[PATCH 6/7] KVM: arm64: Test that feature ID regs survive a reset

Oliver Upton
2024-05-02T23:35:50Z

One of the expectations with feature ID registers is that their values
survive a vCPU reset. Start testing that.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
.../selftests/kvm/aarch64/set_id_regs.c | 41 +++++++++++++++----
1 file changed, 33 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/kvm/aarch64/set_id_regs.c b/tools/testing/selftests/kvm/aarch64/set_id_regs.c
index 7c8d33fa2ae6..24b248c78f5d 100644
--- a/tools/testing/selftests/kvm/aarch64/set_id_regs.c
+++ b/tools/testing/selftests/kvm/aarch64/set_id_regs.c
@@ -457,13 +457,36 @@ static void test_guest_reg_read(struct kvm_vcpu *vcpu)
}
}

+static void test_assert_id_reg_unchanged(struct kvm_vcpu *vcpu, uint32_t encoding)
+{
+ size_t idx = encoding_to_range_idx(encoding);
+ uint64_t observed;
+
+ vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(encoding), &observed);
+ TEST_ASSERT_EQ(test_reg_vals[idx], observed);
+}
+
+static void test_reset_preserves_id_regs(struct kvm_vcpu *vcpu)
+{
+ /*
+ * Calls KVM_ARM_VCPU_INIT behind the scenes, which will do an
+ * architectural reset of the vCPU.
+ */
+ aarch64_vcpu_setup(vcpu, NULL);
+
+ for (int i = 0; i < ARRAY_SIZE(test_regs); i++)
+ test_assert_id_reg_unchanged(vcpu, test_regs[i].reg);
+
+ ksft_test_result_pass("%s\n", __func__);
+}
+
int main(void)
{
struct kvm_vcpu *vcpu;
struct kvm_vm *vm;
bool aarch64_only;
uint64_t val, el0;
- int ftr_cnt;
+ int test_cnt;

TEST_REQUIRE(kvm_has_cap(KVM_CAP_ARM_SUPPORTED_REG_MASK_RANGES));

@@ -476,18 +499,20 @@ int main(void)

ksft_print_header();

- ftr_cnt = ARRAY_SIZE(ftr_id_aa64dfr0_el1) + ARRAY_SIZE(ftr_id_dfr0_el1) +
- ARRAY_SIZE(ftr_id_aa64isar0_el1) + ARRAY_SIZE(ftr_id_aa64isar1_el1) +
- ARRAY_SIZE(ftr_id_aa64isar2_el1) + ARRAY_SIZE(ftr_id_aa64pfr0_el1) +
- ARRAY_SIZE(ftr_id_aa64mmfr0_el1) + ARRAY_SIZE(ftr_id_aa64mmfr1_el1) +
- ARRAY_SIZE(ftr_id_aa64mmfr2_el1) + ARRAY_SIZE(ftr_id_aa64zfr0_el1) -
- ARRAY_SIZE(test_regs);
+ test_cnt = ARRAY_SIZE(ftr_id_aa64dfr0_el1) + ARRAY_SIZE(ftr_id_dfr0_el1) +
+ ARRAY_SIZE(ftr_id_aa64isar0_el1) + ARRAY_SIZE(ftr_id_aa64isar1_el1) +
+ ARRAY_SIZE(ftr_id_aa64isar2_el1) + ARRAY_SIZE(ftr_id_aa64pfr0_el1) +
+ ARRAY_SIZE(ftr_id_aa64mmfr0_el1) + ARRAY_SIZE(ftr_id_aa64mmfr1_el1) +
+ ARRAY_SIZE(ftr_id_aa64mmfr2_el1) + ARRAY_SIZE(ftr_id_aa64zfr0_el1) -
+ ARRAY_SIZE(test_regs) + 1;

- ksft_set_plan(ftr_cnt);
+ ksft_set_plan(test_cnt);

test_vm_ftr_id_regs(vcpu, aarch64_only);
test_guest_reg_read(vcpu);

+ test_reset_preserves_id_regs(vcpu);
+
kvm_vm_free(vm);

ksft_finished();