Re: [Qemu-devel] [PATCH v3 5/5] tests/tcg/aarch64: userspace system register test

["Alex Bennée" <alex.bennee@linaro.org>]

Alex Bennée <alex.bennee@linaro.org> writes:

> This tests a bunch of registers that the kernel allows userspace to
> read including the CPUID registers.
>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> ---
>  tests/tcg/aarch64/Makefile.target |  2 +-
>  tests/tcg/aarch64/sysregs.c       | 99 +++++++++++++++++++++++++++++++
>  2 files changed, 100 insertions(+), 1 deletion(-)
>  create mode 100644 tests/tcg/aarch64/sysregs.c
>
> diff --git a/tests/tcg/aarch64/Makefile.target b/tests/tcg/aarch64/Makefile.target
> index 08c45b8470..cc1a7eb486 100644
> --- a/tests/tcg/aarch64/Makefile.target
> +++ b/tests/tcg/aarch64/Makefile.target
> @@ -7,7 +7,7 @@ VPATH 		+= $(AARCH64_SRC)
>
>  # we don't build any of the ARM tests
>  AARCH64_TESTS=$(filter-out $(ARM_TESTS), $(TESTS))
> -AARCH64_TESTS+=fcvt
> +AARCH64_TESTS+=fcvt sysregs
>  TESTS:=$(AARCH64_TESTS)
>
>  fcvt: LDFLAGS+=-lm
> diff --git a/tests/tcg/aarch64/sysregs.c b/tests/tcg/aarch64/sysregs.c
> new file mode 100644
> index 0000000000..177d1fe33b
> --- /dev/null
> +++ b/tests/tcg/aarch64/sysregs.c
> @@ -0,0 +1,99 @@
> +/*
> + * Check emulated system register access for linux-user mode.
> + *
> + * See: https://www.kernel.org/doc/Documentation/arm64/cpu-feature-registers.txt
> + */
> +
> +#include <asm/hwcap.h>
> +#include <stdio.h>
> +#include <sys/auxv.h>
> +#include <signal.h>
> +#include <string.h>
> +#include <stdbool.h>
> +
<snip>
> +
> +    /* when (getauxval(AT_HWCAP) & HWCAP_CPUID), since 4.11*/
> +    if (!(getauxval(AT_HWCAP) & HWCAP_CPUID)) {
> +        printf("CPUID registers unavailable\n");
> +        return 1;
> +    } else {
> +        printf("Checking CPUID registers\n");
> +    }

Annoyingly this fails on qemu:debian-arm64-cross as it uses an older set
of headers than my desktop cross environment:

  aarch64-linux-gnu-gcc (Ubuntu/Linaro 7.3.0-16ubuntu3) 7.3.0

with the libc:

  Source: cross-toolchain-base (25ubuntu6)
  Version: 2.27-3ubuntu1cross1
  Provides: libc6-arm64-dcv1

So I'm thinking an #ifndef HWCAP_CPUID and define it would be acceptable
for a test case.

--
Alex Bennée