xref: /openbmc/qemu/hw/s390x/s390-skeys.c (revision dd873966)
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 "hw/s390x/storage-keys.h"
16 #include "qemu/error-report.h"
17 #include "sysemu/kvm.h"
18 #include "migration/register.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     DeviceClass *dc = DEVICE_CLASS(oc);
233 
234     skeyclass->skeys_enabled = qemu_s390_skeys_enabled;
235     skeyclass->get_skeys = qemu_s390_skeys_get;
236     skeyclass->set_skeys = qemu_s390_skeys_set;
237 
238     /* Reason: Internal device (only one skeys device for the whole memory) */
239     dc->user_creatable = false;
240 }
241 
242 static const TypeInfo qemu_s390_skeys_info = {
243     .name          = TYPE_QEMU_S390_SKEYS,
244     .parent        = TYPE_S390_SKEYS,
245     .instance_init = qemu_s390_skeys_init,
246     .instance_size = sizeof(QEMUS390SKeysState),
247     .class_init    = qemu_s390_skeys_class_init,
248     .class_size    = sizeof(S390SKeysClass),
249 };
250 
251 static void s390_storage_keys_save(QEMUFile *f, void *opaque)
252 {
253     S390SKeysState *ss = S390_SKEYS(opaque);
254     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
255     uint64_t pages_left = ram_size / TARGET_PAGE_SIZE;
256     uint64_t read_count, eos = S390_SKEYS_SAVE_FLAG_EOS;
257     vaddr cur_gfn = 0;
258     int error = 0;
259     uint8_t *buf;
260 
261     if (!skeyclass->skeys_enabled(ss)) {
262         goto end_stream;
263     }
264 
265     buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
266     if (!buf) {
267         error_report("storage key save could not allocate memory");
268         goto end_stream;
269     }
270 
271     /* We only support initial memory. Standby memory is not handled yet. */
272     qemu_put_be64(f, (cur_gfn * TARGET_PAGE_SIZE) | S390_SKEYS_SAVE_FLAG_SKEYS);
273     qemu_put_be64(f, pages_left);
274 
275     while (pages_left) {
276         read_count = MIN(pages_left, S390_SKEYS_BUFFER_SIZE);
277 
278         if (!error) {
279             error = skeyclass->get_skeys(ss, cur_gfn, read_count, buf);
280             if (error) {
281                 /*
282                  * If error: we want to fill the stream with valid data instead
283                  * of stopping early so we pad the stream with 0x00 values and
284                  * use S390_SKEYS_SAVE_FLAG_ERROR to indicate failure to the
285                  * reading side.
286                  */
287                 error_report("S390_GET_KEYS error %d", error);
288                 memset(buf, 0, S390_SKEYS_BUFFER_SIZE);
289                 eos = S390_SKEYS_SAVE_FLAG_ERROR;
290             }
291         }
292 
293         qemu_put_buffer(f, buf, read_count);
294         cur_gfn += read_count;
295         pages_left -= read_count;
296     }
297 
298     g_free(buf);
299 end_stream:
300     qemu_put_be64(f, eos);
301 }
302 
303 static int s390_storage_keys_load(QEMUFile *f, void *opaque, int version_id)
304 {
305     S390SKeysState *ss = S390_SKEYS(opaque);
306     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
307     int ret = 0;
308 
309     while (!ret) {
310         ram_addr_t addr;
311         int flags;
312 
313         addr = qemu_get_be64(f);
314         flags = addr & ~TARGET_PAGE_MASK;
315         addr &= TARGET_PAGE_MASK;
316 
317         switch (flags) {
318         case S390_SKEYS_SAVE_FLAG_SKEYS: {
319             const uint64_t total_count = qemu_get_be64(f);
320             uint64_t handled_count = 0, cur_count;
321             uint64_t cur_gfn = addr / TARGET_PAGE_SIZE;
322             uint8_t *buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
323 
324             if (!buf) {
325                 error_report("storage key load could not allocate memory");
326                 ret = -ENOMEM;
327                 break;
328             }
329 
330             while (handled_count < total_count) {
331                 cur_count = MIN(total_count - handled_count,
332                                 S390_SKEYS_BUFFER_SIZE);
333                 qemu_get_buffer(f, buf, cur_count);
334 
335                 ret = skeyclass->set_skeys(ss, cur_gfn, cur_count, buf);
336                 if (ret < 0) {
337                     error_report("S390_SET_KEYS error %d", ret);
338                     break;
339                 }
340                 handled_count += cur_count;
341                 cur_gfn += cur_count;
342             }
343             g_free(buf);
344             break;
345         }
346         case S390_SKEYS_SAVE_FLAG_ERROR: {
347             error_report("Storage key data is incomplete");
348             ret = -EINVAL;
349             break;
350         }
351         case S390_SKEYS_SAVE_FLAG_EOS:
352             /* normal exit */
353             return 0;
354         default:
355             error_report("Unexpected storage key flag data: %#x", flags);
356             ret = -EINVAL;
357         }
358     }
359 
360     return ret;
361 }
362 
363 static inline bool s390_skeys_get_migration_enabled(Object *obj, Error **errp)
364 {
365     S390SKeysState *ss = S390_SKEYS(obj);
366 
367     return ss->migration_enabled;
368 }
369 
370 static SaveVMHandlers savevm_s390_storage_keys = {
371     .save_state = s390_storage_keys_save,
372     .load_state = s390_storage_keys_load,
373 };
374 
375 static inline void s390_skeys_set_migration_enabled(Object *obj, bool value,
376                                             Error **errp)
377 {
378     S390SKeysState *ss = S390_SKEYS(obj);
379 
380     /* Prevent double registration of savevm handler */
381     if (ss->migration_enabled == value) {
382         return;
383     }
384 
385     ss->migration_enabled = value;
386 
387     if (ss->migration_enabled) {
388         register_savevm_live(NULL, TYPE_S390_SKEYS, 0, 1,
389                              &savevm_s390_storage_keys, ss);
390     } else {
391         unregister_savevm(DEVICE(ss), TYPE_S390_SKEYS, ss);
392     }
393 }
394 
395 static void s390_skeys_instance_init(Object *obj)
396 {
397     object_property_add_bool(obj, "migration-enabled",
398                              s390_skeys_get_migration_enabled,
399                              s390_skeys_set_migration_enabled, NULL);
400     object_property_set_bool(obj, true, "migration-enabled", NULL);
401 }
402 
403 static void s390_skeys_class_init(ObjectClass *oc, void *data)
404 {
405     DeviceClass *dc = DEVICE_CLASS(oc);
406 
407     dc->hotpluggable = false;
408     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
409 }
410 
411 static const TypeInfo s390_skeys_info = {
412     .name          = TYPE_S390_SKEYS,
413     .parent        = TYPE_DEVICE,
414     .instance_init = s390_skeys_instance_init,
415     .instance_size = sizeof(S390SKeysState),
416     .class_init    = s390_skeys_class_init,
417     .class_size    = sizeof(S390SKeysClass),
418     .abstract = true,
419 };
420 
421 static void qemu_s390_skeys_register_types(void)
422 {
423     type_register_static(&s390_skeys_info);
424     type_register_static(&qemu_s390_skeys_info);
425 }
426 
427 type_init(qemu_s390_skeys_register_types)
428