[OE-core] [PATCH v3] runqemu: support multiple NICs

[Richard Purdie]

On Sat, 2020-03-07 at 16:01 +0100, Adrian Freihofer wrote:
> Emulating more than one network interface with runqemu is sometimes a
> bit tricky, but possible. For example, this leads to an emulated device
> with eth0 and eth1:
> 
> QB_NETWORK_DEVICE_prepend = " \
>     -device virtio-net-device,mac=52:54:00:12:34:03 \
> "
> 
> Note:
>  On some emulated NIC types, Qemu and the kernel enumerate the eths in
>  the guest in reverse order to how the device parameters are passed to
>  Qemu. So in this case it is important that the additional NICs are
>  prepended to the -device parameter, which gets automatically added by
>  Qemu. Otherwise, the interface eth1 will be connected to the host, but
>  eth0 will be assigned the IP address 192.168.7.x, which obviously does
>  not work.
> 
> When booting Qemu with two NICs, but only one set of network
> configuration parameters gets passed to the kernel, the kernel seems to
> search for a configuration for all NICs. This delays the boot process
> for a very long time.
> 
> This change solves the timeout problem. Tested with:
>  oe-selftest --run-tests runqemu

This appears to break our automated testing, e.g.:

https://autobuilder.yoctoproject.org/typhoon/#/builders/76/builds/1657

(there is a full list of failures on 
https://autobuilder.yoctoproject.org/typhoon/#/builders/83/builds/779
but the missing xz ones aren't yours!)

Cheers,

Richard