Re: [PATCH v3 2/3] KVM: selftests: Enable pre_fault_memory_test for arm64

[Vincent Donnefort <vdonnefort@google.com>]

On Wed, Nov 19, 2025 at 03:49:09PM +0000, Jack Thomson wrote:
> From: Jack Thomson <jackabt@amazon.com>
> 
> Enable the pre_fault_memory_test to run on arm64 by making it work with
> different guest page sizes and testing multiple guest configurations.
> 
> Update the test_assert to compare against the UCALL_EXIT_REASON, for
> portability, as arm64 exits with KVM_EXIT_MMIO while x86 uses
> KVM_EXIT_IO.
> 
> Signed-off-by: Jack Thomson <jackabt@amazon.com>
> ---
>  tools/testing/selftests/kvm/Makefile.kvm      |  1 +
>  .../selftests/kvm/pre_fault_memory_test.c     | 78 ++++++++++++++-----
>  2 files changed, 58 insertions(+), 21 deletions(-)
> 
> diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm
> index 148d427ff24b..0ddd8db60197 100644
> --- a/tools/testing/selftests/kvm/Makefile.kvm
> +++ b/tools/testing/selftests/kvm/Makefile.kvm
> @@ -183,6 +183,7 @@ TEST_GEN_PROGS_arm64 += memslot_perf_test
>  TEST_GEN_PROGS_arm64 += mmu_stress_test
>  TEST_GEN_PROGS_arm64 += rseq_test
>  TEST_GEN_PROGS_arm64 += steal_time
> +TEST_GEN_PROGS_arm64 += pre_fault_memory_test
>  
>  TEST_GEN_PROGS_s390 = $(TEST_GEN_PROGS_COMMON)
>  TEST_GEN_PROGS_s390 += s390/memop
> diff --git a/tools/testing/selftests/kvm/pre_fault_memory_test.c b/tools/testing/selftests/kvm/pre_fault_memory_test.c
> index f04768c1d2e4..674931e7bb3a 100644
> --- a/tools/testing/selftests/kvm/pre_fault_memory_test.c
> +++ b/tools/testing/selftests/kvm/pre_fault_memory_test.c
> @@ -11,19 +11,29 @@
>  #include <kvm_util.h>
>  #include <processor.h>
>  #include <pthread.h>
> +#include <guest_modes.h>
>  
>  /* Arbitrarily chosen values */
> -#define TEST_SIZE		(SZ_2M + PAGE_SIZE)
> -#define TEST_NPAGES		(TEST_SIZE / PAGE_SIZE)

After applying on top of the base commit
8a4821412cf2c1429fffa07c012dd150f2edf78c, it does not build.

That TEST_NPAGES seems to still be used in delete_slot_worker(). I believe
that's because of

  "KVM: selftests: Test prefault memory during concurrent memslot removal"

Related issues with the pre_fault_memory() prototype.

Is that the correct base-commit or shall I use something else?

> +#define TEST_BASE_SIZE		SZ_2M
>  #define TEST_SLOT		10
>

[...]