Re: [Qemu-devel] Significant slowdown after qemu-kvm-1.2.0

["Andreas Färber" <afaerber@suse.de>]

Hi,

Am 02.07.2013 00:24, schrieb jinho hwang:
> Thank you for your reply. I tried qemu-1.5.0 with --enable-kvm, but
> there is still a big difference between qemu-kvm-1.2.0 and qemu-1.5.0.
> They both use the same command line to create VM. Am I missing something
> in the command-line?
> 
> sudo qemu-system-x86_64 -name vm -m 1g -hda /home/jinho/virt/vms/vm1.img
> -device e1000,netdev=net0,mac=00:0c:29:f0:bc:33 -netdev tap,id=net0 -vnc :1

Yes, you are still missing -enable-kvm on the QEMU command line, or
alternatively the more modern -machine accel=kvm.

Regards,
Andreas

P.S. Please avoid top-posting and HTML on the mailing list.

> On Mon, Jul 1, 2013 at 5:54 PM, Paolo Bonzini <pbonzini@redhat.com
> <mailto:pbonzini@redhat.com>> wrote:
> 
>     Il 01/07/2013 23:51, jinho hwang ha scritto:
>     > Hi Guys,
>     >
>     > I am new to kvm development (used to work on Xen). I used
>     qemu-kvm-1.2.0
>     > first, and then due to pci memory size (x64 bit support), I switched
>     > from 1.2.0 to qemu-kvm-1.5.0 (same for 1.3.0~).
> 
>     There is no qemu-kvm 1.5.0.  You are using qemu 1.5.0.
> 
>     > After that, my VM slows
>     > down significantly including booting and execution. Also, sometimes
>     > kernel messages "CPU stuck for x seconds" show in dmesg. I think CPU
>     > scheduling has been changed or should be set up properly, but I
>     have no
>     > clue for now. Can anyone help me to figure out this? I really need
>     some
>     > fast VMs as I used to run with qemu-kvm-1.2.0.
>     >
>     > I am currently running ubuntu-12.10_64 in VM, and my configure was
>     >
>     > ./configure --prefix=/usr
>     --target-list=x86_64-linux-user,x86_64-softmmu
>     >
>     > sudo qemu-system-x86_64 -name vm -m 1g -hda
>     /home/jinho/virt/vms/vm1.img
>     > -device e1000,netdev=net0,mac=00:0c:29:f0:bc:33 -netdev
>     tap,id=net0 -vnc
>     > 135.207.127.181:1 <http://135.207.127.181:1>
>     <http://135.207.127.181:1>
> 
>     You are not using kvm.  Add --enable-kvm to the command line.
> 
>     Paolo
> 


-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg