http://patchwork.ozlabs.org/patch/170838/

Hi all,
   
   I reproduce this issue on the kernel-2.6.32-284.el6.x86_64 and qemu-kvm-0.12.1.2-2.295.el6.x86_64 host with the Fedora_17_x86_64 guest.

Version-Release number of selected component (if applicable):
host info:
# uname -r && rpm -q qemu-kvm
2.6.32-284.el6.x86_64
qemu-kvm-0.12.1.2-2.295.el6.x86_64
guest info:
Fedora_17_x86_64

Steps to Reproduce:
1.install fedora 17 guest on rhel 6.3 host.
2.create a usb-storage.
# qemu-img create -f qcow2 usb-storage.qcow2 20G
3.boot the guest adding a usb-storage device.
eg: # /usr/libexec/qemu-kvm -M rhel6.3.0 -cpu host -enable-kvm -m 2048 -smp 2 -usb -name sluo -uuid `uuidgen` -drive file=Fedora_17_x86_64.qcow2,format=qcow2,if=none,id=drive-virtio-disk0,cache=none,werror=stop,rerror=stop -device virtio-blk-pci,bus=pci.0,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1 -netdev tap,id=hostnet0,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet0,id=virtio-net-pci0,mac=08:2E:5F:0A:0D:B3 -spice disable-ticketing,port=5931 -vga qxl -global qxl-vga.vram_size=67108864 -device usb-ehci,id=ehci -drive file=/home/usb-storage.qcow2,if=none,id=storage0,media=disk,cache=none,format=qcow2 -device usb-storage,drive=storage0,id=usb-storage0,bus=ehci.0 -monitor stdio
4.write something to it (create filesystem for example).
# fdisk -l --> find the usb-storage disk in guest.
# mkfs.ext4 /dev/sda
5.check the guests kernel log.
# dmesg

Test results:
After the step 5, we can see a constant stream of "reset high-speed USB device number" in Fedora 17 guest's kernel log. I will attach the kernel log later.
# dmesg
[    0.000000] Initializing cgroup subsys cpuset
[    0.000000] Initializing cgroup subsys cpu
...
[   57.556246] SELinux: initialized (dev fusectl, type fusectl), uses genfs_contexts
[   57.595447] SELinux: initialized (dev fuse, type fuse), uses genfs_contexts
[  554.995113] usb 1-1: reset high-speed USB device number 2 using ehci_hcd
[  555.241106] usb 1-1: reset high-speed USB device number 2 using ehci_hcd 

   BTW, I also tried the rhel6.3 guest, it do not have this issue.

Best wish.
sluo

Created attachment 598397 [details]
the fedora 17 guest kernel log.

patch posted.

I Verify this issue on the kernel-2.6.32-315.el6.x86_64 and
qemu-kvm-0.12.1.2-2.320.el6.x86_64 host with the the same steps as comment #2.

Host info:
# uname -r && rpm -q qemu-kvm
2.6.32-315.el6.x86_64
qemu-kvm-0.12.1.2-2.320.el6.x86_64
Guest info:
Fedora_17_x86_64

Steps:
as same as comment #2

Test results:
After the step 5, 
we *cannot* see any stream of "reset high-speed USB device number" in Fedora 17 guest's kernel log, so this issue disappear.

Base on above and comment #2, this issue has been fixed correctly.

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHBA-2013-0527.html