scrolling (with a scroll wheel mouse) down and up during a long time 
(ten minutes more or less) a long file (7.5Gb, 315 pages, Adobe Acrobat 
Reader) or a long html page (with firefox) : mouse and keyboard freeze. 
The guest OS runs always.

Version-Release number of selected component (if applicable):
virtio-win-0.1.126.iso
Host: debian jessie
Guest: windows server 2012
Package: qemu-system-x86 - Version: 1:2.1+dfsg-12+deb8u6
Spice
libvirt: 1.2.9.9
virt-manager: 1.0.1
qemu-kvm: 1:2.1
uname -a: Linux debian 3.16.0-4-amd64 #1 SMP Debian 3.16.39-1+deb8u2 
(2017-03-07) x86_64 GNU/Linux
Guest:
windows server 2012
Memory: 16Gb
Video qxl: 64Mb
Qemu Guest agent: qemu-ga-x64.msi 02-04-2017
Spice guest tools: 0.1-100
  RHEV Spice Agent:29.3.2015 (vdagent.exe,vdservice.exe)


Qemu cmd line:
2017-05-01 00:01:08.468+0000: starting up
LC_ALL=C 
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin 
QEMU_AUDIO_DRV=spice /usr/bin/kvm -name ws2012 -S
-machine pc-1.1,accel=kvm,usb=off -cpu 
Nehalem,+invtsc,+rdtscp,+dca,+pdcm,+xtpr,+tm2,+est,+vmx,+ds_cpl,+monitor,+dtes64,+pbe,+tm,+ht,
+ss,+acpi,+ds,+vme -m 16384 -realtime mlock=off -smp 
4,sockets=4,cores=1,threads=1 -uuid 586323c5-080a-4746-860e-9c8b11278891
-no-user-config -nodefaults -chardev 
socket,id=charmonitor,path=/var/lib/libvirt/qemu/ws2012.monitor,server,nowait
-mon chardev=charmonitor,id=monitor,mode=control -rtc 
base=localtime,driftfix=slew -global kvm-pit.lost_tick_policy=discard
 -no-hpet -no-shutdown -global PIIX4_PM.disable_s3=1 -global 
PIIX4_PM.disable_s4=1 -boot strict=on
-device ich9-usb-ehci1,id=usb,bus=pci.0,addr=0x5.0x7 -device 
ich9-usb-uhci1,masterbus=usb.0,firstport=0,bus=pci.0,multifunction=on,addr=0x5
 -device 
ich9-usb-uhci2,masterbus=usb.0,firstport=2,bus=pci.0,addr=0x5.0x1 
-device ich9-usb-uhci3,masterbus=usb.0,firstport=4,bus=pci.0,addr=0x5.0x2
 -device ahci,id=ahci0,bus=pci.0,addr=0x9 -device 
virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x6 -drive file=/dev/sr0,
if=none,id=drive-ide0-0-1,readonly=on,format=raw -device 
ide-cd,bus=ide.0,unit=1,drive=drive-ide0-0-1,id=ide0-0-1
-drive 
file=/home/jpc/Téléchargements/virtio-win-0.1.135.iso,if=none,id=drive-ide0-1-0,readonly=on,format=raw 
-device ide-cd,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0 -drive 
file=/var/lib/libvirt/images/sbs2012-1.img,if=none,id=drive-virtio-disk0,
format=raw,cache=none -device 
virtio-blk-pci,scsi=off,bus=pci.0,addr=0x8,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1 

-netdev tap,fd=24,id=hostnet0,vhost=on,vhostfd=25 -device 
virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:65:72:73,bus=pci.0,addr=0x3 

-chardev pty,id=charserial0 -device 
isa-serial,chardev=charserial0,id=serial0 -chardev 
spicevmc,id=charchannel0,name=vdagent
-device 
virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=com.redhat.spice.0 

-chardev 
socket,id=charchannel1,path=/var/lib/libvirt/qemu/channel/target/ws2012.org.qemu.guest_agent.0,server,nowait 

-device 
virtserialport,bus=virtio-serial0.0,nr=2,chardev=charchannel1,id=channel1,name=org.qemu.guest_agent.0
-device usb-tablet,id=input0 -spice 
port=5900,addr=127.0.0.1,disable-ticketing,seamless-migration=on
-device 
qxl-vga,id=video0,ram_size=67108864,vram_size=67108864,bus=pci.0,addr=0x2 
-device intel-hda,id=sound0,bus=pci.0,addr=0x4
-device hda-duplex,id=sound0-codec0,bus=sound0.0,cad=0 -chardev 
spicevmc,id=charredir0,name=usbredir -device 
usb-redir,chardev=charredir0,id=redir0
 -chardev spicevmc,id=charredir1,name=usbredir -device 
usb-redir,chardev=charredir1,id=redir1 -chardev 
spicevmc,id=charredir2,name=usbredir
-device usb-redir,chardev=charredir2,id=redir2 -chardev 
spicevmc,id=charredir3,name=usbredir -device 
usb-redir,chardev=charredir3,id=redir3
-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x7 -global 
qxl-vga.guestdebug=3 -msg timestamp=on
2017-05-04T14:13:34.078820Z qemu-system-x86_64: virtio-serial-bus: 
Unexpected port id 2426994688 for device virtio-serial0.0
2017-05-04T14:13:54.093482Z qemu-system-x86_64: virtio-serial-bus: 
Unexpected port id 209475280 for device virtio-serial0.0
2017-05-04T14:14:13.516683Z qemu-system-x86_64: virtio-serial-bus: Guest 
failure in adding device virtio-serial0.0


How reproducible:
yes but randomly

Steps to Reproduce:
1. see description
2.
3.

Actual results:


Expected results:


Additional info:
same bug with the previous virtio-win packages.