xref: /qemu/tests/unit/test-xs-node.c (revision 6e1330090d361d5904587b492afaad5041e63b66)
1 /*
2  * QEMU XenStore XsNode testing
3  *
4  * Copyright © 2023 Amazon.com, Inc. or its affiliates. All Rights Reserved.
5 
6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
7  * See the COPYING file in the top-level directory.
8  */
9 
10 #include "qemu/osdep.h"
11 #include "qapi/error.h"
12 #include "qemu/module.h"
13 
14 static int nr_xs_nodes;
15 static GList *xs_node_list;
16 
17 #define XS_NODE_UNIT_TEST
18 
19 /*
20  * We don't need the core Xen definitions. And we *do* want to be able
21  * to run the unit tests even on architectures that Xen doesn't support
22  * (because life's too short to bother doing otherwise, and test coverage
23  * doesn't hurt).
24  */
25 #define __XEN_PUBLIC_XEN_H__
26 
27 #include "hw/i386/kvm/xenstore_impl.c"
28 
29 #define DOMID_QEMU 0
30 #define DOMID_GUEST 1
31 
32 /* This doesn't happen in qemu but we want to make valgrind happy */
33 static void xs_impl_delete(XenstoreImplState *s)
34 {
35     int err;
36 
37     xs_impl_reset_watches(s, DOMID_GUEST);
38     g_assert(!s->nr_domu_watches);
39 
40     err = xs_impl_rm(s, DOMID_QEMU, XBT_NULL, "/local");
41     g_assert(!err);
42     g_assert(s->nr_nodes == 1);
43 
44     g_hash_table_unref(s->watches);
45     xs_node_unref(s->root);
46     g_free(s);
47 
48     if (xs_node_list) {
49         GList *l;
50         for (l = xs_node_list; l; l = l->next) {
51             XsNode *n = l->data;
52             printf("Remaining node at %p name %s ref %u\n", n, n->name,
53                    n->ref);
54         }
55     }
56     g_assert(!nr_xs_nodes);
57 }
58 
59 static int write_str(XenstoreImplState *s, unsigned int dom_id,
60                           unsigned int tx_id, const char *path,
61                           const char *content)
62 {
63     GByteArray *d = g_byte_array_new();
64     int err;
65 
66     g_byte_array_append(d, (void *)content, strlen(content));
67     err = xs_impl_write(s, dom_id, tx_id, path, d);
68     g_byte_array_unref(d);
69     return err;
70 }
71 
72 static void watch_cb(void *_str, const char *path, const char *token)
73 {
74     GString *str = _str;
75 
76     g_string_append(str, path);
77     g_string_append(str, token);
78 }
79 
80 static XenstoreImplState *setup(void)
81 {
82    XenstoreImplState *s = xs_impl_create();
83    char *abspath;
84    int err;
85 
86    abspath = g_strdup_printf("/local/domain/%u", DOMID_GUEST);
87 
88    err = write_str(s, DOMID_QEMU, XBT_NULL, abspath, "");
89    g_assert(!err);
90    g_assert(s->nr_nodes == 4);
91 
92    g_free(abspath);
93 
94    abspath = g_strdup_printf("/local/domain/%u/some", DOMID_GUEST);
95 
96    err = write_str(s, DOMID_QEMU, XBT_NULL, abspath, "");
97    g_assert(!err);
98    g_assert(s->nr_nodes == 5);
99 
100    g_free(abspath);
101 
102    return s;
103 }
104 
105 static void test_xs_node_simple(void)
106 {
107     GByteArray *data = g_byte_array_new();
108     XenstoreImplState *s = setup();
109     GString *guest_watches = g_string_new(NULL);
110     GString *qemu_watches = g_string_new(NULL);
111     GList *items = NULL;
112     XsNode *old_root;
113     uint64_t gencnt;
114     int err;
115 
116     g_assert(s);
117 
118     err = xs_impl_watch(s, DOMID_GUEST, "some", "guestwatch",
119                         watch_cb, guest_watches);
120     g_assert(!err);
121     g_assert(guest_watches->len == strlen("someguestwatch"));
122     g_assert(!strcmp(guest_watches->str, "someguestwatch"));
123     g_string_truncate(guest_watches, 0);
124 
125     err = xs_impl_watch(s, 0, "/local/domain/1/some", "qemuwatch",
126                         watch_cb, qemu_watches);
127     g_assert(!err);
128     g_assert(qemu_watches->len == strlen("/local/domain/1/someqemuwatch"));
129     g_assert(!strcmp(qemu_watches->str, "/local/domain/1/someqemuwatch"));
130     g_string_truncate(qemu_watches, 0);
131 
132     /* Read gives ENOENT when it should */
133     err = xs_impl_read(s, DOMID_GUEST, XBT_NULL, "foo", data);
134     g_assert(err == ENOENT);
135 
136     /* Write works */
137     err = write_str(s, DOMID_GUEST, XBT_NULL, "some/relative/path",
138                     "something");
139     g_assert(s->nr_nodes == 7);
140     g_assert(!err);
141     g_assert(!strcmp(guest_watches->str,
142                      "some/relative/pathguestwatch"));
143     g_assert(!strcmp(qemu_watches->str,
144                      "/local/domain/1/some/relative/pathqemuwatch"));
145 
146     g_string_truncate(qemu_watches, 0);
147     g_string_truncate(guest_watches, 0);
148     xs_impl_reset_watches(s, 0);
149 
150     /* Read gives back what we wrote */
151     err = xs_impl_read(s, DOMID_GUEST, XBT_NULL, "some/relative/path", data);
152     g_assert(!err);
153     g_assert(data->len == strlen("something"));
154     g_assert(!memcmp(data->data, "something", data->len));
155 
156     /* Even if we use an abolute path */
157     g_byte_array_set_size(data, 0);
158     err = xs_impl_read(s, DOMID_GUEST, XBT_NULL,
159                        "/local/domain/1/some/relative/path", data);
160     g_assert(!err);
161     g_assert(data->len == strlen("something"));
162 
163     g_assert(!qemu_watches->len);
164     g_assert(!guest_watches->len);
165     /* Keep a copy, to force COW mode */
166     old_root = xs_node_ref(s->root);
167 
168     /* Write works again */
169     err = write_str(s, DOMID_GUEST, XBT_NULL,
170                     "/local/domain/1/some/relative/path2",
171                     "something else");
172     g_assert(!err);
173     g_assert(s->nr_nodes == 8);
174     g_assert(!qemu_watches->len);
175     g_assert(!strcmp(guest_watches->str, "some/relative/path2guestwatch"));
176     g_string_truncate(guest_watches, 0);
177 
178     /* Overwrite an existing node */
179     err = write_str(s, DOMID_GUEST, XBT_NULL, "some/relative/path",
180                     "another thing");
181     g_assert(!err);
182     g_assert(s->nr_nodes == 8);
183     g_assert(!qemu_watches->len);
184     g_assert(!strcmp(guest_watches->str, "some/relative/pathguestwatch"));
185     g_string_truncate(guest_watches, 0);
186 
187     /* We can list the two files we wrote */
188     err = xs_impl_directory(s, DOMID_GUEST, XBT_NULL, "some/relative", &gencnt,
189                             &items);
190     g_assert(!err);
191     g_assert(items);
192     g_assert(gencnt == 2);
193     g_assert(!strcmp(items->data, "path"));
194     g_assert(items->next);
195     g_assert(!strcmp(items->next->data, "path2"));
196     g_assert(!items->next->next);
197     g_list_free_full(items, g_free);
198 
199     err = xs_impl_unwatch(s, DOMID_GUEST, "some", "guestwatch",
200                           watch_cb, guest_watches);
201     g_assert(!err);
202 
203     err = xs_impl_unwatch(s, DOMID_GUEST, "some", "guestwatch",
204                           watch_cb, guest_watches);
205     g_assert(err == ENOENT);
206 
207     err = xs_impl_watch(s, DOMID_GUEST, "some/relative/path2", "watchp2",
208                         watch_cb, guest_watches);
209     g_assert(!err);
210     g_assert(guest_watches->len == strlen("some/relative/path2watchp2"));
211     g_assert(!strcmp(guest_watches->str, "some/relative/path2watchp2"));
212     g_string_truncate(guest_watches, 0);
213 
214     err = xs_impl_watch(s, DOMID_GUEST, "/local/domain/1/some/relative",
215                         "watchrel", watch_cb, guest_watches);
216     g_assert(!err);
217     g_assert(guest_watches->len ==
218              strlen("/local/domain/1/some/relativewatchrel"));
219     g_assert(!strcmp(guest_watches->str,
220                      "/local/domain/1/some/relativewatchrel"));
221     g_string_truncate(guest_watches, 0);
222 
223     /* Write somewhere else which already existed */
224     err = write_str(s, DOMID_GUEST, XBT_NULL, "some/relative", "moredata");
225     g_assert(!err);
226     g_assert(s->nr_nodes == 8);
227 
228     g_assert(!strcmp(guest_watches->str,
229                      "/local/domain/1/some/relativewatchrel"));
230     g_string_truncate(guest_watches, 0);
231 
232     g_byte_array_set_size(data, 0);
233     err = xs_impl_read(s, DOMID_GUEST, XBT_NULL, "some/relative", data);
234     g_assert(!err);
235     g_assert(data->len == strlen("moredata"));
236     g_assert(!memcmp(data->data, "moredata", data->len));
237 
238     /* Overwrite existing data */
239     err = write_str(s, DOMID_GUEST, XBT_NULL, "some/relative", "otherdata");
240     g_assert(!err);
241     g_string_truncate(guest_watches, 0);
242 
243     g_byte_array_set_size(data, 0);
244     err = xs_impl_read(s, DOMID_GUEST, XBT_NULL, "some/relative", data);
245     g_assert(!err);
246     g_assert(data->len == strlen("otherdata"));
247     g_assert(!memcmp(data->data, "otherdata", data->len));
248 
249     /* Remove the subtree */
250     err = xs_impl_rm(s, DOMID_GUEST, XBT_NULL, "some/relative");
251     g_assert(!err);
252     g_assert(s->nr_nodes == 5);
253 
254     /* Each watch fires with the least specific relevant path */
255     g_assert(strstr(guest_watches->str,
256                     "some/relative/path2watchp2"));
257     g_assert(strstr(guest_watches->str,
258                     "/local/domain/1/some/relativewatchrel"));
259     g_string_truncate(guest_watches, 0);
260 
261     g_byte_array_set_size(data, 0);
262     err = xs_impl_read(s, DOMID_GUEST, XBT_NULL, "some/relative", data);
263     g_assert(err == ENOENT);
264     g_byte_array_unref(data);
265 
266     xs_impl_reset_watches(s, DOMID_GUEST);
267     g_string_free(qemu_watches, true);
268     g_string_free(guest_watches, true);
269     xs_node_unref(old_root);
270     xs_impl_delete(s);
271 }
272 
273 
274 int main(int argc, char **argv)
275 {
276     g_test_init(&argc, &argv, NULL);
277     module_call_init(MODULE_INIT_QOM);
278 
279     g_test_add_func("/xs_node/simple", test_xs_node_simple);
280 
281     return g_test_run();
282 }
283