ovmf hangs at efi with virtio-net memory hotplug

with qemu 2.9 it hangs at the efi stage when memory-hotplug is enabled and it has a virtio-net devices

the ovmf images where compiled from https://github.com/tianocore/edk2 (current master)

reproducer:

qemu-system-x86_64 -drive 'if=pflash,unit=0,format=raw,readonly,file=./OVMF_CODE.fd' -drive 'if=pflash,unit=1,format=raw,file=./my_OVMF_VARS.fd' -smp 1 -vga std -netdev 'type=tap,id=mynet' -device 'virtio-net-pci,netdev=mynet' -display sdl -nodefaults -m 'size=1G,slots=256,maxmem=1024G'

interestingly, it works when you do the following:

- omit the virtio-net-pci device
- use seabios
- use less maxmem, e.g. 512G

qemu was compiled from source (v2.9.0) with following options:

./configure --target-list=x86_64-softmmu --disable-xen --enable-gnutls --enable-sdl --enable-linux-aio --enable-rbd --enable-libiscsi --disable-smartcard --audio-drv-list="alsa" --enable
-spice --enable-usb-redir --enable-glusterfs --enable-libusb --disable-gtk --enable-xfsctl --enable-numa --disable-strip --enable-jemalloc --enable-virtfs --disable-libnfs --disable-fdt --disable-guest-agent --disable-guest-agent-msi