[PATCH bpf-next] selftests/bpf: Skip all serial_test_get_branch_snapshot in vm

[PATCH bpf-next] selftests/bpf: Skip all serial_test_get_branch_snapshot in vm

[Song Liu]

Skipping the second half of the test is not enough to silent the warning
in dmesg. Skip the whole test before we can either properly silent the
warning in kernel, or fix LBR snapshot for VM.

Fixes: 025bd7c753aa ("selftests/bpf: Add test for bpf_get_branch_snapshot")
Fixes: aa67fdb46436 ("selftests/bpf: Skip the second half of get_branch_snapshot in vm")
Signed-off-by: Song Liu <songliubraving@fb.com>
---
 .../bpf/prog_tests/get_branch_snapshot.c         | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c b/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c
index d6d70a359aeb5..81402e4439844 100644
--- a/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c
+++ b/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c
@@ -78,6 +78,12 @@ void serial_test_get_branch_snapshot(void)
 	struct get_branch_snapshot *skel = NULL;
 	int err;
 
+	/* Skip the test before we fix LBR snapshot for hypervisor. */
+	if (is_hypervisor()) {
+		test__skip();
+		return;
+	}
+
 	if (create_perf_events()) {
 		test__skip();  /* system doesn't support LBR */
 		goto cleanup;
@@ -107,16 +113,6 @@ void serial_test_get_branch_snapshot(void)
 		goto cleanup;
 	}
 
-	if (is_hypervisor()) {
-		/* As of today, LBR in hypervisor cannot be stopped before
-		 * too many entries are flushed. Skip the hit/waste test
-		 * for now in hypervisor until we optimize the LBR in
-		 * hypervisor.
-		 */
-		test__skip();
-		goto cleanup;
-	}
-
 	ASSERT_GT(skel->bss->test1_hits, 6, "find_looptest_in_lbr");
 
 	/* Given we stop LBR in software, we will waste a few entries.
-- 
2.30.2

Re: [PATCH bpf-next] selftests/bpf: Skip all serial_test_get_branch_snapshot in vm

[Andrii Nakryiko]

On Mon, Oct 25, 2021 at 5:07 PM Song Liu <songliubraving@fb.com> wrote:
>
> Skipping the second half of the test is not enough to silent the warning
> in dmesg. Skip the whole test before we can either properly silent the
> warning in kernel, or fix LBR snapshot for VM.
>
> Fixes: 025bd7c753aa ("selftests/bpf: Add test for bpf_get_branch_snapshot")
> Fixes: aa67fdb46436 ("selftests/bpf: Skip the second half of get_branch_snapshot in vm")
> Signed-off-by: Song Liu <songliubraving@fb.com>
> ---

Applied to bpf-next, thanks for the fix!

>  .../bpf/prog_tests/get_branch_snapshot.c         | 16 ++++++----------
>  1 file changed, 6 insertions(+), 10 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c b/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c
> index d6d70a359aeb5..81402e4439844 100644
> --- a/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c
> +++ b/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c
> @@ -78,6 +78,12 @@ void serial_test_get_branch_snapshot(void)
>         struct get_branch_snapshot *skel = NULL;
>         int err;
>
> +       /* Skip the test before we fix LBR snapshot for hypervisor. */
> +       if (is_hypervisor()) {
> +               test__skip();
> +               return;
> +       }
> +
>         if (create_perf_events()) {
>                 test__skip();  /* system doesn't support LBR */
>                 goto cleanup;
> @@ -107,16 +113,6 @@ void serial_test_get_branch_snapshot(void)
>                 goto cleanup;
>         }
>
> -       if (is_hypervisor()) {
> -               /* As of today, LBR in hypervisor cannot be stopped before
> -                * too many entries are flushed. Skip the hit/waste test
> -                * for now in hypervisor until we optimize the LBR in
> -                * hypervisor.
> -                */
> -               test__skip();
> -               goto cleanup;
> -       }
> -
>         ASSERT_GT(skel->bss->test1_hits, 6, "find_looptest_in_lbr");
>
>         /* Given we stop LBR in software, we will waste a few entries.
> --
> 2.30.2
>