KVM: selftests: Track unavailable_mask for PMU events as 32-bit value

Track the mask of "unavailable" PMU events as a 32-bit value. While bits
31:9 are currently reserved, silently truncating those bits is unnecessary
and asking for missed coverage. To avoid running afoul of the sanity check
in vcpu_set_cpuid_property(), explicitly adjust the mask based on the
non-reserved bits as reported by KVM's supported CPUID.

Opportunistically update the "all ones" testcase to pass -1u instead of
0xff.

Reviewed-by: Dapeng Mi <[e-mail]>
Tested-by: Dapeng Mi <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Sean Christopherson <[e-mail]>

tools/testing/selftests/kvm/x86/pmu_counters_test.c

···
 }
 
 static void test_arch_events(uint8_t pmu_version, uint64_t perf_capabilities,
-			     uint8_t length, uint8_t unavailable_mask)
+			     uint8_t length, uint32_t unavailable_mask)
 {
 	struct kvm_vcpu *vcpu;
 	struct kvm_vm *vm;
···
 	/* Testing arch events requires a vPMU (there are no negative tests). */
 	if (!pmu_version)
 		return;
+
+	unavailable_mask &= GENMASK(X86_PROPERTY_PMU_EVENTS_MASK.hi_bit,
+				    X86_PROPERTY_PMU_EVENTS_MASK.lo_bit);
 
 	vm = pmu_vm_create_with_one_vcpu(&vcpu, guest_test_arch_events,
 					 pmu_version, perf_capabilities);
···
 			 */
 			for (j = 0; j <= NR_INTEL_ARCH_EVENTS + 1; j++) {
 				test_arch_events(v, perf_caps[i], j, 0);
-				test_arch_events(v, perf_caps[i], j, 0xff);
+				test_arch_events(v, perf_caps[i], j, -1u);
 
 				for (k = 0; k < NR_INTEL_ARCH_EVENTS; k++)
 					test_arch_events(v, perf_caps[i], j, BIT(k));