Re: QEMU User Networking (SLIRP) with Xilinx-zcu102

[Peter Maydell]

On Thu, 1 Jul 2021 at 11:43, asif siddiqui <asifsiddiqui120@gmail.com> wrote:
> I am able to transfer files successfully between host os linux and guest 
> using SCP when ssh is launched.
>
> But i am not able to ping from guest to host or host to guest.  Also if i 
> want to debug a qnx application using gdb remote debug it does not work.
> Is it because of QEMU user networking(SLIRP) and it does not support other 
> Network services ?
>
> I tried following the steps given in the "Enabling ping in the guest, on 
> Linux hosts" section from the link 
> https://wiki.qemu.org/Documentation/Networking#User_Networking_.28SLIRP.29
> but it did not work.
>
> Can you please suggest what changes are required in qemu command line so that 
> i can ping from guest to host or host to guest as this is required for remote 
> debug.

I doubt that ping is required for remote debug. (Even with the
stuff in the wiki page, ping will only be enabled from guest to host,
not host to guest, because user mode networking does not give the guest
a host-visible IP address that you could ping in the first place.)

What you will need to do is add a port-forwarding option to your
"-netdev user" option, because with usermode networking you can
only connect from the host into the guest (here, from a gdb running
on the host to the gdbstub running in the guest) if you forward the
TCP port you are using for the gdb connection.
The syntax for this is
-netdev user,id=xzynq0,hostfwd=tcp::HOSTPORT-:GUESTPORT

(fill in the HOSTPORT and GUESTPORT values as required)

-- PMM