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

[Shunsuke Mie]

This patchset introduce a virtio-net EP device function. It provides a
new option to communiate between PCIe host and endpoint over IP.
Advantage of this option is that the driver fully uses a PCIe embedded DMA.
It is used to transport data between virtio ring directly each other. It
can be expected to better throughput.

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://lore.kernel.org/dmaengine/20221223022608.550697-1-mie@xxxxxxxxxx/
- [RFC PATCH 0/3] Deal with alignment restriction on EP side
link: https://lore.kernel.org/linux-pci/20230113090350.1103494-1-mie@xxxxxxxxxx/
- [RFC PATCH v2 0/7] Introduce a vringh accessor for IO memory
link: https://lore.kernel.org/virtualization/20230202090934.549556-1-mie@xxxxxxxxxx/

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