xref: /openbmc/qemu/hw/s390x/s390-skeys.c (revision 4a09d0bb)
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 "qmp-commands.h"
15 #include "migration/qemu-file.h"
16 #include "hw/s390x/storage-keys.h"
17 #include "qemu/error-report.h"
18 #include "sysemu/kvm.h"
19 
20 #define S390_SKEYS_BUFFER_SIZE 131072  /* Room for 128k storage keys */
21 #define S390_SKEYS_SAVE_FLAG_EOS 0x01
22 #define S390_SKEYS_SAVE_FLAG_SKEYS 0x02
23 #define S390_SKEYS_SAVE_FLAG_ERROR 0x04
24 
25 S390SKeysState *s390_get_skeys_device(void)
26 {
27     S390SKeysState *ss;
28 
29     ss = S390_SKEYS(object_resolve_path_type("", TYPE_S390_SKEYS, NULL));
30     assert(ss);
31     return ss;
32 }
33 
34 void s390_skeys_init(void)
35 {
36     Object *obj;
37 
38     if (kvm_enabled()) {
39         obj = object_new(TYPE_KVM_S390_SKEYS);
40     } else {
41         obj = object_new(TYPE_QEMU_S390_SKEYS);
42     }
43     object_property_add_child(qdev_get_machine(), TYPE_S390_SKEYS,
44                               obj, NULL);
45     object_unref(obj);
46 
47     qdev_init_nofail(DEVICE(obj));
48 }
49 
50 static void write_keys(FILE *f, uint8_t *keys, uint64_t startgfn,
51                        uint64_t count, Error **errp)
52 {
53     uint64_t curpage = startgfn;
54     uint64_t maxpage = curpage + count - 1;
55 
56     for (; curpage <= maxpage; curpage++) {
57         uint8_t acc = (*keys & 0xF0) >> 4;
58         int fp =  (*keys & 0x08);
59         int ref = (*keys & 0x04);
60         int ch = (*keys & 0x02);
61         int res = (*keys & 0x01);
62 
63         fprintf(f, "page=%03" PRIx64 ": key(%d) => ACC=%X, FP=%d, REF=%d,"
64                 " ch=%d, reserved=%d\n",
65                 curpage, *keys, acc, fp, ref, ch, res);
66         keys++;
67     }
68 }
69 
70 void hmp_info_skeys(Monitor *mon, const QDict *qdict)
71 {
72     S390SKeysState *ss = s390_get_skeys_device();
73     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
74     uint64_t addr = qdict_get_int(qdict, "addr");
75     uint8_t key;
76     int r;
77 
78     /* Quick check to see if guest is using storage keys*/
79     if (!skeyclass->skeys_enabled(ss)) {
80         monitor_printf(mon, "Error: This guest is not using storage keys\n");
81         return;
82     }
83 
84     r = skeyclass->get_skeys(ss, addr / TARGET_PAGE_SIZE, 1, &key);
85     if (r < 0) {
86         monitor_printf(mon, "Error: %s\n", strerror(-r));
87         return;
88     }
89 
90     monitor_printf(mon, "  key: 0x%X\n", key);
91 }
92 
93 void hmp_dump_skeys(Monitor *mon, const QDict *qdict)
94 {
95     const char *filename = qdict_get_str(qdict, "filename");
96     Error *err = NULL;
97 
98     qmp_dump_skeys(filename, &err);
99     if (err) {
100         error_report_err(err);
101     }
102 }
103 
104 void qmp_dump_skeys(const char *filename, Error **errp)
105 {
106     S390SKeysState *ss = s390_get_skeys_device();
107     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
108     const uint64_t total_count = ram_size / TARGET_PAGE_SIZE;
109     uint64_t handled_count = 0, cur_count;
110     Error *lerr = NULL;
111     vaddr cur_gfn = 0;
112     uint8_t *buf;
113     int ret;
114     int fd;
115     FILE *f;
116 
117     /* Quick check to see if guest is using storage keys*/
118     if (!skeyclass->skeys_enabled(ss)) {
119         error_setg(errp, "This guest is not using storage keys - "
120                          "nothing to dump");
121         return;
122     }
123 
124     fd = qemu_open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600);
125     if (fd < 0) {
126         error_setg_file_open(errp, errno, filename);
127         return;
128     }
129     f = fdopen(fd, "wb");
130     if (!f) {
131         close(fd);
132         error_setg_file_open(errp, errno, filename);
133         return;
134     }
135 
136     buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
137     if (!buf) {
138         error_setg(errp, "Could not allocate memory");
139         goto out;
140     }
141 
142     /* we'll only dump initial memory for now */
143     while (handled_count < total_count) {
144         /* Calculate how many keys to ask for & handle overflow case */
145         cur_count = MIN(total_count - handled_count, S390_SKEYS_BUFFER_SIZE);
146 
147         ret = skeyclass->get_skeys(ss, cur_gfn, cur_count, buf);
148         if (ret < 0) {
149             error_setg(errp, "get_keys error %d", ret);
150             goto out_free;
151         }
152 
153         /* write keys to stream */
154         write_keys(f, buf, cur_gfn, cur_count, &lerr);
155         if (lerr) {
156             goto out_free;
157         }
158 
159         cur_gfn += cur_count;
160         handled_count += cur_count;
161     }
162 
163 out_free:
164     error_propagate(errp, lerr);
165     g_free(buf);
166 out:
167     fclose(f);
168 }
169 
170 static void qemu_s390_skeys_init(Object *obj)
171 {
172     QEMUS390SKeysState *skeys = QEMU_S390_SKEYS(obj);
173     MachineState *machine = MACHINE(qdev_get_machine());
174 
175     skeys->key_count = machine->maxram_size / TARGET_PAGE_SIZE;
176     skeys->keydata = g_malloc0(skeys->key_count);
177 }
178 
179 static int qemu_s390_skeys_enabled(S390SKeysState *ss)
180 {
181     return 1;
182 }
183 
184 /*
185  * TODO: for memory hotplug support qemu_s390_skeys_set and qemu_s390_skeys_get
186  * will have to make sure that the given gfn belongs to a memory region and not
187  * a memory hole.
188  */
189 static int qemu_s390_skeys_set(S390SKeysState *ss, uint64_t start_gfn,
190                               uint64_t count, uint8_t *keys)
191 {
192     QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss);
193     int i;
194 
195     /* Check for uint64 overflow and access beyond end of key data */
196     if (start_gfn + count > skeydev->key_count || start_gfn + count < count) {
197         error_report("Error: Setting storage keys for page beyond the end "
198                      "of memory: gfn=%" PRIx64 " count=%" PRId64,
199                      start_gfn, count);
200         return -EINVAL;
201     }
202 
203     for (i = 0; i < count; i++) {
204         skeydev->keydata[start_gfn + i] = keys[i];
205     }
206     return 0;
207 }
208 
209 static int qemu_s390_skeys_get(S390SKeysState *ss, uint64_t start_gfn,
210                                uint64_t count, uint8_t *keys)
211 {
212     QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss);
213     int i;
214 
215     /* Check for uint64 overflow and access beyond end of key data */
216     if (start_gfn + count > skeydev->key_count || start_gfn + count < count) {
217         error_report("Error: Getting storage keys for page beyond the end "
218                      "of memory: gfn=%" PRIx64 " count=%" PRId64,
219                      start_gfn, count);
220         return -EINVAL;
221     }
222 
223     for (i = 0; i < count; i++) {
224         keys[i] = skeydev->keydata[start_gfn + i];
225     }
226     return 0;
227 }
228 
229 static void qemu_s390_skeys_class_init(ObjectClass *oc, void *data)
230 {
231     S390SKeysClass *skeyclass = S390_SKEYS_CLASS(oc);
232 
233     skeyclass->skeys_enabled = qemu_s390_skeys_enabled;
234     skeyclass->get_skeys = qemu_s390_skeys_get;
235     skeyclass->set_skeys = qemu_s390_skeys_set;
236 }
237 
238 static const TypeInfo qemu_s390_skeys_info = {
239     .name          = TYPE_QEMU_S390_SKEYS,
240     .parent        = TYPE_S390_SKEYS,
241     .instance_init = qemu_s390_skeys_init,
242     .instance_size = sizeof(QEMUS390SKeysState),
243     .class_init    = qemu_s390_skeys_class_init,
244     .class_size    = sizeof(S390SKeysClass),
245 };
246 
247 static void s390_storage_keys_save(QEMUFile *f, void *opaque)
248 {
249     S390SKeysState *ss = S390_SKEYS(opaque);
250     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
251     uint64_t pages_left = ram_size / TARGET_PAGE_SIZE;
252     uint64_t read_count, eos = S390_SKEYS_SAVE_FLAG_EOS;
253     vaddr cur_gfn = 0;
254     int error = 0;
255     uint8_t *buf;
256 
257     if (!skeyclass->skeys_enabled(ss)) {
258         goto end_stream;
259     }
260 
261     buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
262     if (!buf) {
263         error_report("storage key save could not allocate memory");
264         goto end_stream;
265     }
266 
267     /* We only support initial memory. Standby memory is not handled yet. */
268     qemu_put_be64(f, (cur_gfn * TARGET_PAGE_SIZE) | S390_SKEYS_SAVE_FLAG_SKEYS);
269     qemu_put_be64(f, pages_left);
270 
271     while (pages_left) {
272         read_count = MIN(pages_left, S390_SKEYS_BUFFER_SIZE);
273 
274         if (!error) {
275             error = skeyclass->get_skeys(ss, cur_gfn, read_count, buf);
276             if (error) {
277                 /*
278                  * If error: we want to fill the stream with valid data instead
279                  * of stopping early so we pad the stream with 0x00 values and
280                  * use S390_SKEYS_SAVE_FLAG_ERROR to indicate failure to the
281                  * reading side.
282                  */
283                 error_report("S390_GET_KEYS error %d", error);
284                 memset(buf, 0, S390_SKEYS_BUFFER_SIZE);
285                 eos = S390_SKEYS_SAVE_FLAG_ERROR;
286             }
287         }
288 
289         qemu_put_buffer(f, buf, read_count);
290         cur_gfn += read_count;
291         pages_left -= read_count;
292     }
293 
294     g_free(buf);
295 end_stream:
296     qemu_put_be64(f, eos);
297 }
298 
299 static int s390_storage_keys_load(QEMUFile *f, void *opaque, int version_id)
300 {
301     S390SKeysState *ss = S390_SKEYS(opaque);
302     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
303     int ret = 0;
304 
305     while (!ret) {
306         ram_addr_t addr;
307         int flags;
308 
309         addr = qemu_get_be64(f);
310         flags = addr & ~TARGET_PAGE_MASK;
311         addr &= TARGET_PAGE_MASK;
312 
313         switch (flags) {
314         case S390_SKEYS_SAVE_FLAG_SKEYS: {
315             const uint64_t total_count = qemu_get_be64(f);
316             uint64_t handled_count = 0, cur_count;
317             uint64_t cur_gfn = addr / TARGET_PAGE_SIZE;
318             uint8_t *buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
319 
320             if (!buf) {
321                 error_report("storage key load could not allocate memory");
322                 ret = -ENOMEM;
323                 break;
324             }
325 
326             while (handled_count < total_count) {
327                 cur_count = MIN(total_count - handled_count,
328                                 S390_SKEYS_BUFFER_SIZE);
329                 qemu_get_buffer(f, buf, cur_count);
330 
331                 ret = skeyclass->set_skeys(ss, cur_gfn, cur_count, buf);
332                 if (ret < 0) {
333                     error_report("S390_SET_KEYS error %d", ret);
334                     break;
335                 }
336                 handled_count += cur_count;
337                 cur_gfn += cur_count;
338             }
339             g_free(buf);
340             break;
341         }
342         case S390_SKEYS_SAVE_FLAG_ERROR: {
343             error_report("Storage key data is incomplete");
344             ret = -EINVAL;
345             break;
346         }
347         case S390_SKEYS_SAVE_FLAG_EOS:
348             /* normal exit */
349             return 0;
350         default:
351             error_report("Unexpected storage key flag data: %#x", flags);
352             ret = -EINVAL;
353         }
354     }
355 
356     return ret;
357 }
358 
359 static inline bool s390_skeys_get_migration_enabled(Object *obj, Error **errp)
360 {
361     S390SKeysState *ss = S390_SKEYS(obj);
362 
363     return ss->migration_enabled;
364 }
365 
366 static inline void s390_skeys_set_migration_enabled(Object *obj, bool value,
367                                             Error **errp)
368 {
369     S390SKeysState *ss = S390_SKEYS(obj);
370 
371     /* Prevent double registration of savevm handler */
372     if (ss->migration_enabled == value) {
373         return;
374     }
375 
376     ss->migration_enabled = value;
377 
378     if (ss->migration_enabled) {
379         register_savevm(NULL, TYPE_S390_SKEYS, 0, 1, s390_storage_keys_save,
380                         s390_storage_keys_load, ss);
381     } else {
382         unregister_savevm(DEVICE(ss), TYPE_S390_SKEYS, ss);
383     }
384 }
385 
386 static void s390_skeys_instance_init(Object *obj)
387 {
388     object_property_add_bool(obj, "migration-enabled",
389                              s390_skeys_get_migration_enabled,
390                              s390_skeys_set_migration_enabled, NULL);
391     object_property_set_bool(obj, true, "migration-enabled", NULL);
392 }
393 
394 static void s390_skeys_class_init(ObjectClass *oc, void *data)
395 {
396     DeviceClass *dc = DEVICE_CLASS(oc);
397 
398     dc->hotpluggable = false;
399     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
400 }
401 
402 static const TypeInfo s390_skeys_info = {
403     .name          = TYPE_S390_SKEYS,
404     .parent        = TYPE_DEVICE,
405     .instance_init = s390_skeys_instance_init,
406     .instance_size = sizeof(S390SKeysState),
407     .class_init    = s390_skeys_class_init,
408     .class_size    = sizeof(S390SKeysClass),
409     .abstract = true,
410 };
411 
412 static void qemu_s390_skeys_register_types(void)
413 {
414     type_register_static(&s390_skeys_info);
415     type_register_static(&qemu_s390_skeys_info);
416 }
417 
418 type_init(qemu_s390_skeys_register_types)
419