xref: /openbmc/qemu/hw/s390x/s390-skeys.c (revision 438c78da)
1 /*
2  * s390 storage key device
3  *
4  * Copyright 2015 IBM Corp.
5  * Author(s): Jason J. Herne <jjherne@linux.vnet.ibm.com>
6  *
7  * This work is licensed under the terms of the GNU GPL, version 2 or (at
8  * your option) any later version. See the COPYING file in the top-level
9  * directory.
10  */
11 
12 #include "qemu/osdep.h"
13 #include "qemu/units.h"
14 #include "hw/boards.h"
15 #include "hw/s390x/storage-keys.h"
16 #include "qapi/error.h"
17 #include "qapi/qapi-commands-misc.h"
18 #include "qapi/qmp/qdict.h"
19 #include "qemu/error-report.h"
20 #include "sysemu/kvm.h"
21 #include "migration/register.h"
22 
23 #define S390_SKEYS_BUFFER_SIZE (128 * KiB)  /* Room for 128k storage keys */
24 #define S390_SKEYS_SAVE_FLAG_EOS 0x01
25 #define S390_SKEYS_SAVE_FLAG_SKEYS 0x02
26 #define S390_SKEYS_SAVE_FLAG_ERROR 0x04
27 
28 S390SKeysState *s390_get_skeys_device(void)
29 {
30     S390SKeysState *ss;
31 
32     ss = S390_SKEYS(object_resolve_path_type("", TYPE_S390_SKEYS, NULL));
33     assert(ss);
34     return ss;
35 }
36 
37 void s390_skeys_init(void)
38 {
39     Object *obj;
40 
41     if (kvm_enabled()) {
42         obj = object_new(TYPE_KVM_S390_SKEYS);
43     } else {
44         obj = object_new(TYPE_QEMU_S390_SKEYS);
45     }
46     object_property_add_child(qdev_get_machine(), TYPE_S390_SKEYS,
47                               obj, NULL);
48     object_unref(obj);
49 
50     qdev_init_nofail(DEVICE(obj));
51 }
52 
53 static void write_keys(FILE *f, uint8_t *keys, uint64_t startgfn,
54                        uint64_t count, Error **errp)
55 {
56     uint64_t curpage = startgfn;
57     uint64_t maxpage = curpage + count - 1;
58 
59     for (; curpage <= maxpage; curpage++) {
60         uint8_t acc = (*keys & 0xF0) >> 4;
61         int fp =  (*keys & 0x08);
62         int ref = (*keys & 0x04);
63         int ch = (*keys & 0x02);
64         int res = (*keys & 0x01);
65 
66         fprintf(f, "page=%03" PRIx64 ": key(%d) => ACC=%X, FP=%d, REF=%d,"
67                 " ch=%d, reserved=%d\n",
68                 curpage, *keys, acc, fp, ref, ch, res);
69         keys++;
70     }
71 }
72 
73 void hmp_info_skeys(Monitor *mon, const QDict *qdict)
74 {
75     S390SKeysState *ss = s390_get_skeys_device();
76     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
77     uint64_t addr = qdict_get_int(qdict, "addr");
78     uint8_t key;
79     int r;
80 
81     /* Quick check to see if guest is using storage keys*/
82     if (!skeyclass->skeys_enabled(ss)) {
83         monitor_printf(mon, "Error: This guest is not using storage keys\n");
84         return;
85     }
86 
87     r = skeyclass->get_skeys(ss, addr / TARGET_PAGE_SIZE, 1, &key);
88     if (r < 0) {
89         monitor_printf(mon, "Error: %s\n", strerror(-r));
90         return;
91     }
92 
93     monitor_printf(mon, "  key: 0x%X\n", key);
94 }
95 
96 void hmp_dump_skeys(Monitor *mon, const QDict *qdict)
97 {
98     const char *filename = qdict_get_str(qdict, "filename");
99     Error *err = NULL;
100 
101     qmp_dump_skeys(filename, &err);
102     if (err) {
103         error_report_err(err);
104     }
105 }
106 
107 void qmp_dump_skeys(const char *filename, Error **errp)
108 {
109     S390SKeysState *ss = s390_get_skeys_device();
110     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
111     const uint64_t total_count = ram_size / TARGET_PAGE_SIZE;
112     uint64_t handled_count = 0, cur_count;
113     Error *lerr = NULL;
114     vaddr cur_gfn = 0;
115     uint8_t *buf;
116     int ret;
117     int fd;
118     FILE *f;
119 
120     /* Quick check to see if guest is using storage keys*/
121     if (!skeyclass->skeys_enabled(ss)) {
122         error_setg(errp, "This guest is not using storage keys - "
123                          "nothing to dump");
124         return;
125     }
126 
127     fd = qemu_open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600);
128     if (fd < 0) {
129         error_setg_file_open(errp, errno, filename);
130         return;
131     }
132     f = fdopen(fd, "wb");
133     if (!f) {
134         close(fd);
135         error_setg_file_open(errp, errno, filename);
136         return;
137     }
138 
139     buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
140     if (!buf) {
141         error_setg(errp, "Could not allocate memory");
142         goto out;
143     }
144 
145     /* we'll only dump initial memory for now */
146     while (handled_count < total_count) {
147         /* Calculate how many keys to ask for & handle overflow case */
148         cur_count = MIN(total_count - handled_count, S390_SKEYS_BUFFER_SIZE);
149 
150         ret = skeyclass->get_skeys(ss, cur_gfn, cur_count, buf);
151         if (ret < 0) {
152             error_setg(errp, "get_keys error %d", ret);
153             goto out_free;
154         }
155 
156         /* write keys to stream */
157         write_keys(f, buf, cur_gfn, cur_count, &lerr);
158         if (lerr) {
159             goto out_free;
160         }
161 
162         cur_gfn += cur_count;
163         handled_count += cur_count;
164     }
165 
166 out_free:
167     error_propagate(errp, lerr);
168     g_free(buf);
169 out:
170     fclose(f);
171 }
172 
173 static void qemu_s390_skeys_init(Object *obj)
174 {
175     QEMUS390SKeysState *skeys = QEMU_S390_SKEYS(obj);
176     MachineState *machine = MACHINE(qdev_get_machine());
177 
178     skeys->key_count = machine->maxram_size / TARGET_PAGE_SIZE;
179     skeys->keydata = g_malloc0(skeys->key_count);
180 }
181 
182 static int qemu_s390_skeys_enabled(S390SKeysState *ss)
183 {
184     return 1;
185 }
186 
187 /*
188  * TODO: for memory hotplug support qemu_s390_skeys_set and qemu_s390_skeys_get
189  * will have to make sure that the given gfn belongs to a memory region and not
190  * a memory hole.
191  */
192 static int qemu_s390_skeys_set(S390SKeysState *ss, uint64_t start_gfn,
193                               uint64_t count, uint8_t *keys)
194 {
195     QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss);
196     int i;
197 
198     /* Check for uint64 overflow and access beyond end of key data */
199     if (start_gfn + count > skeydev->key_count || start_gfn + count < count) {
200         error_report("Error: Setting storage keys for page beyond the end "
201                      "of memory: gfn=%" PRIx64 " count=%" PRId64,
202                      start_gfn, count);
203         return -EINVAL;
204     }
205 
206     for (i = 0; i < count; i++) {
207         skeydev->keydata[start_gfn + i] = keys[i];
208     }
209     return 0;
210 }
211 
212 static int qemu_s390_skeys_get(S390SKeysState *ss, uint64_t start_gfn,
213                                uint64_t count, uint8_t *keys)
214 {
215     QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss);
216     int i;
217 
218     /* Check for uint64 overflow and access beyond end of key data */
219     if (start_gfn + count > skeydev->key_count || start_gfn + count < count) {
220         error_report("Error: Getting storage keys for page beyond the end "
221                      "of memory: gfn=%" PRIx64 " count=%" PRId64,
222                      start_gfn, count);
223         return -EINVAL;
224     }
225 
226     for (i = 0; i < count; i++) {
227         keys[i] = skeydev->keydata[start_gfn + i];
228     }
229     return 0;
230 }
231 
232 static void qemu_s390_skeys_class_init(ObjectClass *oc, void *data)
233 {
234     S390SKeysClass *skeyclass = S390_SKEYS_CLASS(oc);
235     DeviceClass *dc = DEVICE_CLASS(oc);
236 
237     skeyclass->skeys_enabled = qemu_s390_skeys_enabled;
238     skeyclass->get_skeys = qemu_s390_skeys_get;
239     skeyclass->set_skeys = qemu_s390_skeys_set;
240 
241     /* Reason: Internal device (only one skeys device for the whole memory) */
242     dc->user_creatable = false;
243 }
244 
245 static const TypeInfo qemu_s390_skeys_info = {
246     .name          = TYPE_QEMU_S390_SKEYS,
247     .parent        = TYPE_S390_SKEYS,
248     .instance_init = qemu_s390_skeys_init,
249     .instance_size = sizeof(QEMUS390SKeysState),
250     .class_init    = qemu_s390_skeys_class_init,
251     .class_size    = sizeof(S390SKeysClass),
252 };
253 
254 static void s390_storage_keys_save(QEMUFile *f, void *opaque)
255 {
256     S390SKeysState *ss = S390_SKEYS(opaque);
257     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
258     uint64_t pages_left = ram_size / TARGET_PAGE_SIZE;
259     uint64_t read_count, eos = S390_SKEYS_SAVE_FLAG_EOS;
260     vaddr cur_gfn = 0;
261     int error = 0;
262     uint8_t *buf;
263 
264     if (!skeyclass->skeys_enabled(ss)) {
265         goto end_stream;
266     }
267 
268     buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
269     if (!buf) {
270         error_report("storage key save could not allocate memory");
271         goto end_stream;
272     }
273 
274     /* We only support initial memory. Standby memory is not handled yet. */
275     qemu_put_be64(f, (cur_gfn * TARGET_PAGE_SIZE) | S390_SKEYS_SAVE_FLAG_SKEYS);
276     qemu_put_be64(f, pages_left);
277 
278     while (pages_left) {
279         read_count = MIN(pages_left, S390_SKEYS_BUFFER_SIZE);
280 
281         if (!error) {
282             error = skeyclass->get_skeys(ss, cur_gfn, read_count, buf);
283             if (error) {
284                 /*
285                  * If error: we want to fill the stream with valid data instead
286                  * of stopping early so we pad the stream with 0x00 values and
287                  * use S390_SKEYS_SAVE_FLAG_ERROR to indicate failure to the
288                  * reading side.
289                  */
290                 error_report("S390_GET_KEYS error %d", error);
291                 memset(buf, 0, S390_SKEYS_BUFFER_SIZE);
292                 eos = S390_SKEYS_SAVE_FLAG_ERROR;
293             }
294         }
295 
296         qemu_put_buffer(f, buf, read_count);
297         cur_gfn += read_count;
298         pages_left -= read_count;
299     }
300 
301     g_free(buf);
302 end_stream:
303     qemu_put_be64(f, eos);
304 }
305 
306 static int s390_storage_keys_load(QEMUFile *f, void *opaque, int version_id)
307 {
308     S390SKeysState *ss = S390_SKEYS(opaque);
309     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
310     int ret = 0;
311 
312     while (!ret) {
313         ram_addr_t addr;
314         int flags;
315 
316         addr = qemu_get_be64(f);
317         flags = addr & ~TARGET_PAGE_MASK;
318         addr &= TARGET_PAGE_MASK;
319 
320         switch (flags) {
321         case S390_SKEYS_SAVE_FLAG_SKEYS: {
322             const uint64_t total_count = qemu_get_be64(f);
323             uint64_t handled_count = 0, cur_count;
324             uint64_t cur_gfn = addr / TARGET_PAGE_SIZE;
325             uint8_t *buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
326 
327             if (!buf) {
328                 error_report("storage key load could not allocate memory");
329                 ret = -ENOMEM;
330                 break;
331             }
332 
333             while (handled_count < total_count) {
334                 cur_count = MIN(total_count - handled_count,
335                                 S390_SKEYS_BUFFER_SIZE);
336                 qemu_get_buffer(f, buf, cur_count);
337 
338                 ret = skeyclass->set_skeys(ss, cur_gfn, cur_count, buf);
339                 if (ret < 0) {
340                     error_report("S390_SET_KEYS error %d", ret);
341                     break;
342                 }
343                 handled_count += cur_count;
344                 cur_gfn += cur_count;
345             }
346             g_free(buf);
347             break;
348         }
349         case S390_SKEYS_SAVE_FLAG_ERROR: {
350             error_report("Storage key data is incomplete");
351             ret = -EINVAL;
352             break;
353         }
354         case S390_SKEYS_SAVE_FLAG_EOS:
355             /* normal exit */
356             return 0;
357         default:
358             error_report("Unexpected storage key flag data: %#x", flags);
359             ret = -EINVAL;
360         }
361     }
362 
363     return ret;
364 }
365 
366 static inline bool s390_skeys_get_migration_enabled(Object *obj, Error **errp)
367 {
368     S390SKeysState *ss = S390_SKEYS(obj);
369 
370     return ss->migration_enabled;
371 }
372 
373 static SaveVMHandlers savevm_s390_storage_keys = {
374     .save_state = s390_storage_keys_save,
375     .load_state = s390_storage_keys_load,
376 };
377 
378 static inline void s390_skeys_set_migration_enabled(Object *obj, bool value,
379                                             Error **errp)
380 {
381     S390SKeysState *ss = S390_SKEYS(obj);
382 
383     /* Prevent double registration of savevm handler */
384     if (ss->migration_enabled == value) {
385         return;
386     }
387 
388     ss->migration_enabled = value;
389 
390     if (ss->migration_enabled) {
391         register_savevm_live(NULL, TYPE_S390_SKEYS, 0, 1,
392                              &savevm_s390_storage_keys, ss);
393     } else {
394         unregister_savevm(DEVICE(ss), TYPE_S390_SKEYS, ss);
395     }
396 }
397 
398 static void s390_skeys_instance_init(Object *obj)
399 {
400     object_property_add_bool(obj, "migration-enabled",
401                              s390_skeys_get_migration_enabled,
402                              s390_skeys_set_migration_enabled, NULL);
403     object_property_set_bool(obj, true, "migration-enabled", NULL);
404 }
405 
406 static void s390_skeys_class_init(ObjectClass *oc, void *data)
407 {
408     DeviceClass *dc = DEVICE_CLASS(oc);
409 
410     dc->hotpluggable = false;
411     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
412 }
413 
414 static const TypeInfo s390_skeys_info = {
415     .name          = TYPE_S390_SKEYS,
416     .parent        = TYPE_DEVICE,
417     .instance_init = s390_skeys_instance_init,
418     .instance_size = sizeof(S390SKeysState),
419     .class_init    = s390_skeys_class_init,
420     .class_size    = sizeof(S390SKeysClass),
421     .abstract = true,
422 };
423 
424 static void qemu_s390_skeys_register_types(void)
425 {
426     type_register_static(&s390_skeys_info);
427     type_register_static(&qemu_s390_skeys_info);
428 }
429 
430 type_init(qemu_s390_skeys_register_types)
431