Re: [PATCH v7 2/3] KVM: selftests: arm64: Report register reset tests individually

[Lorenzo Stoakes (ARM)]

On Tue, Sep 01, 2026 at 07:50:02PM +0100, Mark Brown wrote:
> set_id_regs tests that registers have their values preserved over reset.
> Currently it reports all registers in a single test with an instantly fatal
> assert which isn't great for diagnostics, it's hard to tell which register
> failed or if it's just one register. Change this to report each register as
> a separate test so that it's clear from the program output which registers
> have problems.

Sounds reasonable.

>
> Reviewed-by: Ben Horgan <ben.horgan@xxxxxxx>
> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>

All LGTM so:

Reviewed-by: Lorenzo Stoakes (ARM) <ljs@xxxxxxxxxx>

> ---
>  tools/testing/selftests/kvm/arm64/set_id_regs.c | 19 +++++++++++++------
>  1 file changed, 13 insertions(+), 6 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/arm64/set_id_regs.c b/tools/testing/selftests/kvm/arm64/set_id_regs.c
> index db6414a93ad3..3aa8886e8b70 100644
> --- a/tools/testing/selftests/kvm/arm64/set_id_regs.c
> +++ b/tools/testing/selftests/kvm/arm64/set_id_regs.c
> @@ -819,13 +819,21 @@ static void test_vcpu_non_ftr_id_regs(struct kvm_vcpu *vcpu)
>  static void test_assert_id_reg_unchanged(struct kvm_vcpu *vcpu, u32 encoding)
>  {
>  	size_t idx = encoding_to_range_idx(encoding);
> -	u64 observed;
> +	u64 observed, expected;
> +	bool pass;
>
>  	observed = vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(encoding));
> -	TEST_ASSERT_EQ(reset_mutable_bits(encoding, test_reg_vals[idx]),
> -		       reset_mutable_bits(encoding, observed));
> +	observed = reset_mutable_bits(encoding, observed);
> +	expected = reset_mutable_bits(encoding, test_reg_vals[idx]);
> +	pass = expected == observed;
> +	if (!pass)
> +		ksft_print_msg("%lx != %lx\n", expected, observed);
> +	ksft_test_result(pass, "%s unchanged by reset\n",
> +			 get_reg_name(encoding));

Ah yeah -> individual tests.

>  }
>
> +#define ID_REG_RESET_UNCHANGED_TEST (ARRAY_SIZE(test_regs) + NUM_EXTRA_REGS)

Yeah can see from original test_reset_preserves_id_regs() that this is correct.

> +
>  static void test_reset_preserves_id_regs(struct kvm_vcpu *vcpu)
>  {
>  	/*
> @@ -843,8 +851,6 @@ static void test_reset_preserves_id_regs(struct kvm_vcpu *vcpu)
>  	test_assert_id_reg_unchanged(vcpu, SYS_MIDR_EL1);
>  	test_assert_id_reg_unchanged(vcpu, SYS_REVIDR_EL1);
>  	test_assert_id_reg_unchanged(vcpu, SYS_AIDR_EL1);
> -
> -	ksft_test_result_pass("%s\n", __func__);
>  }
>
>  int main(void)
> @@ -872,7 +878,8 @@ int main(void)
>
>  	ksft_print_header();
>
> -	test_cnt = 3 + MPAM_IDREG_TEST + MTE_IDREG_TEST + GUEST_READ_TEST;
> +	test_cnt = 2 + MPAM_IDREG_TEST + MTE_IDREG_TEST + GUEST_READ_TEST +
> +		ID_REG_RESET_UNCHANGED_TEST;
>  	for (i = 0; i < ARRAY_SIZE(test_regs); i++)
>  		for (j = 0; test_regs[i].ftr_bits[j].type != FTR_END; j++)
>  			test_cnt++;
>
> --
> 2.47.3
>
>

--
Cheers, Lorenzo