++++++
drivers/pci/endpoint/functions/pci-epf-vnet.h | 62 ++
drivers/pci/endpoint/pci-epf-virtio.c | 113 ++++
drivers/virtio/virtio_ring.c | 2 +-
include/linux/pci-epf-virtio.h | 25 +
include/linux/virtio.h | 2 +-
include/uapi/linux/virtio_pci.h | 2 +
13 files changed, 1590 insertions(+), 2 deletions(-)
create mode 100644 drivers/pci/endpoint/functions/pci-epf-vnet-ep.c
create mode 100644 drivers/pci/endpoint/functions/pci-epf-vnet-rc.c
create mode 100644 drivers/pci/endpoint/functions/pci-epf-vnet.c
create mode 100644 drivers/pci/endpoint/functions/pci-epf-vnet.h
create mode 100644 drivers/pci/endpoint/pci-epf-virtio.c
create mode 100644 include/linux/pci-epf-virtio.h

--
2.25.1
Best,
Shunsuke

Best,

Shunsuke.