Re: [PATCH kvm-next V11 7/7] KVM: guest_memfd: selftests: Add tests for mmap and NUMA policy support

[David Hildenbrand <david@redhat.com>]

On 25.09.25 23:35, Sean Christopherson wrote:
> On Wed, Aug 27, 2025, Shivank Garg wrote:
>> Add tests for NUMA memory policy binding and NUMA aware allocation in
>> guest_memfd. This extends the existing selftests by adding proper
>> validation for:
>> - KVM GMEM set_policy and get_policy() vm_ops functionality using
>>    mbind() and get_mempolicy()
>> - NUMA policy application before and after memory allocation
>>
>> These tests help ensure NUMA support for guest_memfd works correctly.
>>
>> Signed-off-by: Shivank Garg <shivankg@amd.com>
>> ---
>>   tools/testing/selftests/kvm/Makefile.kvm      |   1 +
>>   .../testing/selftests/kvm/guest_memfd_test.c  | 121 ++++++++++++++++++
>>   2 files changed, 122 insertions(+)
>>
>> diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm
>> index 90f03f00cb04..c46cef2a7cd7 100644
>> --- a/tools/testing/selftests/kvm/Makefile.kvm
>> +++ b/tools/testing/selftests/kvm/Makefile.kvm
>> @@ -275,6 +275,7 @@ pgste-option = $(call try-run, echo 'int main(void) { return 0; }' | \
>>   	$(CC) -Werror -Wl$(comma)--s390-pgste -x c - -o "$$TMP",-Wl$(comma)--s390-pgste)
>>   
>>   LDLIBS += -ldl
>> +LDLIBS += -lnuma
> 
> Hrm, this is going to be very annoying.  I don't have libnuma-dev installed on
> any of my <too many> systems, and I doubt I'm alone.  Installing the package is
> trivial, but I'm a little wary of foisting that requirement on all KVM developers
> and build bots.
> 
> I'd be especially curious what ARM and RISC-V think, as NUMA is likely a bit less
> prevelant there.

We unconditionally use it in the mm tests for ksm and migration tests, 
so it's not particularly odd to require it here as well.

What we do with liburing in mm selftests is to detect presence at 
compile time and essentially make the tests behave differently based on 
availability (see check_config.sh).

-- 
Cheers

David / dhildenb