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>
