KVM: selftests: Reject GICv3 ITS with a GICv5 VGIC

Check that a GICv3 ITS and a GICv5 VGIC cannot be paired, regardless
of which device is created first. Skip the check when the host does not
expose a GICv3 ITS.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Fuad Tabba <fuad.tabba@linux.dev>
Link: https://patch.msgid.link/20261020163923.1407856-3-sascha.bischoff@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>

1 files changed, 32 insertions, 0 deletions

diff --git a/tools/testing/selftests/kvm/arm64/vgic_v5.c b/tools/testing/selftests/kvm/arm64/vgic_v5.c
index d5df742b2300..5bf7d99d2914 100644
--- a/tools/testing/selftests/kvm/arm64/vgic_v5.c
+++ b/tools/testing/selftests/kvm/arm64/vgic_v5.c
@@ -2003,8 +2003,40 @@ int test_kvm_device(u32 gic_dev_type)
 	return 0;
 }
 
+static void test_vgic_v3_its_with_vgic_v5(void)
+{
+	struct kvm_vm *vm = vm_create_barebones();
+	int gic_fd, its_fd, ret;
+
+	if (__kvm_test_create_device(vm, KVM_DEV_TYPE_ARM_VGIC_ITS)) {
+		pr_info("No GICv3 ITS support; skipping mixed-model test.\n");
+		kvm_vm_free(vm);
+		return;
+	}
+
+	gic_fd = kvm_create_device(vm, KVM_DEV_TYPE_ARM_VGIC_V5);
+	ret = __kvm_create_device(vm, KVM_DEV_TYPE_ARM_VGIC_ITS);
+	TEST_ASSERT(ret < 0 && errno == ENODEV,
+		    "GICv3 ITS created after GICv5 VGIC: ret=%d errno=%d",
+		    ret, errno);
+	close(gic_fd);
+	kvm_vm_free(vm);
+
+	vm = vm_create_barebones();
+	its_fd = kvm_create_device(vm, KVM_DEV_TYPE_ARM_VGIC_ITS);
+	ret = __kvm_create_device(vm, KVM_DEV_TYPE_ARM_VGIC_V5);
+	TEST_ASSERT(ret < 0 && errno == ENODEV,
+		    "GICv5 VGIC created after GICv3 ITS: ret=%d errno=%d",
+		    ret, errno);
+	close(its_fd);
+	kvm_vm_free(vm);
+}
+
 void run_tests(u32 gic_dev_type)
 {
+	pr_info("Test VGICv5 and GICv3 ITS model mismatch\n");
+	test_vgic_v3_its_with_vgic_v5();
+
 	pr_info("Test VGICv5 address attrs\n");
 	test_vgic_v5_addr_attrs();