Description of problem:
Heavy disk IO caused by running a system upgrade in a Ubuntu 14.04 guest.

Version-Release number of selected component:
qemu-system-x86-2.6.1-1.fc24

Additional info:
reporter:       libreport-2.7.2
backtrace_rating: 4
cmdline:        /usr/bin/qemu-system-x86_64 -machine accel=kvm -name ubuntu14.04,debug-threads=on -S -machine pc-i440fx-2.6,accel=kvm,usb=off,vmport=off -cpu Haswell-noTSX -m 1024 -realtime mlock=off -smp 1,sockets=1,cores=1,threads=1 -uuid fd41167c-6c00-4b33-b54c-60381641e5d4 -no-user-config -nodefaults -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/domain-1-ubuntu14.04/monitor.sock,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc,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=0x6.0x7 -device ich9-usb-uhci1,masterbus=usb.0,firstport=0,bus=pci.0,multifunction=on,addr=0x6 -device ich9-usb-uhci2,masterbus=usb.0,firstport=2,bus=pci.0,addr=0x6.0x1 -device ich9-usb-uhci3,masterbus=usb.0,firstport=4,bus=pci.0,addr=0x6.0x2 -device virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x5 -drive if=none,id=drive-ide0-0-0,readonly=on -device ide-cd,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0 -drive file=/var/lib/libvirt/images/ubuntu14.04.raw,format=raw,if=none,id=drive-virtio-disk0,cache=none,aio=native -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x7,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1 -netdev tap,fd=26,id=hostnet0,vhost=on,vhostfd=28 -device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:ca:3e:ce,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 -device usb-tablet,id=input2 -spice port=5900,addr=127.0.0.1,disable-ticketing,image-compression=off,seamless-migration=on -device vmware-svga,id=video0,vgamem_mb=16,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 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x8 -msg timestamp=on
crash_function: blk_error_action
executable:     /usr/bin/qemu-system-x86_64
global_pid:     24013
kernel:         4.6.7-300.fc24.x86_64
pkg_fingerprint: 73BD E983 81B4 6521
pkg_vendor:     Fedora Project
runlevel:       N 5
type:           CCpp
uid:            107

Truncated backtrace:
Thread no. 1 (6 frames)
 #4 blk_error_action at /usr/src/debug/qemu-2.6.1/block/block-backend.c:1177
 #5 virtio_blk_handle_rw_error at /usr/src/debug/qemu-2.6.1/hw/block/virtio-blk.c:83
 #6 virtio_blk_rw_complete at /usr/src/debug/qemu-2.6.1/hw/block/virtio-blk.c:114
 #7 blk_aio_complete at /usr/src/debug/qemu-2.6.1/block/block-backend.c:871
 #8 coroutine_trampoline at /usr/src/debug/qemu-2.6.1/util/coroutine-ucontext.c:78
 #9 __start_context