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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /tools/testing/selftests/kvm/dirty_log_perf_test.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/testing/selftests/kvm/dirty_log_perf_test.c')
-rw-r--r-- | tools/testing/selftests/kvm/dirty_log_perf_test.c | 435 |
1 files changed, 435 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c b/tools/testing/selftests/kvm/dirty_log_perf_test.c new file mode 100644 index 0000000000..d374dbcf9a --- /dev/null +++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c @@ -0,0 +1,435 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * KVM dirty page logging performance test + * + * Based on dirty_log_test.c + * + * Copyright (C) 2018, Red Hat, Inc. + * Copyright (C) 2020, Google, Inc. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <time.h> +#include <pthread.h> +#include <linux/bitmap.h> + +#include "kvm_util.h" +#include "test_util.h" +#include "memstress.h" +#include "guest_modes.h" + +#ifdef __aarch64__ +#include "aarch64/vgic.h" + +#define GICD_BASE_GPA 0x8000000ULL +#define GICR_BASE_GPA 0x80A0000ULL + +static int gic_fd; + +static void arch_setup_vm(struct kvm_vm *vm, unsigned int nr_vcpus) +{ + /* + * The test can still run even if hardware does not support GICv3, as it + * is only an optimization to reduce guest exits. + */ + gic_fd = vgic_v3_setup(vm, nr_vcpus, 64, GICD_BASE_GPA, GICR_BASE_GPA); +} + +static void arch_cleanup_vm(struct kvm_vm *vm) +{ + if (gic_fd > 0) + close(gic_fd); +} + +#else /* __aarch64__ */ + +static void arch_setup_vm(struct kvm_vm *vm, unsigned int nr_vcpus) +{ +} + +static void arch_cleanup_vm(struct kvm_vm *vm) +{ +} + +#endif + +/* How many host loops to run by default (one KVM_GET_DIRTY_LOG for each loop)*/ +#define TEST_HOST_LOOP_N 2UL + +static int nr_vcpus = 1; +static uint64_t guest_percpu_mem_size = DEFAULT_PER_VCPU_MEM_SIZE; +static bool run_vcpus_while_disabling_dirty_logging; + +/* Host variables */ +static u64 dirty_log_manual_caps; +static bool host_quit; +static int iteration; +static int vcpu_last_completed_iteration[KVM_MAX_VCPUS]; + +static void vcpu_worker(struct memstress_vcpu_args *vcpu_args) +{ + struct kvm_vcpu *vcpu = vcpu_args->vcpu; + int vcpu_idx = vcpu_args->vcpu_idx; + uint64_t pages_count = 0; + struct kvm_run *run; + struct timespec start; + struct timespec ts_diff; + struct timespec total = (struct timespec){0}; + struct timespec avg; + int ret; + + run = vcpu->run; + + while (!READ_ONCE(host_quit)) { + int current_iteration = READ_ONCE(iteration); + + clock_gettime(CLOCK_MONOTONIC, &start); + ret = _vcpu_run(vcpu); + ts_diff = timespec_elapsed(start); + + TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret); + TEST_ASSERT(get_ucall(vcpu, NULL) == UCALL_SYNC, + "Invalid guest sync status: exit_reason=%s\n", + exit_reason_str(run->exit_reason)); + + pr_debug("Got sync event from vCPU %d\n", vcpu_idx); + vcpu_last_completed_iteration[vcpu_idx] = current_iteration; + pr_debug("vCPU %d updated last completed iteration to %d\n", + vcpu_idx, vcpu_last_completed_iteration[vcpu_idx]); + + if (current_iteration) { + pages_count += vcpu_args->pages; + total = timespec_add(total, ts_diff); + pr_debug("vCPU %d iteration %d dirty memory time: %ld.%.9lds\n", + vcpu_idx, current_iteration, ts_diff.tv_sec, + ts_diff.tv_nsec); + } else { + pr_debug("vCPU %d iteration %d populate memory time: %ld.%.9lds\n", + vcpu_idx, current_iteration, ts_diff.tv_sec, + ts_diff.tv_nsec); + } + + /* + * Keep running the guest while dirty logging is being disabled + * (iteration is negative) so that vCPUs are accessing memory + * for the entire duration of zapping collapsible SPTEs. + */ + while (current_iteration == READ_ONCE(iteration) && + READ_ONCE(iteration) >= 0 && !READ_ONCE(host_quit)) {} + } + + avg = timespec_div(total, vcpu_last_completed_iteration[vcpu_idx]); + pr_debug("\nvCPU %d dirtied 0x%lx pages over %d iterations in %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n", + vcpu_idx, pages_count, vcpu_last_completed_iteration[vcpu_idx], + total.tv_sec, total.tv_nsec, avg.tv_sec, avg.tv_nsec); +} + +struct test_params { + unsigned long iterations; + uint64_t phys_offset; + bool partition_vcpu_memory_access; + enum vm_mem_backing_src_type backing_src; + int slots; + uint32_t write_percent; + uint32_t random_seed; + bool random_access; +}; + +static void run_test(enum vm_guest_mode mode, void *arg) +{ + struct test_params *p = arg; + struct kvm_vm *vm; + unsigned long **bitmaps; + uint64_t guest_num_pages; + uint64_t host_num_pages; + uint64_t pages_per_slot; + struct timespec start; + struct timespec ts_diff; + struct timespec get_dirty_log_total = (struct timespec){0}; + struct timespec vcpu_dirty_total = (struct timespec){0}; + struct timespec avg; + struct timespec clear_dirty_log_total = (struct timespec){0}; + int i; + + vm = memstress_create_vm(mode, nr_vcpus, guest_percpu_mem_size, + p->slots, p->backing_src, + p->partition_vcpu_memory_access); + + pr_info("Random seed: %u\n", p->random_seed); + memstress_set_random_seed(vm, p->random_seed); + memstress_set_write_percent(vm, p->write_percent); + + guest_num_pages = (nr_vcpus * guest_percpu_mem_size) >> vm->page_shift; + guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages); + host_num_pages = vm_num_host_pages(mode, guest_num_pages); + pages_per_slot = host_num_pages / p->slots; + + bitmaps = memstress_alloc_bitmaps(p->slots, pages_per_slot); + + if (dirty_log_manual_caps) + vm_enable_cap(vm, KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2, + dirty_log_manual_caps); + + arch_setup_vm(vm, nr_vcpus); + + /* Start the iterations */ + iteration = 0; + host_quit = false; + + clock_gettime(CLOCK_MONOTONIC, &start); + for (i = 0; i < nr_vcpus; i++) + vcpu_last_completed_iteration[i] = -1; + + /* + * Use 100% writes during the population phase to ensure all + * memory is actually populated and not just mapped to the zero + * page. The prevents expensive copy-on-write faults from + * occurring during the dirty memory iterations below, which + * would pollute the performance results. + */ + memstress_set_write_percent(vm, 100); + memstress_set_random_access(vm, false); + memstress_start_vcpu_threads(nr_vcpus, vcpu_worker); + + /* Allow the vCPUs to populate memory */ + pr_debug("Starting iteration %d - Populating\n", iteration); + for (i = 0; i < nr_vcpus; i++) { + while (READ_ONCE(vcpu_last_completed_iteration[i]) != + iteration) + ; + } + + ts_diff = timespec_elapsed(start); + pr_info("Populate memory time: %ld.%.9lds\n", + ts_diff.tv_sec, ts_diff.tv_nsec); + + /* Enable dirty logging */ + clock_gettime(CLOCK_MONOTONIC, &start); + memstress_enable_dirty_logging(vm, p->slots); + ts_diff = timespec_elapsed(start); + pr_info("Enabling dirty logging time: %ld.%.9lds\n\n", + ts_diff.tv_sec, ts_diff.tv_nsec); + + memstress_set_write_percent(vm, p->write_percent); + memstress_set_random_access(vm, p->random_access); + + while (iteration < p->iterations) { + /* + * Incrementing the iteration number will start the vCPUs + * dirtying memory again. + */ + clock_gettime(CLOCK_MONOTONIC, &start); + iteration++; + + pr_debug("Starting iteration %d\n", iteration); + for (i = 0; i < nr_vcpus; i++) { + while (READ_ONCE(vcpu_last_completed_iteration[i]) + != iteration) + ; + } + + ts_diff = timespec_elapsed(start); + vcpu_dirty_total = timespec_add(vcpu_dirty_total, ts_diff); + pr_info("Iteration %d dirty memory time: %ld.%.9lds\n", + iteration, ts_diff.tv_sec, ts_diff.tv_nsec); + + clock_gettime(CLOCK_MONOTONIC, &start); + memstress_get_dirty_log(vm, bitmaps, p->slots); + ts_diff = timespec_elapsed(start); + get_dirty_log_total = timespec_add(get_dirty_log_total, + ts_diff); + pr_info("Iteration %d get dirty log time: %ld.%.9lds\n", + iteration, ts_diff.tv_sec, ts_diff.tv_nsec); + + if (dirty_log_manual_caps) { + clock_gettime(CLOCK_MONOTONIC, &start); + memstress_clear_dirty_log(vm, bitmaps, p->slots, + pages_per_slot); + ts_diff = timespec_elapsed(start); + clear_dirty_log_total = timespec_add(clear_dirty_log_total, + ts_diff); + pr_info("Iteration %d clear dirty log time: %ld.%.9lds\n", + iteration, ts_diff.tv_sec, ts_diff.tv_nsec); + } + } + + /* + * Run vCPUs while dirty logging is being disabled to stress disabling + * in terms of both performance and correctness. Opt-in via command + * line as this significantly increases time to disable dirty logging. + */ + if (run_vcpus_while_disabling_dirty_logging) + WRITE_ONCE(iteration, -1); + + /* Disable dirty logging */ + clock_gettime(CLOCK_MONOTONIC, &start); + memstress_disable_dirty_logging(vm, p->slots); + ts_diff = timespec_elapsed(start); + pr_info("Disabling dirty logging time: %ld.%.9lds\n", + ts_diff.tv_sec, ts_diff.tv_nsec); + + /* + * Tell the vCPU threads to quit. No need to manually check that vCPUs + * have stopped running after disabling dirty logging, the join will + * wait for them to exit. + */ + host_quit = true; + memstress_join_vcpu_threads(nr_vcpus); + + avg = timespec_div(get_dirty_log_total, p->iterations); + pr_info("Get dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n", + p->iterations, get_dirty_log_total.tv_sec, + get_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec); + + if (dirty_log_manual_caps) { + avg = timespec_div(clear_dirty_log_total, p->iterations); + pr_info("Clear dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n", + p->iterations, clear_dirty_log_total.tv_sec, + clear_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec); + } + + memstress_free_bitmaps(bitmaps, p->slots); + arch_cleanup_vm(vm); + memstress_destroy_vm(vm); +} + +static void help(char *name) +{ + puts(""); + printf("usage: %s [-h] [-a] [-i iterations] [-p offset] [-g] " + "[-m mode] [-n] [-b vcpu bytes] [-v vcpus] [-o] [-r random seed ] [-s mem type]" + "[-x memslots] [-w percentage] [-c physical cpus to run test on]\n", name); + puts(""); + printf(" -a: access memory randomly rather than in order.\n"); + printf(" -i: specify iteration counts (default: %"PRIu64")\n", + TEST_HOST_LOOP_N); + printf(" -g: Do not enable KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2. This\n" + " makes KVM_GET_DIRTY_LOG clear the dirty log (i.e.\n" + " KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE is not enabled)\n" + " and writes will be tracked as soon as dirty logging is\n" + " enabled on the memslot (i.e. KVM_DIRTY_LOG_INITIALLY_SET\n" + " is not enabled).\n"); + printf(" -p: specify guest physical test memory offset\n" + " Warning: a low offset can conflict with the loaded test code.\n"); + guest_modes_help(); + printf(" -n: Run the vCPUs in nested mode (L2)\n"); + printf(" -e: Run vCPUs while dirty logging is being disabled. This\n" + " can significantly increase runtime, especially if there\n" + " isn't a dedicated pCPU for the main thread.\n"); + printf(" -b: specify the size of the memory region which should be\n" + " dirtied by each vCPU. e.g. 10M or 3G.\n" + " (default: 1G)\n"); + printf(" -v: specify the number of vCPUs to run.\n"); + printf(" -o: Overlap guest memory accesses instead of partitioning\n" + " them into a separate region of memory for each vCPU.\n"); + printf(" -r: specify the starting random seed.\n"); + backing_src_help("-s"); + printf(" -x: Split the memory region into this number of memslots.\n" + " (default: 1)\n"); + printf(" -w: specify the percentage of pages which should be written to\n" + " as an integer from 0-100 inclusive. This is probabilistic,\n" + " so -w X means each page has an X%% chance of writing\n" + " and a (100-X)%% chance of reading.\n" + " (default: 100 i.e. all pages are written to.)\n"); + kvm_print_vcpu_pinning_help(); + puts(""); + exit(0); +} + +int main(int argc, char *argv[]) +{ + int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS); + const char *pcpu_list = NULL; + struct test_params p = { + .iterations = TEST_HOST_LOOP_N, + .partition_vcpu_memory_access = true, + .backing_src = DEFAULT_VM_MEM_SRC, + .slots = 1, + .random_seed = 1, + .write_percent = 100, + }; + int opt; + + dirty_log_manual_caps = + kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2); + dirty_log_manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE | + KVM_DIRTY_LOG_INITIALLY_SET); + + guest_modes_append_default(); + + while ((opt = getopt(argc, argv, "ab:c:eghi:m:nop:r:s:v:x:w:")) != -1) { + switch (opt) { + case 'a': + p.random_access = true; + break; + case 'b': + guest_percpu_mem_size = parse_size(optarg); + break; + case 'c': + pcpu_list = optarg; + break; + case 'e': + /* 'e' is for evil. */ + run_vcpus_while_disabling_dirty_logging = true; + break; + case 'g': + dirty_log_manual_caps = 0; + break; + case 'h': + help(argv[0]); + break; + case 'i': + p.iterations = atoi_positive("Number of iterations", optarg); + break; + case 'm': + guest_modes_cmdline(optarg); + break; + case 'n': + memstress_args.nested = true; + break; + case 'o': + p.partition_vcpu_memory_access = false; + break; + case 'p': + p.phys_offset = strtoull(optarg, NULL, 0); + break; + case 'r': + p.random_seed = atoi_positive("Random seed", optarg); + break; + case 's': + p.backing_src = parse_backing_src_type(optarg); + break; + case 'v': + nr_vcpus = atoi_positive("Number of vCPUs", optarg); + TEST_ASSERT(nr_vcpus <= max_vcpus, + "Invalid number of vcpus, must be between 1 and %d", max_vcpus); + break; + case 'w': + p.write_percent = atoi_non_negative("Write percentage", optarg); + TEST_ASSERT(p.write_percent <= 100, + "Write percentage must be between 0 and 100"); + break; + case 'x': + p.slots = atoi_positive("Number of slots", optarg); + break; + default: + help(argv[0]); + break; + } + } + + if (pcpu_list) { + kvm_parse_vcpu_pinning(pcpu_list, memstress_args.vcpu_to_pcpu, + nr_vcpus); + memstress_args.pin_vcpus = true; + } + + TEST_ASSERT(p.iterations >= 2, "The test should have at least two iterations"); + + pr_info("Test iterations: %"PRIu64"\n", p.iterations); + + for_each_guest_mode(run_test, &p); + + return 0; +} |