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.
