xref: /openbmc/qemu/hw/s390x/s390-skeys.c (revision dc5bd18f)
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 "hw/boards.h"
14 #include "hw/s390x/storage-keys.h"
15 #include "qapi/error.h"
16 #include "qapi/qapi-commands-misc.h"
17 #include "qapi/qmp/qdict.h"
18 #include "qemu/error-report.h"
19 #include "sysemu/kvm.h"
20 #include "migration/register.h"
21 
22 #define S390_SKEYS_BUFFER_SIZE 131072  /* Room for 128k storage keys */
23 #define S390_SKEYS_SAVE_FLAG_EOS 0x01
24 #define S390_SKEYS_SAVE_FLAG_SKEYS 0x02
25 #define S390_SKEYS_SAVE_FLAG_ERROR 0x04
26 
27 S390SKeysState *s390_get_skeys_device(void)
28 {
29     S390SKeysState *ss;
30 
31     ss = S390_SKEYS(object_resolve_path_type("", TYPE_S390_SKEYS, NULL));
32     assert(ss);
33     return ss;
34 }
35 
36 void s390_skeys_init(void)
37 {
38     Object *obj;
39 
40     if (kvm_enabled()) {
41         obj = object_new(TYPE_KVM_S390_SKEYS);
42     } else {
43         obj = object_new(TYPE_QEMU_S390_SKEYS);
44     }
45     object_property_add_child(qdev_get_machine(), TYPE_S390_SKEYS,
46                               obj, NULL);
47     object_unref(obj);
48 
49     qdev_init_nofail(DEVICE(obj));
50 }
51 
52 static void write_keys(FILE *f, uint8_t *keys, uint64_t startgfn,
53                        uint64_t count, Error **errp)
54 {
55     uint64_t curpage = startgfn;
56     uint64_t maxpage = curpage + count - 1;
57 
58     for (; curpage <= maxpage; curpage++) {
59         uint8_t acc = (*keys & 0xF0) >> 4;
60         int fp =  (*keys & 0x08);
61         int ref = (*keys & 0x04);
62         int ch = (*keys & 0x02);
63         int res = (*keys & 0x01);
64 
65         fprintf(f, "page=%03" PRIx64 ": key(%d) => ACC=%X, FP=%d, REF=%d,"
66                 " ch=%d, reserved=%d\n",
67                 curpage, *keys, acc, fp, ref, ch, res);
68         keys++;
69     }
70 }
71 
72 void hmp_info_skeys(Monitor *mon, const QDict *qdict)
73 {
74     S390SKeysState *ss = s390_get_skeys_device();
75     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
76     uint64_t addr = qdict_get_int(qdict, "addr");
77     uint8_t key;
78     int r;
79 
80     /* Quick check to see if guest is using storage keys*/
81     if (!skeyclass->skeys_enabled(ss)) {
82         monitor_printf(mon, "Error: This guest is not using storage keys\n");
83         return;
84     }
85 
86     r = skeyclass->get_skeys(ss, addr / TARGET_PAGE_SIZE, 1, &key);
87     if (r < 0) {
88         monitor_printf(mon, "Error: %s\n", strerror(-r));
89         return;
90     }
91 
92     monitor_printf(mon, "  key: 0x%X\n", key);
93 }
94 
95 void hmp_dump_skeys(Monitor *mon, const QDict *qdict)
96 {
97     const char *filename = qdict_get_str(qdict, "filename");
98     Error *err = NULL;
99 
100     qmp_dump_skeys(filename, &err);
101     if (err) {
102         error_report_err(err);
103     }
104 }
105 
106 void qmp_dump_skeys(const char *filename, Error **errp)
107 {
108     S390SKeysState *ss = s390_get_skeys_device();
109     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
110     const uint64_t total_count = ram_size / TARGET_PAGE_SIZE;
111     uint64_t handled_count = 0, cur_count;
112     Error *lerr = NULL;
113     vaddr cur_gfn = 0;
114     uint8_t *buf;
115     int ret;
116     int fd;
117     FILE *f;
118 
119     /* Quick check to see if guest is using storage keys*/
120     if (!skeyclass->skeys_enabled(ss)) {
121         error_setg(errp, "This guest is not using storage keys - "
122                          "nothing to dump");
123         return;
124     }
125 
126     fd = qemu_open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600);
127     if (fd < 0) {
128         error_setg_file_open(errp, errno, filename);
129         return;
130     }
131     f = fdopen(fd, "wb");
132     if (!f) {
133         close(fd);
134         error_setg_file_open(errp, errno, filename);
135         return;
136     }
137 
138     buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
139     if (!buf) {
140         error_setg(errp, "Could not allocate memory");
141         goto out;
142     }
143 
144     /* we'll only dump initial memory for now */
145     while (handled_count < total_count) {
146         /* Calculate how many keys to ask for & handle overflow case */
147         cur_count = MIN(total_count - handled_count, S390_SKEYS_BUFFER_SIZE);
148 
149         ret = skeyclass->get_skeys(ss, cur_gfn, cur_count, buf);
150         if (ret < 0) {
151             error_setg(errp, "get_keys error %d", ret);
152             goto out_free;
153         }
154 
155         /* write keys to stream */
156         write_keys(f, buf, cur_gfn, cur_count, &lerr);
157         if (lerr) {
158             goto out_free;
159         }
160 
161         cur_gfn += cur_count;
162         handled_count += cur_count;
163     }
164 
165 out_free:
166     error_propagate(errp, lerr);
167     g_free(buf);
168 out:
169     fclose(f);
170 }
171 
172 static void qemu_s390_skeys_init(Object *obj)
173 {
174     QEMUS390SKeysState *skeys = QEMU_S390_SKEYS(obj);
175     MachineState *machine = MACHINE(qdev_get_machine());
176 
177     skeys->key_count = machine->maxram_size / TARGET_PAGE_SIZE;
178     skeys->keydata = g_malloc0(skeys->key_count);
179 }
180 
181 static int qemu_s390_skeys_enabled(S390SKeysState *ss)
182 {
183     return 1;
184 }
185 
186 /*
187  * TODO: for memory hotplug support qemu_s390_skeys_set and qemu_s390_skeys_get
188  * will have to make sure that the given gfn belongs to a memory region and not
189  * a memory hole.
190  */
191 static int qemu_s390_skeys_set(S390SKeysState *ss, uint64_t start_gfn,
192                               uint64_t count, uint8_t *keys)
193 {
194     QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss);
195     int i;
196 
197     /* Check for uint64 overflow and access beyond end of key data */
198     if (start_gfn + count > skeydev->key_count || start_gfn + count < count) {
199         error_report("Error: Setting storage keys for page beyond the end "
200                      "of memory: gfn=%" PRIx64 " count=%" PRId64,
201                      start_gfn, count);
202         return -EINVAL;
203     }
204 
205     for (i = 0; i < count; i++) {
206         skeydev->keydata[start_gfn + i] = keys[i];
207     }
208     return 0;
209 }
210 
211 static int qemu_s390_skeys_get(S390SKeysState *ss, uint64_t start_gfn,
212                                uint64_t count, uint8_t *keys)
213 {
214     QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss);
215     int i;
216 
217     /* Check for uint64 overflow and access beyond end of key data */
218     if (start_gfn + count > skeydev->key_count || start_gfn + count < count) {
219         error_report("Error: Getting storage keys for page beyond the end "
220                      "of memory: gfn=%" PRIx64 " count=%" PRId64,
221                      start_gfn, count);
222         return -EINVAL;
223     }
224 
225     for (i = 0; i < count; i++) {
226         keys[i] = skeydev->keydata[start_gfn + i];
227     }
228     return 0;
229 }
230 
231 static void qemu_s390_skeys_class_init(ObjectClass *oc, void *data)
232 {
233     S390SKeysClass *skeyclass = S390_SKEYS_CLASS(oc);
234     DeviceClass *dc = DEVICE_CLASS(oc);
235 
236     skeyclass->skeys_enabled = qemu_s390_skeys_enabled;
237     skeyclass->get_skeys = qemu_s390_skeys_get;
238     skeyclass->set_skeys = qemu_s390_skeys_set;
239 
240     /* Reason: Internal device (only one skeys device for the whole memory) */
241     dc->user_creatable = false;
242 }
243 
244 static const TypeInfo qemu_s390_skeys_info = {
245     .name          = TYPE_QEMU_S390_SKEYS,
246     .parent        = TYPE_S390_SKEYS,
247     .instance_init = qemu_s390_skeys_init,
248     .instance_size = sizeof(QEMUS390SKeysState),
249     .class_init    = qemu_s390_skeys_class_init,
250     .class_size    = sizeof(S390SKeysClass),
251 };
252 
253 static void s390_storage_keys_save(QEMUFile *f, void *opaque)
254 {
255     S390SKeysState *ss = S390_SKEYS(opaque);
256     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
257     uint64_t pages_left = ram_size / TARGET_PAGE_SIZE;
258     uint64_t read_count, eos = S390_SKEYS_SAVE_FLAG_EOS;
259     vaddr cur_gfn = 0;
260     int error = 0;
261     uint8_t *buf;
262 
263     if (!skeyclass->skeys_enabled(ss)) {
264         goto end_stream;
265     }
266 
267     buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
268     if (!buf) {
269         error_report("storage key save could not allocate memory");
270         goto end_stream;
271     }
272 
273     /* We only support initial memory. Standby memory is not handled yet. */
274     qemu_put_be64(f, (cur_gfn * TARGET_PAGE_SIZE) | S390_SKEYS_SAVE_FLAG_SKEYS);
275     qemu_put_be64(f, pages_left);
276 
277     while (pages_left) {
278         read_count = MIN(pages_left, S390_SKEYS_BUFFER_SIZE);
279 
280         if (!error) {
281             error = skeyclass->get_skeys(ss, cur_gfn, read_count, buf);
282             if (error) {
283                 /*
284                  * If error: we want to fill the stream with valid data instead
285                  * of stopping early so we pad the stream with 0x00 values and
286                  * use S390_SKEYS_SAVE_FLAG_ERROR to indicate failure to the
287                  * reading side.
288                  */
289                 error_report("S390_GET_KEYS error %d", error);
290                 memset(buf, 0, S390_SKEYS_BUFFER_SIZE);
291                 eos = S390_SKEYS_SAVE_FLAG_ERROR;
292             }
293         }
294 
295         qemu_put_buffer(f, buf, read_count);
296         cur_gfn += read_count;
297         pages_left -= read_count;
298     }
299 
300     g_free(buf);
301 end_stream:
302     qemu_put_be64(f, eos);
303 }
304 
305 static int s390_storage_keys_load(QEMUFile *f, void *opaque, int version_id)
306 {
307     S390SKeysState *ss = S390_SKEYS(opaque);
308     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
309     int ret = 0;
310 
311     while (!ret) {
312         ram_addr_t addr;
313         int flags;
314 
315         addr = qemu_get_be64(f);
316         flags = addr & ~TARGET_PAGE_MASK;
317         addr &= TARGET_PAGE_MASK;
318 
319         switch (flags) {
320         case S390_SKEYS_SAVE_FLAG_SKEYS: {
321             const uint64_t total_count = qemu_get_be64(f);
322             uint64_t handled_count = 0, cur_count;
323             uint64_t cur_gfn = addr / TARGET_PAGE_SIZE;
324             uint8_t *buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
325 
326             if (!buf) {
327                 error_report("storage key load could not allocate memory");
328                 ret = -ENOMEM;
329                 break;
330             }
331 
332             while (handled_count < total_count) {
333                 cur_count = MIN(total_count - handled_count,
334                                 S390_SKEYS_BUFFER_SIZE);
335                 qemu_get_buffer(f, buf, cur_count);
336 
337                 ret = skeyclass->set_skeys(ss, cur_gfn, cur_count, buf);
338                 if (ret < 0) {
339                     error_report("S390_SET_KEYS error %d", ret);
340                     break;
341                 }
342                 handled_count += cur_count;
343                 cur_gfn += cur_count;
344             }
345             g_free(buf);
346             break;
347         }
348         case S390_SKEYS_SAVE_FLAG_ERROR: {
349             error_report("Storage key data is incomplete");
350             ret = -EINVAL;
351             break;
352         }
353         case S390_SKEYS_SAVE_FLAG_EOS:
354             /* normal exit */
355             return 0;
356         default:
357             error_report("Unexpected storage key flag data: %#x", flags);
358             ret = -EINVAL;
359         }
360     }
361 
362     return ret;
363 }
364 
365 static inline bool s390_skeys_get_migration_enabled(Object *obj, Error **errp)
366 {
367     S390SKeysState *ss = S390_SKEYS(obj);
368 
369     return ss->migration_enabled;
370 }
371 
372 static SaveVMHandlers savevm_s390_storage_keys = {
373     .save_state = s390_storage_keys_save,
374     .load_state = s390_storage_keys_load,
375 };
376 
377 static inline void s390_skeys_set_migration_enabled(Object *obj, bool value,
378                                             Error **errp)
379 {
380     S390SKeysState *ss = S390_SKEYS(obj);
381 
382     /* Prevent double registration of savevm handler */
383     if (ss->migration_enabled == value) {
384         return;
385     }
386 
387     ss->migration_enabled = value;
388 
389     if (ss->migration_enabled) {
390         register_savevm_live(NULL, TYPE_S390_SKEYS, 0, 1,
391                              &savevm_s390_storage_keys, ss);
392     } else {
393         unregister_savevm(DEVICE(ss), TYPE_S390_SKEYS, ss);
394     }
395 }
396 
397 static void s390_skeys_instance_init(Object *obj)
398 {
399     object_property_add_bool(obj, "migration-enabled",
400                              s390_skeys_get_migration_enabled,
401                              s390_skeys_set_migration_enabled, NULL);
402     object_property_set_bool(obj, true, "migration-enabled", NULL);
403 }
404 
405 static void s390_skeys_class_init(ObjectClass *oc, void *data)
406 {
407     DeviceClass *dc = DEVICE_CLASS(oc);
408 
409     dc->hotpluggable = false;
410     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
411 }
412 
413 static const TypeInfo s390_skeys_info = {
414     .name          = TYPE_S390_SKEYS,
415     .parent        = TYPE_DEVICE,
416     .instance_init = s390_skeys_instance_init,
417     .instance_size = sizeof(S390SKeysState),
418     .class_init    = s390_skeys_class_init,
419     .class_size    = sizeof(S390SKeysClass),
420     .abstract = true,
421 };
422 
423 static void qemu_s390_skeys_register_types(void)
424 {
425     type_register_static(&s390_skeys_info);
426     type_register_static(&qemu_s390_skeys_info);
427 }
428 
429 type_init(qemu_s390_skeys_register_types)
430