[PATCH 1/3] KVM: selftests: arm64: Report set_id_reg reads of test registers as tests

[Mark Brown]

Currently when we run guest code to validate that the values we wrote to
the registers are seen by the guest we assert that these values match using
a KVM selftests level assert, resulting in unclear diagnostics if the test
fails. Replace this assert with reporting a kselftest test per register.

In order to support getting the names of the registers we repaint the array
of ID_ registers to store the names and open code the rest.

Signed-off-by: Mark Brown <broonie at kernel.org>
---
 tools/testing/selftests/kvm/arm64/set_id_regs.c | 74 +++++++++++++++++++------
 1 file changed, 57 insertions(+), 17 deletions(-)

diff --git a/tools/testing/selftests/kvm/arm64/set_id_regs.c b/tools/testing/selftests/kvm/arm64/set_id_regs.c
index 5e24f77868b5..7a759e976c2c 100644
--- a/tools/testing/selftests/kvm/arm64/set_id_regs.c
+++ b/tools/testing/selftests/kvm/arm64/set_id_regs.c
@@ -40,6 +40,7 @@ struct reg_ftr_bits {
 };
 
 struct test_feature_reg {
+	const char *name;
 	uint32_t reg;
 	const struct reg_ftr_bits *ftr_bits;
 };
@@ -218,24 +219,25 @@ static const struct reg_ftr_bits ftr_id_aa64zfr0_el1[] = {
 
 #define TEST_REG(id, table)			\
 	{					\
-		.reg = id,			\
+		.name = #id,			\
+		.reg = SYS_ ## id,		\
 		.ftr_bits = &((table)[0]),	\
 	}
 
 static struct test_feature_reg test_regs[] = {
-	TEST_REG(SYS_ID_AA64DFR0_EL1, ftr_id_aa64dfr0_el1),
-	TEST_REG(SYS_ID_DFR0_EL1, ftr_id_dfr0_el1),
-	TEST_REG(SYS_ID_AA64ISAR0_EL1, ftr_id_aa64isar0_el1),
-	TEST_REG(SYS_ID_AA64ISAR1_EL1, ftr_id_aa64isar1_el1),
-	TEST_REG(SYS_ID_AA64ISAR2_EL1, ftr_id_aa64isar2_el1),
-	TEST_REG(SYS_ID_AA64ISAR3_EL1, ftr_id_aa64isar3_el1),
-	TEST_REG(SYS_ID_AA64PFR0_EL1, ftr_id_aa64pfr0_el1),
-	TEST_REG(SYS_ID_AA64PFR1_EL1, ftr_id_aa64pfr1_el1),
-	TEST_REG(SYS_ID_AA64MMFR0_EL1, ftr_id_aa64mmfr0_el1),
-	TEST_REG(SYS_ID_AA64MMFR1_EL1, ftr_id_aa64mmfr1_el1),
-	TEST_REG(SYS_ID_AA64MMFR2_EL1, ftr_id_aa64mmfr2_el1),
-	TEST_REG(SYS_ID_AA64MMFR3_EL1, ftr_id_aa64mmfr3_el1),
-	TEST_REG(SYS_ID_AA64ZFR0_EL1, ftr_id_aa64zfr0_el1),
+	TEST_REG(ID_AA64DFR0_EL1, ftr_id_aa64dfr0_el1),
+	TEST_REG(ID_DFR0_EL1, ftr_id_dfr0_el1),
+	TEST_REG(ID_AA64ISAR0_EL1, ftr_id_aa64isar0_el1),
+	TEST_REG(ID_AA64ISAR1_EL1, ftr_id_aa64isar1_el1),
+	TEST_REG(ID_AA64ISAR2_EL1, ftr_id_aa64isar2_el1),
+	TEST_REG(ID_AA64ISAR3_EL1, ftr_id_aa64isar3_el1),
+	TEST_REG(ID_AA64PFR0_EL1, ftr_id_aa64pfr0_el1),
+	TEST_REG(ID_AA64PFR1_EL1, ftr_id_aa64pfr1_el1),
+	TEST_REG(ID_AA64MMFR0_EL1, ftr_id_aa64mmfr0_el1),
+	TEST_REG(ID_AA64MMFR1_EL1, ftr_id_aa64mmfr1_el1),
+	TEST_REG(ID_AA64MMFR2_EL1, ftr_id_aa64mmfr2_el1),
+	TEST_REG(ID_AA64MMFR3_EL1, ftr_id_aa64mmfr3_el1),
+	TEST_REG(ID_AA64ZFR0_EL1, ftr_id_aa64zfr0_el1),
 };
 
 #define GUEST_REG_SYNC(id) GUEST_SYNC_ARGS(0, id, read_sysreg_s(id), 0, 0);
@@ -265,6 +267,34 @@ static void guest_code(void)
 	GUEST_DONE();
 }
 
+#define GUEST_READ_TEST (ARRAY_SIZE(test_regs) + 6)
+
+static const char *get_reg_name(u64 id)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(test_regs); i++)
+		if (test_regs[i].reg == id)
+			return test_regs[i].name;
+
+	switch (id) {
+	case SYS_MPIDR_EL1:
+		return "MPIDR_EL1";
+	case SYS_CLIDR_EL1:
+		return "CLIDR_EL1";
+	case SYS_CTR_EL0:
+		return "CTR_EL0";
+	case SYS_MIDR_EL1:
+		return "MIDR_EL1";
+	case SYS_REVIDR_EL1:
+		return "REVIDR_EL1";
+	case SYS_AIDR_EL1:
+		return "AIDR_EL1";
+	default:
+		TEST_FAIL("Unknown register");
+	}
+}
+
 /* Return a safe value to a given ftr_bits an ftr value */
 uint64_t get_safe_value(const struct reg_ftr_bits *ftr_bits, uint64_t ftr)
 {
@@ -635,6 +665,8 @@ static void test_guest_reg_read(struct kvm_vcpu *vcpu)
 {
 	bool done = false;
 	struct ucall uc;
+	uint64_t reg_id, expected_val, guest_val;
+	bool match;
 
 	while (!done) {
 		vcpu_run(vcpu);
@@ -645,8 +677,16 @@ static void test_guest_reg_read(struct kvm_vcpu *vcpu)
 			break;
 		case UCALL_SYNC:
 			/* Make sure the written values are seen by guest */
-			TEST_ASSERT_EQ(test_reg_vals[encoding_to_range_idx(uc.args[2])],
-				       uc.args[3]);
+			reg_id = uc.args[2];
+			guest_val = uc.args[3];
+			expected_val = test_reg_vals[encoding_to_range_idx(reg_id)];
+			match = expected_val == guest_val;
+			if (!match)
+				ksft_print_msg("%lx != %lx\n",
+					       expected_val, guest_val);
+			ksft_test_result(match,
+					 "%s value seen in guest\n",
+					 get_reg_name(reg_id));
 			break;
 		case UCALL_DONE:
 			done = true;
@@ -786,7 +826,7 @@ int main(void)
 
 	ksft_print_header();
 
-	test_cnt = 3 + MPAM_IDREG_TEST + MTE_IDREG_TEST;
+	test_cnt = 3 + MPAM_IDREG_TEST + MTE_IDREG_TEST + GUEST_READ_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++;

-- 
2.47.2