Re: Shadow Code Reorganization

[Gerd Knorr <kraxel@suse.de>]

  Hi,

> Depends what you mean by "normal". The mode that we need for migration
> of a paravirtualized guest is log_dity but with refcounts in the *guest*
> pages i.e. SHM_refcounts is not set.

Ah, *that* the log_dirty option is good for.  Looked like some
performance measurement counter on a first quick look ...

> > But it's not clear to me how the transition between "normal" 
> > and "translated" shadow mode works.  Does that need support 
> > by the guest os?
> 
> Guests typically don't make this transition -- it's currently a guest
> compile time option whether to use the paravirtualized or translated
> shadow mode interface. This isn't strictly necessary.

Ok, more general:  How does xen and/or the guest os handle the
changes in machine<=>phys mapping as they happen on
suspend/resume and migration because the guest gets a different
set of machine pages?  Especially the guest page table updates?

  Gerd

-- 
panic("it works"); /* avoid being flooded with debug messages */