Re: How to use designware-root-port and designware-root-host devices ?

[Thomas Huth <thuth@redhat.com>]

On 20/06/2024 10.28, Arthur Tumanyan wrote:
> Hi all,
> 
> My question may sound stupid, however...

  Hi Arthur,

no worries, the question how to use which device in QEMU can be quite tricky ;-)

> Currently I'm trying to make 
> available designware-root-{port,host} devices  in linux when I run it in qemu.
> 
> I try the following way to run:
> 
> qemu-system-arm -M virt -m 2G \
>       -kernel images/Image \
>       -append "rootwait root=/dev/vda ro" \
>       -drive file=images/rootfs.ext2,format=raw,id=hd0 \
>       -device designware-root-port,id=rp0,chassis=1,slot=0,bus=pcie.0,addr=1 \
>       -device e1000,netdev=net0,mac=52:54:00:12:34:56,bus=rp0,addr=0 \
>       -netdev user,id=net0
> 
> but it seems designware device is not enabled by default: qemu-system-arm: 
> -device designware-root-port,id=rp0,chassis=1,slot=0,bus=pcie.0,addr=1: 
> 'designware-root-port' is not a valid device model name

Are you sure about the names?

$ grep -r 'designware' *
...
include/hw/pci-host/designware.h:#define TYPE_DESIGNWARE_PCIE_HOST 
"designware-pcie-host"
include/hw/pci-host/designware.h:#define TYPE_DESIGNWARE_PCIE_ROOT 
"designware-pcie-root"

> when I enable it from Kconfig/meson.build it says the device is already 
> registered and exits with abort().
> 
>  From the other hand the device is declared as non pluggable: 
> dc->user_creatable = false;

Well, that means that you cannot use those with "-device". They can only be 
instantiated via the code that creates the machine.

> Can you please help me to use designware-root-host/port devices ?

It seems like the i.MX7 SABRE machine is using this device, so instead of 
"-M virt", you could have a try with "-M mcimx7d-sabre" (and a kernel that 
supports this machine) instead.

  HTH,
   Thomas