1.Boot VM
/usr/libexec/qemu-kvm \
    -name 'avocado-vt-vm1'  \
    -sandbox on \
    -machine q35 \
    -device '{"id": "pcie-pci-bridge-0", "driver": "pcie-pci-bridge", "addr": "0x0", "bus": "pcie-root-port-0"}'  \
    -nodefaults \
    -device '{"driver": "VGA", "bus": "pcie.0", "addr": "0x2"}' \
    -m 8G \
    -smp 8,maxcpus=16,cores=8,threads=1,dies=1,sockets=2  \
    -cpu 'Skylake-Server-IBRS',ss=on,vmx=on,pdcm=on,hypervisor=on,tsc-adjust=on,clflushopt=on,umip=on,pku=on,md-clear=on,stibp=on,flush-l1d=on,arch-capabilities=on,ssbd=on,xsaves=on,ibpb=on,ibrs=on,amd-stibp=on,amd-ssbd=on,rsba=on,skip-l1dfl-vmentry=on,pschange-mc-no=on,kvm_pv_unhalt=on \
    -device pcie-root-port,id=pcie-root-port-0,multifunction=on,bus=pcie.0,addr=0x3,chassis=1 \
    -device pcie-root-port,id=pcie-root-port-1,port=0x1,addr=0x3.0x1,bus=pcie.0,chassis=2 \
    -device pcie-root-port,id=pcie-root-port-2,port=0x2,addr=0x3.0x2,bus=pcie.0,chassis=3 \
    -device pcie-root-port,id=pcie-root-port-3,port=0x3,addr=0x3.0x3,bus=pcie.0,chassis=4 \
    -device pcie-root-port,id=pcie-root-port-4,port=0x4,addr=0x3.0x4,bus=pcie.0,chassis=5 \
    -device pcie-root-port,id=pcie-root-port-5,port=0x5,addr=0x3.0x5,bus=pcie.0,chassis=6 \
    -device pcie-root-port,id=pcie-root-port-6,port=0x6,addr=0x3.0x6,bus=pcie.0,chassis=7 \
    -device pcie-root-port,id=pcie-root-port-7,port=0x7,addr=0x3.0x7,bus=pcie.0,chassis=8 \
    -device pcie-root-port,id=pcie-root-port-8,multifunction=on,bus=pcie.0,addr=0x4,chassis=9 \
    -device pcie-root-port,id=pcie-root-port-9,port=0x1,addr=0x4.0x1,bus=pcie.0,chassis=10 \
    -device '{"driver": "qemu-xhci", "id": "usb1", "bus": "pcie-root-port-1", "addr": "0x0"}' \
    -device '{"driver": "usb-tablet", "id": "usb-tablet1", "bus": "usb1.0", "port": "1"}' \
    -object '{"qom-type": "iothread", "id": "t1"}' \
    -object '{"qom-type": "iothread", "id": "t2"}' \
    -object '{"qom-type": "iothread", "id": "t3"}' \
    -object '{"qom-type": "iothread", "id": "t4"}' \
    -device '{"id": "scsi0", "driver": "virtio-scsi-pci",  "iothread": "t1"}' \
    -blockdev '{"node-name": "file_image1", "driver": "file", "auto-read-only": true, "discard": "unmap", "aio": "threads", "filename": "/home/kvm_autotest_root/images/rhel940-64-virtio-scsi.qcow2", "cache": {"direct": true, "no-flush": false}}' \
    -blockdev '{"node-name": "drive_image1", "driver": "qcow2", "read-only": false, "cache": {"direct": true, "no-flush": false}, "file": "file_image1"}' \
    -device '{"driver": "scsi-hd", "id": "image1", "drive": "drive_image1", "write-cache": "on"}' \
    \
    -blockdev '{"node-name": "file_stg1", "driver": "file","filename": "/home/kvm_autotest_root/images/mstg1.qcow2","auto-read-only": true, "discard": "unmap", "aio": "threads", "cache": {"direct": true, "no-flush": false}}' \
    -blockdev '{"node-name": "drive_stg1", "driver": "qcow2", "file": "file_stg1","read-only": false, "cache": {"direct": true, "no-flush": false}}' \
    -device '{"driver": "virtio-blk-pci", "id": "stg1", "bus":"pcie-root-port-4","drive": "drive_stg1", "serial": "stg1", "iothread-vq-mapping": [{"iothread":"t1"},{"iothread":"t2"},{"iothread":"t3"},{"iothread":"t4"}],"write-cache": "on"}' \
    \
    -blockdev '{"node-name": "file_stg2", "driver": "file","filename": "/home/kvm_autotest_root/images/mstg2.qcow2","auto-read-only": true, "discard": "unmap", "aio": "threads", "cache": {"direct": true, "no-flush": false}}' \
    -blockdev '{"node-name": "drive_stg2", "driver": "qcow2", "file": "file_stg2","read-only": false, "cache": {"direct": true, "no-flush": false}}' \
    -device '{"driver": "virtio-blk-pci", "id": "stg2", "bus":"pcie-root-port-5","drive": "drive_stg2", "serial": "stg2", "iothread-vq-mapping": [{"iothread":"t1"},{"iothread":"t3"}],"write-cache": "on"}' \
    \
    -blockdev '{"node-name": "file_stg3", "driver": "file","filename": "/home/kvm_autotest_root/images/mstg3.qcow2","auto-read-only": true, "discard": "unmap", "aio": "threads", "cache": {"direct": true, "no-flush": false}}' \
    -blockdev '{"node-name": "drive_stg3", "driver": "qcow2", "file": "file_stg3","read-only": false, "cache": {"direct": true, "no-flush": false}}' \
    -device '{"driver": "virtio-blk-pci", "id": "stg3", "bus":"pcie-root-port-6","drive": "drive_stg3", "serial": "stg3", "iothread-vq-mapping": [{"iothread":"t1","vqs":[0,1,2,3]},{"iothread":"t2","vqs":[4,5,6,7]}],"write-cache": "on"}' \
    \
    -blockdev '{"node-name": "file_stg4", "driver": "file","filename": "/home/kvm_autotest_root/images/mstg4.qcow2","auto-read-only": true, "discard": "unmap", "aio": "threads", "cache": {"direct": true, "no-flush": false}}' \
    -blockdev '{"node-name": "drive_stg4", "driver": "qcow2", "file": "file_stg4","read-only": false, "cache": {"direct": true, "no-flush": false}}' \
    -device '{"driver": "virtio-blk-pci", "id": "stg4", "bus":"pcie-root-port-7","drive": "drive_stg4", "serial": "stg4", "num-queues":6,"iothread-vq-mapping": [{"iothread":"t1","vqs":[0,1,2,3]},{"iothread":"t2","vqs":[4,5]}],"write-cache": "on"}' \
    \
    -device '{"driver": "virtio-net-pci", "mac": "9a:44:a1:67:9c:25", "id": "ideRavgQ", "netdev": "idiQdf3z", "bus": "pcie-root-port-3", "addr": "0x0"}'  \
    -netdev tap,id=idiQdf3z,vhost=on  \
    -vnc :5 \
    -monitor stdio \
    -qmp tcp:0:5955,server=on,wait=off \
    -boot menu=on,reboot-timeout=1000,strict=off \
    \

2.hotplug disk with iothread-vq-mapping
{"execute": "blockdev-add", "arguments": {"node-name": "file_stg6", "driver": "file", "aio": "threads", "filename": "/home/kvm_autotest_root/images/mstg6.qcow2", "cache": {"direct": true, "no-flush": false}}}

{"execute": "blockdev-add", "arguments": {"node-name": "drive_stg6", "driver": "qcow2", "read-only": false, "file": "file_stg6"}}


{"execute": "device_add", "arguments": {"driver": "virtio-blk-pci", "id": "stg6", "drive": "drive_stg6", "write-cache": "on", "bus": "pcie-root-port-8",  "iothread-vq-mapping": [{"iothread":"t1"},{"iothread":"t2"}]}, "id": "DXHZZ3FW"}

3.login guest to check disk existence

4.execute qom-get to check property iothread-vq-mapping
{"execute": "qom-get", "arguments": {"path": "stg1", "property": "iothread-vq-mapping"}}
{"return": [{"iothread": "t1"}, {"iothread": "t2"}, {"iothread": "t3"}, {"iothread": "t4"}]}

{"execute": "qom-get", "arguments": {"path": "stg6", "property": "iothread-vq-mapping"}}
{"return": []}