An error of ENOENT for the KVM_ARM_VCPU_INIT ioctl indicates that one of
the requested feature flags is not supported by the kernel/hardware.
Detect the case when KVM doesn't support the requested features and skip
the test rather than failing it.

Cc: Andrew Jones <redacted>
Signed-off-by: Oliver Upton <redacted>
---
Applies to 5.14-rc6. Tested by running all selftests on an Ampere Mt.
Jade system.

  .../testing/selftests/kvm/lib/aarch64/processor.c | 15 ++++++++++++++-
  1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/lib/aarch64/processor.c b/tools/testing/selftests/kvm/lib/aarch64/processor.c
index 632b74d6b3ca..b1064a0c5e62 100644
--- a/tools/testing/selftests/kvm/lib/aarch64/processor.c
+++ b/tools/testing/selftests/kvm/lib/aarch64/processor.c

@@ -216,6 +216,7 @@ void aarch64_vcpu_setup(struct kvm_vm *vm, int vcpuid, struct kvm_vcpu_init *ini
  {
  	struct kvm_vcpu_init default_init = { .target = -1, };
  	uint64_t sctlr_el1, tcr_el1;
+	int ret;
  
  	if (!init)
  		init = &default_init;

@@ -226,7 +227,19 @@ void aarch64_vcpu_setup(struct kvm_vm *vm, int vcpuid, struct kvm_vcpu_init *ini
  		init->target = preferred.target;
  	}
  
-	vcpu_ioctl(vm, vcpuid, KVM_ARM_VCPU_INIT, init);
+	ret = _vcpu_ioctl(vm, vcpuid, KVM_ARM_VCPU_INIT, init);
+
+	/*
+	 * Missing kernel feature support should result in skipping the test,
+	 * not failing it.
+	 */
+	if (ret && errno == ENOENT) {
+		print_skip("requested vCPU features not supported; skipping test.");
+		exit(KSFT_SKIP);
+	}
+
+	TEST_ASSERT(!ret, "KVM_ARM_VCPU_INIT failed, rc: %i errno: %i (%s)",
+		    ret, errno, strerror(errno));
  
  	/*
  	 * Enable FP/ASIMD to avoid trapping when accessing Q0-Q15