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 "perf_test_util.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
34 static int nr_vcpus = 1;
35 static uint64_t guest_percpu_mem_size = DEFAULT_PER_VCPU_MEM_SIZE;
36
37 static bool run_vcpus = true;
38
vcpu_worker(struct perf_test_vcpu_args * vcpu_args)39 static void vcpu_worker(struct perf_test_vcpu_args *vcpu_args)
40 {
41 int ret;
42 int vcpu_id = vcpu_args->vcpu_id;
43 struct kvm_vm *vm = perf_test_args.vm;
44 struct kvm_run *run;
45
46 run = vcpu_state(vm, vcpu_id);
47
48 /* Let the guest access its memory until a stop signal is received */
49 while (READ_ONCE(run_vcpus)) {
50 ret = _vcpu_run(vm, vcpu_id);
51 TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
52
53 if (get_ucall(vm, vcpu_id, NULL) == UCALL_SYNC)
54 continue;
55
56 TEST_ASSERT(false,
57 "Invalid guest sync status: exit_reason=%s\n",
58 exit_reason_str(run->exit_reason));
59 }
60 }
61
62 struct memslot_antagonist_args {
63 struct kvm_vm *vm;
64 useconds_t delay;
65 uint64_t nr_modifications;
66 };
67
add_remove_memslot(struct kvm_vm * vm,useconds_t delay,uint64_t nr_modifications)68 static void add_remove_memslot(struct kvm_vm *vm, useconds_t delay,
69 uint64_t nr_modifications)
70 {
71 const uint64_t pages = 1;
72 uint64_t gpa;
73 int i;
74
75 /*
76 * Add the dummy memslot just below the perf_test_util memslot, which is
77 * at the top of the guest physical address space.
78 */
79 gpa = perf_test_args.gpa - pages * vm_get_page_size(vm);
80
81 for (i = 0; i < nr_modifications; i++) {
82 usleep(delay);
83 vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, gpa,
84 DUMMY_MEMSLOT_INDEX, pages, 0);
85
86 vm_mem_region_delete(vm, DUMMY_MEMSLOT_INDEX);
87 }
88 }
89
90 struct test_params {
91 useconds_t memslot_modification_delay;
92 uint64_t nr_memslot_modifications;
93 bool partition_vcpu_memory_access;
94 };
95
run_test(enum vm_guest_mode mode,void * arg)96 static void run_test(enum vm_guest_mode mode, void *arg)
97 {
98 struct test_params *p = arg;
99 struct kvm_vm *vm;
100
101 vm = perf_test_create_vm(mode, nr_vcpus, guest_percpu_mem_size, 1,
102 VM_MEM_SRC_ANONYMOUS,
103 p->partition_vcpu_memory_access);
104
105 pr_info("Finished creating vCPUs\n");
106
107 perf_test_start_vcpu_threads(nr_vcpus, vcpu_worker);
108
109 pr_info("Started all vCPUs\n");
110
111 add_remove_memslot(vm, p->memslot_modification_delay,
112 p->nr_memslot_modifications);
113
114 run_vcpus = false;
115
116 perf_test_join_vcpu_threads(nr_vcpus);
117 pr_info("All vCPU threads joined\n");
118
119 perf_test_destroy_vm(vm);
120 }
121
help(char * name)122 static void help(char *name)
123 {
124 puts("");
125 printf("usage: %s [-h] [-m mode] [-d delay_usec]\n"
126 " [-b memory] [-v vcpus] [-o] [-i iterations]\n", name);
127 guest_modes_help();
128 printf(" -d: add a delay between each iteration of adding and\n"
129 " deleting a memslot in usec.\n");
130 printf(" -b: specify the size of the memory region which should be\n"
131 " accessed by each vCPU. e.g. 10M or 3G.\n"
132 " Default: 1G\n");
133 printf(" -v: specify the number of vCPUs to run.\n");
134 printf(" -o: Overlap guest memory accesses instead of partitioning\n"
135 " them into a separate region of memory for each vCPU.\n");
136 printf(" -i: specify the number of iterations of adding and removing\n"
137 " a memslot.\n"
138 " Default: %d\n", DEFAULT_MEMSLOT_MODIFICATION_ITERATIONS);
139 puts("");
140 exit(0);
141 }
142
main(int argc,char * argv[])143 int main(int argc, char *argv[])
144 {
145 int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS);
146 int opt;
147 struct test_params p = {
148 .memslot_modification_delay = 0,
149 .nr_memslot_modifications =
150 DEFAULT_MEMSLOT_MODIFICATION_ITERATIONS,
151 .partition_vcpu_memory_access = true
152 };
153
154 guest_modes_append_default();
155
156 while ((opt = getopt(argc, argv, "hm:d:b:v:oi:")) != -1) {
157 switch (opt) {
158 case 'm':
159 guest_modes_cmdline(optarg);
160 break;
161 case 'd':
162 p.memslot_modification_delay = strtoul(optarg, NULL, 0);
163 TEST_ASSERT(p.memslot_modification_delay >= 0,
164 "A negative delay is not supported.");
165 break;
166 case 'b':
167 guest_percpu_mem_size = parse_size(optarg);
168 break;
169 case 'v':
170 nr_vcpus = atoi(optarg);
171 TEST_ASSERT(nr_vcpus > 0 && nr_vcpus <= max_vcpus,
172 "Invalid number of vcpus, must be between 1 and %d",
173 max_vcpus);
174 break;
175 case 'o':
176 p.partition_vcpu_memory_access = false;
177 break;
178 case 'i':
179 p.nr_memslot_modifications = atoi(optarg);
180 break;
181 case 'h':
182 default:
183 help(argv[0]);
184 break;
185 }
186 }
187
188 for_each_guest_mode(run_test, &p);
189
190 return 0;
191 }
192