Description of problem:
Test win2019 guest booting with different vectors. Guest network works well with vectors 0/2/3/4/5, however network is down when vectors=1.

Version-Release number of selected component (if applicable):
kernel-4.18.0-71.el8.x86_64
virtio-win-1.9.7-3.el8.noarch
qemu-kvm-2.12.0-63.module+el8+2833+c7d6d092.x86_64

How reproducible:
4/4

Steps to Reproduce:
1.Boot win2019 guest with queues=4 and vecttors=1.qemu prompts errors.

/usr/libexec/qemu-kvm -name Win2019 \
-M q35,kernel-irqchip=split -m 4g \
-cpu EPYC,hv_stimer,hv_synic,hv_time,hv_relaxed,hv_vpindex,hv_spinlocks=0xfff,hv_vapic,hv_reset,hv_crash \
-device intel-iommu,intremap=true,caching-mode=true \
-smp 4,sockets=1,cores=4,threads=1 \
-device pcie-root-port,id=root.1,chassis=1 \
-device pcie-root-port,id=root.2,chassis=2 \
-blockdev driver=file,cache.direct=off,cache.no-flush=on,filename=/home/win2019.qcow2,node-name=my_file \
-blockdev driver=qcow2,node-name=my,file=my_file \
-device virtio-blk-pci,drive=my,id=virtio-blk0,bus=root.1 \
-drive id=drive_cd1,if=none,snapshot=off,aio=native,cache=none,media=cdrom,file=/home/en_windows_server_2019_x64_dvd_4cb967d8.iso \
-device ide-cd,id=cd1,drive=drive_cd1,bus=ide.0,unit=0 \
-drive id=drive_winutils,if=none,snapshot=off,aio=native,cache=none,media=cdrom,file=/usr/share/virtio-win/virtio-win-1.9.7.iso \
-device ide-cd,id=winutils,drive=drive_winutils,bus=ide.1,unit=0 \
-vnc :3 \
-vga qxl \
-monitor stdio \
-usb -device usb-tablet \
-boot menu=on \
-netdev tap,id=hostnet1,vhost=on,queues=4 \
-device virtio-net-pci,indirect_desc=off,netdev=hostnet1,id=net1,mac=18:66:da:5f:d1:02,bus=root.2,vectors=1,mq=on \

(qemu) qemu-kvm: unable to start vhost net: 14: falling back on userspace virtio
qemu-kvm: warning: guest updated active QH
qemu-kvm: warning: guest updated active QH

2.Check guest Network status-->Not connected

Actual results:
Network is down.

Expected results:
Network is up.

Additional info:
1. Fast train bug:
Bug 1684063 - Network doesn't work well in win2019 guest when booting qemu with 4 queues and 1 vector