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Description of problem: boot a guest with usb device, boot failed from usb device, then send "ctrl-alt-delete" to guest via remote-viewer, qemu promt "Request for more bytes than allowed, processing error - resetting ehci HC " Version-Release number of selected component (if applicable): kernel-2.6.32-590.el6.x86_64 qemu-kvm-rhev-0.12.1.2-2.482.el6.x86_64 How reproducible: 100% Steps to Reproduce: 1.launch guest with: /usr/libexec/qemu-kvm -name virtio -m 1024 -cpu Westmere,check -realtime mlock=off -smp 2 -global PIIX4_PM.disable_s4=1 -boot order=c,menu=on -device virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x6 -drive file=/home/sn1_rhel6.7_virtio.qcow2,format=qcow2,if=none,id=block-virtio,cache=none,werror=stop,rerror=stop -device virtio-blk-pci,bus=pci.0,addr=0x8,drive=block-virtio,id=block-virtio -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x7 -monitor stdio -vnc :4 -vga cirrus -device usb-ehci,id=ehci -drive file=/home/usb.qcow2,if=none,id=drive-usb-2-0,media=disk,format=raw,cache=none -device usb-storage,drive=drive-usb-2-0,id=usb-0-0,removable=on,bus=ehci.0,port=1 -device e1000,netdev=hostnet0,id=net0,mac=D4:AE:52:E9:57:36 -netdev tap,id=hostnet0,vhost=on 2.send "ctrl-alt-delete" after boot failed. 3. Actual results: (qemu) Request for more bytes than allowed processing error - resetting ehci HC Expected results: no error prompt Additional info:
It's probably ehci data structures being overwritten, therefore ehci going to read and trying to process gibberish. Happens because we do a soft reset on ctrl-alt-del in RHEL-6. Should be fixed in RHEL-7 because we do a hard reset there. It should have no side effects other than printing this debug message, i.e. the guest should re-initialize ehci and should be able to continue using it. Is that correct?
(In reply to Gerd Hoffmann from comment #2) > It's probably ehci data structures being overwritten, therefore ehci going > to read and trying to process gibberish. Happens because we do a soft reset > on ctrl-alt-del in RHEL-6. Should be fixed in RHEL-7 because we do a hard > reset there. > > It should have no side effects other than printing this debug message, i.e. > the guest should re-initialize ehci and should be able to continue using it. > > Is that correct? Yes, guest was able to continue using it, it could not be noticed by user if there is no debug message.
Cornercase, harmless, fixed in rhel7/upstream already.