Description of problem:
Boot guest with device assignment+vIOMMU, then reboot guest, qemu will prompt "qemu-kvm: vtd_interrupt_remap_msi: MSI address low 32 bit invalid: 0x0".


Version-Release number of selected component (if applicable):
qemu-kvm-3.1.0-2.module+el8+2606+2c716ad7.x86_64
4.18.0-57.el8.x86_64


How reproducible:
100%


Steps to Reproduce:
1. Boot qemu, see[1]

2. In guest, reboot, qemu terminal will prompt invalid message.
# reboot

(qemu) qemu-kvm: vtd_interrupt_remap_msi: MSI address low 32 bit invalid: 0x0

Actual results:
qemu prompts invalid message when first reboot guest.


Expected results:
qemu should not prompts invalid message.


Additional info:
1. Without vIOMMU, everything works well.

Reference:
[1]
/usr/libexec/qemu-kvm -name rhel8.0 \
-M q35,kernel-irqchip=split \
-cpu Haswell-noTSX -m 8G \
-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 \
-device pcie-root-port,id=root.3,chassis=3 \
-device pcie-root-port,id=root.4,chassis=4 \
-blockdev driver=file,cache.direct=off,cache.no-flush=on,filename=/home/rhel8.0.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 \
-netdev tap,id=hostnet0,vhost=on \
-device virtio-net-pci,netdev=hostnet0,id=net0,mac=18:66:da:5f:dd:02,bus=root.2,iommu_platform=on,ats=on \
-vnc :2 \
-monitor stdio \
-device vfio-pci,host=0000:3b:00.0,bus=root.3 \
-device vfio-pci,host=0000:3b:00.1,bus=root.4 \