RE: [PATCH v8 1/6] arm64: hyperv: Add Hyper-V hypercall and register access utilities

Sunil Muthuswamy
2021-03-04T00:31:39Z

> > +
> > + /*
> > + * Allocate a power of 2 size so alignment to that size is
> > + * guaranteed, since the hypercall input and output areas
> > + * must not cross a page boundary.
> > + */
> > + input = kzalloc(roundup_pow_of_two(sizeof(input->header) +
> > + sizeof(input->element[0])), GFP_ATOMIC);
> > + output = kmalloc(roundup_pow_of_two(sizeof(*output)), GFP_ATOMIC);
> > +
> Check for null from these malloc routines? Here and in other places.

Between, is there a plan to setup a percpu input/output page for hypercall
input/output on ARM (like we do for x64)? I didn't check the specific size requirement
for this particular call, but, that generally will remove the need for these
allocations.