On Mon, May 11, 2026 at 07:56:50AM -0700, Sean Christopherson wrote: > On Mon, May 11, 2026, Piotr Zarycki wrote: > > Use KVM_SYNC_X86_VALID_FIELDS instead of open-coding the same three > > flags, ensuring the test stays in sync with any future additions. > > > > Signed-off-by: Piotr Zarycki <[email protected]> > > --- > > tools/testing/selftests/kvm/x86/sync_regs_test.c | 3 +-- > > 1 file changed, 1 insertion(+), 2 deletions(-) > > > > diff --git a/tools/testing/selftests/kvm/x86/sync_regs_test.c > > b/tools/testing/selftests/kvm/x86/sync_regs_test.c > > index e0c52321f87c..8f9239f9d357 100644 > > --- a/tools/testing/selftests/kvm/x86/sync_regs_test.c > > +++ b/tools/testing/selftests/kvm/x86/sync_regs_test.c > > @@ -79,7 +79,7 @@ static void compare_vcpu_events(struct kvm_vcpu_events > > *left, > > { > > } > > > > -#define TEST_SYNC_FIELDS > > (KVM_SYNC_X86_REGS|KVM_SYNC_X86_SREGS|KVM_SYNC_X86_EVENTS) > > +#define TEST_SYNC_FIELDS KVM_SYNC_X86_VALID_FIELDS > > Explicitly defining the set of fields to test is very deliberate. (a) we want > to detect ABI breakage, e.g. if KVM removes a valid field. (b) if a field is > added in the future, the test likely needs to be updated, i.e. would break if > KVM extends KVM_SYNC_X86_VALID_FIELDS. (c) KVM_SYNC_X86_VALID_FIELDS probably > shouldn't be defined in a uapi header; for all intents and purposes it's a > KVM- > internal details. > > > #define INVALID_SYNC_FIELD 0x80000000 > > > > /* > > @@ -255,7 +255,6 @@ KVM_ONE_VCPU_TEST(sync_regs_test, > > req_and_verify_all_valid, guest_code) > > struct kvm_regs regs; > > > > /* Request and verify all valid register sets. */ > > - /* TODO: BUILD TIME CHECK: TEST_ASSERT(KVM_SYNC_X86_NUM_FIELDS != 3); */ > > run->kvm_valid_regs = TEST_SYNC_FIELDS; > > vcpu_run(vcpu); > > TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO); > > -- > > 2.54.0 > >
Thanks for the explanation. What's the preferred way to implement the build-time check mentioned in the TODO?
