KVM: selftests: arm64: Test writes to MIDR,REVIDR,AIDR

Assert that MIDR_EL1, REVIDR_EL1, AIDR_EL1 are writable from userspace,
that the changed values are visible to guests, and that they are
preserved across a vCPU reset.

Signed-off-by: Sebastian Ott <sebott@redhat.com>
Link: https://lore.kernel.org/r/20250225005401.679536-6-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>

diff --git a/tools/testing/selftests/kvm/arm64/set_id_regs.c b/tools/testing/selftests/kvm/arm64/set_id_regs.c
index 217541fe653601a82697134c8d773e901a205cfe..1d65f4a09e6f3dfe8bbe2f03d337022d37dac22d 100644 (file)
--- a/tools/testing/selftests/kvm/arm64/set_id_regs.c
+++ b/tools/testing/selftests/kvm/arm64/set_id_regs.c
@@ -230,6 +230,9 @@ static void guest_code(void)
        GUEST_REG_SYNC(SYS_ID_AA64MMFR2_EL1);
        GUEST_REG_SYNC(SYS_ID_AA64ZFR0_EL1);
        GUEST_REG_SYNC(SYS_CTR_EL0);
+       GUEST_REG_SYNC(SYS_MIDR_EL1);
+       GUEST_REG_SYNC(SYS_REVIDR_EL1);
+       GUEST_REG_SYNC(SYS_AIDR_EL1);
 
        GUEST_DONE();
 }
@@ -609,18 +612,31 @@ static void test_ctr(struct kvm_vcpu *vcpu)
        test_reg_vals[encoding_to_range_idx(SYS_CTR_EL0)] = ctr;
 }
 
-static void test_vcpu_ftr_id_regs(struct kvm_vcpu *vcpu)
+static void test_id_reg(struct kvm_vcpu *vcpu, u32 id)
 {
        u64 val;
 
+       val = vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(id));
+       val++;
+       vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(id), val);
+       test_reg_vals[encoding_to_range_idx(id)] = val;
+}
+
+static void test_vcpu_ftr_id_regs(struct kvm_vcpu *vcpu)
+{
        test_clidr(vcpu);
        test_ctr(vcpu);
 
-       val = vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_MPIDR_EL1));
-       val++;
-       vcpu_set_reg(vcpu, KVM_ARM64_SYS_REG(SYS_MPIDR_EL1), val);
+       test_id_reg(vcpu, SYS_MPIDR_EL1);
+       ksft_test_result_pass("%s\n", __func__);
+}
+
+static void test_vcpu_non_ftr_id_regs(struct kvm_vcpu *vcpu)
+{
+       test_id_reg(vcpu, SYS_MIDR_EL1);
+       test_id_reg(vcpu, SYS_REVIDR_EL1);
+       test_id_reg(vcpu, SYS_AIDR_EL1);
 
-       test_reg_vals[encoding_to_range_idx(SYS_MPIDR_EL1)] = val;
        ksft_test_result_pass("%s\n", __func__);
 }
 
@@ -647,6 +663,9 @@ static void test_reset_preserves_id_regs(struct kvm_vcpu *vcpu)
        test_assert_id_reg_unchanged(vcpu, SYS_MPIDR_EL1);
        test_assert_id_reg_unchanged(vcpu, SYS_CLIDR_EL1);
        test_assert_id_reg_unchanged(vcpu, SYS_CTR_EL0);
+       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__);
 }
@@ -660,8 +679,11 @@ int main(void)
        int test_cnt;
 
        TEST_REQUIRE(kvm_has_cap(KVM_CAP_ARM_SUPPORTED_REG_MASK_RANGES));
+       TEST_REQUIRE(kvm_has_cap(KVM_CAP_ARM_WRITABLE_IMP_ID_REGS));
 
-       vm = vm_create_with_one_vcpu(&vcpu, guest_code);
+       vm = vm_create(1);
+       vm_enable_cap(vm, KVM_CAP_ARM_WRITABLE_IMP_ID_REGS, 0);
+       vcpu = vm_vcpu_add(vm, 0, guest_code);
 
        /* Check for AARCH64 only system */
        val = vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_ID_AA64PFR0_EL1));
@@ -675,13 +697,14 @@ int main(void)
                   ARRAY_SIZE(ftr_id_aa64isar2_el1) + ARRAY_SIZE(ftr_id_aa64pfr0_el1) +
                   ARRAY_SIZE(ftr_id_aa64pfr1_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) + 2 +
+                  ARRAY_SIZE(ftr_id_aa64zfr0_el1) - ARRAY_SIZE(test_regs) + 3 +
                   MPAM_IDREG_TEST;
 
        ksft_set_plan(test_cnt);
 
        test_vm_ftr_id_regs(vcpu, aarch64_only);
        test_vcpu_ftr_id_regs(vcpu);
+       test_vcpu_non_ftr_id_regs(vcpu);
        test_user_set_mpam_reg(vcpu);
 
        test_guest_reg_read(vcpu);