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 #include <stdio.h>
10 #include <stdlib.h>
11 #include <sys/syscall.h>
12 #include <unistd.h>
13 #include <asm/unistd.h>
14 #include <time.h>
15 #include <poll.h>
16 #include <pthread.h>
17 #include <linux/bitmap.h>
18 #include <linux/bitops.h>
19 #include <linux/userfaultfd.h>
20
21 #include "memstress.h"
22 #include "processor.h"
23 #include "test_util.h"
24 #include "guest_modes.h"
25
26 #define DUMMY_MEMSLOT_INDEX 7
27
28 #define DEFAULT_MEMSLOT_MODIFICATION_ITERATIONS 10
29
30
31 static int nr_vcpus = 1;
32 static uint64_t guest_percpu_mem_size = DEFAULT_PER_VCPU_MEM_SIZE;
33
vcpu_worker(struct memstress_vcpu_args * vcpu_args)34 static void vcpu_worker(struct memstress_vcpu_args *vcpu_args)
35 {
36 struct kvm_vcpu *vcpu = vcpu_args->vcpu;
37 struct kvm_run *run;
38 int ret;
39
40 run = vcpu->run;
41
42 /* Let the guest access its memory until a stop signal is received */
43 while (!READ_ONCE(memstress_args.stop_vcpus)) {
44 ret = _vcpu_run(vcpu);
45 TEST_ASSERT(ret == 0, "vcpu_run failed: %d", ret);
46
47 if (get_ucall(vcpu, NULL) == UCALL_SYNC)
48 continue;
49
50 TEST_ASSERT(false,
51 "Invalid guest sync status: exit_reason=%s\n",
52 exit_reason_str(run->exit_reason));
53 }
54 }
55
add_remove_memslot(struct kvm_vm * vm,useconds_t delay,uint64_t nr_modifications)56 static void add_remove_memslot(struct kvm_vm *vm, useconds_t delay,
57 uint64_t nr_modifications)
58 {
59 uint64_t pages = max_t(int, vm->page_size, getpagesize()) / vm->page_size;
60 uint64_t gpa;
61 int i;
62
63 /*
64 * Add the dummy memslot just below the memstress memslot, which is
65 * at the top of the guest physical address space.
66 */
67 gpa = memstress_args.gpa - pages * vm->page_size;
68
69 for (i = 0; i < nr_modifications; i++) {
70 usleep(delay);
71 vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, gpa,
72 DUMMY_MEMSLOT_INDEX, pages, 0);
73
74 vm_mem_region_delete(vm, DUMMY_MEMSLOT_INDEX);
75 }
76 }
77
78 struct test_params {
79 useconds_t delay;
80 uint64_t nr_iterations;
81 bool partition_vcpu_memory_access;
82 bool disable_slot_zap_quirk;
83 };
84
run_test(enum vm_guest_mode mode,void * arg)85 static void run_test(enum vm_guest_mode mode, void *arg)
86 {
87 struct test_params *p = arg;
88 struct kvm_vm *vm;
89
90 vm = memstress_create_vm(mode, nr_vcpus, guest_percpu_mem_size, 1,
91 VM_MEM_SRC_ANONYMOUS,
92 p->partition_vcpu_memory_access);
93 #ifdef __x86_64__
94 if (p->disable_slot_zap_quirk)
95 vm_enable_cap(vm, KVM_CAP_DISABLE_QUIRKS2, KVM_X86_QUIRK_SLOT_ZAP_ALL);
96
97 pr_info("Memslot zap quirk %s\n", p->disable_slot_zap_quirk ?
98 "disabled" : "enabled");
99 #endif
100
101 pr_info("Finished creating vCPUs\n");
102
103 memstress_start_vcpu_threads(nr_vcpus, vcpu_worker);
104
105 pr_info("Started all vCPUs\n");
106
107 add_remove_memslot(vm, p->delay, p->nr_iterations);
108
109 memstress_join_vcpu_threads(nr_vcpus);
110 pr_info("All vCPU threads joined\n");
111
112 memstress_destroy_vm(vm);
113 }
114
help(char * name)115 static void help(char *name)
116 {
117 puts("");
118 printf("usage: %s [-h] [-m mode] [-d delay_usec] [-q]\n"
119 " [-b memory] [-v vcpus] [-o] [-i iterations]\n", name);
120 guest_modes_help();
121 printf(" -d: add a delay between each iteration of adding and\n"
122 " deleting a memslot in usec.\n");
123 printf(" -q: Disable memslot zap quirk.\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
main(int argc,char * argv[])137 int 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:qb: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 #ifdef __x86_64__
173 case 'q':
174 p.disable_slot_zap_quirk = true;
175
176 TEST_REQUIRE(kvm_check_cap(KVM_CAP_DISABLE_QUIRKS2) &
177 KVM_X86_QUIRK_SLOT_ZAP_ALL);
178 break;
179 #endif
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