Re: [Qemu-devel] Libvirt add ftrace option

["Daniel P. Berrange" <berrange@redhat.com>]

On Tue, Aug 16, 2016 at 07:33:30PM +0530, Gadre Nayan wrote:
> Hi,
> 
> I am able to get traces from Guest kernel + QEMU + Host kernel using the
> qemu -trace evetns=/tmp/events option
> 
> My complete command line is:
> /home/gnayan/QEMU-devel/qemu-ubuntu/qemu/x86_64-softmmu/qemu-system-x86_64
> -trace events=/home/gnayan/qemu_events -drive
> file=/home/gnayan/CUSTOM_QEMU_SYSTEM/UBUNTU/ubuntu.img,if=virtio,format=raw
> -drive file=/home/gnayan/CUSTOM_QEMU_SYSTEM/UBUNTU/u1.img,if=virtio,format=raw
> -m 1G -net nic,model=virtio -net user -redir tcp:2222::22 -redir
> udp:5050::5050 -enable-kvm
> 
> How can I get the same using libvirt based tools:
> 
> I create the domain using:
> 
> virt-install -n vm1 -r 1024 --disk
> path=/home/gnayan/CUSTOM_QEMU_SYSTEM/UBUNTU/ubuntu.img,bus=virtio
> --network network=default,model=virtio
> 
> Is the trace option available ?

With libvirt you should use the dtrace/systemtap backend instead as that's
far more flexible, not requiring changes to the QEMU configuration every
time you want to change what events are output.

Regards,
Daniel
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