Red Hat Bugzilla – Bug 616796
KVM uses wrong permissions for large guest pages
Last modified: 2013-01-10 22:08:46 EST
This bug has been copied from bug #615225 and has been proposed
to be backported to 5.5 z-stream (EUS).
Tried to reproduce this problem with kvm-83-164.el5_5.12 using the following steps, hit the guest crash issue for 4 times during 8 tests.
1. start 1 guest with 4G mem and run dd in guest( host has 4G mem totally)
# /usr/libexec/qemu-kvm -m 4G -smp 2 -cpu qemu64,+sse2tor stdio -drive file=/root/rhel5.5-64-virtio.qcow2,if=virtio,boot=on,cache=none -net nic,macaddr=20:20:20:12:23:18,model=virtio,vlan=0 -net tap,script=/etc/qemu-ifup,vlan=0 -usbdevice tablet -vnc :10
for((;;)); do dd if=/dev/urandom of=testfile bs=2M count=1024; rm -fr testfile; done
2. start to install rhel6 guest with modified initrd(hack the initrd.img to set khugepaged/scan_sleep_millisecs = 1):
# /usr/libexec/qemu-kvm -no-hpet -rtc-td-hack -cpu qemu64,+sse2 -smp 2 -m 1G -uuid `uuidgen` -usbdevice tablet -drive file=rhel6-64-virtio.qcow2,if=virtio,boot=on,format=qcow2,cache=none -net nic,macaddr=20:20:20:12:23:16,model=virtio,vlan=0 -net tap,script=/etc/qemu-ifup,vlan=0 -monitor stdio -kernel /root/michen/vmlinuz -initrd /root/michen/initrd-1.img -append method=http://download.englab.nay.redhat.com/pub/rhel/rel-eng/RHEL6.0-20100730.5/6.0/Server/x86_64/os -vnc :9
Tested with kvm-83-164.el5_5.20 with the above steps and try 12 times, did not hit guest crash during installation.
Technical note added. If any revisions are required, please edit the "Technical Notes" field
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Installation of a system was occasionally failing in KVM. This was caused by KVM using wrong permissions for large guest pages. With this update, the installation completes successfully.
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.