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 000000000000..504f6fe980e8
--- /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", ret);
+		TEST_ASSERT(get_ucall(vcpu, NULL) == UCALL_SYNC,
+			    "Invalid guest sync status: exit_reason=%s",
+			    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;
+}