KVM: selftests: Add test cases for unsupported PMU event filter input values

Add test cases to verify the handling of unsupported input values for the
PMU event filter. The tests cover unsupported "action" values, unsupported
"flags" values, and unsupported "nevents" values. All these cases should
return an error, as they are currently not supported by the filter.
Furthermore, the tests also cover the case where setting non-existent
fixed counters in the fixed bitmap does not fail.

Signed-off-by: Jinrong Liang <cloudliang@tencent.com>
Reviewed-by: Isaku Yamahata <isaku.yamahata@intel.com>
Link: https://lore.kernel.org/r/20230810090945.16053-5-cloudliang@tencent.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: Jinrong Liang

tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c

@@ -32,6 +32,10 @@
 #define MAX_FILTER_EVENTS		300
 #define MAX_TEST_EVENTS		10
 
+#define PMU_EVENT_FILTER_INVALID_ACTION		(KVM_PMU_EVENT_DENY + 1)
+#define PMU_EVENT_FILTER_INVALID_FLAGS			(KVM_PMU_EVENT_FLAGS_VALID_MASK << 1)
+#define PMU_EVENT_FILTER_INVALID_NEVENTS		(MAX_FILTER_EVENTS + 1)
+
 /*
  * This is how the event selector and unit mask are stored in an AMD
  * core performance event-select register. Intel's format is similar,
@@ -760,6 +764,8 @@ static int set_pmu_single_event_filter(struct kvm_vcpu *vcpu, uint64_t event,
 
 static void test_filter_ioctl(struct kvm_vcpu *vcpu)
 {
+	uint8_t nr_fixed_counters = kvm_cpu_property(X86_PROPERTY_PMU_NR_FIXED_COUNTERS);
+	struct __kvm_pmu_event_filter f;
 	uint64_t e = ~0ul;
 	int r;
 
@@ -780,6 +786,26 @@ static void test_filter_ioctl(struct kvm_vcpu *vcpu)
 					KVM_PMU_EVENT_FLAG_MASKED_EVENTS,
 					KVM_PMU_EVENT_ALLOW);
 	TEST_ASSERT(r == 0, "Valid PMU Event Filter is failing");
+
+	f = base_event_filter;
+	f.action = PMU_EVENT_FILTER_INVALID_ACTION;
+	r = set_pmu_event_filter(vcpu, &f);
+	TEST_ASSERT(r, "Set invalid action is expected to fail");
+
+	f = base_event_filter;
+	f.flags = PMU_EVENT_FILTER_INVALID_FLAGS;
+	r = set_pmu_event_filter(vcpu, &f);
+	TEST_ASSERT(r, "Set invalid flags is expected to fail");
+
+	f = base_event_filter;
+	f.nevents = PMU_EVENT_FILTER_INVALID_NEVENTS;
+	r = set_pmu_event_filter(vcpu, &f);
+	TEST_ASSERT(r, "Exceeding the max number of filter events should fail");
+
+	f = base_event_filter;
+	f.fixed_counter_bitmap = ~GENMASK_ULL(nr_fixed_counters, 0);
+	r = set_pmu_event_filter(vcpu, &f);
+	TEST_ASSERT(!r, "Masking non-existent fixed counters should be allowed");
 }
 
 int main(int argc, char *argv[])