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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /tools/testing/selftests/kvm/dirty_log_perf_test.c
parentInitial commit. (diff)
downloadlinux-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.c465
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;
+}