Re-tested against latest qemu-kvm master branch with commit 0a948cbb. And found this issue has gone. Jan Kiszka's following patch fixed this bug.
commit 0cdd3d14447da1a04e778c219c77db8b96f9cf33 Author: Jan Kiszka Date: Wed Jun 6 16:28:42 2012 +0200 kvm: i8254: Fix conversion of in-kernel to userspace state Due to a offset between the clock used to generate the in-kernel count_load_time (CLOCK_MONOTONIC) and the clock used for processing this in userspace (vm_clock), reading back the output of PIT channel 2 via port 0x61 was broken. One use cases that suffered from it was the CPU frequency calibration of SeaBIOS, which also affected IDE/AHCI timeouts. This fixes it by calibrating the offset between both clocks on kvm_pit_get and adjusting the kernel value before saving it in the userspace state. As the calibration only works while the vm_clock is running, we cache the in-kernel state across stopped phases. Signed-off-by: Jan Kiszka ** Changed in: qemu Status: New => Fix Released -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1002121 Title: disk error when guest boot up via qcow2 image Status in QEMU: Fix Released Bug description: Host OS (ia32/ia32e/IA64): ia32e Guest OS (ia32/ia32e/IA64): ia32e Guest OS Type (Linux/Windows): Linux(rhel6u1) kvm.git Commit: 51bfd2998113e1f8ce8dcf853407b76a04b5f2a0 qemu-kvm Commit: e54f008ef8f968cfc2f3ecab78491d180fa31efc Host Kernel Version:3.4.0-rc7 Hardware: WSM-EP, Romley-EP Bug detailed description: -------------------------- If I boot up a guest using qcow2 image, the guest show “disk read error”. If you press some key to continue, after being automatically repaired, the guest can boot up. This should be a qemu-kvm regression. kvm + qemu-kvm = result 51bfd299 + e54f008e = bad 51bfd299 + b320b8b7 = good Note: 1. guest rhel6u1, guest show “disk error” guest rhel6u2, guest show black screen this phenomenon occurs at the first time to create guest 2. create guest with raw image, this phenomenon doesn’t appear. Reproduce steps: ---------------- 1.start up a host with kvm (commit: 51bfd299) and use qemu-kvm (commit:e54f008e) 2.qemu-img create –b /share/ia32e_rhel6u1.img –f qcow2 /root/rhel6u1.qcow 3.qemu-system-x86_64 -mem 1024 –hda /root/rhel6u1.qcow Current result: ---------------- Guest console shows: error 25:Disk read error Prss any key to continue... Expected result: ---------------- Guest boot up correctly To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1002121/+subscriptions