This patch implements the following tests for kvmclock:
- A simple wall clock test to check whether a consistent value was
returned.
- A monotonic cycle test to check whether the kvmclock driver could
return monotnic cycles in SMP guests.
- A raw cycle test to check whether the hypervios could provide
monotonic cycles.
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
kvm/test/x86/kvmclock_test.c | 128 ++++++++++++++++++++++++++++++++++++++++++
kvm/test/x86/unittests.cfg | 4 +
2 files changed, 132 insertions(+), 0 deletions(-)
create mode 100644 kvm/test/x86/kvmclock_test.c
diff --git a/kvm/test/config-x86-common.mak b/kvm/test/config-x86-common.mak
index a6ee18c..3dfd450 100644
--- a/kvm/test/config-x86-common.mak
+++ b/kvm/test/config-x86-common.mak
@@ -25,7 +25,8 @@ FLATLIBS = lib/libcflat.a $(libgcc)
tests-common = $(TEST_DIR)/vmexit.flat $(TEST_DIR)/tsc.flat \
$(TEST_DIR)/smptest.flat $(TEST_DIR)/port80.flat \
$(TEST_DIR)/realmode.flat $(TEST_DIR)/msr.flat \
- $(TEST_DIR)/hypercall.flat $(TEST_DIR)/sieve.flat
+ $(TEST_DIR)/hypercall.flat $(TEST_DIR)/sieve.flat \
+ $(TEST_DIR)/kvmclock_test.flat
tests_and_config = $(TEST_DIR)/*.flat $(TEST_DIR)/unittests.cfg
@@ -67,6 +68,9 @@ $(TEST_DIR)/xsave.flat: $(cstart.o) $(TEST_DIR)/idt.o $(TEST_DIR)/xsave.o
$(TEST_DIR)/rmap_chain.flat: $(cstart.o) $(TEST_DIR)/rmap_chain.o \
$(TEST_DIR)/vm.o
+$(TEST_DIR)/kvmclock_test.flat: $(cstart.o) $(TEST_DIR)/kvmclock.o \
+ $(TEST_DIR)/kvmclock_test.o
+
arch_clean:
$(RM) $(TEST_DIR)/*.o $(TEST_DIR)/*.flat \
$(TEST_DIR)/.*.d $(TEST_DIR)/lib/.*.d $(TEST_DIR)/lib/*.o
diff --git a/kvm/test/x86/kvmclock_test.c b/kvm/test/x86/kvmclock_test.c
new file mode 100644
index 0000000..8530a89
--- /dev/null
+++ b/kvm/test/x86/kvmclock_test.c
@@ -0,0 +1,128 @@
+#include "libcflat.h"
+#include "smp.h"
+#include "kvmclock.h"
+
+#define TEST_LOOPS 100000000
+
+static inline int atomic_read(int *v)
+{
+ return (*(volatile int *)&(v));
+}
+
+static inline void atomic_dec(int *v)
+{
+ asm volatile("lock decl %0": "+m" (*v));
+}
+
+struct test_info {
+ struct spinlock lock;
+ u64 loops; /* test loops */
+ u64 warps; /* warp count */
+ long long worst; /* worst warp */
+ volatile cycle_t last; /* last cycle seen by test */
+ int ncpus; /* number of cpu in the test*/
+};
+
+struct test_info ti[2];
+
+static int wallclock_test()
+{
+ int i;
+ struct timespec ts, ts_last;
+
+ kvm_get_wallclock(&ts_last);
+
+ for (i=0; i < 100; i++){
+ kvm_get_wallclock(&ts);
+ if (ts.nsec != ts_last.nsec || ts.sec != ts_last.sec){
+ printf ("Inconsistent wall clock returned!\n");
+ return 1;
+ }
+ }
+ return 0;
+}
+
+static void kvm_clock_test(void *data)
+{
+ struct test_info *hv_test_info = (struct test_info *)data;
+ int index = smp_id();
+ int i;
+
+ for (i = 0; i < hv_test_info->loops; i++){
+ cycle_t t0, t1;
+ long long delta;
+
+ spin_lock(&hv_test_info->lock);
+ t1 = kvm_clock_read();
+ t0 = hv_test_info->last;
+ hv_test_info->last = kvm_clock_read();
+ spin_unlock(&hv_test_info->lock);
+
+ delta = t1 - t0;
+ if (delta < 0){
+ spin_lock(&hv_test_info->lock);
+ ++hv_test_info->warps;
+ if (delta < hv_test_info->worst){
+ hv_test_info->worst = delta;
+ printf("Worst warp %lld %\n", hv_test_info->worst);
+ }
+ spin_unlock(&hv_test_info->lock);
+ }
+
+ if (!((unsigned long)i & 31))
+ asm volatile("rep; nop");
+ }
+
+ atomic_dec(&hv_test_info->ncpus);
+}
+
+static int cycle_test(int ncpus, int loops, struct test_info *ti)
+{
+ int i;
+
+ ti->ncpus = ncpus;
+ ti->loops = loops;
+ for (i = ncpus - 1; i >= 0; --i)
+ on_cpu_async(i, kvm_clock_test, (void *)ti);
+
+ /* Wait for the end of other vcpu */
+ while(!atomic_read(&ti->ncpus))
+ ;
+
+ printf("Total vcpus: %d\n", ncpus);
+ printf("Total loops: %lld\n", ti->loops * ncpus);
+ printf("Total warps: %lld\n", ti->warps);
+ printf("Worst warp: %lld\n", ti->worst);
+
+ return ti->warps ? 1 : 0;
+}
+
+int main()
+{
+ int ncpus = cpu_count();
+ int nerr = 0, i;
+
+ smp_init();
+
+ if (ncpus > MAX_CPU)
+ ncpus = MAX_CPU;
+ for (i = 0; i < ncpus; ++i)
+ on_cpu(i, kvm_clock_init, (void *)0);
+
+ printf("Wallclock test:\n");
+ nerr += wallclock_test();
+
+ pvclock_set_flags(PVCLOCK_TSC_STABLE_BIT);
+ printf("Monotonic cycle test:\n");
+ nerr += cycle_test(ncpus, TEST_LOOPS, &ti[0]);
+
+ pvclock_set_flags(PVCLOCK_TSC_STABLE_BIT
+ | PVCLOCK_CYCLE_RAW_TEST_BIT);
+ printf("Raw cycle test:\n");
+ nerr += cycle_test(ncpus, TEST_LOOPS, &ti[1]);
+
+ for (i = 0; i < ncpus; ++i)
+ on_cpu(i, kvm_clock_clear, (void *)0);
+
+ return nerr > 0 ? 1 : 0;
+}
diff --git a/kvm/test/x86/unittests.cfg b/kvm/test/x86/unittests.cfg
index f39c5bd..0d077ac 100644
--- a/kvm/test/x86/unittests.cfg
+++ b/kvm/test/x86/unittests.cfg
@@ -53,3 +53,7 @@ file = xsave.flat
[rmap_chain]
file = rmap_chain.flat
+
+[kvmclock]
+file = kvmclock_test.flat
+smp = 2
--
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