| Message ID | 20170703175853.1939-2-rkrcmar@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c index 567f7143b427..25e91aa81477 100644 --- a/x86/vmx_tests.c +++ b/x86/vmx_tests.c @@ -1354,10 +1354,10 @@ static void pml_main() report("PML - Dirty GPA Logging", vmx_get_test_stage() == 1); while (vmx_get_test_stage() == 1) { + vmcall(); *((u32 *)data_page2) = 0x1; if (count++ > PML_INDEX) break; - vmcall(); } report("PML Full Event", vmx_get_test_stage() == 2); }
Recent patches triggered an unexpected stage error. This happened because report() now adds one extra entry to the PML. The writes done during a page walk are logged into PML, which means that we are guaranteed to get multiple entries. The PML test adds 4 entries in each loop while waiting for the PML full event and unluckily, the one extra entry fills PML just before the vmcall (3 entries are added before checking the stage and one after). The vmcall then sees a wrong stage and exits. This solution makes sure that the PML exit will not happen between the check for stage and the vmcall. (It wastes the first vmcall, but the loop happens ~125 times anyway, so it's not a huge waste.) Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> --- x86/vmx_tests.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)