Re: [Qemu-devel] [PATCH v2 00/38] Delay destruction of memory regions to instance_finalize

[Michael S. Tsirkin]

On Tue, Sep 17, 2013 at 04:41:45PM +0200, Paolo Bonzini wrote:
> Il 17/09/2013 14:47, Michael S. Tsirkin ha scritto:
> > Ergo, to make sure a referenced MR does not get
> > destroyed, we must make sure only finalize
> > calls memory_region_destroy.
> > 
> > So I think this patchset should do exactly that,
> > not try to move out more stuff to finalize.
> 
> Yes, this is the part of the problem that applies to all devices.
> 
> Some devices may have timers or other dynamically-allocated data that
> may be used between exit and finalize.  The same applies to capabilities
> such as MSI and MSI-X.  All this must also be moved to finalize, but
> this can be done in separate patches.
> 
> I'll separate the series as follows:
> 
> - memory_region_destroy
> 
> - unregister_savevm

What's the problem here exactly?

> - other dynamically allocated data

And here? I don't think we should move rundom stuff out to finalize
just because we can.

> - del_vm_change_state_handler
> 
> - MSI-X
> 
> - SHPC, AER and other PCI/bridge stuff
> 
> Paolo

Let's document specific problems and fix them.
Randomly moving cleanup order has a high chance to
introduce bugs.