KVM: arm64: selftests: Add helper to check for VGICv3 support

Introduce a proper predicate for probing VGICv3 by performing a 'test'
creation of the device on a dummy VM.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>

tools/testing/selftests/kvm/arm64/arch_timer.c

@@ -184,6 +184,8 @@ struct kvm_vm *test_vm_create(void)
 	unsigned int i;
 	int nr_vcpus = test_args.nr_vcpus;
 
+	TEST_REQUIRE(kvm_supports_vgic_v3());
+
 	vm = vm_create_with_vcpus(nr_vcpus, guest_code, vcpus);
 
 	vm_init_descriptor_tables(vm);
@@ -205,7 +207,6 @@ struct kvm_vm *test_vm_create(void)
 
 	test_init_timer_irq(vm);
 	gic_fd = vgic_v3_setup(vm, nr_vcpus, 64);
-	__TEST_REQUIRE(gic_fd >= 0, "Failed to create vgic-v3");
 
 	/* Make all the test's cmdline args visible to the guest */
 	sync_global_to_guest(vm, test_args);

tools/testing/selftests/kvm/arm64/arch_timer_edge_cases.c

@@ -952,7 +952,6 @@ static void test_vm_create(struct kvm_vm **vm, struct kvm_vcpu **vcpu,
 
 	test_init_timer_irq(*vm, *vcpu);
 	gic_fd = vgic_v3_setup(*vm, 1, 64);
-	__TEST_REQUIRE(gic_fd >= 0, "Failed to create vgic-v3");
 
 	sync_global_to_guest(*vm, test_args);
 	sync_global_to_guest(*vm, CVAL_MAX);
@@ -1042,6 +1041,8 @@ int main(int argc, char *argv[])
 	/* Tell stdout not to buffer its content */
 	setbuf(stdout, NULL);
 
+	TEST_REQUIRE(kvm_supports_vgic_v3());
+
 	if (!parse_args(argc, argv))
 		exit(KSFT_SKIP);
 

tools/testing/selftests/kvm/arm64/vgic_irq.c

@@ -752,7 +752,6 @@ static void test_vgic(uint32_t nr_irqs, bool level_sensitive, bool eoi_split)
 	vcpu_args_set(vcpu, 1, args_gva);
 
 	gic_fd = vgic_v3_setup(vm, 1, nr_irqs);
-	__TEST_REQUIRE(gic_fd >= 0, "Failed to create vgic-v3, skipping");
 
 	vm_install_exception_handler(vm, VECTOR_IRQ_CURRENT,
 		guest_irq_handlers[args.eoi_split][args.level_sensitive]);
@@ -802,6 +801,8 @@ int main(int argc, char **argv)
 	int opt;
 	bool eoi_split = false;
 
+	TEST_REQUIRE(kvm_supports_vgic_v3());
+
 	while ((opt = getopt(argc, argv, "hn:e:l:")) != -1) {
 		switch (opt) {
 		case 'n':

tools/testing/selftests/kvm/arm64/vgic_lpi_stress.c

@@ -215,8 +215,6 @@ static void setup_test_data(void)
 static void setup_gic(void)
 {
 	gic_fd = vgic_v3_setup(vm, test_data.nr_cpus, 64);
-	__TEST_REQUIRE(gic_fd >= 0, "Failed to create GICv3");
-
 	its_fd = vgic_its_setup(vm);
 }
 
@@ -374,6 +372,8 @@ int main(int argc, char **argv)
 	u32 nr_threads;
 	int c;
 
+	TEST_REQUIRE(kvm_supports_vgic_v3());
+
 	while ((c = getopt(argc, argv, "hv:d:e:i:")) != -1) {
 		switch (c) {
 		case 'v':

tools/testing/selftests/kvm/arm64/vpmu_counter_access.c

@@ -436,8 +436,6 @@ static void create_vpmu_vm(void *guest_code)
 	vpmu_vm.vcpu = aarch64_vcpu_add(vpmu_vm.vm, 0, &init, guest_code);
 	vcpu_init_descriptor_tables(vpmu_vm.vcpu);
 	vpmu_vm.gic_fd = vgic_v3_setup(vpmu_vm.vm, 1, 64);
-	__TEST_REQUIRE(vpmu_vm.gic_fd >= 0,
-		       "Failed to create vgic-v3, skipping");
 
 	/* Make sure that PMUv3 support is indicated in the ID register */
 	dfr0 = vcpu_get_reg(vpmu_vm.vcpu, KVM_ARM64_SYS_REG(SYS_ID_AA64DFR0_EL1));
@@ -634,6 +632,7 @@ int main(void)
 	uint64_t i, pmcr_n;
 
 	TEST_REQUIRE(kvm_has_cap(KVM_CAP_ARM_PMU_V3));
+	TEST_REQUIRE(kvm_supports_vgic_v3());
 
 	pmcr_n = get_pmcr_n_limit();
 	for (i = 0; i <= pmcr_n; i++) {

tools/testing/selftests/kvm/include/arm64/vgic.h

@@ -16,6 +16,7 @@
 	((uint64_t)(flags) << 12) | \
 	index)
 
+bool kvm_supports_vgic_v3(void);
 int vgic_v3_setup(struct kvm_vm *vm, unsigned int nr_vcpus, uint32_t nr_irqs);
 
 #define VGIC_MAX_RESERVED	1023

tools/testing/selftests/kvm/lib/arm64/vgic.c

@@ -15,6 +15,17 @@
 #include "gic.h"
 #include "gic_v3.h"
 
+bool kvm_supports_vgic_v3(void)
+{
+	struct kvm_vm *vm = vm_create_barebones();
+	int r;
+
+	r = __kvm_test_create_device(vm, KVM_DEV_TYPE_ARM_VGIC_V3);
+	kvm_vm_free(vm);
+
+	return !r;
+}
+
 /*
  * vGIC-v3 default host setup
  *