Re: [PATCH v4 1/9] tests/tcg/aarch64: Adjust pauth tests for FEAT_FPAC

[Peter Maydell]

On Tue, 22 Aug 2023 at 05:27, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> With FEAT_FPAC, AUT* instructions that fail authentication
> do not produce an error value but instead fault.
>
> For pauth-2, install a signal handler and verify it gets called.
>
> For pauth-4 and pauth-5, we are explicitly testing the error value,
> so there's nothing to test with FEAT_FPAC, so exit early.
> Adjust the makefile to use -cpu neoverse-v1, which has FEAT_EPAC
> but not FEAT_FPAC.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  tests/tcg/aarch64/pauth-2.c       | 61 +++++++++++++++++++++++++++----
>  tests/tcg/aarch64/pauth-4.c       | 28 ++++++++++++--
>  tests/tcg/aarch64/pauth-5.c       | 20 ++++++++++
>  tests/tcg/aarch64/Makefile.target |  5 ++-
>  4 files changed, 101 insertions(+), 13 deletions(-)


>  int main()
>  {
> +    static const struct sigaction sa = {
> +        .sa_sigaction = sigill,
> +        .sa_flags = SA_SIGINFO
> +    };
> +    unsigned long isar1, isar2;
> +
> +    assert(getauxval(AT_HWCAP) & HWCAP_CPUID);
> +
> +    asm("mrs %0, id_aa64isar1_el1" : "=r"(isar1));
> +    asm("mrs %0, id_aa64isar2_el1" : "=r"(isar2));

You need to use the S3_n_Cn_Cn_n encoding for
ID_AA64ISAR2_EL1 in this test and the others,
to avoid problems with older binutils. Compare
how tests/tcg/aarch64/sysregs.c does it.

> diff --git a/tests/tcg/aarch64/Makefile.target 
> b/tests/tcg/aarch64/Makefile.target
> index 681dfa077c..780ab3f183 100644
> --- a/tests/tcg/aarch64/Makefile.target
> +++ b/tests/tcg/aarch64/Makefile.target
> @@ -42,7 +42,10 @@ endif
>  ifneq ($(CROSS_CC_HAS_ARMV8_3),)
>  AARCH64_TESTS += pauth-1 pauth-2 pauth-4 pauth-5
>  pauth-%: CFLAGS += -march=armv8.3-a
> -run-pauth-%: QEMU_OPTS += -cpu max
> +run-pauth-1: QEMU_OPTS += -cpu max
> +run-pauth-2: QEMU_OPTS += -cpu max
> +run-pauth-4: QEMU_OPTS += -cpu neoverse-v1
> +run-pauth-5: QEMU_OPTS += -cpu neoverse-v1

Why do we need to specify neoverse-v1 here ? A comment
would help.

Otherwise
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM