xref: /qemu/hw/s390x/s390-skeys.c (revision e688df6b)
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 "qapi/error.h"
17 #include "qemu/error-report.h"
18 #include "sysemu/kvm.h"
19 #include "migration/register.h"
20 
21 #define S390_SKEYS_BUFFER_SIZE 131072  /* Room for 128k storage keys */
22 #define S390_SKEYS_SAVE_FLAG_EOS 0x01
23 #define S390_SKEYS_SAVE_FLAG_SKEYS 0x02
24 #define S390_SKEYS_SAVE_FLAG_ERROR 0x04
25 
26 S390SKeysState *s390_get_skeys_device(void)
27 {
28     S390SKeysState *ss;
29 
30     ss = S390_SKEYS(object_resolve_path_type("", TYPE_S390_SKEYS, NULL));
31     assert(ss);
32     return ss;
33 }
34 
35 void s390_skeys_init(void)
36 {
37     Object *obj;
38 
39     if (kvm_enabled()) {
40         obj = object_new(TYPE_KVM_S390_SKEYS);
41     } else {
42         obj = object_new(TYPE_QEMU_S390_SKEYS);
43     }
44     object_property_add_child(qdev_get_machine(), TYPE_S390_SKEYS,
45                               obj, NULL);
46     object_unref(obj);
47 
48     qdev_init_nofail(DEVICE(obj));
49 }
50 
51 static void write_keys(FILE *f, uint8_t *keys, uint64_t startgfn,
52                        uint64_t count, Error **errp)
53 {
54     uint64_t curpage = startgfn;
55     uint64_t maxpage = curpage + count - 1;
56 
57     for (; curpage <= maxpage; curpage++) {
58         uint8_t acc = (*keys & 0xF0) >> 4;
59         int fp =  (*keys & 0x08);
60         int ref = (*keys & 0x04);
61         int ch = (*keys & 0x02);
62         int res = (*keys & 0x01);
63 
64         fprintf(f, "page=%03" PRIx64 ": key(%d) => ACC=%X, FP=%d, REF=%d,"
65                 " ch=%d, reserved=%d\n",
66                 curpage, *keys, acc, fp, ref, ch, res);
67         keys++;
68     }
69 }
70 
71 void hmp_info_skeys(Monitor *mon, const QDict *qdict)
72 {
73     S390SKeysState *ss = s390_get_skeys_device();
74     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
75     uint64_t addr = qdict_get_int(qdict, "addr");
76     uint8_t key;
77     int r;
78 
79     /* Quick check to see if guest is using storage keys*/
80     if (!skeyclass->skeys_enabled(ss)) {
81         monitor_printf(mon, "Error: This guest is not using storage keys\n");
82         return;
83     }
84 
85     r = skeyclass->get_skeys(ss, addr / TARGET_PAGE_SIZE, 1, &key);
86     if (r < 0) {
87         monitor_printf(mon, "Error: %s\n", strerror(-r));
88         return;
89     }
90 
91     monitor_printf(mon, "  key: 0x%X\n", key);
92 }
93 
94 void hmp_dump_skeys(Monitor *mon, const QDict *qdict)
95 {
96     const char *filename = qdict_get_str(qdict, "filename");
97     Error *err = NULL;
98 
99     qmp_dump_skeys(filename, &err);
100     if (err) {
101         error_report_err(err);
102     }
103 }
104 
105 void qmp_dump_skeys(const char *filename, Error **errp)
106 {
107     S390SKeysState *ss = s390_get_skeys_device();
108     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
109     const uint64_t total_count = ram_size / TARGET_PAGE_SIZE;
110     uint64_t handled_count = 0, cur_count;
111     Error *lerr = NULL;
112     vaddr cur_gfn = 0;
113     uint8_t *buf;
114     int ret;
115     int fd;
116     FILE *f;
117 
118     /* Quick check to see if guest is using storage keys*/
119     if (!skeyclass->skeys_enabled(ss)) {
120         error_setg(errp, "This guest is not using storage keys - "
121                          "nothing to dump");
122         return;
123     }
124 
125     fd = qemu_open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600);
126     if (fd < 0) {
127         error_setg_file_open(errp, errno, filename);
128         return;
129     }
130     f = fdopen(fd, "wb");
131     if (!f) {
132         close(fd);
133         error_setg_file_open(errp, errno, filename);
134         return;
135     }
136 
137     buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
138     if (!buf) {
139         error_setg(errp, "Could not allocate memory");
140         goto out;
141     }
142 
143     /* we'll only dump initial memory for now */
144     while (handled_count < total_count) {
145         /* Calculate how many keys to ask for & handle overflow case */
146         cur_count = MIN(total_count - handled_count, S390_SKEYS_BUFFER_SIZE);
147 
148         ret = skeyclass->get_skeys(ss, cur_gfn, cur_count, buf);
149         if (ret < 0) {
150             error_setg(errp, "get_keys error %d", ret);
151             goto out_free;
152         }
153 
154         /* write keys to stream */
155         write_keys(f, buf, cur_gfn, cur_count, &lerr);
156         if (lerr) {
157             goto out_free;
158         }
159 
160         cur_gfn += cur_count;
161         handled_count += cur_count;
162     }
163 
164 out_free:
165     error_propagate(errp, lerr);
166     g_free(buf);
167 out:
168     fclose(f);
169 }
170 
171 static void qemu_s390_skeys_init(Object *obj)
172 {
173     QEMUS390SKeysState *skeys = QEMU_S390_SKEYS(obj);
174     MachineState *machine = MACHINE(qdev_get_machine());
175 
176     skeys->key_count = machine->maxram_size / TARGET_PAGE_SIZE;
177     skeys->keydata = g_malloc0(skeys->key_count);
178 }
179 
180 static int qemu_s390_skeys_enabled(S390SKeysState *ss)
181 {
182     return 1;
183 }
184 
185 /*
186  * TODO: for memory hotplug support qemu_s390_skeys_set and qemu_s390_skeys_get
187  * will have to make sure that the given gfn belongs to a memory region and not
188  * a memory hole.
189  */
190 static int qemu_s390_skeys_set(S390SKeysState *ss, uint64_t start_gfn,
191                               uint64_t count, uint8_t *keys)
192 {
193     QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss);
194     int i;
195 
196     /* Check for uint64 overflow and access beyond end of key data */
197     if (start_gfn + count > skeydev->key_count || start_gfn + count < count) {
198         error_report("Error: Setting storage keys for page beyond the end "
199                      "of memory: gfn=%" PRIx64 " count=%" PRId64,
200                      start_gfn, count);
201         return -EINVAL;
202     }
203 
204     for (i = 0; i < count; i++) {
205         skeydev->keydata[start_gfn + i] = keys[i];
206     }
207     return 0;
208 }
209 
210 static int qemu_s390_skeys_get(S390SKeysState *ss, uint64_t start_gfn,
211                                uint64_t count, uint8_t *keys)
212 {
213     QEMUS390SKeysState *skeydev = QEMU_S390_SKEYS(ss);
214     int i;
215 
216     /* Check for uint64 overflow and access beyond end of key data */
217     if (start_gfn + count > skeydev->key_count || start_gfn + count < count) {
218         error_report("Error: Getting storage keys for page beyond the end "
219                      "of memory: gfn=%" PRIx64 " count=%" PRId64,
220                      start_gfn, count);
221         return -EINVAL;
222     }
223 
224     for (i = 0; i < count; i++) {
225         keys[i] = skeydev->keydata[start_gfn + i];
226     }
227     return 0;
228 }
229 
230 static void qemu_s390_skeys_class_init(ObjectClass *oc, void *data)
231 {
232     S390SKeysClass *skeyclass = S390_SKEYS_CLASS(oc);
233     DeviceClass *dc = DEVICE_CLASS(oc);
234 
235     skeyclass->skeys_enabled = qemu_s390_skeys_enabled;
236     skeyclass->get_skeys = qemu_s390_skeys_get;
237     skeyclass->set_skeys = qemu_s390_skeys_set;
238 
239     /* Reason: Internal device (only one skeys device for the whole memory) */
240     dc->user_creatable = false;
241 }
242 
243 static const TypeInfo qemu_s390_skeys_info = {
244     .name          = TYPE_QEMU_S390_SKEYS,
245     .parent        = TYPE_S390_SKEYS,
246     .instance_init = qemu_s390_skeys_init,
247     .instance_size = sizeof(QEMUS390SKeysState),
248     .class_init    = qemu_s390_skeys_class_init,
249     .class_size    = sizeof(S390SKeysClass),
250 };
251 
252 static void s390_storage_keys_save(QEMUFile *f, void *opaque)
253 {
254     S390SKeysState *ss = S390_SKEYS(opaque);
255     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
256     uint64_t pages_left = ram_size / TARGET_PAGE_SIZE;
257     uint64_t read_count, eos = S390_SKEYS_SAVE_FLAG_EOS;
258     vaddr cur_gfn = 0;
259     int error = 0;
260     uint8_t *buf;
261 
262     if (!skeyclass->skeys_enabled(ss)) {
263         goto end_stream;
264     }
265 
266     buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
267     if (!buf) {
268         error_report("storage key save could not allocate memory");
269         goto end_stream;
270     }
271 
272     /* We only support initial memory. Standby memory is not handled yet. */
273     qemu_put_be64(f, (cur_gfn * TARGET_PAGE_SIZE) | S390_SKEYS_SAVE_FLAG_SKEYS);
274     qemu_put_be64(f, pages_left);
275 
276     while (pages_left) {
277         read_count = MIN(pages_left, S390_SKEYS_BUFFER_SIZE);
278 
279         if (!error) {
280             error = skeyclass->get_skeys(ss, cur_gfn, read_count, buf);
281             if (error) {
282                 /*
283                  * If error: we want to fill the stream with valid data instead
284                  * of stopping early so we pad the stream with 0x00 values and
285                  * use S390_SKEYS_SAVE_FLAG_ERROR to indicate failure to the
286                  * reading side.
287                  */
288                 error_report("S390_GET_KEYS error %d", error);
289                 memset(buf, 0, S390_SKEYS_BUFFER_SIZE);
290                 eos = S390_SKEYS_SAVE_FLAG_ERROR;
291             }
292         }
293 
294         qemu_put_buffer(f, buf, read_count);
295         cur_gfn += read_count;
296         pages_left -= read_count;
297     }
298 
299     g_free(buf);
300 end_stream:
301     qemu_put_be64(f, eos);
302 }
303 
304 static int s390_storage_keys_load(QEMUFile *f, void *opaque, int version_id)
305 {
306     S390SKeysState *ss = S390_SKEYS(opaque);
307     S390SKeysClass *skeyclass = S390_SKEYS_GET_CLASS(ss);
308     int ret = 0;
309 
310     while (!ret) {
311         ram_addr_t addr;
312         int flags;
313 
314         addr = qemu_get_be64(f);
315         flags = addr & ~TARGET_PAGE_MASK;
316         addr &= TARGET_PAGE_MASK;
317 
318         switch (flags) {
319         case S390_SKEYS_SAVE_FLAG_SKEYS: {
320             const uint64_t total_count = qemu_get_be64(f);
321             uint64_t handled_count = 0, cur_count;
322             uint64_t cur_gfn = addr / TARGET_PAGE_SIZE;
323             uint8_t *buf = g_try_malloc(S390_SKEYS_BUFFER_SIZE);
324 
325             if (!buf) {
326                 error_report("storage key load could not allocate memory");
327                 ret = -ENOMEM;
328                 break;
329             }
330 
331             while (handled_count < total_count) {
332                 cur_count = MIN(total_count - handled_count,
333                                 S390_SKEYS_BUFFER_SIZE);
334                 qemu_get_buffer(f, buf, cur_count);
335 
336                 ret = skeyclass->set_skeys(ss, cur_gfn, cur_count, buf);
337                 if (ret < 0) {
338                     error_report("S390_SET_KEYS error %d", ret);
339                     break;
340                 }
341                 handled_count += cur_count;
342                 cur_gfn += cur_count;
343             }
344             g_free(buf);
345             break;
346         }
347         case S390_SKEYS_SAVE_FLAG_ERROR: {
348             error_report("Storage key data is incomplete");
349             ret = -EINVAL;
350             break;
351         }
352         case S390_SKEYS_SAVE_FLAG_EOS:
353             /* normal exit */
354             return 0;
355         default:
356             error_report("Unexpected storage key flag data: %#x", flags);
357             ret = -EINVAL;
358         }
359     }
360 
361     return ret;
362 }
363 
364 static inline bool s390_skeys_get_migration_enabled(Object *obj, Error **errp)
365 {
366     S390SKeysState *ss = S390_SKEYS(obj);
367 
368     return ss->migration_enabled;
369 }
370 
371 static SaveVMHandlers savevm_s390_storage_keys = {
372     .save_state = s390_storage_keys_save,
373     .load_state = s390_storage_keys_load,
374 };
375 
376 static inline void s390_skeys_set_migration_enabled(Object *obj, bool value,
377                                             Error **errp)
378 {
379     S390SKeysState *ss = S390_SKEYS(obj);
380 
381     /* Prevent double registration of savevm handler */
382     if (ss->migration_enabled == value) {
383         return;
384     }
385 
386     ss->migration_enabled = value;
387 
388     if (ss->migration_enabled) {
389         register_savevm_live(NULL, TYPE_S390_SKEYS, 0, 1,
390                              &savevm_s390_storage_keys, ss);
391     } else {
392         unregister_savevm(DEVICE(ss), TYPE_S390_SKEYS, ss);
393     }
394 }
395 
396 static void s390_skeys_instance_init(Object *obj)
397 {
398     object_property_add_bool(obj, "migration-enabled",
399                              s390_skeys_get_migration_enabled,
400                              s390_skeys_set_migration_enabled, NULL);
401     object_property_set_bool(obj, true, "migration-enabled", NULL);
402 }
403 
404 static void s390_skeys_class_init(ObjectClass *oc, void *data)
405 {
406     DeviceClass *dc = DEVICE_CLASS(oc);
407 
408     dc->hotpluggable = false;
409     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
410 }
411 
412 static const TypeInfo s390_skeys_info = {
413     .name          = TYPE_S390_SKEYS,
414     .parent        = TYPE_DEVICE,
415     .instance_init = s390_skeys_instance_init,
416     .instance_size = sizeof(S390SKeysState),
417     .class_init    = s390_skeys_class_init,
418     .class_size    = sizeof(S390SKeysClass),
419     .abstract = true,
420 };
421 
422 static void qemu_s390_skeys_register_types(void)
423 {
424     type_register_static(&s390_skeys_info);
425     type_register_static(&qemu_s390_skeys_info);
426 }
427 
428 type_init(qemu_s390_skeys_register_types)
429