> > Now with this function being reintroduced, it becomes more complicated
> > to determine which version of the mem_access API does Xen actually
> > provide. A #define indicating mem_access API version would nicely
> > overcome this issue, or  naming xc_mem_event_enable something else.
>
> Doesn't configure support checking for functions with a given prototype?
>

It does but in a very hacky way, essentially trying to compile code where
the function is being called with different prototypes. We can work around
it but a clean solution would be preferred at some point.



> > Furthermore, the new xc_mem_event_enable function unconditionally
> > unpauses the VM. This may not be a desired behavior in all cases,
> > especially if the VM was in a paused state when the function was
> > called.
>
> domain pauses are referenced counted on the hypervisor side.
>

> Ian.
>
>
I did a quick test with xc_domain_pause being called twice, then
xc_domain_unpause once and the domain was in unpaused state at the end.
Same with the xen-access example, a paused domain gets automatically
unpaused by libxc, either though the xen-access code doesn't specifically
say it should be. This is now a rather opaque behavior of libxc. As it is
not merged into master I guess I will just submit a patch for it..

Tamas