1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * KVM memslot modification stress test
  4 * Adapted from demand_paging_test.c
  5 *
  6 * Copyright (C) 2018, Red Hat, Inc.
  7 * Copyright (C) 2020, Google, Inc.
  8 */
  9
 10#define _GNU_SOURCE /* for program_invocation_name */
 11
 12#include <stdio.h>
 13#include <stdlib.h>
 14#include <sys/syscall.h>
 15#include <unistd.h>
 16#include <asm/unistd.h>
 17#include <time.h>
 18#include <poll.h>
 19#include <pthread.h>
 20#include <linux/bitmap.h>
 21#include <linux/bitops.h>
 22#include <linux/userfaultfd.h>
 23
 24#include "memstress.h"
 25#include "processor.h"
 26#include "test_util.h"
 27#include "guest_modes.h"
 28
 29#define DUMMY_MEMSLOT_INDEX 7
 30
 31#define DEFAULT_MEMSLOT_MODIFICATION_ITERATIONS 10
 32
 33
 34static int nr_vcpus = 1;
 35static uint64_t guest_percpu_mem_size = DEFAULT_PER_VCPU_MEM_SIZE;
 36
 37static void vcpu_worker(struct memstress_vcpu_args *vcpu_args)
 38{
 39	struct kvm_vcpu *vcpu = vcpu_args->vcpu;
 40	struct kvm_run *run;
 41	int ret;
 42
 43	run = vcpu->run;
 44
 45	/* Let the guest access its memory until a stop signal is received */
 46	while (!READ_ONCE(memstress_args.stop_vcpus)) {
 47		ret = _vcpu_run(vcpu);
 48		TEST_ASSERT(ret == 0, "vcpu_run failed: %d", ret);
 49
 50		if (get_ucall(vcpu, NULL) == UCALL_SYNC)
 51			continue;
 52
 53		TEST_ASSERT(false,
 54			    "Invalid guest sync status: exit_reason=%s\n",
 55			    exit_reason_str(run->exit_reason));
 56	}
 57}
 58
 59struct memslot_antagonist_args {
 60	struct kvm_vm *vm;
 61	useconds_t delay;
 62	uint64_t nr_modifications;
 63};
 64
 65static void add_remove_memslot(struct kvm_vm *vm, useconds_t delay,
 66			       uint64_t nr_modifications)
 67{
 68	uint64_t pages = max_t(int, vm->page_size, getpagesize()) / vm->page_size;
 69	uint64_t gpa;
 70	int i;
 71
 72	/*
 73	 * Add the dummy memslot just below the memstress memslot, which is
 74	 * at the top of the guest physical address space.
 75	 */
 76	gpa = memstress_args.gpa - pages * vm->page_size;
 77
 78	for (i = 0; i < nr_modifications; i++) {
 79		usleep(delay);
 80		vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, gpa,
 81					    DUMMY_MEMSLOT_INDEX, pages, 0);
 82
 83		vm_mem_region_delete(vm, DUMMY_MEMSLOT_INDEX);
 84	}
 85}
 86
 87struct test_params {
 88	useconds_t delay;
 89	uint64_t nr_iterations;
 90	bool partition_vcpu_memory_access;
 91};
 92
 93static void run_test(enum vm_guest_mode mode, void *arg)
 94{
 95	struct test_params *p = arg;
 96	struct kvm_vm *vm;
 97
 98	vm = memstress_create_vm(mode, nr_vcpus, guest_percpu_mem_size, 1,
 99				 VM_MEM_SRC_ANONYMOUS,
100				 p->partition_vcpu_memory_access);
101
102	pr_info("Finished creating vCPUs\n");
103
104	memstress_start_vcpu_threads(nr_vcpus, vcpu_worker);
105
106	pr_info("Started all vCPUs\n");
107
108	add_remove_memslot(vm, p->delay, p->nr_iterations);
109
110	memstress_join_vcpu_threads(nr_vcpus);
111	pr_info("All vCPU threads joined\n");
112
113	memstress_destroy_vm(vm);
114}
115
116static void help(char *name)
117{
118	puts("");
119	printf("usage: %s [-h] [-m mode] [-d delay_usec]\n"
120	       "          [-b memory] [-v vcpus] [-o] [-i iterations]\n", name);
121	guest_modes_help();
122	printf(" -d: add a delay between each iteration of adding and\n"
123	       "     deleting a memslot in usec.\n");
124	printf(" -b: specify the size of the memory region which should be\n"
125	       "     accessed by each vCPU. e.g. 10M or 3G.\n"
126	       "     Default: 1G\n");
127	printf(" -v: specify the number of vCPUs to run.\n");
128	printf(" -o: Overlap guest memory accesses instead of partitioning\n"
129	       "     them into a separate region of memory for each vCPU.\n");
130	printf(" -i: specify the number of iterations of adding and removing\n"
131	       "     a memslot.\n"
132	       "     Default: %d\n", DEFAULT_MEMSLOT_MODIFICATION_ITERATIONS);
133	puts("");
134	exit(0);
135}
136
137int main(int argc, char *argv[])
138{
139	int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS);
140	int opt;
141	struct test_params p = {
142		.delay = 0,
143		.nr_iterations = DEFAULT_MEMSLOT_MODIFICATION_ITERATIONS,
144		.partition_vcpu_memory_access = true
145	};
146
147	guest_modes_append_default();
148
149	while ((opt = getopt(argc, argv, "hm:d:b:v:oi:")) != -1) {
150		switch (opt) {
151		case 'm':
152			guest_modes_cmdline(optarg);
153			break;
154		case 'd':
155			p.delay = atoi_non_negative("Delay", optarg);
156			break;
157		case 'b':
158			guest_percpu_mem_size = parse_size(optarg);
159			break;
160		case 'v':
161			nr_vcpus = atoi_positive("Number of vCPUs", optarg);
162			TEST_ASSERT(nr_vcpus <= max_vcpus,
163				    "Invalid number of vcpus, must be between 1 and %d",
164				    max_vcpus);
165			break;
166		case 'o':
167			p.partition_vcpu_memory_access = false;
168			break;
169		case 'i':
170			p.nr_iterations = atoi_positive("Number of iterations", optarg);
171			break;
172		case 'h':
173		default:
174			help(argv[0]);
175			break;
176		}
177	}
178
179	for_each_guest_mode(run_test, &p);
180
181	return 0;
182}