Re: [kvm-unit-tests PATCH v4 1/2] nSVM: Add helper to report fatal errors in guest

[Sean Christopherson <seanjc@google.com>]

On Thu, Apr 06, 2023, Mathias Krause wrote:
> On 05.04.23 22:51, Sean Christopherson wrote:
> > Add a helper macro to dedup nSVM test code that handles fatal errors
> > by reporting the failure, setting the test stage to a magic number, and
> > invoking VMMCALL to bail to the host and terminate.
> > 
> > Note, the V_TPR fails if report() is invoked.  Punt on the issue for
> > now as most users already report only failures, but leave a TODO for
> > future developers.
> > 
> > Signed-off-by: Sean Christopherson <seanjc@google.com>
> > ---
> >  x86/svm_tests.c | 127 ++++++++++++++++--------------------------------
> >  1 file changed, 42 insertions(+), 85 deletions(-)
> > 
> > diff --git a/x86/svm_tests.c b/x86/svm_tests.c
> > index 27ce47b4..e87db3fa 100644
> > --- a/x86/svm_tests.c
> > +++ b/x86/svm_tests.c
> > @@ -947,6 +947,21 @@ static bool lat_svm_insn_check(struct svm_test *test)
> >  	return true;
> >  }
> >  
> > +/*
> > + * Report failures from SVM guest code, and on failure, set the stage to -1 and
> > + * do VMMCALL to terminate the test (host side must treat -1 as "finished").
> > + * TODO: fix the tests that don't play nice with a straight report, e.g. the
> > + * V_TPR test fails if report() is invoked.
> > + */
> > +#define report_svm_guest(cond, test, fmt, args...)	\
> > +do {							\
> > +	if (!(cond)) {					\
> 
> > +		report_fail("why didn't my format '" fmt "' format?", ##args);\
>                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Debug artifact? Should probably be this instead (making use of C99):

Yes.  I'm just glad I posted the PG version and not the rated R version.