Bug 770926

Summary: Can not disable kvmclock in kvm CML via -kvmclock
Product: Red Hat Enterprise Linux 5 Reporter: Sibiao Luo <sluo>
Component: kvmAssignee: Eduardo Habkost <ehabkost>
Status: CLOSED WONTFIX QA Contact: Virtualization Bugs <virt-bugs>
Severity: medium Docs Contact:
Priority: medium    
Version: 5.8CC: bcao, chayang, flang, juzhang, michen, mkenneth, qzhang, shu, tburke, virt-maint, wdai
Target Milestone: rc   
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2012-01-01 09:11:30 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:

Description Sibiao Luo 2011-12-30 09:21:40 UTC 
Description of problem:
Disable cpu flag via "-cpu qemu64,-flag(kvmclock)", and there is "CPU feature kvmclock not found" message display in the qemu monitor. 

Version-Release number of selected component (if applicable):
host info:
# uname -r && rpm -q kvm
2.6.18-302.el5
kvm-83-246.el5

How reproducible:
100%

Steps to Reproduce:
1.boot the guest with -cpu qemu64,-flag (kvmclock）.
eg: # /usr/libexec/qemu-kvm -M rhel5.6.0 -m 4G -smp 2,cores=2,threads=1,sockets=1 -cpu qemu64,-kvmclock -name rhel5.8 -usbdevice tablet -rtc-td-hack -uuid de2fd1ba-4b8b-40d4-84d3-5488366f871e -boot c -drive file=/home/rhel-5.8-64.qcow2,if=ide,boot=on,bus=0,unit=0,format=qcow2,cache=none,boot=on,werror=stop -net nic,macaddr=84:52:5f:1d:33:47,vlan=0,model=virtio -net tap,vlan=0,script=/etc/qemu-ifup -balloon none -monitor stdio -spice host=0,ic=on,port=5915,disable-ticketing -qxl 1
2.take "# dmesg | grep -i time.c" in the guest.

  
Actual results:
1.There is "CPU feature kvmclock not found" message display in the qemu monitor.
2.After the step 2, the result as following:
# dmesg | grep -i time.c
time.c: Using 1.193182 MHz WALL KVM GTOD KVM timer.
time.c: Detected 2826.246 MHz processor.
Real Time Clock Driver v1.12ac

Expected results:
RHEL5.8 should support the kvmclock flag in qemu64 cpu model, and take "# dmesg | grep -i time.c" should not display any message.

Additional info:
Comment 1 juzhang 2011-12-31 02:08:17 UTC 
Mark this bug as qa+ first and proposed to rhel5.9,however,still have a question,do we support disable kvmclock via kvm CML  -kvmclock?

Additional infos
Boot guest with -cpu qemu64,-kvmclock
# /usr/libexec/qemu-kvm -M rhel5.6.0 -m 4G -smp 2,cores=2,threads=1,sockets=1 -cpu qemu64,-kvmclock ......
CPU feature kvmclock not found
CPU feature kvmclock not found
Comment 2 Dor Laor 2012-01-01 09:11:30 UTC 
Too low priority, closed as won't fix