xref: /openbmc/qemu/hw/acpi/erst.c (revision b8003f99565c9d7862938c586fecd1d9a56ee22d)
1  /*
2   * ACPI Error Record Serialization Table, ERST, Implementation
3   *
4   * ACPI ERST introduced in ACPI 4.0, June 16, 2009.
5   * ACPI Platform Error Interfaces : Error Serialization
6   *
7   * Copyright (c) 2021 Oracle and/or its affiliates.
8   *
9   * SPDX-License-Identifier: GPL-2.0-or-later
10   */
11  
12  #include "qemu/osdep.h"
13  #include "qapi/error.h"
14  #include "hw/qdev-core.h"
15  #include "exec/memory.h"
16  #include "qom/object.h"
17  #include "hw/pci/pci.h"
18  #include "qom/object_interfaces.h"
19  #include "qemu/error-report.h"
20  #include "migration/vmstate.h"
21  #include "hw/qdev-properties.h"
22  #include "hw/acpi/acpi.h"
23  #include "hw/acpi/acpi-defs.h"
24  #include "hw/acpi/aml-build.h"
25  #include "hw/acpi/bios-linker-loader.h"
26  #include "exec/address-spaces.h"
27  #include "sysemu/hostmem.h"
28  #include "hw/acpi/erst.h"
29  #include "trace.h"
30  
31  /* ACPI 4.0: Table 17-16 Serialization Actions */
32  #define ACTION_BEGIN_WRITE_OPERATION         0x0
33  #define ACTION_BEGIN_READ_OPERATION          0x1
34  #define ACTION_BEGIN_CLEAR_OPERATION         0x2
35  #define ACTION_END_OPERATION                 0x3
36  #define ACTION_SET_RECORD_OFFSET             0x4
37  #define ACTION_EXECUTE_OPERATION             0x5
38  #define ACTION_CHECK_BUSY_STATUS             0x6
39  #define ACTION_GET_COMMAND_STATUS            0x7
40  #define ACTION_GET_RECORD_IDENTIFIER         0x8
41  #define ACTION_SET_RECORD_IDENTIFIER         0x9
42  #define ACTION_GET_RECORD_COUNT              0xA
43  #define ACTION_BEGIN_DUMMY_WRITE_OPERATION   0xB
44  #define ACTION_RESERVED                      0xC
45  #define ACTION_GET_ERROR_LOG_ADDRESS_RANGE   0xD
46  #define ACTION_GET_ERROR_LOG_ADDRESS_LENGTH  0xE
47  #define ACTION_GET_ERROR_LOG_ADDRESS_RANGE_ATTRIBUTES 0xF
48  #define ACTION_GET_EXECUTE_OPERATION_TIMINGS 0x10 /* ACPI 6.3 */
49  
50  /* ACPI 4.0: Table 17-17 Command Status Definitions */
51  #define STATUS_SUCCESS                0x00
52  #define STATUS_NOT_ENOUGH_SPACE       0x01
53  #define STATUS_HARDWARE_NOT_AVAILABLE 0x02
54  #define STATUS_FAILED                 0x03
55  #define STATUS_RECORD_STORE_EMPTY     0x04
56  #define STATUS_RECORD_NOT_FOUND       0x05
57  
58  /* ACPI 4.0: Table 17-19 Serialization Instructions */
59  #define INST_READ_REGISTER                 0x00
60  #define INST_READ_REGISTER_VALUE           0x01
61  #define INST_WRITE_REGISTER                0x02
62  #define INST_WRITE_REGISTER_VALUE          0x03
63  #define INST_NOOP                          0x04
64  #define INST_LOAD_VAR1                     0x05
65  #define INST_LOAD_VAR2                     0x06
66  #define INST_STORE_VAR1                    0x07
67  #define INST_ADD                           0x08
68  #define INST_SUBTRACT                      0x09
69  #define INST_ADD_VALUE                     0x0A
70  #define INST_SUBTRACT_VALUE                0x0B
71  #define INST_STALL                         0x0C
72  #define INST_STALL_WHILE_TRUE              0x0D
73  #define INST_SKIP_NEXT_INSTRUCTION_IF_TRUE 0x0E
74  #define INST_GOTO                          0x0F
75  #define INST_SET_SRC_ADDRESS_BASE          0x10
76  #define INST_SET_DST_ADDRESS_BASE          0x11
77  #define INST_MOVE_DATA                     0x12
78  
79  /* UEFI 2.1: Appendix N Common Platform Error Record */
80  #define UEFI_CPER_RECORD_MIN_SIZE 128U
81  #define UEFI_CPER_RECORD_LENGTH_OFFSET 20U
82  #define UEFI_CPER_RECORD_ID_OFFSET 96U
83  
84  /*
85   * NOTE that when accessing CPER fields within a record, memcpy()
86   * is utilized to avoid a possible misaligned access on the host.
87   */
88  
89  /*
90   * This implementation is an ACTION (cmd) and VALUE (data)
91   * interface consisting of just two 64-bit registers.
92   */
93  #define ERST_REG_SIZE (16UL)
94  #define ERST_ACTION_OFFSET (0UL) /* action (cmd) */
95  #define ERST_VALUE_OFFSET  (8UL) /* argument/value (data) */
96  
97  /*
98   * ERST_RECORD_SIZE is the buffer size for exchanging ERST
99   * record contents. Thus, it defines the maximum record size.
100   * As this is mapped through a PCI BAR, it must be a power of
101   * two and larger than UEFI_CPER_RECORD_MIN_SIZE.
102   * The backing storage is divided into fixed size "slots",
103   * each ERST_RECORD_SIZE in length, and each "slot"
104   * storing a single record. No attempt at optimizing storage
105   * through compression, compaction, etc is attempted.
106   * NOTE that slot 0 is reserved for the backing storage header.
107   * Depending upon the size of the backing storage, additional
108   * slots will be part of the slot 0 header in order to account
109   * for a record_id for each available remaining slot.
110   */
111  /* 8KiB records, not too small, not too big */
112  #define ERST_RECORD_SIZE (8192UL)
113  
114  #define ACPI_ERST_MEMDEV_PROP "memdev"
115  #define ACPI_ERST_RECORD_SIZE_PROP "record_size"
116  
117  /*
118   * From the ACPI ERST spec sections:
119   * A record id of all 0s is used to indicate 'unspecified' record id.
120   * A record id of all 1s is used to indicate empty or end.
121   */
122  #define ERST_UNSPECIFIED_RECORD_ID (0UL)
123  #define ERST_EMPTY_END_RECORD_ID (~0UL)
124  
125  #define ERST_IS_VALID_RECORD_ID(rid) \
126      ((rid != ERST_UNSPECIFIED_RECORD_ID) && \
127       (rid != ERST_EMPTY_END_RECORD_ID))
128  
129  /*
130   * Implementation-specific definitions and types.
131   * Values are arbitrary and chosen for this implementation.
132   * See erst.rst documentation for details.
133   */
134  #define ERST_EXECUTE_OPERATION_MAGIC 0x9CUL
135  #define ERST_STORE_MAGIC 0x524F545354535245UL /* ERSTSTOR */
136  typedef struct {
137      uint64_t magic;
138      uint32_t record_size;
139      uint32_t storage_offset; /* offset to record storage beyond header */
140      uint16_t version;
141      uint16_t reserved;
142      uint32_t record_count;
143      uint64_t map[]; /* contains record_ids, and position indicates index */
144  } __attribute__((packed)) ERSTStorageHeader;
145  
146  /*
147   * Object cast macro
148   */
149  #define ACPIERST(obj) \
150      OBJECT_CHECK(ERSTDeviceState, (obj), TYPE_ACPI_ERST)
151  
152  /*
153   * Main ERST device state structure
154   */
155  typedef struct {
156      PCIDevice parent_obj;
157  
158      /* Backend storage */
159      HostMemoryBackend *hostmem;
160      MemoryRegion *hostmem_mr;
161      uint32_t storage_size;
162      uint32_t default_record_size;
163  
164      /* Programming registers */
165      MemoryRegion iomem_mr;
166  
167      /* Exchange buffer */
168      MemoryRegion exchange_mr;
169  
170      /* Interface state */
171      uint8_t operation;
172      uint8_t busy_status;
173      uint8_t command_status;
174      uint32_t record_offset;
175      uint64_t reg_action;
176      uint64_t reg_value;
177      uint64_t record_identifier;
178      ERSTStorageHeader *header;
179      unsigned first_record_index;
180      unsigned last_record_index;
181      unsigned next_record_index;
182  
183  } ERSTDeviceState;
184  
185  /*******************************************************************/
186  /*******************************************************************/
187  typedef struct {
188      GArray *table_data;
189      pcibus_t bar;
190      uint8_t instruction;
191      uint8_t flags;
192      uint8_t register_bit_width;
193      pcibus_t register_offset;
194  } BuildSerializationInstructionEntry;
195  
196  /* ACPI 4.0: 17.4.1.2 Serialization Instruction Entries */
197  static void build_serialization_instruction(
198      BuildSerializationInstructionEntry *e,
199      uint8_t serialization_action,
200      uint64_t value)
201  {
202      /* ACPI 4.0: Table 17-18 Serialization Instruction Entry */
203      struct AcpiGenericAddress gas;
204      uint64_t mask;
205  
206      /* Serialization Action */
207      build_append_int_noprefix(e->table_data, serialization_action, 1);
208      /* Instruction */
209      build_append_int_noprefix(e->table_data, e->instruction, 1);
210      /* Flags */
211      build_append_int_noprefix(e->table_data, e->flags, 1);
212      /* Reserved */
213      build_append_int_noprefix(e->table_data, 0, 1);
214      /* Register Region */
215      gas.space_id = AML_SYSTEM_MEMORY;
216      gas.bit_width = e->register_bit_width;
217      gas.bit_offset = 0;
218      gas.access_width = (uint8_t)ctz32(e->register_bit_width) - 2;
219      gas.address = (uint64_t)(e->bar + e->register_offset);
220      build_append_gas_from_struct(e->table_data, &gas);
221      /* Value */
222      build_append_int_noprefix(e->table_data, value, 8);
223      /* Mask */
224      mask = (1ULL << (e->register_bit_width - 1) << 1) - 1;
225      build_append_int_noprefix(e->table_data, mask, 8);
226  }
227  
228  /* ACPI 4.0: 17.4.1 Serialization Action Table */
229  void build_erst(GArray *table_data, BIOSLinker *linker, Object *erst_dev,
230      const char *oem_id, const char *oem_table_id)
231  {
232      /*
233       * Serialization Action Table
234       * The serialization action table must be generated first
235       * so that its size can be known in order to populate the
236       * Instruction Entry Count field.
237       */
238      unsigned action;
239      GArray *table_instruction_data = g_array_new(FALSE, FALSE, sizeof(char));
240      pcibus_t bar0 = pci_get_bar_addr(PCI_DEVICE(erst_dev), 0);
241      AcpiTable table = { .sig = "ERST", .rev = 1, .oem_id = oem_id,
242                          .oem_table_id = oem_table_id };
243      /* Contexts for the different ways ACTION and VALUE are accessed */
244      BuildSerializationInstructionEntry rd_value_32_val = {
245          .table_data = table_instruction_data, .bar = bar0, .flags = 0,
246          .instruction = INST_READ_REGISTER_VALUE,
247          .register_bit_width = 32,
248          .register_offset = ERST_VALUE_OFFSET,
249      };
250      BuildSerializationInstructionEntry rd_value_32 = {
251          .table_data = table_instruction_data, .bar = bar0, .flags = 0,
252          .instruction = INST_READ_REGISTER,
253          .register_bit_width = 32,
254          .register_offset = ERST_VALUE_OFFSET,
255      };
256      BuildSerializationInstructionEntry rd_value_64 = {
257          .table_data = table_instruction_data, .bar = bar0, .flags = 0,
258          .instruction = INST_READ_REGISTER,
259          .register_bit_width = 64,
260          .register_offset = ERST_VALUE_OFFSET,
261      };
262      BuildSerializationInstructionEntry wr_value_32_val = {
263          .table_data = table_instruction_data, .bar = bar0, .flags = 0,
264          .instruction = INST_WRITE_REGISTER_VALUE,
265          .register_bit_width = 32,
266          .register_offset = ERST_VALUE_OFFSET,
267      };
268      BuildSerializationInstructionEntry wr_value_32 = {
269          .table_data = table_instruction_data, .bar = bar0, .flags = 0,
270          .instruction = INST_WRITE_REGISTER,
271          .register_bit_width = 32,
272          .register_offset = ERST_VALUE_OFFSET,
273      };
274      BuildSerializationInstructionEntry wr_value_64 = {
275          .table_data = table_instruction_data, .bar = bar0, .flags = 0,
276          .instruction = INST_WRITE_REGISTER,
277          .register_bit_width = 64,
278          .register_offset = ERST_VALUE_OFFSET,
279      };
280      BuildSerializationInstructionEntry wr_action = {
281          .table_data = table_instruction_data, .bar = bar0, .flags = 0,
282          .instruction = INST_WRITE_REGISTER_VALUE,
283          .register_bit_width = 32,
284          .register_offset = ERST_ACTION_OFFSET,
285      };
286  
287      trace_acpi_erst_pci_bar_0(bar0);
288  
289      /* Serialization Instruction Entries */
290      action = ACTION_BEGIN_WRITE_OPERATION;
291      build_serialization_instruction(&wr_action, action, action);
292  
293      action = ACTION_BEGIN_READ_OPERATION;
294      build_serialization_instruction(&wr_action, action, action);
295  
296      action = ACTION_BEGIN_CLEAR_OPERATION;
297      build_serialization_instruction(&wr_action, action, action);
298  
299      action = ACTION_END_OPERATION;
300      build_serialization_instruction(&wr_action, action, action);
301  
302      action = ACTION_SET_RECORD_OFFSET;
303      build_serialization_instruction(&wr_value_32, action, 0);
304      build_serialization_instruction(&wr_action, action, action);
305  
306      action = ACTION_EXECUTE_OPERATION;
307      build_serialization_instruction(&wr_value_32_val, action,
308          ERST_EXECUTE_OPERATION_MAGIC);
309      build_serialization_instruction(&wr_action, action, action);
310  
311      action = ACTION_CHECK_BUSY_STATUS;
312      build_serialization_instruction(&wr_action, action, action);
313      build_serialization_instruction(&rd_value_32_val, action, 0x01);
314  
315      action = ACTION_GET_COMMAND_STATUS;
316      build_serialization_instruction(&wr_action, action, action);
317      build_serialization_instruction(&rd_value_32, action, 0);
318  
319      action = ACTION_GET_RECORD_IDENTIFIER;
320      build_serialization_instruction(&wr_action, action, action);
321      build_serialization_instruction(&rd_value_64, action, 0);
322  
323      action = ACTION_SET_RECORD_IDENTIFIER;
324      build_serialization_instruction(&wr_value_64, action, 0);
325      build_serialization_instruction(&wr_action, action, action);
326  
327      action = ACTION_GET_RECORD_COUNT;
328      build_serialization_instruction(&wr_action, action, action);
329      build_serialization_instruction(&rd_value_32, action, 0);
330  
331      action = ACTION_BEGIN_DUMMY_WRITE_OPERATION;
332      build_serialization_instruction(&wr_action, action, action);
333  
334      action = ACTION_GET_ERROR_LOG_ADDRESS_RANGE;
335      build_serialization_instruction(&wr_action, action, action);
336      build_serialization_instruction(&rd_value_64, action, 0);
337  
338      action = ACTION_GET_ERROR_LOG_ADDRESS_LENGTH;
339      build_serialization_instruction(&wr_action, action, action);
340      build_serialization_instruction(&rd_value_64, action, 0);
341  
342      action = ACTION_GET_ERROR_LOG_ADDRESS_RANGE_ATTRIBUTES;
343      build_serialization_instruction(&wr_action, action, action);
344      build_serialization_instruction(&rd_value_32, action, 0);
345  
346      action = ACTION_GET_EXECUTE_OPERATION_TIMINGS;
347      build_serialization_instruction(&wr_action, action, action);
348      build_serialization_instruction(&rd_value_64, action, 0);
349  
350      /* Serialization Header */
351      acpi_table_begin(&table, table_data);
352  
353      /* Serialization Header Size */
354      build_append_int_noprefix(table_data, 48, 4);
355  
356      /* Reserved */
357      build_append_int_noprefix(table_data,  0, 4);
358  
359      /*
360       * Instruction Entry Count
361       * Each instruction entry is 32 bytes
362       */
363      g_assert((table_instruction_data->len) % 32 == 0);
364      build_append_int_noprefix(table_data,
365          (table_instruction_data->len / 32), 4);
366  
367      /* Serialization Instruction Entries */
368      g_array_append_vals(table_data, table_instruction_data->data,
369          table_instruction_data->len);
370      g_array_free(table_instruction_data, TRUE);
371  
372      acpi_table_end(linker, &table);
373  }
374  
375  /*******************************************************************/
376  /*******************************************************************/
377  static uint8_t *get_nvram_ptr_by_index(ERSTDeviceState *s, unsigned index)
378  {
379      uint8_t *rc = NULL;
380      off_t offset = (index * le32_to_cpu(s->header->record_size));
381  
382      g_assert(offset < s->storage_size);
383  
384      rc = memory_region_get_ram_ptr(s->hostmem_mr);
385      rc += offset;
386  
387      return rc;
388  }
389  
390  static void make_erst_storage_header(ERSTDeviceState *s)
391  {
392      ERSTStorageHeader *header = s->header;
393      unsigned mapsz, headersz;
394  
395      header->magic = cpu_to_le64(ERST_STORE_MAGIC);
396      header->record_size = cpu_to_le32(s->default_record_size);
397      header->version = cpu_to_le16(0x0100);
398      header->reserved = cpu_to_le16(0x0000);
399  
400      /* Compute mapsize */
401      mapsz = s->storage_size / s->default_record_size;
402      mapsz *= sizeof(uint64_t);
403      /* Compute header+map size */
404      headersz = sizeof(ERSTStorageHeader) + mapsz;
405      /* Round up to nearest integer multiple of ERST_RECORD_SIZE */
406      headersz = QEMU_ALIGN_UP(headersz, s->default_record_size);
407      header->storage_offset = cpu_to_le32(headersz);
408  
409      /*
410       * The HostMemoryBackend initializes contents to zero,
411       * so all record_ids stashed in the map are zero'd.
412       * As well the record_count is zero. Properly initialized.
413       */
414  }
415  
416  static void check_erst_backend_storage(ERSTDeviceState *s, Error **errp)
417  {
418      ERSTStorageHeader *header;
419      uint32_t record_size;
420  
421      header = memory_region_get_ram_ptr(s->hostmem_mr);
422      s->header = header;
423  
424      /* Ensure pointer to header is 64-bit aligned */
425      g_assert(QEMU_PTR_IS_ALIGNED(header, sizeof(uint64_t)));
426  
427      /*
428       * Check if header is uninitialized; HostMemoryBackend inits to 0
429       */
430      if (le64_to_cpu(header->magic) == 0UL) {
431          make_erst_storage_header(s);
432      }
433  
434      /* Validity check record_size */
435      record_size = le32_to_cpu(header->record_size);
436      if (!(
437          (record_size) && /* non zero */
438          (record_size >= UEFI_CPER_RECORD_MIN_SIZE) &&
439          (((record_size - 1) & record_size) == 0) && /* is power of 2 */
440          (record_size >= 4096) /* PAGE_SIZE */
441          )) {
442          error_setg(errp, "ERST record_size %u is invalid", record_size);
443      }
444  
445      /* Validity check header */
446      if (!(
447          (le64_to_cpu(header->magic) == ERST_STORE_MAGIC) &&
448          ((le32_to_cpu(header->storage_offset) % record_size) == 0) &&
449          (le16_to_cpu(header->version) == 0x0100) &&
450          (le16_to_cpu(header->reserved) == 0)
451          )) {
452          error_setg(errp, "ERST backend storage header is invalid");
453      }
454  
455      /* Check storage_size against record_size */
456      if (((s->storage_size % record_size) != 0) ||
457           (record_size > s->storage_size)) {
458          error_setg(errp, "ACPI ERST requires storage size be multiple of "
459              "record size (%uKiB)", record_size);
460      }
461  
462      /* Compute offset of first and last record storage slot */
463      s->first_record_index = le32_to_cpu(header->storage_offset)
464          / record_size;
465      s->last_record_index = (s->storage_size / record_size);
466  }
467  
468  static void update_map_entry(ERSTDeviceState *s, unsigned index,
469      uint64_t record_id)
470  {
471      if (index < s->last_record_index) {
472          s->header->map[index] = cpu_to_le64(record_id);
473      }
474  }
475  
476  static unsigned find_next_empty_record_index(ERSTDeviceState *s)
477  {
478      unsigned rc = 0; /* 0 not a valid index */
479      unsigned index = s->first_record_index;
480  
481      for (; index < s->last_record_index; ++index) {
482          if (le64_to_cpu(s->header->map[index]) == ERST_UNSPECIFIED_RECORD_ID) {
483              rc = index;
484              break;
485          }
486      }
487  
488      return rc;
489  }
490  
491  static unsigned lookup_erst_record(ERSTDeviceState *s,
492      uint64_t record_identifier)
493  {
494      unsigned rc = 0; /* 0 not a valid index */
495  
496      /* Find the record_identifier in the map */
497      if (record_identifier != ERST_UNSPECIFIED_RECORD_ID) {
498          /*
499           * Count number of valid records encountered, and
500           * short-circuit the loop if identifier not found
501           */
502          uint32_t record_count = le32_to_cpu(s->header->record_count);
503          unsigned count = 0;
504          unsigned index;
505          for (index = s->first_record_index; index < s->last_record_index &&
506                  count < record_count; ++index) {
507              if (le64_to_cpu(s->header->map[index]) == record_identifier) {
508                  rc = index;
509                  break;
510              }
511              if (le64_to_cpu(s->header->map[index]) !=
512                  ERST_UNSPECIFIED_RECORD_ID) {
513                  ++count;
514              }
515          }
516      }
517  
518      return rc;
519  }
520  
521  /*
522   * ACPI 4.0: 17.4.1.1 Serialization Actions, also see
523   * ACPI 4.0: 17.4.2.2 Operations - Reading 6.c and 2.c
524   */
525  static unsigned get_next_record_identifier(ERSTDeviceState *s,
526      uint64_t *record_identifier, bool first)
527  {
528      unsigned found = 0;
529      unsigned index;
530  
531      /* For operations needing to return 'first' record identifier */
532      if (first) {
533          /* Reset initial index to beginning */
534          s->next_record_index = s->first_record_index;
535      }
536      index = s->next_record_index;
537  
538      *record_identifier = ERST_EMPTY_END_RECORD_ID;
539  
540      if (le32_to_cpu(s->header->record_count)) {
541          for (; index < s->last_record_index; ++index) {
542              if (le64_to_cpu(s->header->map[index]) !=
543                      ERST_UNSPECIFIED_RECORD_ID) {
544                      /* where to start next time */
545                      s->next_record_index = index + 1;
546                      *record_identifier = le64_to_cpu(s->header->map[index]);
547                      found = 1;
548                      break;
549              }
550          }
551      }
552      if (!found) {
553          /* at end (ie scan complete), reset */
554          s->next_record_index = s->first_record_index;
555      }
556  
557      return STATUS_SUCCESS;
558  }
559  
560  /* ACPI 4.0: 17.4.2.3 Operations - Clearing */
561  static unsigned clear_erst_record(ERSTDeviceState *s)
562  {
563      unsigned rc = STATUS_RECORD_NOT_FOUND;
564      unsigned index;
565  
566      /* Check for valid record identifier */
567      if (!ERST_IS_VALID_RECORD_ID(s->record_identifier)) {
568          return STATUS_FAILED;
569      }
570  
571      index = lookup_erst_record(s, s->record_identifier);
572      if (index) {
573          /* No need to wipe record, just invalidate its map entry */
574          uint32_t record_count;
575          update_map_entry(s, index, ERST_UNSPECIFIED_RECORD_ID);
576          record_count = le32_to_cpu(s->header->record_count);
577          record_count -= 1;
578          s->header->record_count = cpu_to_le32(record_count);
579          rc = STATUS_SUCCESS;
580      }
581  
582      return rc;
583  }
584  
585  /* ACPI 4.0: 17.4.2.2 Operations - Reading */
586  static unsigned read_erst_record(ERSTDeviceState *s)
587  {
588      unsigned rc = STATUS_RECORD_NOT_FOUND;
589      unsigned exchange_length;
590      unsigned index;
591  
592      /* Check if backend storage is empty */
593      if (le32_to_cpu(s->header->record_count) == 0) {
594          return STATUS_RECORD_STORE_EMPTY;
595      }
596  
597      exchange_length = memory_region_size(&s->exchange_mr);
598  
599      /* Check for record identifier of all 0s */
600      if (s->record_identifier == ERST_UNSPECIFIED_RECORD_ID) {
601          /* Set to 'first' record in storage */
602          get_next_record_identifier(s, &s->record_identifier, true);
603          /* record_identifier is now a valid id, or all 1s */
604      }
605  
606      /* Check for record identifier of all 1s */
607      if (s->record_identifier == ERST_EMPTY_END_RECORD_ID) {
608          return STATUS_FAILED;
609      }
610  
611      /* Validate record_offset */
612      if (s->record_offset > (exchange_length - UEFI_CPER_RECORD_MIN_SIZE)) {
613          return STATUS_FAILED;
614      }
615  
616      index = lookup_erst_record(s, s->record_identifier);
617      if (index) {
618          uint8_t *nvram;
619          uint8_t *exchange;
620          uint32_t record_length;
621  
622          /* Obtain pointer to the exchange buffer */
623          exchange = memory_region_get_ram_ptr(&s->exchange_mr);
624          exchange += s->record_offset;
625          /* Obtain pointer to slot in storage */
626          nvram = get_nvram_ptr_by_index(s, index);
627          /* Validate CPER record_length */
628          memcpy((uint8_t *)&record_length,
629              &nvram[UEFI_CPER_RECORD_LENGTH_OFFSET],
630              sizeof(uint32_t));
631          record_length = le32_to_cpu(record_length);
632          if (record_length < UEFI_CPER_RECORD_MIN_SIZE) {
633              rc = STATUS_FAILED;
634          }
635          if ((s->record_offset + record_length) > exchange_length) {
636              rc = STATUS_FAILED;
637          }
638          /* If all is ok, copy the record to the exchange buffer */
639          if (rc != STATUS_FAILED) {
640              memcpy(exchange, nvram, record_length);
641              rc = STATUS_SUCCESS;
642          }
643      } else {
644          /*
645           * See "Reading : 'The steps performed by the platform ...' 2.c"
646           * Set to 'first' record in storage
647           */
648          get_next_record_identifier(s, &s->record_identifier, true);
649      }
650  
651      return rc;
652  }
653  
654  /* ACPI 4.0: 17.4.2.1 Operations - Writing */
655  static unsigned write_erst_record(ERSTDeviceState *s)
656  {
657      unsigned rc = STATUS_FAILED;
658      unsigned exchange_length;
659      unsigned index;
660      uint64_t record_identifier;
661      uint32_t record_length;
662      uint8_t *exchange;
663      uint8_t *nvram = NULL;
664      bool record_found = false;
665  
666      exchange_length = memory_region_size(&s->exchange_mr);
667  
668      /* Validate record_offset */
669      if (s->record_offset > (exchange_length - UEFI_CPER_RECORD_MIN_SIZE)) {
670          return STATUS_FAILED;
671      }
672  
673      /* Obtain pointer to record in the exchange buffer */
674      exchange = memory_region_get_ram_ptr(&s->exchange_mr);
675      exchange += s->record_offset;
676  
677      /* Validate CPER record_length */
678      memcpy((uint8_t *)&record_length, &exchange[UEFI_CPER_RECORD_LENGTH_OFFSET],
679          sizeof(uint32_t));
680      record_length = le32_to_cpu(record_length);
681      if (record_length < UEFI_CPER_RECORD_MIN_SIZE) {
682          return STATUS_FAILED;
683      }
684      if ((s->record_offset + record_length) > exchange_length) {
685          return STATUS_FAILED;
686      }
687  
688      /* Extract record identifier */
689      memcpy((uint8_t *)&record_identifier, &exchange[UEFI_CPER_RECORD_ID_OFFSET],
690          sizeof(uint64_t));
691      record_identifier = le64_to_cpu(record_identifier);
692  
693      /* Check for valid record identifier */
694      if (!ERST_IS_VALID_RECORD_ID(record_identifier)) {
695          return STATUS_FAILED;
696      }
697  
698      index = lookup_erst_record(s, record_identifier);
699      if (index) {
700          /* Record found, overwrite existing record */
701          nvram = get_nvram_ptr_by_index(s, index);
702          record_found = true;
703      } else {
704          /* Record not found, not an overwrite, allocate for write */
705          index = find_next_empty_record_index(s);
706          if (index) {
707              nvram = get_nvram_ptr_by_index(s, index);
708          } else {
709              /* All slots are occupied */
710              rc = STATUS_NOT_ENOUGH_SPACE;
711          }
712      }
713      if (nvram) {
714          /* Write the record into the slot */
715          memcpy(nvram, exchange, record_length);
716          memset(nvram + record_length, exchange_length - record_length, 0xFF);
717          /* If a new record, increment the record_count */
718          if (!record_found) {
719              uint32_t record_count;
720              record_count = le32_to_cpu(s->header->record_count);
721              record_count += 1; /* writing new record */
722              s->header->record_count = cpu_to_le32(record_count);
723          }
724          update_map_entry(s, index, record_identifier);
725          rc = STATUS_SUCCESS;
726      }
727  
728      return rc;
729  }
730  
731  /*******************************************************************/
732  
733  static uint64_t erst_rd_reg64(hwaddr addr,
734      uint64_t reg, unsigned size)
735  {
736      uint64_t rdval;
737      uint64_t mask;
738      unsigned shift;
739  
740      if (size == sizeof(uint64_t)) {
741          /* 64b access */
742          mask = 0xFFFFFFFFFFFFFFFFUL;
743          shift = 0;
744      } else {
745          /* 32b access */
746          mask = 0x00000000FFFFFFFFUL;
747          shift = ((addr & 0x4) == 0x4) ? 32 : 0;
748      }
749  
750      rdval = reg;
751      rdval >>= shift;
752      rdval &= mask;
753  
754      return rdval;
755  }
756  
757  static uint64_t erst_wr_reg64(hwaddr addr,
758      uint64_t reg, uint64_t val, unsigned size)
759  {
760      uint64_t wrval;
761      uint64_t mask;
762      unsigned shift;
763  
764      if (size == sizeof(uint64_t)) {
765          /* 64b access */
766          mask = 0xFFFFFFFFFFFFFFFFUL;
767          shift = 0;
768      } else {
769          /* 32b access */
770          mask = 0x00000000FFFFFFFFUL;
771          shift = ((addr & 0x4) == 0x4) ? 32 : 0;
772      }
773  
774      val &= mask;
775      val <<= shift;
776      mask <<= shift;
777      wrval = reg;
778      wrval &= ~mask;
779      wrval |= val;
780  
781      return wrval;
782  }
783  
784  static void erst_reg_write(void *opaque, hwaddr addr,
785      uint64_t val, unsigned size)
786  {
787      ERSTDeviceState *s = (ERSTDeviceState *)opaque;
788  
789      /*
790       * NOTE: All actions/operations/side effects happen on the WRITE,
791       * by this implementation's design. The READs simply return the
792       * reg_value contents.
793       */
794      trace_acpi_erst_reg_write(addr, val, size);
795  
796      switch (addr) {
797      case ERST_VALUE_OFFSET + 0:
798      case ERST_VALUE_OFFSET + 4:
799          s->reg_value = erst_wr_reg64(addr, s->reg_value, val, size);
800          break;
801      case ERST_ACTION_OFFSET + 0:
802          /*
803           * NOTE: all valid values written to this register are of the
804           * ACTION_* variety. Thus there is no need to make this a 64-bit
805           * register, 32-bits is appropriate. As such ERST_ACTION_OFFSET+4
806           * is not needed.
807           */
808          switch (val) {
809          case ACTION_BEGIN_WRITE_OPERATION:
810          case ACTION_BEGIN_READ_OPERATION:
811          case ACTION_BEGIN_CLEAR_OPERATION:
812          case ACTION_BEGIN_DUMMY_WRITE_OPERATION:
813          case ACTION_END_OPERATION:
814              s->operation = val;
815              break;
816          case ACTION_SET_RECORD_OFFSET:
817              s->record_offset = s->reg_value;
818              break;
819          case ACTION_EXECUTE_OPERATION:
820              if ((uint8_t)s->reg_value == ERST_EXECUTE_OPERATION_MAGIC) {
821                  s->busy_status = 1;
822                  switch (s->operation) {
823                  case ACTION_BEGIN_WRITE_OPERATION:
824                      s->command_status = write_erst_record(s);
825                      break;
826                  case ACTION_BEGIN_READ_OPERATION:
827                      s->command_status = read_erst_record(s);
828                      break;
829                  case ACTION_BEGIN_CLEAR_OPERATION:
830                      s->command_status = clear_erst_record(s);
831                      break;
832                  case ACTION_BEGIN_DUMMY_WRITE_OPERATION:
833                      s->command_status = STATUS_SUCCESS;
834                      break;
835                  case ACTION_END_OPERATION:
836                      s->command_status = STATUS_SUCCESS;
837                      break;
838                  default:
839                      s->command_status = STATUS_FAILED;
840                      break;
841                  }
842                  s->busy_status = 0;
843              }
844              break;
845          case ACTION_CHECK_BUSY_STATUS:
846              s->reg_value = s->busy_status;
847              break;
848          case ACTION_GET_COMMAND_STATUS:
849              s->reg_value = s->command_status;
850              break;
851          case ACTION_GET_RECORD_IDENTIFIER:
852              s->command_status = get_next_record_identifier(s,
853                                      &s->reg_value, false);
854              break;
855          case ACTION_SET_RECORD_IDENTIFIER:
856              s->record_identifier = s->reg_value;
857              break;
858          case ACTION_GET_RECORD_COUNT:
859              s->reg_value = le32_to_cpu(s->header->record_count);
860              break;
861          case ACTION_GET_ERROR_LOG_ADDRESS_RANGE:
862              s->reg_value = (hwaddr)pci_get_bar_addr(PCI_DEVICE(s), 1);
863              break;
864          case ACTION_GET_ERROR_LOG_ADDRESS_LENGTH:
865              s->reg_value = le32_to_cpu(s->header->record_size);
866              break;
867          case ACTION_GET_ERROR_LOG_ADDRESS_RANGE_ATTRIBUTES:
868              s->reg_value = 0x0; /* intentional, not NVRAM mode */
869              break;
870          case ACTION_GET_EXECUTE_OPERATION_TIMINGS:
871              s->reg_value =
872                  (100ULL << 32) | /* 100us max time */
873                  (10ULL  <<  0) ; /*  10us min time */
874              break;
875          default:
876              /* Unknown action/command, NOP */
877              break;
878          }
879          break;
880      default:
881          /* This should not happen, but if it does, NOP */
882          break;
883      }
884  }
885  
886  static uint64_t erst_reg_read(void *opaque, hwaddr addr,
887                                  unsigned size)
888  {
889      ERSTDeviceState *s = (ERSTDeviceState *)opaque;
890      uint64_t val = 0;
891  
892      switch (addr) {
893      case ERST_ACTION_OFFSET + 0:
894      case ERST_ACTION_OFFSET + 4:
895          val = erst_rd_reg64(addr, s->reg_action, size);
896          break;
897      case ERST_VALUE_OFFSET + 0:
898      case ERST_VALUE_OFFSET + 4:
899          val = erst_rd_reg64(addr, s->reg_value, size);
900          break;
901      default:
902          break;
903      }
904      trace_acpi_erst_reg_read(addr, val, size);
905      return val;
906  }
907  
908  static const MemoryRegionOps erst_reg_ops = {
909      .read = erst_reg_read,
910      .write = erst_reg_write,
911      .endianness = DEVICE_NATIVE_ENDIAN,
912  };
913  
914  /*******************************************************************/
915  /*******************************************************************/
916  static int erst_post_load(void *opaque, int version_id)
917  {
918      ERSTDeviceState *s = opaque;
919  
920      /* Recompute pointer to header */
921      s->header = (ERSTStorageHeader *)get_nvram_ptr_by_index(s, 0);
922      trace_acpi_erst_post_load(s->header, le32_to_cpu(s->header->record_size));
923  
924      return 0;
925  }
926  
927  static const VMStateDescription erst_vmstate  = {
928      .name = "acpi-erst",
929      .version_id = 1,
930      .minimum_version_id = 1,
931      .post_load = erst_post_load,
932      .fields = (VMStateField[]) {
933          VMSTATE_UINT8(operation, ERSTDeviceState),
934          VMSTATE_UINT8(busy_status, ERSTDeviceState),
935          VMSTATE_UINT8(command_status, ERSTDeviceState),
936          VMSTATE_UINT32(record_offset, ERSTDeviceState),
937          VMSTATE_UINT64(reg_action, ERSTDeviceState),
938          VMSTATE_UINT64(reg_value, ERSTDeviceState),
939          VMSTATE_UINT64(record_identifier, ERSTDeviceState),
940          VMSTATE_UINT32(next_record_index, ERSTDeviceState),
941          VMSTATE_END_OF_LIST()
942      }
943  };
944  
945  static void erst_realizefn(PCIDevice *pci_dev, Error **errp)
946  {
947      ERSTDeviceState *s = ACPIERST(pci_dev);
948  
949      trace_acpi_erst_realizefn_in();
950  
951      if (!s->hostmem) {
952          error_setg(errp, "'" ACPI_ERST_MEMDEV_PROP "' property is not set");
953          return;
954      } else if (host_memory_backend_is_mapped(s->hostmem)) {
955          error_setg(errp, "can't use already busy memdev: %s",
956                     object_get_canonical_path_component(OBJECT(s->hostmem)));
957          return;
958      }
959  
960      s->hostmem_mr = host_memory_backend_get_memory(s->hostmem);
961  
962      /* HostMemoryBackend size will be multiple of PAGE_SIZE */
963      s->storage_size = object_property_get_int(OBJECT(s->hostmem), "size", errp);
964  
965      /* Initialize backend storage and record_count */
966      check_erst_backend_storage(s, errp);
967  
968      /* BAR 0: Programming registers */
969      memory_region_init_io(&s->iomem_mr, OBJECT(pci_dev), &erst_reg_ops, s,
970                            TYPE_ACPI_ERST, ERST_REG_SIZE);
971      pci_register_bar(pci_dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY, &s->iomem_mr);
972  
973      /* BAR 1: Exchange buffer memory */
974      memory_region_init_ram(&s->exchange_mr, OBJECT(pci_dev),
975                              "erst.exchange",
976                              le32_to_cpu(s->header->record_size), errp);
977      pci_register_bar(pci_dev, 1, PCI_BASE_ADDRESS_SPACE_MEMORY,
978                          &s->exchange_mr);
979  
980      /* Include the backend storage in the migration stream */
981      vmstate_register_ram_global(s->hostmem_mr);
982  
983      trace_acpi_erst_realizefn_out(s->storage_size);
984  }
985  
986  static void erst_reset(DeviceState *dev)
987  {
988      ERSTDeviceState *s = ACPIERST(dev);
989  
990      trace_acpi_erst_reset_in(le32_to_cpu(s->header->record_count));
991      s->operation = 0;
992      s->busy_status = 0;
993      s->command_status = STATUS_SUCCESS;
994      s->record_identifier = ERST_UNSPECIFIED_RECORD_ID;
995      s->record_offset = 0;
996      s->next_record_index = s->first_record_index;
997      /* NOTE: first/last_record_index are computed only once */
998      trace_acpi_erst_reset_out(le32_to_cpu(s->header->record_count));
999  }
1000  
1001  static Property erst_properties[] = {
1002      DEFINE_PROP_LINK(ACPI_ERST_MEMDEV_PROP, ERSTDeviceState, hostmem,
1003                       TYPE_MEMORY_BACKEND, HostMemoryBackend *),
1004      DEFINE_PROP_UINT32(ACPI_ERST_RECORD_SIZE_PROP, ERSTDeviceState,
1005                       default_record_size, ERST_RECORD_SIZE),
1006      DEFINE_PROP_END_OF_LIST(),
1007  };
1008  
1009  static void erst_class_init(ObjectClass *klass, void *data)
1010  {
1011      DeviceClass *dc = DEVICE_CLASS(klass);
1012      PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
1013  
1014      trace_acpi_erst_class_init_in();
1015      k->realize = erst_realizefn;
1016      k->vendor_id = PCI_VENDOR_ID_REDHAT;
1017      k->device_id = PCI_DEVICE_ID_REDHAT_ACPI_ERST;
1018      k->revision = 0x00;
1019      k->class_id = PCI_CLASS_OTHERS;
1020      dc->reset = erst_reset;
1021      dc->vmsd = &erst_vmstate;
1022      dc->user_creatable = true;
1023      dc->hotpluggable = false;
1024      device_class_set_props(dc, erst_properties);
1025      dc->desc = "ACPI Error Record Serialization Table (ERST) device";
1026      set_bit(DEVICE_CATEGORY_MISC, dc->categories);
1027      trace_acpi_erst_class_init_out();
1028  }
1029  
1030  static const TypeInfo erst_type_info = {
1031      .name          = TYPE_ACPI_ERST,
1032      .parent        = TYPE_PCI_DEVICE,
1033      .class_init    = erst_class_init,
1034      .instance_size = sizeof(ERSTDeviceState),
1035      .interfaces = (InterfaceInfo[]) {
1036          { INTERFACE_CONVENTIONAL_PCI_DEVICE },
1037          { }
1038      }
1039  };
1040  
1041  static void erst_register_types(void)
1042  {
1043      type_register_static(&erst_type_info);
1044  }
1045  
1046  type_init(erst_register_types)
1047