Plea for advice with PCIe on QEMU for iMX6 and plan to add FlexCAN controller support

[Pavel Pisa <pisa@fel.cvut.cz>]

Dear Nikita and other,

my student Matyas Bobek has chosen to work
on QEMU CAN support in a frame of his study
final project.

We have identified iMX6 FlexCAN as the next interesting
CAN controller for emulation. One of our industrial partners
is using iMX6 based system with CAN and iMX6 SabreLite
is supported by QEMU. iMX6 is often used in industry
still and FlexCAN has use even for iMX8 emulation
if it is added into QEMU in the future.

In the preparatory work, we want to setup
shared directory between host and guest
kernel using 9P FS on PCI virtio.

The development environment is based on current
mainline QEMU and mainline Linux kernel sources.

We use standard QEMU options

  -virtfs local,path=shareddir,security_model=none,mount_tag=shareddir

and the 1af4:1009 is seen by monitor command "info pci"
but on the guest kernel side only "16c3:abcd" DWC_usb3 / PCIe bridge
is seen but none from the mapped devices, virtio (1af4:1009),
CTU CAN FD, Kvaser CAN.

The imx6q-sabrelite DTS is used with standard device-tree

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/nxp/imx/imx6q-sabrelite.dts

We hope that all required drivers are enabled
in the kernel. But it is possible that something
has been overlooked.

Do you have some hint or some kernel
and QEMU working example for iMX6 PCIe
device mapping?

Thanks in advance.

Best wishes,

                Pavel
--
                Pavel Pisa
    phone:      +420 603531357
    e-mail:     pisa@cmp.felk.cvut.cz
    Department of Control Engineering FEE CVUT
    Karlovo namesti 13, 121 35, Prague 2
    university: http://control.fel.cvut.cz/
    personal:   http://cmp.felk.cvut.cz/~pisa
    social:     https://social.kernel.org/ppisa
    projects:   https://www.openhub.net/accounts/ppisa
    CAN related:http://canbus.pages.fel.cvut.cz/
    RISC-V education: https://comparch.edu.cvut.cz/
    Open Technologies Research Education and Exchange Services
    https://gitlab.fel.cvut.cz/otrees/org/-/wikis/home