KVM: selftests: use unified time type for comparison

With test case kvm_page_table_test, start time is acquired with
time type CLOCK_MONOTONIC_RAW, however end time in timespec_elapsed()
is acquired with time type CLOCK_MONOTONIC. This can cause inaccurate
elapsed time calculation due to mixing timebases, e.g. LoongArch in
particular will see weirdness.

Modify kvm_page_table_test to use unified time type CLOCK_MONOTONIC for
start time.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20230731022405.854884-1-maobibo@loongson.cn
[sean: massage changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/tools/testing/selftests/kvm/kvm_page_table_test.c b/tools/testing/selftests/kvm/kvm_page_table_test.c
index b3b00be..69f26d8 100644 (file)
--- a/tools/testing/selftests/kvm/kvm_page_table_test.c
+++ b/tools/testing/selftests/kvm/kvm_page_table_test.c
@@ -200,7 +200,7 @@ static void *vcpu_worker(void *data)
                if (READ_ONCE(host_quit))
                        return NULL;
 
-               clock_gettime(CLOCK_MONOTONIC_RAW, &start);
+               clock_gettime(CLOCK_MONOTONIC, &start);
                ret = _vcpu_run(vcpu);
                ts_diff = timespec_elapsed(start);
 
@@ -367,7 +367,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
        /* Test the stage of KVM creating mappings */
        *current_stage = KVM_CREATE_MAPPINGS;
 
-       clock_gettime(CLOCK_MONOTONIC_RAW, &start);
+       clock_gettime(CLOCK_MONOTONIC, &start);
        vcpus_complete_new_stage(*current_stage);
        ts_diff = timespec_elapsed(start);
 
@@ -380,7 +380,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 
        *current_stage = KVM_UPDATE_MAPPINGS;
 
-       clock_gettime(CLOCK_MONOTONIC_RAW, &start);
+       clock_gettime(CLOCK_MONOTONIC, &start);
        vcpus_complete_new_stage(*current_stage);
        ts_diff = timespec_elapsed(start);
 
@@ -392,7 +392,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 
        *current_stage = KVM_ADJUST_MAPPINGS;
 
-       clock_gettime(CLOCK_MONOTONIC_RAW, &start);
+       clock_gettime(CLOCK_MONOTONIC, &start);
        vcpus_complete_new_stage(*current_stage);
        ts_diff = timespec_elapsed(start);