Bug 1455015

Description of problem:
Boot RHEL7.4 guest with multiple virtio-vsock devices. Then execute script nc-vsock.c between host and guest. The first virtio-vsock works, But for the second virtio-vsock,nc-vsock script shows "Connection timed out" on host.  

Version-Release number of selected component (if applicable):
host and guest kernel version:
3.10.0-671.el7.x86_64

qemu version:
qemu-kvm-rhev-2.9.0-6.el7.x86_64


How reproducible:
100%

Steps to Reproduce:
1.Boot RHEL7.4 guest with multiple virtio-vsock devices

/usr/libexec/qemu-kvm -name guest=r7,debug-threads=on -enable-kvm -M pc -cpu SandyBridge -m 4096 -realtime mlock=off -smp 4,sockets=1,cores=4,threads=1 -boot strict=on -rtc base=localtime,clock=host,driftfix=slew -drive file=rhel74.qcow2,if=none,id=drive-system-disk,format=qcow2,cache=none,aio=native,werror=ignore,rerror=ignore,serial=QEMU-DISK1 -device virtio-scsi-pci,id=scsi0,bus=pci.0,ioeventfd=off -device scsi-hd,bus=scsi0.0,drive=drive-system-disk,id=system-disk,channel=0,scsi-id=0,lun=0,ver=mike,serial=ababab,bootindex=1 -device qxl-vga,id=video0,ram_size=67108864,vram_size=67108864,vram64_size_mb=0,vgamem_mb=16,bus=pci.0,addr=0x4 -vnc :2 -monitor stdio -netdev tap,id=hostnet0,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet0,id=net0,mac=12:54:00:5c:88:61 -qmp tcp:0:4444,server,nowait \


-device vhost-vsock-pci,id=vhost-vsock-pci5,guest-cid=5 -device vhost-vsock-pci,id=vhost-vsock-pci6,guest-cid=6 -device vhost-vsock-pci,id=vhost-vsock-pci7,guest-cid=7 -device vhost-vsock-pci,id=vhost-vsock-pci8,guest-cid=8 \

2. In guest:
#./nc-vsock -l 12345
#./nc-vsock -l 12346

3.On host:
# ./nc-vsock 5 12345
# ./nc-vsock 6 12346

Actual results:
# ./nc-vsock 5 12345
works

# ./nc-vsock 6 12346
connect: Connection timed out

Expected results:
multiple virtio-vsock work

Additional info:
Download and compile nc-vsock from this link: https://github.com/stefanha/nc-vsock/blob/master/nc-vsock.c
#gcc -o nc-vsock nc-vsock.c