Re: [RFC PATCH 00/22] Enhance VHOST to enable SoC-to-SoC communication

Michael S. Tsirkin
2020-07-02T09:51:48Z

On Thu, Jul 02, 2020 at 01:51:21PM +0530, Kishon Vijay Abraham I wrote:
> This series enhances Linux Vhost support to enable SoC-to-SoC
> communication over MMIO. This series enables rpmsg communication between
> two SoCs using both PCIe RC<->EP and HOST1-NTB-HOST2
>
> 1) Modify vhost to use standard Linux driver model
> 2) Add support in vring to access virtqueue over MMIO
> 3) Add vhost client driver for rpmsg
> 4) Add PCIe RC driver (uses virtio) and PCIe EP driver (uses vhost) for
> rpmsg communication between two SoCs connected to each other
> 5) Add NTB Virtio driver and NTB Vhost driver for rpmsg communication
> between two SoCs connected via NTB
> 6) Add configfs to configure the components
>
> UseCase1 :
>
> VHOST RPMSG VIRTIO RPMSG
> + +
> | |
> | |
> | |
> | |
> +-----v------+ +------v-------+
> | Linux | | Linux |
> | Endpoint | | Root Complex |
> | <-----------------> |
> | | | |
> | SOC1 | | SOC2 |
> +------------+ +--------------+
>
> UseCase 2:
>
> VHOST RPMSG VIRTIO RPMSG
> + +
> | |
> | |
> | |
> | |
> +------v------+ +------v------+
> | | | |
> | HOST1 | | HOST2 |
> | | | |
> +------^------+ +------^------+
> | |
> | |
> +---------------------------------------------------------------------+
> | +------v------+ +------v------+ |
> | | | | | |
> | | EP | | EP | |
> | | CONTROLLER1 | | CONTROLLER2 | |
> | | <-----------------------------------> | |
> | | | | | |
> | | | | | |
> | | | SoC With Multiple EP Instances | | |
> | | | (Configured using NTB Function) | | |
> | +-------------+ +-------------+ |
> +---------------------------------------------------------------------+
>
> Software Layering:
>
> The high-level SW layering should look something like below. This series
> adds support only for RPMSG VHOST, however something similar should be
> done for net and scsi. With that any vhost device (PCI, NTB, Platform
> device, user) can use any of the vhost client driver.
>
>
> +----------------+ +-----------+ +------------+ +----------+
> | RPMSG VHOST | | NET VHOST | | SCSI VHOST | | X |
> +-------^--------+ +-----^-----+ +-----^------+ +----^-----+
> | | | |
> | | | |
> | | | |
> +-----------v-----------------v--------------v--------------v----------+
> | VHOST CORE |
> +--------^---------------^--------------------^------------------^-----+
> | | | |
> | | | |
> | | | |
> +--------v-------+ +----v------+ +----------v----------+ +----v-----+
> | PCI EPF VHOST | | NTB VHOST | |PLATFORM DEVICE VHOST| | X |
> +----------------+ +-----------+ +---------------------+ +----------+
>
> This was initially proposed here [1]
>
> [1] -> https://lore.kernel.org/r/2cf00ec4-1ed6-f66e-6897-006d1a5b6390@ti.com

I find this very interesting. A huge patchset so will take a bit
to review, but I certainly plan to do that. Thanks!

>
> Kishon Vijay Abraham I (22):
> vhost: Make _feature_ bits a property of vhost device
> vhost: Introduce standard Linux driver model in VHOST
> vhost: Add ops for the VHOST driver to configure VHOST device
> vringh: Add helpers to access vring in MMIO
> vhost: Add MMIO helpers for operations on vhost virtqueue
> vhost: Introduce configfs entry for configuring VHOST
> virtio_pci: Use request_threaded_irq() instead of request_irq()
> rpmsg: virtio_rpmsg_bus: Disable receive virtqueue callback when
> reading messages
> rpmsg: Introduce configfs entry for configuring rpmsg
> rpmsg: virtio_rpmsg_bus: Add Address Service Notification support
> rpmsg: virtio_rpmsg_bus: Move generic rpmsg structure to
> rpmsg_internal.h
> virtio: Add ops to allocate and free buffer
> rpmsg: virtio_rpmsg_bus: Use virtio_alloc_buffer() and
> virtio_free_buffer()
> rpmsg: Add VHOST based remote processor messaging bus
> samples/rpmsg: Setup delayed work to send message
> samples/rpmsg: Wait for address to be bound to rpdev for sending
> message
> rpmsg.txt: Add Documentation to configure rpmsg using configfs
> virtio_pci: Add VIRTIO driver for VHOST on Configurable PCIe Endpoint
> device
> PCI: endpoint: Add EP function driver to provide VHOST interface
> NTB: Add a new NTB client driver to implement VIRTIO functionality
> NTB: Add a new NTB client driver to implement VHOST functionality
> NTB: Describe the ntb_virtio and ntb_vhost client in the documentation
>
> Documentation/driver-api/ntb.rst | 11 +
> Documentation/rpmsg.txt | 56 +
> drivers/ntb/Kconfig | 18 +
> drivers/ntb/Makefile | 2 +
> drivers/ntb/ntb_vhost.c | 776 +++++++++++
> drivers/ntb/ntb_virtio.c | 853 ++++++++++++
> drivers/ntb/ntb_virtio.h | 56 +
> drivers/pci/endpoint/functions/Kconfig | 11 +
> drivers/pci/endpoint/functions/Makefile | 1 +
> .../pci/endpoint/functions/pci-epf-vhost.c | 1144 ++++++++++++++++
> drivers/rpmsg/Kconfig | 10 +
> drivers/rpmsg/Makefile | 3 +-
> drivers/rpmsg/rpmsg_cfs.c | 394 ++++++
> drivers/rpmsg/rpmsg_core.c | 7 +
> drivers/rpmsg/rpmsg_internal.h | 136 ++
> drivers/rpmsg/vhost_rpmsg_bus.c | 1151 +++++++++++++++++
> drivers/rpmsg/virtio_rpmsg_bus.c | 184 ++-
> drivers/vhost/Kconfig | 1 +
> drivers/vhost/Makefile | 2 +-
> drivers/vhost/net.c | 10 +-
> drivers/vhost/scsi.c | 24 +-
> drivers/vhost/test.c | 17 +-
> drivers/vhost/vdpa.c | 2 +-
> drivers/vhost/vhost.c | 730 ++++++++++-
> drivers/vhost/vhost_cfs.c | 341 +++++
> drivers/vhost/vringh.c | 332 +++++
> drivers/vhost/vsock.c | 20 +-
> drivers/virtio/Kconfig | 9 +
> drivers/virtio/Makefile | 1 +
> drivers/virtio/virtio_pci_common.c | 25 +-
> drivers/virtio/virtio_pci_epf.c | 670 ++++++++++
> include/linux/mod_devicetable.h | 6 +
> include/linux/rpmsg.h | 6 +
> {drivers/vhost => include/linux}/vhost.h | 132 +-
> include/linux/virtio.h | 3 +
> include/linux/virtio_config.h | 42 +
> include/linux/vringh.h | 46 +
> samples/rpmsg/rpmsg_client_sample.c | 32 +-
> tools/virtio/virtio_test.c | 2 +-
> 39 files changed, 7083 insertions(+), 183 deletions(-)
> create mode 100644 drivers/ntb/ntb_vhost.c
> create mode 100644 drivers/ntb/ntb_virtio.c
> create mode 100644 drivers/ntb/ntb_virtio.h
> create mode 100644 drivers/pci/endpoint/functions/pci-epf-vhost.c
> create mode 100644 drivers/rpmsg/rpmsg_cfs.c
> create mode 100644 drivers/rpmsg/vhost_rpmsg_bus.c
> create mode 100644 drivers/vhost/vhost_cfs.c
> create mode 100644 drivers/virtio/virtio_pci_epf.c
> rename {drivers/vhost => include/linux}/vhost.h (66%)
>
> --
> 2.17.1
>