Re: [Qemu-devel] Where is the VM live migration code?

[Zhang Haoyu]

> Hi,
> 
> I saw this page:
> 
> http://www.linux-kvm.org/page/Migration.
> 
> It looks like Migration is a feature provided by KVM? But when I look
> at the Linux kernel source code, i.e., virt/kvm, and arch/x86/kvm, I
> don't see the code for this migration feature.
> 
Most of live migration code is in qemu migration.c, savevm.c, arch_init.c,
block-migration.c, and the other devices's save/load handler, .etc,
only log/sync dirty page implemented in kernel.
You can read the most important function migration_thread(),
process_incoming_migration_co().

> So I wonder where is the source code for the live migration? Is it
>purely implemented in user space? Because I see there are the
> following files in the qemu source code:
> 
> migration.c  migration-exec.c  migration-fd.c  migration-rdma.c
> migration-tcp.c  migration-unix.c
> 
> If I wish to understand the implementation of migration in Qemu/KVM,
> are these above files the ones I should read? Thanks.
> 
> -Jidong