[Qemu-discuss] Kvm qemu dirty page log facility

[hellen maziku]

Greetings!
I am new to kvm qemu and are writing a python script to 
get the number of pre-copy cycles during a remote vm migration given 
memory size M  of a VM in MB, the page dirty rate R of a vm in MB/s. My 
question is on how to get the page dirty rate. Does kvm qemu provide a dirty 
page 
log facility that provides user space with a bitmap of modified pages 
since the last call? And if yes, please kindly direct me on how to get 
started. I am using libvirt (virt manager) to manage my virtual machines. I 
have searched and come across things like 

VIR_NODE_MEMORY_STATS  and 

kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log, int *is_dirty), 

I do not know if this these are the ones and if yes how can I use them? or ways 
to implement them. 

Thank you very much