----- "Zachary Amsden" <zamsden@xxxxxxxxxx> wrote:
> On 08/26/2010 07:49 PM, Jason Wang wrote:
> > This patch implements two tests for kvmclock. First one check
> whether
> > the date of time returned by kvmclock matches the value got from
> > host. Second one check whether the cycle of kvmclock grows
> > monotonically in smp guest.
> >
>
> Technically, it's not monotonic, it's non-decreasing.
>
> > Three parameters were accepted by the test: test loops, seconds
> > since 1970-01-01 00:00:00 UTC which could be easily get through
> date
> > +%s and the max accepted offset value between the tod of guest and
> > host.
> >
>
> This in general looks awesome.
>
> > Signed-off-by: Jason Wang<jasowang@xxxxxxxxxx>
> > ---
> > config-x86-common.mak | 6 ++
> > x86/README | 2 +
> > x86/kvmclock_test.c | 145
> +++++++++++++++++++++++++++++++++++++++++++++++++
> > x86/unittests.cfg | 5 ++
> > 4 files changed, 157 insertions(+), 1 deletions(-)
> > create mode 100644 x86/kvmclock_test.c
> >
> > diff --git a/config-x86-common.mak b/config-x86-common.mak
> > index b8ca859..b541c1c 100644
> > --- a/config-x86-common.mak
> > +++ b/config-x86-common.mak
> > @@ -26,7 +26,8 @@ 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
> >
> > @@ -70,6 +71,9 @@ $(TEST_DIR)/rmap_chain.flat: $(cstart.o)
> $(TEST_DIR)/rmap_chain.o \
> >
> > $(TEST_DIR)/svm.flat: $(cstart.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/x86/README b/x86/README
> > index ab5a2ae..4b90080 100644
> > --- a/x86/README
> > +++ b/x86/README
> > @@ -12,3 +12,5 @@ sieve: heavy memory access with no paging and with
> paging static and with paging
> > smptest: run smp_id() on every cpu and compares return value to
> number
> > tsc: write to tsc(0) and write to tsc(100000000000) and read it
> back
> > vmexit: long loops for each: cpuid, vmcall, mov_from_cr8,
> mov_to_cr8, inl_pmtimer, ipi, ipi+halt
> > +kvmclock_test: monotonic cycle test of kvmclock and a sanity test
> of
> > +wallclock
> > diff --git a/x86/kvmclock_test.c b/x86/kvmclock_test.c
> > new file mode 100644
> > index 0000000..cd80915
> > --- /dev/null
> > +++ b/x86/kvmclock_test.c
> > @@ -0,0 +1,145 @@
> > +#include "libcflat.h"
> > +#include "smp.h"
> > +#include "atomic.h"
> > +#include "string.h"
> > +#include "kvmclock.h"
> > +
> > +#define DEFAULT_TEST_LOOPS 100000000L
> > +#define DEFAULT_THRESHOLD 60L
> > +
> > +struct test_info {
> > + struct spinlock lock;
> > + long loops; /* test loops */
> > + u64 warps; /* warp count */
> > + long long worst; /* worst warp */
> > + volatile cycle_t last; /* last cycle seen by test */
> > + atomic_t ncpus; /* number of cpu in the test*/
> > +};
> > +
> > +struct test_info ti[2];
> > +
> > +static int wallclock_test(long sec, long threshold)
> > +{
> > + int i;
> > + long ksec, offset;
> > + struct timespec ts, ts_last;
> > +
> > + printf("Wallclock test, threshold %ld\n", threshold);
> > + kvm_get_wallclock(&ts_last);
> > + ksec = ts_last.sec + ts_last.nsec / NSEC_PER_SEC;
> > +
> > + offset = ksec - sec;
> > + printf("Seconds get from host: %ld\n", sec);
> > + printf("Seconds get from kvmclock: %ld\n", ksec);
> > +
> > + if (offset> threshold || offset< -threshold) {
> > + printf("Seconds get from kvmclock: %ld\n", ksec);
> > + return 1;
> > + }
> > +
> > + 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 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, long loops, struct test_info *ti)
> > +{
> > + int i;
> > +
> > + atomic_set(&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("Test loops: %ld\n", ti->loops);
> > + printf("Total warps: %lld\n", ti->warps);
> > + printf("Worst warp: %lld\n", ti->worst);
> > +
> > + return ti->warps ? 1 : 0;
> > +}
> > +
> > +int main(int ac, char **av)
> > +{
> > + int ncpus = cpu_count();
> > + int nerr = 0, i;
> > + long loops = DEFAULT_TEST_LOOPS;
> > + long sec = 0;
> > + long threshold = DEFAULT_THRESHOLD;
> > +
> > + if (ac> 1)
> > + loops = atol(av[1]);
> > + if (ac> 2)
> > + sec = atol(av[2]);
> > + if (ac> 3)
> > + threshold = atol(av[3]);
> > +
> > + smp_init();
> > +
> > + if (ncpus> MAX_CPU)
> > + ncpus = MAX_CPU;
> > + for (i = 0; i< ncpus; ++i)
> > + on_cpu(i, kvm_clock_init, (void *)0);
> > +
> > + if (ac> 2)
> > + nerr += wallclock_test(sec, threshold);
> > +
> > + printf("Check the stability of raw cycle\n");
> > + pvclock_set_flags(PVCLOCK_TSC_STABLE_BIT
> > + | PVCLOCK_RAW_CYCLE_BIT);
> >
>
> What is this RAW_CYCLE_BIT ? Did I miss something?
RAW_CYCLE_BIT is used to tell the driver return unadjusted cycle value
as could be used to test whether the host could supply a stable cycle.
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe kvm" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
