Re: [PATCH v4 07/10] KVM: selftests: Support multiple vCPUs in demand paging test

From: Andrew Jones
Date: Mon Jan 27 2020 - 03:39:58 EST


On Sat, Jan 25, 2020 at 10:39:20AM +0100, Paolo Bonzini wrote:
> On 24/01/20 11:49, Andrew Jones wrote:
> >> +
> >> + /*
> >> + * Reserve twice the ammount of memory needed to map the test region and
> >> + * the page table / stacks region, at 4k, for page tables. Do the
> >> + * calculation with 4K page size: the smallest of all archs. (e.g., 64K
> >> + * page size guest will need even less memory for page tables).
> >> + */
> >> + pages += (2 * pages) / PTES_PER_4K_PT;
> >> + pages += ((2 * vcpus * vcpu_memory_bytes) >> PAGE_SHIFT_4K) /
> >> + PTES_PER_4K_PT;
> > pages needs to be rounded up to the next multiple of 16 in order for this
> > to work on aarch64 machines with 64k pages.
>
> I think this is best done with a generic function that does the rounding
> and an arch-specific function that returns the page size. Can you send
> a patch to implement this?
>

Sure. Will do.

Thanks,
drew