Description of problem: The kvm clock couldn't adjust to back after stop/continue. The following is the details. [root@dhcp-66-83-61 ~]# ntpdate -q clock.redhat.com server 66.187.233.4, stratum 1, offset -1.420393, delay 0.31921 21 Apr 10:22:37 ntpdate[2826]: step time server 66.187.233.4 offset -1.420393 sec [root@dhcp-66-83-61 ~]# [root@dhcp-66-83-61 ~]# ntpdate -b clock.redhat.com 21 Apr 10:22:44 ntpdate[2827]: step time server 66.187.233.4 offset -1.419668 sec [root@dhcp-66-83-61 ~]# [root@dhcp-66-83-61 ~]# ntpdate -q clock.redhat.com server 66.187.233.4, stratum 1, offset -0.003611, delay 0.31802 21 Apr 10:22:49 ntpdate[2830]: adjust time server 66.187.233.4 offset -0.003611 sec stop + 10mins + continue [root@dhcp-66-83-61 ~]# ntpdate -q clock.redhat.com server 66.187.233.4, stratum 1, offset 77.590888, delay 0.32227 21 Apr 10:33:11 ntpdate[2833]: step time server 66.187.233.4 offset 77.590888 sec 10 mins later [root@dhcp-66-83-61 ~]# ntpdate -q clock.redhat.com server 66.187.233.4, stratum 1, offset 77.577350, delay 0.31375 21 Apr 10:44:16 ntpdate[2861]: step time server 66.187.233.4 offset 77.577350 sec 10 mins later [root@dhcp-66-83-61 ~]# ntpdate -q clock.redhat.com server 66.187.233.4, stratum 1, offset 77.568127, delay 0.31583 21 Apr 10:54:29 ntpdate[2881]: step time server 66.187.233.4 offset 77.568127 sec 2 hours later [root@dhcp-66-83-61 ~]# ntpdate -q clock.redhat.com server 66.187.233.4, stratum 1, offset 77.438987, delay 0.31610 21 Apr 13:06:37 ntpdate[3778]: step time server 66.187.233.4 offset 77.438987 sec Version-Release number of selected component (if applicable): kernel 2.6.32-19.el6.x86_64 qemu-kvm-0.12.1.2-2.38.el6.x86_64 How reproducible: 2/2 Steps to Reproduce: 1. start host with 'processor.max_cstate=1' in kernel line 2. load host # for(( I=0; I<`cat /proc/cpuinfo | grep processor | wc -l`;I++)) ; do echo $I; taskset -c $I /bin/bash -c 'for ((;;)); do X=1; done &' ; done 3. start guest and run ntpdate -b clock.redhat.com # /usr/libexec/qemu-kvm -no-hpet -usbdevice tablet -rtc-td-hack -startdate now -cpu qemu64,+sse2 -drive file=/mnt/RHEL-Server-5.5-64.qcow2,if=ide,boot=on -net nic,model=e1000,macaddr=20:20:11:23:22:00,vlan=0 -net tap,script=/etc/qemu-ifup,downscript=no,vlan=0 -vnc :1 -m 2G -smp 2 -balloon none -boot c -monitor stdio -uuid `uuidgen` -no-kvm-pit-reinjection 4. run (qemu)stop and wait 10 minutes 5. run (qemu)continue and run ntpdate -q clock.redhat.com 6. run ntpdate -q clock.redhat.com after 10 minutes Actual results: The offset is 77.568127 Expected results: no big offset after stop/continus, it could be adjusted Additional info:
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux major release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Major release. This request is not yet committed for inclusion.
Please post your guest dmesg as well.
(In reply to comment #3) > Please post your guest dmesg as well. Attached the guest dmesg. please refer to attachment
Created attachment 419305 [details] guest dmesg
Note added to all kvmclock bugs: Please retest with kernel-2.6.18-202.el5 (RHEL5) or kernel-2.6.32-33.el6 (RHEL6) in your guest kernel. In case it works, please close as a DUP of bugs 570824 (RHEL5) or 569603 (RHEL6)
Please re-test with latest code.
This is a guest kernel bug, thus, not RHEL6. Moving components.
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux maintenance release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Update release for currently deployed products. This request is not yet committed for inclusion in an Update release.
in kernel-2.6.18-206.el5 You can download this test kernel from http://people.redhat.com/jwilson/el5 Detailed testing feedback is always welcomed.
Cannot reproduce this bug with the following environment: Host: qemu-kvm-0.12.1.2-2.96.el6.x86_64 kernel 2.6.32-44.1.el6.x86_64el Guest: kernel 2.6.18-206.el5 cmdline: /usr/libexec/qemu-kvm -usbdevice tablet -rtc base=localtime,clock=vm,driftfix=slew -cpu qemu64,+x2apic -m 2G -smp 2 -drive file=/opt/r5u5_64.raw,if=none,cache=none,format=raw,werror=stop,rerror=stop,id=drive-ide0-0-0 -device ide-drive,bus=ide.0,drive=drive-ide0-0-0,id=ide0-0-0 -netdev tap,id=hostnet0,script=/etc/qemu-ifup -device rtl8139,netdev=hostnet0,mac=00:10:20:03:07:1c,bus=pci.0,addr=0x7,id=hostnet0 -uuid `uuidgen` -boot c -startdate now -balloon none -no-kvm-pit-reinjection -vnc :2
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. http://rhn.redhat.com/errata/RHSA-2011-0017.html