[PATCH v2] kselftest: kvm/arm64: Skip tests if we can't create a vgic-v3

[Mark Brown]

The arch_timer and vgic_irq kselftests assume that they can create a
vgic-v3, using the library function vgic_v3_setup() which aborts with a
test failure if it is not possible to do so. Since vgic-v3 can only be
instantiated on systems where the host has GICv3 this leads to false
positives on older systems where that is not the case.

Fix this by changing vgic_v3_setup() to return an error if the vgic can't
be instantiated and have the callers skip if this happens. We could also
exit flagging a skip in vgic_v3_setup() but this would prevent future test
cases conditionally deciding which GIC to use or generally doing more
complex output.

Signed-off-by: Mark Brown <broonie at kernel.org>
---

v2:
 - The test for being able to create the GIC doesn't actually
   instantiate it, add a call doing so in that case.

 tools/testing/selftests/kvm/aarch64/arch_timer.c | 7 ++++++-
 tools/testing/selftests/kvm/aarch64/vgic_irq.c   | 4 ++++
 tools/testing/selftests/kvm/lib/aarch64/vgic.c   | 5 ++++-
 3 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/kvm/aarch64/arch_timer.c b/tools/testing/selftests/kvm/aarch64/arch_timer.c
index 9ad38bd360a4..791d38404652 100644
--- a/tools/testing/selftests/kvm/aarch64/arch_timer.c
+++ b/tools/testing/selftests/kvm/aarch64/arch_timer.c
@@ -366,6 +366,7 @@ static struct kvm_vm *test_vm_create(void)
 {
 	struct kvm_vm *vm;
 	unsigned int i;
+	int ret;
 	int nr_vcpus = test_args.nr_vcpus;
 
 	vm = vm_create_default_with_vcpus(nr_vcpus, 0, 0, guest_code, NULL);
@@ -382,7 +383,11 @@ static struct kvm_vm *test_vm_create(void)
 
 	ucall_init(vm, NULL);
 	test_init_timer_irq(vm);
-	vgic_v3_setup(vm, nr_vcpus, 64, GICD_BASE_GPA, GICR_BASE_GPA);
+	ret = vgic_v3_setup(vm, nr_vcpus, 64, GICD_BASE_GPA, GICR_BASE_GPA);
+	if (ret < 0) {
+		pr_info("Failed to create vgic-v3, skipping\n");
+		exit(KSFT_SKIP);
+	}
 
 	/* Make all the test's cmdline args visible to the guest */
 	sync_global_to_guest(vm, test_args);
diff --git a/tools/testing/selftests/kvm/aarch64/vgic_irq.c b/tools/testing/selftests/kvm/aarch64/vgic_irq.c
index e6c7d7f8fbd1..b127a261fd29 100644
--- a/tools/testing/selftests/kvm/aarch64/vgic_irq.c
+++ b/tools/testing/selftests/kvm/aarch64/vgic_irq.c
@@ -761,6 +761,10 @@ static void test_vgic(uint32_t nr_irqs, bool level_sensitive, bool eoi_split)
 
 	gic_fd = vgic_v3_setup(vm, 1, nr_irqs,
 			GICD_BASE_GPA, GICR_BASE_GPA);
+	if (gic_fd < 0) {
+		pr_info("Failed to create vgic-v3, skipping\n");
+		exit(KSFT_SKIP);
+	}
 
 	vm_install_exception_handler(vm, VECTOR_IRQ_CURRENT,
 		guest_irq_handlers[args.eoi_split][args.level_sensitive]);
diff --git a/tools/testing/selftests/kvm/lib/aarch64/vgic.c b/tools/testing/selftests/kvm/lib/aarch64/vgic.c
index b3a0fca0d780..4ea65e119bdd 100644
--- a/tools/testing/selftests/kvm/lib/aarch64/vgic.c
+++ b/tools/testing/selftests/kvm/lib/aarch64/vgic.c
@@ -51,7 +51,10 @@ int vgic_v3_setup(struct kvm_vm *vm, unsigned int nr_vcpus, uint32_t nr_irqs,
 			"Number of vCPUs requested (%u) doesn't match with the ones created for the VM (%u)\n",
 			nr_vcpus, nr_vcpus_created);
 
-	/* Distributor setup */
+	/* Distributor setup - test if it's possible then actually do it */
+	gic_fd = kvm_create_device(vm, KVM_DEV_TYPE_ARM_VGIC_V3, true);
+	if (gic_fd != 0)
+		return -1;
 	gic_fd = kvm_create_device(vm, KVM_DEV_TYPE_ARM_VGIC_V3, false);
 
 	kvm_device_access(gic_fd, KVM_DEV_ARM_VGIC_GRP_NR_IRQS,
-- 
2.30.2