Re: [Qemu-devel] Enabling vhost-net cause insane high memory usage.

[Stefan Hajnoczi <stefanha@gmail.com>]

On Fri, Jan 10, 2014 at 12:00:31AM +0100, Piotr Karbowski wrote:
> kernel 3.12.5, qemu-1.7.0.
> 
> With vhost=on, qemu shortly after start uses all its assigned memory
> (2G for example), without vhost-net enabled it does not go to more
> than 200 MB on my idling test virtual machine. 100% reproducable. I
> think its not how it should be.
> 
> Full command:
> /usr/bin/qemu-system-x86_64 -machine accel=kvm -name _debian -usb
> -machine accel=kvm -cpu host,level=9 -smp cpus=2 -vga std -monitor unix://home/piotr/src/vmninja/sockets/_debian.monitor.socket,server,nowait
> -vnc unix://home/piotr/src/vmninja/sockets/_debian.vnc.socket -m
> 2048 -boot order=d,menu=on -drive
> if=ide,index=2,media=cdrom,id=virtcd -netdev
> tap,id=if0,helper=/usr/libexec/qemu-bridge-helper --br=lebridge0
> -device virtio-net-pci,netdev=if0,mac=de:ee:b3:9e:a3:d5,romfile=
> -drive
> file=/home/piotr/virt/kvm/_debian.raw,if=virtio,cache=writeback

How are you measuring memory usage?  Please post the output of the
command.

Did previous kernel/qemu versions work better?

Maybe Michael or Jason can give you hints on debugging this.

Stefan