[PATCH 2/2] KVM: arm64: selftests: Test empty SMCCC filter range at base 0

[Karl Mehltretter]

test_invalid_nr_functions() only checks an empty range at
PSCI_0_2_FN64_CPU_ON, which KVM's end < start check happens to catch.
It never exercised base 0, where the inclusive end wraps to U32_MAX
instead.

Add the base 0 case. Without the preceding fix it fails with EEXIST.

Assisted-by: LLM
Signed-off-by: Karl Mehltretter <kmehltretter@xxxxxxxxx>
---
 tools/testing/selftests/kvm/arm64/smccc_filter.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/testing/selftests/kvm/arm64/smccc_filter.c b/tools/testing/selftests/kvm/arm64/smccc_filter.c
index 21e41880261b..a41ed3e016ba 100644
--- a/tools/testing/selftests/kvm/arm64/smccc_filter.c
+++ b/tools/testing/selftests/kvm/arm64/smccc_filter.c
@@ -140,6 +140,10 @@ static void test_invalid_nr_functions(void)
 	TEST_ASSERT(r < 0 && errno == EINVAL,
 		    "Attempt to filter 0 functions should return EINVAL");
 
+	r = __set_smccc_filter(vm, 0, 0, KVM_SMCCC_FILTER_DENY);
+	TEST_ASSERT(r < 0 && errno == EINVAL,
+		    "Attempt to filter 0 functions at base 0 should return EINVAL");
+
 	kvm_vm_free(vm);
 }
 
-- 
2.39.5 (Apple Git-154)