Re: [PATCH v2 3/4] KVM: s390: selftests: Use TAP interface in the tprot test

Janosch Frank
2022-04-20T10:23:14Z

On 4/19/22 20:58, Thomas Huth wrote:
> The tprot test currently does not have any output (unless one of
> the TEST_ASSERT statement fails), so it's hard to say for a user
> whether a certain new sub-test has been included in the binary or
> not. Let's make this a little bit more user-friendly and include
> some TAP output via the kselftests.h interface.
>
> Signed-off-by: Thomas Huth <thuth@redhat.com>

Reviewed-by: Janosch Frank <frankja@linux.ibm.com>

Some comments below.

> ---
> tools/testing/selftests/kvm/s390x/tprot.c | 28 +++++++++++++++++++----
> 1 file changed, 23 insertions(+), 5 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/s390x/tprot.c b/tools/testing/selftests/kvm/s390x/tprot.c
> index c097b9db495e..baba883d7a6d 100644
> --- a/tools/testing/selftests/kvm/s390x/tprot.c
> +++ b/tools/testing/selftests/kvm/s390x/tprot.c
> @@ -8,6 +8,7 @@
> #include <sys/mman.h>
> #include "test_util.h"
> #include "kvm_util.h"
> +#include "kselftest.h"
>
> #define PAGE_SHIFT 12
> #define PAGE_SIZE (1 << PAGE_SHIFT)
> @@ -63,12 +64,12 @@ static enum permission test_protection(void *addr, uint8_t key)
> }
>
> enum stage {
> - STAGE_END,
> STAGE_INIT_SIMPLE,
> TEST_SIMPLE,
> STAGE_INIT_FETCH_PROT_OVERRIDE,
> TEST_FETCH_PROT_OVERRIDE,
> TEST_STORAGE_PROT_OVERRIDE,
> + STAGE_END /* this must be the last entry */

...so we can use it to calculate the test number

> };
>
> struct test {
> @@ -182,7 +183,7 @@ static void guest_code(void)
> GUEST_SYNC(perform_next_stage(&i, mapped_0));
> }
>

> @@ -212,9 +222,13 @@ int main(int argc, char *argv[])
> HOST_SYNC(vm, TEST_SIMPLE);
>
> guest_0_page = vm_vaddr_alloc(vm, PAGE_SIZE, 0);
> - if (guest_0_page != 0)
> - print_skip("Did not allocate page at 0 for fetch protection override tests");
> - HOST_SYNC(vm, STAGE_INIT_FETCH_PROT_OVERRIDE);
> + if (guest_0_page != 0) {

Maybe add:
/* Use no_tap so we don't get a PASS print */

> + HOST_SYNC_NO_TAP(vm, STAGE_INIT_FETCH_PROT_OVERRIDE);
> + ksft_test_result_skip("STAGE_INIT_FETCH_PROT_OVERRIDE - "
> + "Did not allocate page at 0\n");
> + } else {
> + HOST_SYNC(vm, STAGE_INIT_FETCH_PROT_OVERRIDE);
> + }

Otherwise this would look weird.

> if (guest_0_page == 0)
> mprotect(addr_gva2hva(vm, (vm_vaddr_t)0), PAGE_SIZE, PROT_READ);
> run->s.regs.crs[0] |= CR0_FETCH_PROTECTION_OVERRIDE;
> @@ -224,4 +238,8 @@ int main(int argc, char *argv[])
> run->s.regs.crs[0] |= CR0_STORAGE_PROTECTION_OVERRIDE;
> run->kvm_dirty_regs = KVM_SYNC_CRS;
> HOST_SYNC(vm, TEST_STORAGE_PROT_OVERRIDE);
> +
> + kvm_vm_free(vm);
> +
> + ksft_finished();
> }