Re: [PATCH v3 3/9] xen/balloon: Share common memory reservation routines

[Oleksandr Andrushchenko]

On 06/13/2018 04:07 AM, Boris Ostrovsky wrote:
> On 06/12/2018 09:41 AM, Oleksandr Andrushchenko wrote:
>
>
>
> One more thing: please add a comment here saying that frames array is 
> array of PFNs (in Xen granularity), which is what 
> XENMEM_populate_physmap requires. And remove (or update to name the 
> actual call you are making) the corresponding comment in 
> increase_reservation().
I will remove corresponding comments from the balloon's 
{increase|decrease}_reservation
and move those into xenmem_reservation{increase|decrease} where they 
belong now.
I will also put a comment close to xenmem_reservation{increase|decrease}:

/* @frames is an array of PFNs */
int xenmem_reservation_increase(int count, xen_pfn_t *frames)
{
ÂÂÂ [...]
}

/* @frames is an array of GFNs */
int xenmem_reservation_decrease(int count, xen_pfn_t *frames)
{
ÂÂÂ [...]
}
> > +
> > +int xenmem_reservation_increase(int count, xen_pfn_t *frames)
> > +{
> > +ÂÂÂ struct xen_memory_reservation reservation = {
> > +ÂÂÂÂÂÂÂ .address_bits = 0,
> > +ÂÂÂÂÂÂÂ .extent_order = EXTENT_ORDER,
> > +ÂÂÂÂÂÂÂ .domidÂÂÂÂÂÂÂ = DOMID_SELF
> > +ÂÂÂ };
> > +
> > +ÂÂÂ set_xen_guest_handle(reservation.extent_start, frames);
> > +ÂÂÂ reservation.nr_extents = count;
> > +ÂÂÂ return HYPERVISOR_memory_op(XENMEM_populate_physmap, &reservation);
> > +}
> > +EXPORT_SYMBOL_GPL(xenmem_reservation_increase);
>
>
> And similarly, here we are requesting GFNs, and update 
> decrease_reservation().
Please see above
> -boris
Thank you,
Oleksandr
> > +
> > +int xenmem_reservation_decrease(int count, xen_pfn_t *frames)
> > +{
> > +ÂÂÂ struct xen_memory_reservation reservation = {
> > +ÂÂÂÂÂÂÂ .address_bits = 0,
> > +ÂÂÂÂÂÂÂ .extent_order = EXTENT_ORDER,
> > +ÂÂÂÂÂÂÂ .domidÂÂÂÂÂÂÂ = DOMID_SELF
> > +ÂÂÂ };
> > +
> > +ÂÂÂ set_xen_guest_handle(reservation.extent_start, frames);
> > +ÂÂÂ reservation.nr_extents = count;
> > +ÂÂÂ return HYPERVISOR_memory_op(XENMEM_decrease_reservation, 
> > &reservation);