iPXE does not try nic1

[devjr]

I downloaded current iPXE, and then built it :
git clone http://git.ipxe.org/ipxe.git
make bin/virtio-net.rom

Then I copied the binary file into the iPXE dir :
cp ~/ipxe/src/bin/virtio-net.rom /usr/lib/ipxe/qemu/pxe-virtio-new.rom

And told libvirt to use this file putting this XML code im my VM definition :
<rom file='/usr/lib/ipxe/qemu/pxe-virtio-new.rom'/>

The corresponding qemu command line is :
/usr/bin/qemu-system-x86_64 -name guest=testipxe,debug-threads=on -S -object secret,id=masterKey0,format=raw,file=/var/lib/libvirt/qemu/domain-8-testipxe/master-key.aes -machine pc-i440fx-3.1,accel=kvm,usb=off,dump-guest-core=off -cpu Skylake-Client-IBRS,ss=on,hypervisor=on,tsc_adjust=on,clflushopt=on,umip=on,ssbd=on,xsaves=on -m 512 -realtime mlock=off -smp 1,sockets=1,cores=1,threads=1 -uuid eb3195b2-aa36-4d4c-a728-2ee2579bf1f0 -no-user-config -nodefaults -chardev socket,id=charmonitor,fd=26,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc -no-shutdown -boot strict=on -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 -drive file=/var/lib/libvirt/images/testipxe.qcow2,format=qcow2,if=none,id=drive-virtio-disk0 -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x5,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1 -netdev tap,fd=28,id=hostnet0,vhost=on,vhostfd=29 -device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:4b:53:74,bus=pci.0,addr=0x3,romfile=/usr/lib/ipxe/qemu/pxe-virtio-new.rom,bootindex=2 -netdev tap,fd=30,id=hostnet1,vhost=on,vhostfd=31 -device virtio-net-pci,netdev=hostnet1,id=net1,mac=52:54:001:b1:b4,bus=pci.0,addr=0x4,romfile=/usr/lib/ipxe/qemu/pxe-virtio-new.rom -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -vnc 127.0.0.1:0 -device cirrus-vga,id=video0,bus=pci.0,addr=0x2 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x6 -sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny -msg timestamp=on

Now the VNC console doesn't even show the iPXE boot...

I tried to delete all PXE files in /usr/lib/ipxe/qemu/ dir to see which was used by default, it seems that this is efi-virtio.rom.
That was a surprise, since on boot the VM show Seabios and not UEFI.
So I tried to manually specify <rom file='/usr/lib/ipxe/qemu/efi-virtio.rom'/> : it also prevents iPXE from launching.
It seems that I'm not skilled enough with libvirt to make this work.

Anyway, this is not iPXE's fault.

I'll try to figure this out.
Many thanks for your help !