Re: [Qemu-devel] [PATCH 0/7] CAN bus support for QEMU (SJA1000 PCI so far)

[Oleksij Rempel]

Hi,

thank you for your work!

we integrated your patches in our OSALES BSP [1] and did some basic tests:
- communication between host and guest
- communication between real CAN/J1939 device over the host to guest.

J1939(real device) -> candleLight v1.1 -> host (kernel v4.13) -> QEMU
(with your CAN patches) -> kernel (with experimental J1939 support) ->
J1939 App
So far it works without noticeable issues.

We are working on a CAN/J1939/ISObus protocol development for linux
kernel and create some regression testing infrastructure to reduce
possible problems before our patches will go to kernel mainline.
In this case QEMU is really helpful.

I hope your patches will go QEMU mainline soon :)

[1]
https://git.pengutronix.de/cgit/OSELAS.BSP-Pengutronix-J1939/?h=bst/x86-wip

On 06.01.2018 21:47, address@hidden wrote:
> From: Pavel Pisa <address@hidden>
> 
> Basic emulation of CAN bus controller and interconnection for QEMU.
> 
> Patches version 3:
> Support to connect to host SocketCAN interface has been
> separated from the core bus implementation. Only simple
> statically initialize pointer to the connection function
> is used, no QOM concept for now.
> SJA1000 message filters redone and code unified where
> possible.
> Basic documentation added.
> QEMU_ALIGNED used in definition of CAN frame structure,
> structure and defines still separated from Linux/SocketCAN
> API defined ones to allow to keep QEMU message format
> independed from host system one. Check for correspondence
> to socketcan one added.
> 
> Patches version 2:
> The bus emulation and the SJA1000 chip emulation introduced
> by individual patches as suggested by Frederic Konrad.
> Simple example board to test SJA1000 as single memory-mapped BAR
> has been omitted in a new series because emulation of real
> existing boards can provide same functions now.
> Conditionalized debug printfs changed to be exposed to compiler
> syntax check as suggested in review.
> 
> The work has been started by Jin Yang in the frame of GSoC 2013 slot
> contributed by RTEMS project which has been looking for environment
> to allow develop and test CAN drivers for multiple CPU architectures.
> 
> I have menthored the project and then done substantial code cleanup
> and update to QOM. Deniz Eren then used emulation for SJA1000 base card
> driver development for other operating system and contributed
> PCM-3680I and MIOe-3680 support.
> 
> Some page about the project
> 
>   https://gitlab.fel.cvut.cz/canbus/qemu-canbus/wikis/home
> 
> FEE CTU GitLab repository with can-pci branch for 2.3, 2.4, 2.7, 2.8, 2.10 
> and 2.11
> version if QEMU is available there
> 
>   https://gitlab.fel.cvut.cz/canbus/qemu-canbus/tree/can-pci
> 
> mirror at GitHub
> 
>   https://github.com/CTU-IIG/qemu
> 
> There are many areas for improvement and extension of the code still
> (for example freeze and migration is not implemented. CAN controllers
> use proper QOM model but bus/interconnection emulation uses simple broadcast
> connection which is required for CAN, but it is not based on QEMU bus model).
> I have tried to look into QEMU VLANs implementation but it
> does not map straightforward to CAN and I would need some help/opinion
> from more advanced developers to decide what is their right
> mapping to CAN.
> 
> CAN-FD support would be interesting requires other developers/
> companies contributions or setup of some project to allow invite
> some students and colleagues from my university into project.
> 
> But I believe that (even in its actual state) provided solution
> is great help for embedded systems developers when they can connect
> SocketCAN from one or more embedded systems running in virtual
> environment together or with Linux host SocketCAN virtual
> or real bus interfaces.
> 
> We have even tested our generic CANopen device configured
> for CANopen 401 profile for generic I/O running in the virtual
> system which can control GPIO inputs/outputs through virtual
> industrial I/O card.
> 
> Generally QEMU can be interesting setup which allows
> to test complete industrial and automotive applications
> in virtual environment even before real hardware is availabe.
> 
> Deniz Eren (2):
>   CAN bus PCM-3680I PCI (dual SJA1000 channel) emulation added.
>   CAN bus MIOe-3680 PCI (dual SJA1000 channel) emulation added.
> 
> Pavel Pisa (5):
>   CAN bus simple messages transport implementation for QEMU
>   CAN bus support to connect bust to Linux host SocketCAN interface.
>   CAN bus SJA1000 chip register level emulation for QEMU
>   CAN bus Kvaser PCI CAN-S (single SJA1000 channel) emulation added.
>   QEMU CAN bus emulation documentation
> 
>  default-configs/pci.mak   |   3 +
>  docs/can.txt              |  78 ++++
>  hw/Makefile.objs          |   1 +
>  hw/can/Makefile.objs      |  14 +
>  hw/can/can_core.c         | 129 ++++++
>  hw/can/can_host_stub.c    |  36 ++
>  hw/can/can_kvaser_pci.c   | 375 +++++++++++++++++
>  hw/can/can_mioe3680_pci.c | 335 ++++++++++++++++
>  hw/can/can_pcm3680_pci.c  | 335 ++++++++++++++++
>  hw/can/can_sja1000.c      | 996 
> ++++++++++++++++++++++++++++++++++++++++++++++
>  hw/can/can_sja1000.h      | 176 ++++++++
>  hw/can/can_socketcan.c    | 294 ++++++++++++++
>  include/can/can_emu.h     | 143 +++++++
>  13 files changed, 2915 insertions(+)
>  create mode 100644 docs/can.txt
>  create mode 100644 hw/can/Makefile.objs
>  create mode 100644 hw/can/can_core.c
>  create mode 100644 hw/can/can_host_stub.c
>  create mode 100644 hw/can/can_kvaser_pci.c
>  create mode 100644 hw/can/can_mioe3680_pci.c
>  create mode 100644 hw/can/can_pcm3680_pci.c
>  create mode 100644 hw/can/can_sja1000.c
>  create mode 100644 hw/can/can_sja1000.h
>  create mode 100644 hw/can/can_socketcan.c
>  create mode 100644 include/can/can_emu.h
>