tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
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#include "ucall_common.h"
26
27#define DUMMY_MEMSLOT_INDEX 7
28
29#define DEFAULT_MEMSLOT_MODIFICATION_ITERATIONS 10
30
31
32static int nr_vcpus = 1;
33static uint64_t guest_percpu_mem_size = DEFAULT_PER_VCPU_MEM_SIZE;
34
35static void vcpu_worker(struct memstress_vcpu_args *vcpu_args)
36{
37 struct kvm_vcpu *vcpu = vcpu_args->vcpu;
38 struct kvm_run *run;
39 int ret;
40
41 run = vcpu->run;
42
43 /* Let the guest access its memory until a stop signal is received */
44 while (!READ_ONCE(memstress_args.stop_vcpus)) {
45 ret = _vcpu_run(vcpu);
46 TEST_ASSERT(ret == 0, "vcpu_run failed: %d", ret);
47
48 if (get_ucall(vcpu, NULL) == UCALL_SYNC)
49 continue;
50
51 TEST_ASSERT(false,
52 "Invalid guest sync status: exit_reason=%s\n",
53 exit_reason_str(run->exit_reason));
54 }
55}
56
57static void add_remove_memslot(struct kvm_vm *vm, useconds_t delay,
58 uint64_t nr_modifications)
59{
60 uint64_t pages = max_t(int, vm->page_size, getpagesize()) / vm->page_size;
61 uint64_t gpa;
62 int i;
63
64 /*
65 * Add the dummy memslot just below the memstress memslot, which is
66 * at the top of the guest physical address space.
67 */
68 gpa = memstress_args.gpa - pages * vm->page_size;
69
70 for (i = 0; i < nr_modifications; i++) {
71 usleep(delay);
72 vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, gpa,
73 DUMMY_MEMSLOT_INDEX, pages, 0);
74
75 vm_mem_region_delete(vm, DUMMY_MEMSLOT_INDEX);
76 }
77}
78
79struct test_params {
80 useconds_t delay;
81 uint64_t nr_iterations;
82 bool partition_vcpu_memory_access;
83 bool disable_slot_zap_quirk;
84};
85
86static void run_test(enum vm_guest_mode mode, void *arg)
87{
88 struct test_params *p = arg;
89 struct kvm_vm *vm;
90
91 vm = memstress_create_vm(mode, nr_vcpus, guest_percpu_mem_size, 1,
92 VM_MEM_SRC_ANONYMOUS,
93 p->partition_vcpu_memory_access);
94#ifdef __x86_64__
95 if (p->disable_slot_zap_quirk)
96 vm_enable_cap(vm, KVM_CAP_DISABLE_QUIRKS2, KVM_X86_QUIRK_SLOT_ZAP_ALL);
97
98 pr_info("Memslot zap quirk %s\n", p->disable_slot_zap_quirk ?
99 "disabled" : "enabled");
100#endif
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] [-q]\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(" -q: Disable memslot zap quirk.\n");
125 printf(" -b: specify the size of the memory region which should be\n"
126 " accessed by each vCPU. e.g. 10M or 3G.\n"
127 " Default: 1G\n");
128 printf(" -v: specify the number of vCPUs to run.\n");
129 printf(" -o: Overlap guest memory accesses instead of partitioning\n"
130 " them into a separate region of memory for each vCPU.\n");
131 printf(" -i: specify the number of iterations of adding and removing\n"
132 " a memslot.\n"
133 " Default: %d\n", DEFAULT_MEMSLOT_MODIFICATION_ITERATIONS);
134 puts("");
135 exit(0);
136}
137
138int main(int argc, char *argv[])
139{
140 int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS);
141 int opt;
142 struct test_params p = {
143 .delay = 0,
144 .nr_iterations = DEFAULT_MEMSLOT_MODIFICATION_ITERATIONS,
145 .partition_vcpu_memory_access = true
146 };
147
148 guest_modes_append_default();
149
150 while ((opt = getopt(argc, argv, "hm:d:qb:v:oi:")) != -1) {
151 switch (opt) {
152 case 'm':
153 guest_modes_cmdline(optarg);
154 break;
155 case 'd':
156 p.delay = atoi_non_negative("Delay", optarg);
157 break;
158 case 'b':
159 guest_percpu_mem_size = parse_size(optarg);
160 break;
161 case 'v':
162 nr_vcpus = atoi_positive("Number of vCPUs", optarg);
163 TEST_ASSERT(nr_vcpus <= max_vcpus,
164 "Invalid number of vcpus, must be between 1 and %d",
165 max_vcpus);
166 break;
167 case 'o':
168 p.partition_vcpu_memory_access = false;
169 break;
170 case 'i':
171 p.nr_iterations = atoi_positive("Number of iterations", optarg);
172 break;
173#ifdef __x86_64__
174 case 'q':
175 p.disable_slot_zap_quirk = true;
176
177 TEST_REQUIRE(kvm_check_cap(KVM_CAP_DISABLE_QUIRKS2) &
178 KVM_X86_QUIRK_SLOT_ZAP_ALL);
179 break;
180#endif
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}