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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /tools/testing/selftests/kvm/dirty_log_perf_test.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
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 | 465 |
1 files changed, 465 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 000000000..f99e39a67 --- /dev/null +++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c @@ -0,0 +1,465 @@ +// 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 "perf_test_util.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 perf_test_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; + int wr_fract; + bool partition_vcpu_memory_access; + enum vm_mem_backing_src_type backing_src; + int slots; +}; + +static void toggle_dirty_logging(struct kvm_vm *vm, int slots, bool enable) +{ + int i; + + for (i = 0; i < slots; i++) { + int slot = PERF_TEST_MEM_SLOT_INDEX + i; + int flags = enable ? KVM_MEM_LOG_DIRTY_PAGES : 0; + + vm_mem_region_set_flags(vm, slot, flags); + } +} + +static inline void enable_dirty_logging(struct kvm_vm *vm, int slots) +{ + toggle_dirty_logging(vm, slots, true); +} + +static inline void disable_dirty_logging(struct kvm_vm *vm, int slots) +{ + toggle_dirty_logging(vm, slots, false); +} + +static void get_dirty_log(struct kvm_vm *vm, unsigned long *bitmaps[], int slots) +{ + int i; + + for (i = 0; i < slots; i++) { + int slot = PERF_TEST_MEM_SLOT_INDEX + i; + + kvm_vm_get_dirty_log(vm, slot, bitmaps[i]); + } +} + +static void clear_dirty_log(struct kvm_vm *vm, unsigned long *bitmaps[], + int slots, uint64_t pages_per_slot) +{ + int i; + + for (i = 0; i < slots; i++) { + int slot = PERF_TEST_MEM_SLOT_INDEX + i; + + kvm_vm_clear_dirty_log(vm, slot, bitmaps[i], 0, pages_per_slot); + } +} + +static unsigned long **alloc_bitmaps(int slots, uint64_t pages_per_slot) +{ + unsigned long **bitmaps; + int i; + + bitmaps = malloc(slots * sizeof(bitmaps[0])); + TEST_ASSERT(bitmaps, "Failed to allocate bitmaps array."); + + for (i = 0; i < slots; i++) { + bitmaps[i] = bitmap_zalloc(pages_per_slot); + TEST_ASSERT(bitmaps[i], "Failed to allocate slot bitmap."); + } + + return bitmaps; +} + +static void free_bitmaps(unsigned long *bitmaps[], int slots) +{ + int i; + + for (i = 0; i < slots; i++) + free(bitmaps[i]); + + free(bitmaps); +} + +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 = perf_test_create_vm(mode, nr_vcpus, guest_percpu_mem_size, + p->slots, p->backing_src, + p->partition_vcpu_memory_access); + + perf_test_set_wr_fract(vm, p->wr_fract); + + 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 = 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; + + perf_test_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); + 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); + + 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); + 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); + 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); + 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; + perf_test_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); + } + + free_bitmaps(bitmaps, p->slots); + arch_cleanup_vm(vm); + perf_test_destroy_vm(vm); +} + +static void help(char *name) +{ + puts(""); + printf("usage: %s [-h] [-i iterations] [-p offset] [-g] " + "[-m mode] [-n] [-b vcpu bytes] [-v vcpus] [-o] [-s mem type]" + "[-x memslots]\n", name); + puts(""); + 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(" -f: specify the fraction of pages which should be written to\n" + " as opposed to simply read, in the form\n" + " 1/<fraction of pages to write>.\n" + " (default: 1 i.e. all pages are written to.)\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"); + backing_src_help("-s"); + printf(" -x: Split the memory region into this number of memslots.\n" + " (default: 1)\n"); + puts(""); + exit(0); +} + +int main(int argc, char *argv[]) +{ + int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS); + struct test_params p = { + .iterations = TEST_HOST_LOOP_N, + .wr_fract = 1, + .partition_vcpu_memory_access = true, + .backing_src = DEFAULT_VM_MEM_SRC, + .slots = 1, + }; + 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, "eghi:p:m:nb:f:v:os:x:")) != -1) { + switch (opt) { + case 'e': + /* 'e' is for evil. */ + run_vcpus_while_disabling_dirty_logging = true; + case 'g': + dirty_log_manual_caps = 0; + break; + case 'i': + p.iterations = atoi(optarg); + break; + case 'p': + p.phys_offset = strtoull(optarg, NULL, 0); + break; + case 'm': + guest_modes_cmdline(optarg); + break; + case 'n': + perf_test_args.nested = true; + break; + case 'b': + guest_percpu_mem_size = parse_size(optarg); + break; + case 'f': + p.wr_fract = atoi(optarg); + TEST_ASSERT(p.wr_fract >= 1, + "Write fraction cannot be less than one"); + break; + case 'v': + nr_vcpus = atoi(optarg); + TEST_ASSERT(nr_vcpus > 0 && nr_vcpus <= max_vcpus, + "Invalid number of vcpus, must be between 1 and %d", max_vcpus); + break; + case 'o': + p.partition_vcpu_memory_access = false; + break; + case 's': + p.backing_src = parse_backing_src_type(optarg); + break; + case 'x': + p.slots = atoi(optarg); + break; + case 'h': + default: + help(argv[0]); + break; + } + } + + 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; +} |