Re: Qemu network connectivity issue

[Peter Maydell]

On Thu, 15 Feb 2024 at 16:32, Faiq Ali Sayed <faiqueali.109@gmail.com> wrote:
>
> Hi my name is Faiq Ali Sayed
> Currently, I am trading to create a Qemu VM with the command below and 
> getting an error and the terminal hangs after that
>
> Command:
>
> qemu-system-aarch64 -M xlnx-zcu102 -m 16G -serial mon:stdio -display none
> -device loader,file=QNX-IFS,addr=0x00100000,cpu-num=0
> -net nic,model=cadence_gem -net nic,model=cadence_gem -net 
> nic,model=cadence_gem -net nic,model=cadence_gem,netdev=xzynq0 -netdev 
> user,id=xzynq0,tftp=/tftpboot
> -nographic -global xlnx,zynqmp-boot.cpu-num=0 -global 
> 'xlnx,zynqmp-boot.use-pmufw=true'
>
>
> Error:
> qemu-system-aarch64: warning: hub 0 is not connected to host network
>
> any help in this regard is highly appreciated.

That message is not an error; it is only a warning. It is telling
you that you have some ethernet devices which aren't connected
anywhere. That is, you have one NIC which you've connected to your
user netdev backend (using the netdev=xzynq0 suboption), but the
other three NICs are not connected to anything (as if you hadn't
plugged a network cable into the back of them). If you're OK
with those network devices not being connected, you can ignore
the warning.

The warning is not going to be related to the reason why you
see no output. That is almost certainly going to be because
your guest binary has crashed before it sent any output to
the serial port. To find out the exact details, you should
debug what your guest is doing, either with QEMU's gdb stub
or with some of the logging available via the '-d' option.

A good first check is "is this guest binary built to run on
the machine type I'm using" (in your case xlnx-zcu102).
You can't in general run a guest that was built for one Arm
machine on a model of a different machine.

thanks
-- PMM