On Sat, Jan 25, 2020 at 11:16 PM Krish Sadhukhan
<krish.sadhukhan@xxxxxxxxxx> wrote:
>
>
> On 1/24/20 3:46 PM, Sean Christopherson wrote:
> > Snapshot the delta of the last run and display it in the report if the
> > test fails. Abort the run loop as soon as the threshold is reached so
> > that the displayed delta is guaranteed to a failed delta. Displaying
> > the delta helps triage failures, e.g. is my system completely broken or
> > did I get unlucky, and aborting the loop early saves 99900 runs when
> > the system is indeed broken.
> >
> > Cc: Nadav Amit <nadav.amit@xxxxxxxxx>
> > Cc: Aaron Lewis <aaronlewis@xxxxxxxxxx>
> > Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
> > ---
> > x86/vmx_tests.c | 11 ++++++-----
> > 1 file changed, 6 insertions(+), 5 deletions(-)
> >
> > diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c
> > index b31c360..4049dec 100644
> > --- a/x86/vmx_tests.c
> > +++ b/x86/vmx_tests.c
> > @@ -9204,6 +9204,7 @@ static unsigned long long rdtsc_vmexit_diff_test_iteration(void)
> >
> > static void rdtsc_vmexit_diff_test(void)
> > {
> > + unsigned long long delta;
> > int fail = 0;
> > int i;
> >
> > @@ -9226,17 +9227,17 @@ static void rdtsc_vmexit_diff_test(void)
> > vmcs_write(EXI_MSR_ST_CNT, 1);
> > vmcs_write(EXIT_MSR_ST_ADDR, virt_to_phys(exit_msr_store));
> >
> > - for (i = 0; i < RDTSC_DIFF_ITERS; i++) {
> > - if (rdtsc_vmexit_diff_test_iteration() >=
> > - HOST_CAPTURED_GUEST_TSC_DIFF_THRESHOLD)
> > + for (i = 0; i < RDTSC_DIFF_ITERS && fail < RDTSC_DIFF_FAILS; i++) {
> > + delta = rdtsc_vmexit_diff_test_iteration();
> > + if (delta >= HOST_CAPTURED_GUEST_TSC_DIFF_THRESHOLD)
> > fail++;
> > }
> >
> > enter_guest();
> >
> > report(fail < RDTSC_DIFF_FAILS,
> > - "RDTSC to VM-exit delta too high in %d of %d iterations",
> > - fail, RDTSC_DIFF_ITERS);
> > + "RDTSC to VM-exit delta too high in %d of %d iterations, last = %llu",
> > + fail, i, delta);
> > }
> >
> > static int invalid_msr_init(struct vmcs *vmcs)
> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
Reviewed-by: Aaron Lewis <aaronlewis@xxxxxxxxxx>
