Re: [Qemu-devel] [MIGRATION_TO_FILE_ALTERNATIVE] savevm/loadvm to/from a file

[Ian Jackson]

Uri Lublin writes ("[Qemu-devel] [MIGRATION_TO_FILE_ALTERNATIVE] savevm/loadvm 
to/from a file"):
> Sometimes we do not want to save VM state internally (within the image).
> For example raw images (and any other non qcow images) are not capable
> of savevm'ing.

This code is almost identical to the same code in our qemu-dm Xen
tree.  The only real difference is the umask call, and that our code
takes its snapshot of vm_running after calling qemu_aio_flush.

Ie, in our version the assignment I mark here as A is at location B:

A > +    int saved_vm_running = vm_running;
...
  > +    f = qemu_fopen(filename, "wb");
...
  > +    qemu_aio_flush();
B
  > +    vm_stop(0);

I'm not sure exactly how relevant that is but it seems possible that
qemu_aio_flush could stop the VM (eg due to the forthcoming
stop-on-enospc patch).

Modulo this one tiny change, I'm keen to see this go into qemu
upstream.

Ian.