From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: [PATCH kvm-unit-tests v2 8/8] Add tests for kvm-clock Date: Tue, 31 Aug 2010 16:37:49 +0800 Message-ID: <20100831083749.10672.68826.stgit@FreeLancer> References: <20100831083216.10672.20413.stgit@FreeLancer> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit To: zamsden@redhat.com, glommer@redhat.com, mtosatti@redhat.com, avi@redhat.com, kvm@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:26536 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753042Ab0HaIhw (ORCPT ); Tue, 31 Aug 2010 04:37:52 -0400 Received: from int-mx08.intmail.prod.int.phx2.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o7V8bq5L000878 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 31 Aug 2010 04:37:52 -0400 In-Reply-To: <20100831083216.10672.20413.stgit@FreeLancer> Sender: kvm-owner@vger.kernel.org List-ID: This patch implements three 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 and the count of warps and stalls are also recorded. The last test is a performance test to measure the guest cycles cost when trying to read cycle of kvmclock. 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. Signed-off-by: Jason Wang --- config-x86-common.mak | 6 +- x86/README | 1 x86/kvmclock_test.c | 166 +++++++++++++++++++++++++++++++++++++++++++++++++ x86/unittests.cfg | 5 + 4 files changed, 177 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..215fb2f 100644 --- a/x86/README +++ b/x86/README @@ -12,3 +12,4 @@ 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: test of wallclock, monotonic cycle and performance of kvmclock diff --git a/x86/kvmclock_test.c b/x86/kvmclock_test.c new file mode 100644 index 0000000..5b14ae2 --- /dev/null +++ b/x86/kvmclock_test.c @@ -0,0 +1,166 @@ +#include "libcflat.h" +#include "smp.h" +#include "atomic.h" +#include "processor.h" +#include "kvmclock.h" + +#define DEFAULT_TEST_LOOPS 100000000L +#define DEFAULT_THRESHOLD 5L + +struct test_info { + struct spinlock lock; + long loops; /* test loops */ + u64 warps; /* warp count */ + u64 stalls; /* stall count */ + long long worst; /* worst warp */ + volatile cycle_t last; /* last cycle seen by test */ + atomic_t ncpus; /* number of cpu in the test*/ + int check; /* check cycle ? */ +}; + +struct test_info ti[4]; + +static int wallclock_test(long sec, long threshold) +{ + long ksec, offset; + struct timespec ts; + + printf("Wallclock test, threshold %ld\n", threshold); + kvm_get_wallclock(&ts); + ksec = ts.tv_sec; + + offset = ksec - sec; + printf("Seconds get from host: %ld\n", sec); + printf("Seconds get from kvmclock: %ld\n", ksec); + printf("Offset: %ld\n", offset); + + if (offset > threshold || offset < -threshold) { + printf("offset too large!\n"); + return 1; + } + + return 0; +} + +static void kvm_clock_test(void *data) +{ + struct test_info *hv_test_info = (struct test_info *)data; + long i, check = hv_test_info->check; + + for (i = 0; i < hv_test_info->loops; i++){ + cycle_t t0, t1; + long long delta; + + if (check == 0) { + kvm_clock_read(); + continue; + } + + 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 (delta == 0) + ++hv_test_info->stalls; + + if (!((unsigned long)i & 31)) + asm volatile("rep; nop"); + } + + atomic_dec(&hv_test_info->ncpus); +} + +static int cycle_test(int ncpus, long loops, int check, struct test_info *ti) +{ + int i; + unsigned long long begin, end; + + begin = rdtsc(); + + atomic_set(&ti->ncpus, ncpus); + ti->loops = loops; + ti->check = check; + 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)) + ; + + end = rdtsc(); + + printf("Total vcpus: %d\n", ncpus); + printf("Test loops: %ld\n", ti->loops); + if (check == 1) { + printf("Total warps: %lld\n", ti->warps); + printf("Total stalls: %lld\n", ti->stalls); + printf("Worst warp: %lld\n", ti->worst); + } else + printf("TSC cycles: %lld\n", end - begin); + + 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); + if (cycle_test(ncpus, loops, 1, &ti[0])) + printf("Raw cycle is not stable\n"); + else + printf("Raw cycle is stable\n"); + + pvclock_set_flags(PVCLOCK_TSC_STABLE_BIT); + printf("Monotonic cycle test:\n"); + nerr += cycle_test(ncpus, loops, 1, &ti[1]); + + printf("Measure the performance of raw cycle ...\n"); + pvclock_set_flags(PVCLOCK_TSC_STABLE_BIT + | PVCLOCK_RAW_CYCLE_BIT); + cycle_test(ncpus, loops, 0, &ti[2]); + + printf("Measure the performance of adjusted cycle ...\n"); + pvclock_set_flags(PVCLOCK_TSC_STABLE_BIT); + cycle_test(ncpus, loops, 0, &ti[3]); + + for (i = 0; i < ncpus; ++i) + on_cpu(i, kvm_clock_clear, (void *)0); + + return nerr > 0 ? 1 : 0; +} diff --git a/x86/unittests.cfg b/x86/unittests.cfg index 7796e41..228ac1d 100644 --- a/x86/unittests.cfg +++ b/x86/unittests.cfg @@ -63,3 +63,8 @@ extra_params = -enable-nesting -cpu qemu64,+svm file = svm.flat smp = 2 extra_params = -cpu qemu64,-svm + +[kvmclock_test] +file = kvmclock_test.flat +smp = 2 +extra_params = --append "10000000 `date +%s`"