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