KVM: selftests: Verify that KVM returns the configured APIC cycle length

Add checks in the APIC bus clock test to verify that querying
KVM_CAP_X86_APIC_BUS_CYCLES_NS on the VM after changing the frequency
returns the VM's actual APIC cycle length, not KVM's default.  For
giggles, verify that KVM still returns its default frequency for the
system-scoped check.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260522173526.3539407-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/tools/testing/selftests/kvm/x86/apic_bus_clock_test.c b/tools/testing/selftests/kvm/x86/apic_bus_clock_test.c
index 404f0028e110ef12bdd433624b716cd9f158a007..0c84c27ea584776b90b874bab45ca26bffdf2de7 100644 (file)
--- a/tools/testing/selftests/kvm/x86/apic_bus_clock_test.c
+++ b/tools/testing/selftests/kvm/x86/apic_bus_clock_test.c
@@ -137,6 +137,10 @@ static void run_apic_bus_clock_test(u64 apic_hz, u64 delay_ms,
        vm_enable_cap(vm, KVM_CAP_X86_APIC_BUS_CYCLES_NS,
                      NSEC_PER_SEC / apic_hz);
 
+       TEST_ASSERT_EQ(kvm_check_cap(KVM_CAP_X86_APIC_BUS_CYCLES_NS), 1);
+       TEST_ASSERT_EQ(vm_check_cap(vm, KVM_CAP_X86_APIC_BUS_CYCLES_NS),
+                      NSEC_PER_SEC / apic_hz);
+
        vcpu = vm_vcpu_add(vm, 0, apic_guest_code);
        vcpu_args_set(vcpu, 2, apic_hz, delay_ms);