If I had to guess, you probably have SMM malware on your host. Remove
the malware, and the test should pass.
On Fri, Jan 24, 2020 at 4:06 PM Nadav Amit <nadav.amit@xxxxxxxxx> wrote:
>
> > On Jan 24, 2020, at 3:38 PM, Sean Christopherson <sean.j.christopherson@xxxxxxxxx> wrote:
> >
> > On Fri, Jan 24, 2020 at 03:13:44PM -0800, Nadav Amit wrote:
> >>> On Dec 2, 2019, at 12:43 PM, Aaron Lewis <aaronlewis@xxxxxxxxxx> wrote:
> >>>
> >>> Verify that the difference between a guest RDTSC instruction and the
> >>> IA32_TIME_STAMP_COUNTER MSR value stored in the VMCS12's VM-exit
> >>> MSR-store list is less than 750 cycles, 99.9% of the time.
> >>>
> >>> 662f1d1d1931 ("KVM: nVMX: Add support for capturing highest observable L2 TSC”)
> >>>
> >>> Signed-off-by: Aaron Lewis <aaronlewis@xxxxxxxxxx>
> >>> Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx>
> >>
> >> Running this test on bare-metal I get:
> >>
> >> Test suite: rdtsc_vmexit_diff_test
> >> FAIL: RDTSC to VM-exit delta too high in 117 of 100000 iterations
> >>
> >> Any idea why? Should I just play with the 750 cycles magic number?
> >
> > Argh, this reminds me that I have a patch for this test to improve the
> > error message to makes things easier to debug. Give me a few minutes to
> > get it sent out, might help a bit.
>
> Thanks for the quick response. With this patch I get on my bare-metal Skylake:
>
> FAIL: RDTSC to VM-exit delta too high in 100 of 49757 iterations, last = 1152
> FAIL: Guest didn't run to completion.
>
> I’ll try to raise the delta and see what happens.
>
> Sorry for my laziness - it is just that like ~30% of the tests that are
> added fail on bare-metal :(
>
