Bug 978929

Summary:	libvirt starts qemu with double -machine parameters
Product:	[Community] Virtualization Tools	Reporter:	Christoph Anton Mitterer <calestyo>
Component:	libvirt	Assignee:	Libvirt Maintainers <libvirt-maint>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	low	Docs Contact:
Priority:	unspecified
Version:	unspecified	CC:	dyasny, jdenemar
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	All
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2013-06-28 07:57:24 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Christoph Anton Mitterer 2013-06-27 10:02:51 UTC

Hi.

This is likely just a cosmetic issue... on QEMU/KVM VMs set up with virt-manager, libvirt starts these with twice the -machine parameter:
$ ps ax | grep qemu
10204 pts/2    S+     0:01 /usr/bin/python /usr/bin/reportbug qemu-system-x86
13364 ?        Rl     0:16 qemu-system-x86_64 -machine accel=kvm:tcg -name someImage -S -machine pc-1.1,accel=kvm,usb=off -cpu SandyBridge,+erms,+smep,+fsgsbase,+rdrand,+f16c,+osxsave,+pcid,+pdcm,+xtpr,+tm2,+est,+vmx,+ds_cpl,+monitor,+dtes64,+pbe,+tm,+ht,+ss,+acpi,+ds,+vme -m 2048 -realtime mlock=off -smp 1,sockets=1,cores=1,threads=1 -uuid b68a6e41-ae45-bbca-43f0-45219eb41044 -no-user-config -nodefaults -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/someImage.monitor,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc -no-shutdown -boot menu=off -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 -device ahci,id=ahci0,bus=pci.0,addr=0x5 -drive file=/var/lib/libvirt/images/someImage.img,if=none,id=drive-sata0-0-0,format=raw -device ide-hd,bus=ahci0.0,drive=drive-sata0-0-0,id=sata0-0-0,bootindex=1 -netdev tap,fd=24,id=hostnet0 -device e1000,netdev=hostnet0,id=net0,mac=52:54:00:02:32:71,bus=pci.0,addr=0x3 -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -device usb-tablet,id=input0 -spice port=5900,addr=127.0.0.1,seamless-migration=on -vga std -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x4

namely:
-machine accel=kvm:tcg
-machine pc-1.1,accel=kvm,usb=off

I'd guess only the later is actually used... so this is not a critical bug... bot a cosmetic issue... that should be cleaned up to avoid confusion.


Cheers,
Chris.

Comment 1 Jiri Denemark 2013-06-28 07:57:24 UTC

This is not a libvirt bug, the "-machine accel=kvm:tcg" command line option must have been added by something else. Quite possibly there is a wrapper around qemu binary that adds this option. For example, AFAIK gentoo distributes /usr/bin/qemu-kvm, which is a shell script calling qemu-system-x86_64 with an explicitly added -machine option. Your distribution is probably doing similar thing. If that's the case, change the emulator path in domain XML so that it points to the real qemu binary instead of the wrapper script.