Re: [PATCH v4 00/14] Copy Offload in NVMe Fabrics with P2P PCI Memory

[Bjorn Helgaas]

On Mon, Apr 23, 2018 at 05:30:32PM -0600, Logan Gunthorpe wrote:
> Hi Everyone,
> 
> Here's v4 of our series to introduce P2P based copy offload to NVMe
> fabrics. This version has been rebased onto v4.17-rc2. A git repo
> is here:
> 
> https://github.com/sbates130272/linux-p2pmem pci-p2p-v4
> ...

> Logan Gunthorpe (14):
>   PCI/P2PDMA: Support peer-to-peer memory
>   PCI/P2PDMA: Add sysfs group to display p2pmem stats
>   PCI/P2PDMA: Add PCI p2pmem dma mappings to adjust the bus offset
>   PCI/P2PDMA: Clear ACS P2P flags for all devices behind switches
>   docs-rst: Add a new directory for PCI documentation
>   PCI/P2PDMA: Add P2P DMA driver writer's documentation
>   block: Introduce PCI P2P flags for request and request queue
>   IB/core: Ensure we map P2P memory correctly in
>     rdma_rw_ctx_[init|destroy]()
>   nvme-pci: Use PCI p2pmem subsystem to manage the CMB
>   nvme-pci: Add support for P2P memory in requests
>   nvme-pci: Add a quirk for a pseudo CMB
>   nvmet: Introduce helper functions to allocate and free request SGLs
>   nvmet-rdma: Use new SGL alloc/free helper for requests
>   nvmet: Optionally use PCI P2P memory
> 
>  Documentation/ABI/testing/sysfs-bus-pci    |  25 +
>  Documentation/PCI/index.rst                |  14 +
>  Documentation/driver-api/index.rst         |   2 +-
>  Documentation/driver-api/pci/index.rst     |  20 +
>  Documentation/driver-api/pci/p2pdma.rst    | 166 ++++++
>  Documentation/driver-api/{ => pci}/pci.rst |   0
>  Documentation/index.rst                    |   3 +-
>  block/blk-core.c                           |   3 +
>  drivers/infiniband/core/rw.c               |  13 +-
>  drivers/nvme/host/core.c                   |   4 +
>  drivers/nvme/host/nvme.h                   |   8 +
>  drivers/nvme/host/pci.c                    | 118 +++--
>  drivers/nvme/target/configfs.c             |  67 +++
>  drivers/nvme/target/core.c                 | 143 ++++-
>  drivers/nvme/target/io-cmd.c               |   3 +
>  drivers/nvme/target/nvmet.h                |  15 +
>  drivers/nvme/target/rdma.c                 |  22 +-
>  drivers/pci/Kconfig                        |  26 +
>  drivers/pci/Makefile                       |   1 +
>  drivers/pci/p2pdma.c                       | 814 +++++++++++++++++++++++++++++
>  drivers/pci/pci.c                          |   6 +
>  include/linux/blk_types.h                  |  18 +-
>  include/linux/blkdev.h                     |   3 +
>  include/linux/memremap.h                   |  19 +
>  include/linux/pci-p2pdma.h                 | 118 +++++
>  include/linux/pci.h                        |   4 +
>  26 files changed, 1579 insertions(+), 56 deletions(-)
>  create mode 100644 Documentation/PCI/index.rst
>  create mode 100644 Documentation/driver-api/pci/index.rst
>  create mode 100644 Documentation/driver-api/pci/p2pdma.rst
>  rename Documentation/driver-api/{ => pci}/pci.rst (100%)
>  create mode 100644 drivers/pci/p2pdma.c
>  create mode 100644 include/linux/pci-p2pdma.h

How do you envison merging this?  There's a big chunk in drivers/pci, but
really no opportunity for conflicts there, and there's significant stuff in
block and nvme that I don't really want to merge.

If Alex is OK with the ACS situation, I can ack the PCI parts and you could
merge it elsewhere?

Bjorn