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

Paolo Bonzini
2020-01-25T09:39:35Z

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?

Thanks,

Paolo