Re: [PATCH v3 02/14] x86/vmx: Skip vmx_pf_exception_test_fep early if FEP is not available

Sean Christopherson
2025-11-14T00:40:15Z

On Mon, Nov 10, 2025, Yosry Ahmed wrote:
> The check to skip the test is currently performed in the guest code.
> There a few TEST_ASSERTs that happen before the guest is run, which
> internally call report_passed(). The latter increases the number of
> passed tests.
>
> Hence, when vmx_pf_exception_test_fep is run, report_summary() does not
> return a "skip" error code because the total number of tests is larger
> than the number of skipped tests.
>
> Skip early if FEP is not available, before any assertions, such that
> report_summary() finds exactly 1 skipped test and returns the
> appropriate error code.
>
> Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
> ---
> x86/vmx_tests.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c
> index 0b3cfe50c6142..4f214ebdbe1d9 100644
> --- a/x86/vmx_tests.c
> +++ b/x86/vmx_tests.c
> @@ -10644,7 +10644,10 @@ static void vmx_pf_exception_test(void)
>
> static void vmx_pf_exception_forced_emulation_test(void)
> {
> - __vmx_pf_exception_test(NULL, NULL, vmx_pf_exception_forced_emulation_test_guest);
> + if (is_fep_available)
> + __vmx_pf_exception_test(NULL, NULL, vmx_pf_exception_forced_emulation_test_guest);
> + else
> + report_skip("Forced emulation prefix (FEP) not available\n");

To be consistent with other tests, and the kernel's general pattern of:

if (<error>) {
<react>
return;
}

<do useful stuff>

I'll tweak this to

if (!is_fep_available) {
report_skip("Forced emulation prefix (FEP) not available\n");
return;
}

__vmx_pf_exception_test(NULL, NULL, vmx_pf_exception_forced_emulation_test_guest);

when applying.