1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * AMD Secure Encrypted Virtualization (SEV) interface
4 *
5 * Copyright (C) 2016,2019 Advanced Micro Devices, Inc.
6 *
7 * Author: Brijesh Singh <brijesh.singh@amd.com>
8 */
9
10 #include <linux/bitfield.h>
11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 #include <linux/kthread.h>
14 #include <linux/sched.h>
15 #include <linux/interrupt.h>
16 #include <linux/spinlock.h>
17 #include <linux/spinlock_types.h>
18 #include <linux/types.h>
19 #include <linux/mutex.h>
20 #include <linux/delay.h>
21 #include <linux/hw_random.h>
22 #include <linux/ccp.h>
23 #include <linux/firmware.h>
24 #include <linux/panic_notifier.h>
25 #include <linux/gfp.h>
26 #include <linux/cpufeature.h>
27 #include <linux/fs.h>
28 #include <linux/fs_struct.h>
29 #include <linux/psp.h>
30 #include <linux/amd-iommu.h>
31 #include <linux/crash_dump.h>
32
33 #include <asm/smp.h>
34 #include <asm/cacheflush.h>
35 #include <asm/e820/types.h>
36 #include <asm/sev.h>
37 #include <asm/msr.h>
38
39 #include "psp-dev.h"
40 #include "sev-dev.h"
41
42 #define DEVICE_NAME "sev"
43 #define SEV_FW_FILE "amd/sev.fw"
44 #define SEV_FW_NAME_SIZE 64
45
46 /* Minimum firmware version required for the SEV-SNP support */
47 #define SNP_MIN_API_MAJOR 1
48 #define SNP_MIN_API_MINOR 51
49
50 /*
51 * Maximum number of firmware-writable buffers that might be specified
52 * in the parameters of a legacy SEV command buffer.
53 */
54 #define CMD_BUF_FW_WRITABLE_MAX 2
55
56 /* Leave room in the descriptor array for an end-of-list indicator. */
57 #define CMD_BUF_DESC_MAX (CMD_BUF_FW_WRITABLE_MAX + 1)
58
59 static DEFINE_MUTEX(sev_cmd_mutex);
60 static struct sev_misc_dev *misc_dev;
61
62 static int psp_cmd_timeout = 100;
63 module_param(psp_cmd_timeout, int, 0644);
64 MODULE_PARM_DESC(psp_cmd_timeout, " default timeout value, in seconds, for PSP commands");
65
66 static int psp_probe_timeout = 5;
67 module_param(psp_probe_timeout, int, 0644);
68 MODULE_PARM_DESC(psp_probe_timeout, " default timeout value, in seconds, during PSP device probe");
69
70 static char *init_ex_path;
71 module_param(init_ex_path, charp, 0444);
72 MODULE_PARM_DESC(init_ex_path, " Path for INIT_EX data; if set try INIT_EX");
73
74 static bool psp_init_on_probe = true;
75 module_param(psp_init_on_probe, bool, 0444);
76 MODULE_PARM_DESC(psp_init_on_probe, " if true, the PSP will be initialized on module init. Else the PSP will be initialized on the first command requiring it");
77
78 #if IS_ENABLED(CONFIG_PCI_TSM)
79 static bool sev_tio_enabled = true;
80 module_param_named(tio, sev_tio_enabled, bool, 0444);
81 MODULE_PARM_DESC(tio, "Enables TIO in SNP_INIT_EX");
82 #else
83 static const bool sev_tio_enabled = false;
84 #endif
85
86 MODULE_FIRMWARE("amd/amd_sev_fam17h_model0xh.sbin"); /* 1st gen EPYC */
87 MODULE_FIRMWARE("amd/amd_sev_fam17h_model3xh.sbin"); /* 2nd gen EPYC */
88 MODULE_FIRMWARE("amd/amd_sev_fam19h_model0xh.sbin"); /* 3rd gen EPYC */
89 MODULE_FIRMWARE("amd/amd_sev_fam19h_model1xh.sbin"); /* 4th gen EPYC */
90
91 static bool psp_dead;
92 static int psp_timeout;
93
94 enum snp_hv_fixed_pages_state {
95 ALLOCATED,
96 HV_FIXED,
97 };
98
99 struct snp_hv_fixed_pages_entry {
100 struct list_head list;
101 struct page *page;
102 unsigned int order;
103 bool free;
104 enum snp_hv_fixed_pages_state page_state;
105 };
106
107 static LIST_HEAD(snp_hv_fixed_pages);
108
109 /* Trusted Memory Region (TMR):
110 * The TMR is a 1MB area that must be 1MB aligned. Use the page allocator
111 * to allocate the memory, which will return aligned memory for the specified
112 * allocation order.
113 *
114 * When SEV-SNP is enabled the TMR needs to be 2MB aligned and 2MB sized.
115 */
116 #define SEV_TMR_SIZE (1024 * 1024)
117 #define SNP_TMR_SIZE (2 * 1024 * 1024)
118
119 static void *sev_es_tmr;
120 static size_t sev_es_tmr_size = SEV_TMR_SIZE;
121
122 /* INIT_EX NV Storage:
123 * The NV Storage is a 32Kb area and must be 4Kb page aligned. Use the page
124 * allocator to allocate the memory, which will return aligned memory for the
125 * specified allocation order.
126 */
127 #define NV_LENGTH (32 * 1024)
128 static void *sev_init_ex_buffer;
129
130 static void __sev_firmware_shutdown(struct sev_device *sev, bool panic);
131
132 static int snp_shutdown_on_panic(struct notifier_block *nb,
133 unsigned long reason, void *arg);
134
135 static struct notifier_block snp_panic_notifier = {
136 .notifier_call = snp_shutdown_on_panic,
137 };
138
sev_version_greater_or_equal(u8 maj,u8 min)139 static inline bool sev_version_greater_or_equal(u8 maj, u8 min)
140 {
141 struct sev_device *sev = psp_master->sev_data;
142
143 if (sev->api_major > maj)
144 return true;
145
146 if (sev->api_major == maj && sev->api_minor >= min)
147 return true;
148
149 return false;
150 }
151
sev_irq_handler(int irq,void * data,unsigned int status)152 static void sev_irq_handler(int irq, void *data, unsigned int status)
153 {
154 struct sev_device *sev = data;
155 int reg;
156
157 /* Check if it is command completion: */
158 if (!(status & SEV_CMD_COMPLETE))
159 return;
160
161 /* Check if it is SEV command completion: */
162 reg = ioread32(sev->io_regs + sev->vdata->cmdresp_reg);
163 if (FIELD_GET(PSP_CMDRESP_RESP, reg)) {
164 sev->int_rcvd = 1;
165 wake_up(&sev->int_queue);
166 }
167 }
168
sev_wait_cmd_ioc(struct sev_device * sev,unsigned int * reg,unsigned int timeout)169 static int sev_wait_cmd_ioc(struct sev_device *sev,
170 unsigned int *reg, unsigned int timeout)
171 {
172 int ret;
173
174 /*
175 * If invoked during panic handling, local interrupts are disabled,
176 * so the PSP command completion interrupt can't be used. Poll for
177 * PSP command completion instead.
178 */
179 if (irqs_disabled()) {
180 unsigned long timeout_usecs = (timeout * USEC_PER_SEC) / 10;
181
182 /* Poll for SEV command completion: */
183 while (timeout_usecs--) {
184 *reg = ioread32(sev->io_regs + sev->vdata->cmdresp_reg);
185 if (*reg & PSP_CMDRESP_RESP)
186 return 0;
187
188 udelay(10);
189 }
190 return -ETIMEDOUT;
191 }
192
193 ret = wait_event_timeout(sev->int_queue,
194 sev->int_rcvd, timeout * HZ);
195 if (!ret)
196 return -ETIMEDOUT;
197
198 *reg = ioread32(sev->io_regs + sev->vdata->cmdresp_reg);
199
200 return 0;
201 }
202
sev_cmd_buffer_len(int cmd)203 static int sev_cmd_buffer_len(int cmd)
204 {
205 switch (cmd) {
206 case SEV_CMD_INIT: return sizeof(struct sev_data_init);
207 case SEV_CMD_INIT_EX: return sizeof(struct sev_data_init_ex);
208 case SEV_CMD_SNP_SHUTDOWN_EX: return sizeof(struct sev_data_snp_shutdown_ex);
209 case SEV_CMD_SNP_INIT_EX: return sizeof(struct sev_data_snp_init_ex);
210 case SEV_CMD_PLATFORM_STATUS: return sizeof(struct sev_user_data_status);
211 case SEV_CMD_PEK_CSR: return sizeof(struct sev_data_pek_csr);
212 case SEV_CMD_PEK_CERT_IMPORT: return sizeof(struct sev_data_pek_cert_import);
213 case SEV_CMD_PDH_CERT_EXPORT: return sizeof(struct sev_data_pdh_cert_export);
214 case SEV_CMD_LAUNCH_START: return sizeof(struct sev_data_launch_start);
215 case SEV_CMD_LAUNCH_UPDATE_DATA: return sizeof(struct sev_data_launch_update_data);
216 case SEV_CMD_LAUNCH_UPDATE_VMSA: return sizeof(struct sev_data_launch_update_vmsa);
217 case SEV_CMD_LAUNCH_FINISH: return sizeof(struct sev_data_launch_finish);
218 case SEV_CMD_LAUNCH_MEASURE: return sizeof(struct sev_data_launch_measure);
219 case SEV_CMD_ACTIVATE: return sizeof(struct sev_data_activate);
220 case SEV_CMD_DEACTIVATE: return sizeof(struct sev_data_deactivate);
221 case SEV_CMD_DECOMMISSION: return sizeof(struct sev_data_decommission);
222 case SEV_CMD_GUEST_STATUS: return sizeof(struct sev_data_guest_status);
223 case SEV_CMD_DBG_DECRYPT: return sizeof(struct sev_data_dbg);
224 case SEV_CMD_DBG_ENCRYPT: return sizeof(struct sev_data_dbg);
225 case SEV_CMD_SEND_START: return sizeof(struct sev_data_send_start);
226 case SEV_CMD_SEND_UPDATE_DATA: return sizeof(struct sev_data_send_update_data);
227 case SEV_CMD_SEND_UPDATE_VMSA: return sizeof(struct sev_data_send_update_vmsa);
228 case SEV_CMD_SEND_FINISH: return sizeof(struct sev_data_send_finish);
229 case SEV_CMD_RECEIVE_START: return sizeof(struct sev_data_receive_start);
230 case SEV_CMD_RECEIVE_FINISH: return sizeof(struct sev_data_receive_finish);
231 case SEV_CMD_RECEIVE_UPDATE_DATA: return sizeof(struct sev_data_receive_update_data);
232 case SEV_CMD_RECEIVE_UPDATE_VMSA: return sizeof(struct sev_data_receive_update_vmsa);
233 case SEV_CMD_LAUNCH_UPDATE_SECRET: return sizeof(struct sev_data_launch_secret);
234 case SEV_CMD_DOWNLOAD_FIRMWARE: return sizeof(struct sev_data_download_firmware);
235 case SEV_CMD_GET_ID: return sizeof(struct sev_data_get_id);
236 case SEV_CMD_ATTESTATION_REPORT: return sizeof(struct sev_data_attestation_report);
237 case SEV_CMD_SEND_CANCEL: return sizeof(struct sev_data_send_cancel);
238 case SEV_CMD_SNP_GCTX_CREATE: return sizeof(struct sev_data_snp_addr);
239 case SEV_CMD_SNP_LAUNCH_START: return sizeof(struct sev_data_snp_launch_start);
240 case SEV_CMD_SNP_LAUNCH_UPDATE: return sizeof(struct sev_data_snp_launch_update);
241 case SEV_CMD_SNP_ACTIVATE: return sizeof(struct sev_data_snp_activate);
242 case SEV_CMD_SNP_DECOMMISSION: return sizeof(struct sev_data_snp_addr);
243 case SEV_CMD_SNP_PAGE_RECLAIM: return sizeof(struct sev_data_snp_page_reclaim);
244 case SEV_CMD_SNP_GUEST_STATUS: return sizeof(struct sev_data_snp_guest_status);
245 case SEV_CMD_SNP_LAUNCH_FINISH: return sizeof(struct sev_data_snp_launch_finish);
246 case SEV_CMD_SNP_DBG_DECRYPT: return sizeof(struct sev_data_snp_dbg);
247 case SEV_CMD_SNP_DBG_ENCRYPT: return sizeof(struct sev_data_snp_dbg);
248 case SEV_CMD_SNP_VERIFY_MITIGATION: return sizeof(struct sev_data_snp_verify_mitigation);
249 case SEV_CMD_SNP_PAGE_UNSMASH: return sizeof(struct sev_data_snp_page_unsmash);
250 case SEV_CMD_SNP_PLATFORM_STATUS: return sizeof(struct sev_data_snp_addr);
251 case SEV_CMD_SNP_GUEST_REQUEST: return sizeof(struct sev_data_snp_guest_request);
252 case SEV_CMD_SNP_CONFIG: return sizeof(struct sev_user_data_snp_config);
253 case SEV_CMD_SNP_COMMIT: return sizeof(struct sev_data_snp_commit);
254 case SEV_CMD_SNP_FEATURE_INFO: return sizeof(struct sev_data_snp_feature_info);
255 case SEV_CMD_SNP_VLEK_LOAD: return sizeof(struct sev_user_data_snp_vlek_load);
256 default: return sev_tio_cmd_buffer_len(cmd);
257 }
258
259 return 0;
260 }
261
open_file_as_root(const char * filename,int flags,umode_t mode)262 static struct file *open_file_as_root(const char *filename, int flags, umode_t mode)
263 {
264 CLASS(prepare_creds, cred)();
265 if (!cred)
266 return ERR_PTR(-ENOMEM);
267
268 cred->fsuid = GLOBAL_ROOT_UID;
269
270 scoped_with_init_fs() {
271 scoped_with_creds(cred)
272 return filp_open(filename, flags, mode);
273 }
274 }
275
sev_read_init_ex_file(void)276 static int sev_read_init_ex_file(void)
277 {
278 struct sev_device *sev = psp_master->sev_data;
279 struct file *fp;
280 ssize_t nread;
281
282 lockdep_assert_held(&sev_cmd_mutex);
283
284 if (!sev_init_ex_buffer)
285 return -EOPNOTSUPP;
286
287 fp = open_file_as_root(init_ex_path, O_RDONLY, 0);
288 if (IS_ERR(fp)) {
289 int ret = PTR_ERR(fp);
290
291 if (ret == -ENOENT) {
292 dev_info(sev->dev,
293 "SEV: %s does not exist and will be created later.\n",
294 init_ex_path);
295 ret = 0;
296 } else {
297 dev_err(sev->dev,
298 "SEV: could not open %s for read, error %d\n",
299 init_ex_path, ret);
300 }
301 return ret;
302 }
303
304 nread = kernel_read(fp, sev_init_ex_buffer, NV_LENGTH, NULL);
305 if (nread != NV_LENGTH) {
306 dev_info(sev->dev,
307 "SEV: could not read %u bytes to non volatile memory area, ret %ld\n",
308 NV_LENGTH, nread);
309 }
310
311 dev_dbg(sev->dev, "SEV: read %ld bytes from NV file\n", nread);
312 filp_close(fp, NULL);
313
314 return 0;
315 }
316
sev_write_init_ex_file(void)317 static int sev_write_init_ex_file(void)
318 {
319 struct sev_device *sev = psp_master->sev_data;
320 struct file *fp;
321 loff_t offset = 0;
322 ssize_t nwrite;
323
324 lockdep_assert_held(&sev_cmd_mutex);
325
326 if (!sev_init_ex_buffer)
327 return 0;
328
329 fp = open_file_as_root(init_ex_path, O_CREAT | O_WRONLY, 0600);
330 if (IS_ERR(fp)) {
331 int ret = PTR_ERR(fp);
332
333 dev_err(sev->dev,
334 "SEV: could not open file for write, error %d\n",
335 ret);
336 return ret;
337 }
338
339 nwrite = kernel_write(fp, sev_init_ex_buffer, NV_LENGTH, &offset);
340 vfs_fsync(fp, 0);
341 filp_close(fp, NULL);
342
343 if (nwrite != NV_LENGTH) {
344 dev_err(sev->dev,
345 "SEV: failed to write %u bytes to non volatile memory area, ret %ld\n",
346 NV_LENGTH, nwrite);
347 return -EIO;
348 }
349
350 dev_dbg(sev->dev, "SEV: write successful to NV file\n");
351
352 return 0;
353 }
354
sev_write_init_ex_file_if_required(int cmd_id)355 static int sev_write_init_ex_file_if_required(int cmd_id)
356 {
357 lockdep_assert_held(&sev_cmd_mutex);
358
359 if (!sev_init_ex_buffer)
360 return 0;
361
362 /*
363 * Only a few platform commands modify the SPI/NV area, but none of the
364 * non-platform commands do. Only INIT(_EX), PLATFORM_RESET, PEK_GEN,
365 * PEK_CERT_IMPORT, and PDH_GEN do.
366 */
367 switch (cmd_id) {
368 case SEV_CMD_FACTORY_RESET:
369 case SEV_CMD_INIT_EX:
370 case SEV_CMD_PDH_GEN:
371 case SEV_CMD_PEK_CERT_IMPORT:
372 case SEV_CMD_PEK_GEN:
373 break;
374 default:
375 return 0;
376 }
377
378 return sev_write_init_ex_file();
379 }
380
snp_reclaim_pages(unsigned long paddr,unsigned int npages,bool locked)381 int snp_reclaim_pages(unsigned long paddr, unsigned int npages, bool locked)
382 {
383 int ret, err, i;
384
385 paddr = __sme_clr(ALIGN_DOWN(paddr, PAGE_SIZE));
386
387 for (i = 0; i < npages; i++, paddr += PAGE_SIZE) {
388 struct sev_data_snp_page_reclaim data = {0};
389
390 data.paddr = paddr;
391
392 if (locked)
393 ret = __sev_do_cmd_locked(SEV_CMD_SNP_PAGE_RECLAIM, &data, &err);
394 else
395 ret = sev_do_cmd(SEV_CMD_SNP_PAGE_RECLAIM, &data, &err);
396
397 if (ret)
398 goto cleanup;
399
400 ret = rmp_make_shared(__phys_to_pfn(paddr), PG_LEVEL_4K);
401 if (ret)
402 goto cleanup;
403 }
404
405 return 0;
406
407 cleanup:
408 /*
409 * If there was a failure reclaiming the page then it is no longer safe
410 * to release it back to the system; leak it instead.
411 */
412 snp_leak_pages(__phys_to_pfn(paddr), npages - i);
413 return ret;
414 }
415 EXPORT_SYMBOL_GPL(snp_reclaim_pages);
416
rmp_mark_pages_firmware(unsigned long paddr,unsigned int npages,bool locked)417 static int rmp_mark_pages_firmware(unsigned long paddr, unsigned int npages, bool locked)
418 {
419 unsigned long pfn = __sme_clr(paddr) >> PAGE_SHIFT;
420 int rc, i;
421
422 for (i = 0; i < npages; i++, pfn++) {
423 rc = rmp_make_private(pfn, 0, PG_LEVEL_4K, 0, true);
424 if (rc)
425 goto cleanup;
426 }
427
428 return 0;
429
430 cleanup:
431 /*
432 * Try unrolling the firmware state changes by
433 * reclaiming the pages which were already changed to the
434 * firmware state.
435 */
436 snp_reclaim_pages(paddr, i, locked);
437
438 return rc;
439 }
440
__snp_alloc_firmware_pages(gfp_t gfp_mask,int order,bool locked)441 static struct page *__snp_alloc_firmware_pages(gfp_t gfp_mask, int order, bool locked)
442 {
443 unsigned long npages = 1ul << order, paddr;
444 struct sev_device *sev;
445 struct page *page;
446
447 if (!psp_master || !psp_master->sev_data)
448 return NULL;
449
450 page = alloc_pages(gfp_mask, order);
451 if (!page)
452 return NULL;
453
454 /* If SEV-SNP is initialized then add the page in RMP table. */
455 sev = psp_master->sev_data;
456 if (!sev->snp_initialized)
457 return page;
458
459 paddr = __pa((unsigned long)page_address(page));
460 if (rmp_mark_pages_firmware(paddr, npages, locked))
461 return NULL;
462
463 return page;
464 }
465
snp_alloc_firmware_page(gfp_t gfp_mask)466 void *snp_alloc_firmware_page(gfp_t gfp_mask)
467 {
468 struct page *page;
469
470 page = __snp_alloc_firmware_pages(gfp_mask, 0, false);
471
472 return page ? page_address(page) : NULL;
473 }
474 EXPORT_SYMBOL_GPL(snp_alloc_firmware_page);
475
__snp_free_firmware_pages(struct page * page,int order,bool locked)476 static void __snp_free_firmware_pages(struct page *page, int order, bool locked)
477 {
478 struct sev_device *sev = psp_master->sev_data;
479 unsigned long paddr, npages = 1ul << order;
480
481 if (!page)
482 return;
483
484 paddr = __pa((unsigned long)page_address(page));
485 if (sev->snp_initialized &&
486 snp_reclaim_pages(paddr, npages, locked))
487 return;
488
489 __free_pages(page, order);
490 }
491
snp_free_firmware_page(void * addr)492 void snp_free_firmware_page(void *addr)
493 {
494 if (!addr)
495 return;
496
497 __snp_free_firmware_pages(virt_to_page(addr), 0, false);
498 }
499 EXPORT_SYMBOL_GPL(snp_free_firmware_page);
500
sev_fw_alloc(unsigned long len)501 static void *sev_fw_alloc(unsigned long len)
502 {
503 struct page *page;
504
505 page = __snp_alloc_firmware_pages(GFP_KERNEL, get_order(len), true);
506 if (!page)
507 return NULL;
508
509 return page_address(page);
510 }
511
512 /**
513 * struct cmd_buf_desc - descriptors for managing legacy SEV command address
514 * parameters corresponding to buffers that may be written to by firmware.
515 *
516 * @paddr_ptr: pointer to the address parameter in the command buffer which may
517 * need to be saved/restored depending on whether a bounce buffer
518 * is used. In the case of a bounce buffer, the command buffer
519 * needs to be updated with the address of the new bounce buffer
520 * snp_map_cmd_buf_desc() has allocated specifically for it. Must
521 * be NULL if this descriptor is only an end-of-list indicator.
522 *
523 * @paddr_orig: storage for the original address parameter, which can be used to
524 * restore the original value in @paddr_ptr in cases where it is
525 * replaced with the address of a bounce buffer.
526 *
527 * @len: length of buffer located at the address originally stored at @paddr_ptr
528 *
529 * @guest_owned: true if the address corresponds to guest-owned pages, in which
530 * case bounce buffers are not needed.
531 */
532 struct cmd_buf_desc {
533 u64 *paddr_ptr;
534 u64 paddr_orig;
535 u32 len;
536 bool guest_owned;
537 };
538
539 /*
540 * If a legacy SEV command parameter is a memory address, those pages in
541 * turn need to be transitioned to/from firmware-owned before/after
542 * executing the firmware command.
543 *
544 * Additionally, in cases where those pages are not guest-owned, a bounce
545 * buffer is needed in place of the original memory address parameter.
546 *
547 * A set of descriptors are used to keep track of this handling, and
548 * initialized here based on the specific commands being executed.
549 */
snp_populate_cmd_buf_desc_list(int cmd,void * cmd_buf,struct cmd_buf_desc * desc_list)550 static void snp_populate_cmd_buf_desc_list(int cmd, void *cmd_buf,
551 struct cmd_buf_desc *desc_list)
552 {
553 switch (cmd) {
554 case SEV_CMD_PDH_CERT_EXPORT: {
555 struct sev_data_pdh_cert_export *data = cmd_buf;
556
557 desc_list[0].paddr_ptr = &data->pdh_cert_address;
558 desc_list[0].len = data->pdh_cert_len;
559 desc_list[1].paddr_ptr = &data->cert_chain_address;
560 desc_list[1].len = data->cert_chain_len;
561 break;
562 }
563 case SEV_CMD_GET_ID: {
564 struct sev_data_get_id *data = cmd_buf;
565
566 desc_list[0].paddr_ptr = &data->address;
567 desc_list[0].len = data->len;
568 break;
569 }
570 case SEV_CMD_PEK_CSR: {
571 struct sev_data_pek_csr *data = cmd_buf;
572
573 desc_list[0].paddr_ptr = &data->address;
574 desc_list[0].len = data->len;
575 break;
576 }
577 case SEV_CMD_LAUNCH_UPDATE_DATA: {
578 struct sev_data_launch_update_data *data = cmd_buf;
579
580 desc_list[0].paddr_ptr = &data->address;
581 desc_list[0].len = data->len;
582 desc_list[0].guest_owned = true;
583 break;
584 }
585 case SEV_CMD_LAUNCH_UPDATE_VMSA: {
586 struct sev_data_launch_update_vmsa *data = cmd_buf;
587
588 desc_list[0].paddr_ptr = &data->address;
589 desc_list[0].len = data->len;
590 desc_list[0].guest_owned = true;
591 break;
592 }
593 case SEV_CMD_LAUNCH_MEASURE: {
594 struct sev_data_launch_measure *data = cmd_buf;
595
596 desc_list[0].paddr_ptr = &data->address;
597 desc_list[0].len = data->len;
598 break;
599 }
600 case SEV_CMD_LAUNCH_UPDATE_SECRET: {
601 struct sev_data_launch_secret *data = cmd_buf;
602
603 desc_list[0].paddr_ptr = &data->guest_address;
604 desc_list[0].len = data->guest_len;
605 desc_list[0].guest_owned = true;
606 break;
607 }
608 case SEV_CMD_DBG_DECRYPT: {
609 struct sev_data_dbg *data = cmd_buf;
610
611 desc_list[0].paddr_ptr = &data->dst_addr;
612 desc_list[0].len = data->len;
613 desc_list[0].guest_owned = true;
614 break;
615 }
616 case SEV_CMD_DBG_ENCRYPT: {
617 struct sev_data_dbg *data = cmd_buf;
618
619 desc_list[0].paddr_ptr = &data->dst_addr;
620 desc_list[0].len = data->len;
621 desc_list[0].guest_owned = true;
622 break;
623 }
624 case SEV_CMD_ATTESTATION_REPORT: {
625 struct sev_data_attestation_report *data = cmd_buf;
626
627 desc_list[0].paddr_ptr = &data->address;
628 desc_list[0].len = data->len;
629 break;
630 }
631 case SEV_CMD_SEND_START: {
632 struct sev_data_send_start *data = cmd_buf;
633
634 desc_list[0].paddr_ptr = &data->session_address;
635 desc_list[0].len = data->session_len;
636 break;
637 }
638 case SEV_CMD_SEND_UPDATE_DATA: {
639 struct sev_data_send_update_data *data = cmd_buf;
640
641 desc_list[0].paddr_ptr = &data->hdr_address;
642 desc_list[0].len = data->hdr_len;
643 desc_list[1].paddr_ptr = &data->trans_address;
644 desc_list[1].len = data->trans_len;
645 break;
646 }
647 case SEV_CMD_SEND_UPDATE_VMSA: {
648 struct sev_data_send_update_vmsa *data = cmd_buf;
649
650 desc_list[0].paddr_ptr = &data->hdr_address;
651 desc_list[0].len = data->hdr_len;
652 desc_list[1].paddr_ptr = &data->trans_address;
653 desc_list[1].len = data->trans_len;
654 break;
655 }
656 case SEV_CMD_RECEIVE_UPDATE_DATA: {
657 struct sev_data_receive_update_data *data = cmd_buf;
658
659 desc_list[0].paddr_ptr = &data->guest_address;
660 desc_list[0].len = data->guest_len;
661 desc_list[0].guest_owned = true;
662 break;
663 }
664 case SEV_CMD_RECEIVE_UPDATE_VMSA: {
665 struct sev_data_receive_update_vmsa *data = cmd_buf;
666
667 desc_list[0].paddr_ptr = &data->guest_address;
668 desc_list[0].len = data->guest_len;
669 desc_list[0].guest_owned = true;
670 break;
671 }
672 default:
673 break;
674 }
675 }
676
snp_map_cmd_buf_desc(struct cmd_buf_desc * desc)677 static int snp_map_cmd_buf_desc(struct cmd_buf_desc *desc)
678 {
679 unsigned int npages;
680
681 if (!desc->len)
682 return 0;
683
684 /* Allocate a bounce buffer if this isn't a guest owned page. */
685 if (!desc->guest_owned) {
686 struct page *page;
687
688 page = alloc_pages(GFP_KERNEL_ACCOUNT, get_order(desc->len));
689 if (!page) {
690 pr_warn("Failed to allocate bounce buffer for SEV legacy command.\n");
691 return -ENOMEM;
692 }
693
694 desc->paddr_orig = *desc->paddr_ptr;
695 *desc->paddr_ptr = __psp_pa(page_to_virt(page));
696 }
697
698 npages = PAGE_ALIGN(desc->len) >> PAGE_SHIFT;
699
700 /* Transition the buffer to firmware-owned. */
701 if (rmp_mark_pages_firmware(*desc->paddr_ptr, npages, true)) {
702 pr_warn("Error moving pages to firmware-owned state for SEV legacy command.\n");
703 return -EFAULT;
704 }
705
706 return 0;
707 }
708
snp_unmap_cmd_buf_desc(struct cmd_buf_desc * desc)709 static int snp_unmap_cmd_buf_desc(struct cmd_buf_desc *desc)
710 {
711 unsigned int npages;
712
713 if (!desc->len)
714 return 0;
715
716 npages = PAGE_ALIGN(desc->len) >> PAGE_SHIFT;
717
718 /* Transition the buffers back to hypervisor-owned. */
719 if (snp_reclaim_pages(*desc->paddr_ptr, npages, true)) {
720 pr_warn("Failed to reclaim firmware-owned pages while issuing SEV legacy command.\n");
721 return -EFAULT;
722 }
723
724 /* Copy data from bounce buffer and then free it. */
725 if (!desc->guest_owned) {
726 void *bounce_buf = __va(__sme_clr(*desc->paddr_ptr));
727 void *dst_buf = __va(__sme_clr(desc->paddr_orig));
728
729 memcpy(dst_buf, bounce_buf, desc->len);
730 __free_pages(virt_to_page(bounce_buf), get_order(desc->len));
731
732 /* Restore the original address in the command buffer. */
733 *desc->paddr_ptr = desc->paddr_orig;
734 }
735
736 return 0;
737 }
738
snp_map_cmd_buf_desc_list(int cmd,void * cmd_buf,struct cmd_buf_desc * desc_list)739 static int snp_map_cmd_buf_desc_list(int cmd, void *cmd_buf, struct cmd_buf_desc *desc_list)
740 {
741 int i;
742
743 snp_populate_cmd_buf_desc_list(cmd, cmd_buf, desc_list);
744
745 for (i = 0; i < CMD_BUF_DESC_MAX; i++) {
746 struct cmd_buf_desc *desc = &desc_list[i];
747
748 if (!desc->paddr_ptr)
749 break;
750
751 if (snp_map_cmd_buf_desc(desc))
752 goto err_unmap;
753 }
754
755 return 0;
756
757 err_unmap:
758 for (i--; i >= 0; i--)
759 snp_unmap_cmd_buf_desc(&desc_list[i]);
760
761 return -EFAULT;
762 }
763
snp_unmap_cmd_buf_desc_list(struct cmd_buf_desc * desc_list)764 static int snp_unmap_cmd_buf_desc_list(struct cmd_buf_desc *desc_list)
765 {
766 int i, ret = 0;
767
768 for (i = 0; i < CMD_BUF_DESC_MAX; i++) {
769 struct cmd_buf_desc *desc = &desc_list[i];
770
771 if (!desc->paddr_ptr)
772 break;
773
774 if (snp_unmap_cmd_buf_desc(&desc_list[i]))
775 ret = -EFAULT;
776 }
777
778 return ret;
779 }
780
sev_cmd_buf_writable(int cmd)781 static bool sev_cmd_buf_writable(int cmd)
782 {
783 switch (cmd) {
784 case SEV_CMD_PLATFORM_STATUS:
785 case SEV_CMD_GUEST_STATUS:
786 case SEV_CMD_LAUNCH_START:
787 case SEV_CMD_RECEIVE_START:
788 case SEV_CMD_LAUNCH_MEASURE:
789 case SEV_CMD_SEND_START:
790 case SEV_CMD_SEND_UPDATE_DATA:
791 case SEV_CMD_SEND_UPDATE_VMSA:
792 case SEV_CMD_PEK_CSR:
793 case SEV_CMD_PDH_CERT_EXPORT:
794 case SEV_CMD_GET_ID:
795 case SEV_CMD_ATTESTATION_REPORT:
796 return true;
797 default:
798 return false;
799 }
800 }
801
802 /* After SNP is INIT'ed, the behavior of legacy SEV commands is changed. */
snp_legacy_handling_needed(int cmd)803 static bool snp_legacy_handling_needed(int cmd)
804 {
805 struct sev_device *sev = psp_master->sev_data;
806
807 return cmd < SEV_CMD_SNP_INIT && sev->snp_initialized;
808 }
809
snp_prep_cmd_buf(int cmd,void * cmd_buf,struct cmd_buf_desc * desc_list)810 static int snp_prep_cmd_buf(int cmd, void *cmd_buf, struct cmd_buf_desc *desc_list)
811 {
812 if (!snp_legacy_handling_needed(cmd))
813 return 0;
814
815 if (snp_map_cmd_buf_desc_list(cmd, cmd_buf, desc_list))
816 return -EFAULT;
817
818 /*
819 * Before command execution, the command buffer needs to be put into
820 * the firmware-owned state.
821 */
822 if (sev_cmd_buf_writable(cmd)) {
823 if (rmp_mark_pages_firmware(__pa(cmd_buf), 1, true))
824 return -EFAULT;
825 }
826
827 return 0;
828 }
829
snp_reclaim_cmd_buf(int cmd,void * cmd_buf)830 static int snp_reclaim_cmd_buf(int cmd, void *cmd_buf)
831 {
832 if (!snp_legacy_handling_needed(cmd))
833 return 0;
834
835 /*
836 * After command completion, the command buffer needs to be put back
837 * into the hypervisor-owned state.
838 */
839 if (sev_cmd_buf_writable(cmd))
840 if (snp_reclaim_pages(__pa(cmd_buf), 1, true))
841 return -EFAULT;
842
843 return 0;
844 }
845
__sev_do_cmd_locked(int cmd,void * data,int * psp_ret)846 int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret)
847 {
848 struct cmd_buf_desc desc_list[CMD_BUF_DESC_MAX] = {0};
849 struct psp_device *psp = psp_master;
850 struct sev_device *sev;
851 unsigned int cmdbuff_hi, cmdbuff_lo;
852 unsigned int phys_lsb, phys_msb;
853 unsigned int reg;
854 void *cmd_buf;
855 int buf_len;
856 int ret = 0;
857
858 if (!psp || !psp->sev_data)
859 return -ENODEV;
860
861 if (psp_dead)
862 return -EBUSY;
863
864 sev = psp->sev_data;
865
866 buf_len = sev_cmd_buffer_len(cmd);
867 if (WARN_ON_ONCE(!data != !buf_len))
868 return -EINVAL;
869
870 /*
871 * Copy the incoming data to driver's scratch buffer as __pa() will not
872 * work for some memory, e.g. vmalloc'd addresses, and @data may not be
873 * physically contiguous.
874 */
875 if (data) {
876 /*
877 * Commands are generally issued one at a time and require the
878 * sev_cmd_mutex, but there could be recursive firmware requests
879 * due to SEV_CMD_SNP_PAGE_RECLAIM needing to be issued while
880 * preparing buffers for another command. This is the only known
881 * case of nesting in the current code, so exactly one
882 * additional command buffer is available for that purpose.
883 */
884 if (!sev->cmd_buf_active) {
885 cmd_buf = sev->cmd_buf;
886 sev->cmd_buf_active = true;
887 } else if (!sev->cmd_buf_backup_active) {
888 cmd_buf = sev->cmd_buf_backup;
889 sev->cmd_buf_backup_active = true;
890 } else {
891 dev_err(sev->dev,
892 "SEV: too many firmware commands in progress, no command buffers available.\n");
893 return -EBUSY;
894 }
895
896 memcpy(cmd_buf, data, buf_len);
897
898 /*
899 * The behavior of the SEV-legacy commands is altered when the
900 * SNP firmware is in the INIT state.
901 */
902 ret = snp_prep_cmd_buf(cmd, cmd_buf, desc_list);
903 if (ret) {
904 dev_err(sev->dev,
905 "SEV: failed to prepare buffer for legacy command 0x%x. Error: %d\n",
906 cmd, ret);
907 return ret;
908 }
909 } else {
910 cmd_buf = sev->cmd_buf;
911 }
912
913 /* Get the physical address of the command buffer */
914 phys_lsb = data ? lower_32_bits(__psp_pa(cmd_buf)) : 0;
915 phys_msb = data ? upper_32_bits(__psp_pa(cmd_buf)) : 0;
916
917 dev_dbg(sev->dev, "sev command id %#x buffer 0x%08x%08x timeout %us\n",
918 cmd, phys_msb, phys_lsb, psp_timeout);
919
920 print_hex_dump_debug("(in): ", DUMP_PREFIX_OFFSET, 16, 2, data,
921 buf_len, false);
922
923 iowrite32(phys_lsb, sev->io_regs + sev->vdata->cmdbuff_addr_lo_reg);
924 iowrite32(phys_msb, sev->io_regs + sev->vdata->cmdbuff_addr_hi_reg);
925
926 sev->int_rcvd = 0;
927
928 reg = FIELD_PREP(SEV_CMDRESP_CMD, cmd);
929
930 /*
931 * If invoked during panic handling, local interrupts are disabled so
932 * the PSP command completion interrupt can't be used.
933 * sev_wait_cmd_ioc() already checks for interrupts disabled and
934 * polls for PSP command completion. Ensure we do not request an
935 * interrupt from the PSP if irqs disabled.
936 */
937 if (!irqs_disabled())
938 reg |= SEV_CMDRESP_IOC;
939
940 iowrite32(reg, sev->io_regs + sev->vdata->cmdresp_reg);
941
942 /* wait for command completion */
943 ret = sev_wait_cmd_ioc(sev, ®, psp_timeout);
944 if (ret) {
945 if (psp_ret)
946 *psp_ret = 0;
947
948 dev_err(sev->dev, "sev command %#x timed out, disabling PSP\n", cmd);
949 psp_dead = true;
950
951 return ret;
952 }
953
954 psp_timeout = psp_cmd_timeout;
955
956 if (psp_ret)
957 *psp_ret = FIELD_GET(PSP_CMDRESP_STS, reg);
958
959 if (FIELD_GET(PSP_CMDRESP_STS, reg)) {
960 dev_dbg(sev->dev, "sev command %#x failed (%#010lx)\n",
961 cmd, FIELD_GET(PSP_CMDRESP_STS, reg));
962
963 /*
964 * PSP firmware may report additional error information in the
965 * command buffer registers on error. Print contents of command
966 * buffer registers if they changed.
967 */
968 cmdbuff_hi = ioread32(sev->io_regs + sev->vdata->cmdbuff_addr_hi_reg);
969 cmdbuff_lo = ioread32(sev->io_regs + sev->vdata->cmdbuff_addr_lo_reg);
970 if (cmdbuff_hi != phys_msb || cmdbuff_lo != phys_lsb) {
971 dev_dbg(sev->dev, "Additional error information reported in cmdbuff:");
972 dev_dbg(sev->dev, " cmdbuff hi: %#010x\n", cmdbuff_hi);
973 dev_dbg(sev->dev, " cmdbuff lo: %#010x\n", cmdbuff_lo);
974 }
975 ret = -EIO;
976 } else {
977 ret = sev_write_init_ex_file_if_required(cmd);
978 }
979
980 /*
981 * Copy potential output from the PSP back to data. Do this even on
982 * failure in case the caller wants to glean something from the error.
983 */
984 if (data) {
985 int ret_reclaim;
986 /*
987 * Restore the page state after the command completes.
988 */
989 ret_reclaim = snp_reclaim_cmd_buf(cmd, cmd_buf);
990 if (ret_reclaim) {
991 dev_err(sev->dev,
992 "SEV: failed to reclaim buffer for legacy command %#x. Error: %d\n",
993 cmd, ret_reclaim);
994 return ret_reclaim;
995 }
996
997 memcpy(data, cmd_buf, buf_len);
998
999 if (sev->cmd_buf_backup_active)
1000 sev->cmd_buf_backup_active = false;
1001 else
1002 sev->cmd_buf_active = false;
1003
1004 if (snp_unmap_cmd_buf_desc_list(desc_list))
1005 return -EFAULT;
1006 }
1007
1008 print_hex_dump_debug("(out): ", DUMP_PREFIX_OFFSET, 16, 2, data,
1009 buf_len, false);
1010
1011 return ret;
1012 }
1013
sev_do_cmd(int cmd,void * data,int * psp_ret)1014 int sev_do_cmd(int cmd, void *data, int *psp_ret)
1015 {
1016 int rc;
1017
1018 mutex_lock(&sev_cmd_mutex);
1019 rc = __sev_do_cmd_locked(cmd, data, psp_ret);
1020 mutex_unlock(&sev_cmd_mutex);
1021
1022 return rc;
1023 }
1024 EXPORT_SYMBOL_GPL(sev_do_cmd);
1025
__sev_init_locked(int * error)1026 static int __sev_init_locked(int *error)
1027 {
1028 struct sev_data_init data;
1029
1030 memset(&data, 0, sizeof(data));
1031 if (sev_es_tmr) {
1032 /*
1033 * Do not include the encryption mask on the physical
1034 * address of the TMR (firmware should clear it anyway).
1035 */
1036 data.tmr_address = __pa(sev_es_tmr);
1037
1038 data.flags |= SEV_INIT_FLAGS_SEV_ES;
1039 data.tmr_len = sev_es_tmr_size;
1040 }
1041
1042 return __sev_do_cmd_locked(SEV_CMD_INIT, &data, error);
1043 }
1044
__sev_init_ex_locked(int * error)1045 static int __sev_init_ex_locked(int *error)
1046 {
1047 struct sev_data_init_ex data;
1048
1049 memset(&data, 0, sizeof(data));
1050 data.length = sizeof(data);
1051 data.nv_address = __psp_pa(sev_init_ex_buffer);
1052 data.nv_len = NV_LENGTH;
1053
1054 if (sev_es_tmr) {
1055 /*
1056 * Do not include the encryption mask on the physical
1057 * address of the TMR (firmware should clear it anyway).
1058 */
1059 data.tmr_address = __pa(sev_es_tmr);
1060
1061 data.flags |= SEV_INIT_FLAGS_SEV_ES;
1062 data.tmr_len = sev_es_tmr_size;
1063 }
1064
1065 return __sev_do_cmd_locked(SEV_CMD_INIT_EX, &data, error);
1066 }
1067
__sev_do_init_locked(int * psp_ret)1068 static inline int __sev_do_init_locked(int *psp_ret)
1069 {
1070 if (sev_init_ex_buffer)
1071 return __sev_init_ex_locked(psp_ret);
1072 else
1073 return __sev_init_locked(psp_ret);
1074 }
1075
1076 /* Hypervisor Fixed pages API interface */
snp_hv_fixed_pages_state_update(struct sev_device * sev,enum snp_hv_fixed_pages_state page_state)1077 static void snp_hv_fixed_pages_state_update(struct sev_device *sev,
1078 enum snp_hv_fixed_pages_state page_state)
1079 {
1080 struct snp_hv_fixed_pages_entry *entry;
1081
1082 /* List is protected by sev_cmd_mutex */
1083 lockdep_assert_held(&sev_cmd_mutex);
1084
1085 if (list_empty(&snp_hv_fixed_pages))
1086 return;
1087
1088 list_for_each_entry(entry, &snp_hv_fixed_pages, list)
1089 entry->page_state = page_state;
1090 }
1091
1092 /*
1093 * Allocate HV_FIXED pages in 2MB aligned sizes to ensure the whole
1094 * 2MB pages are marked as HV_FIXED.
1095 */
snp_alloc_hv_fixed_pages(unsigned int num_2mb_pages)1096 struct page *snp_alloc_hv_fixed_pages(unsigned int num_2mb_pages)
1097 {
1098 struct psp_device *psp_master = psp_get_master_device();
1099 struct snp_hv_fixed_pages_entry *entry;
1100 unsigned int order;
1101 struct page *page;
1102
1103 if (!psp_master)
1104 return NULL;
1105
1106 order = get_order(PMD_SIZE * num_2mb_pages);
1107
1108 /*
1109 * SNP_INIT_EX is protected by sev_cmd_mutex, therefore this list
1110 * also needs to be protected using the same mutex.
1111 */
1112 guard(mutex)(&sev_cmd_mutex);
1113
1114 /*
1115 * This API uses SNP_INIT_EX to transition allocated pages to HV_Fixed
1116 * page state, fail if SNP is already initialized.
1117 */
1118 if (psp_master->sev_data &&
1119 ((struct sev_device *)psp_master->sev_data)->snp_initialized)
1120 return NULL;
1121
1122 /* Re-use freed pages that match the request */
1123 list_for_each_entry(entry, &snp_hv_fixed_pages, list) {
1124 /* Hypervisor fixed page allocator implements exact fit policy */
1125 if (entry->order == order && entry->free) {
1126 entry->free = false;
1127 memset(page_address(entry->page), 0,
1128 (1 << entry->order) * PAGE_SIZE);
1129 return entry->page;
1130 }
1131 }
1132
1133 page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
1134 if (!page)
1135 return NULL;
1136
1137 entry = kzalloc_obj(*entry);
1138 if (!entry) {
1139 __free_pages(page, order);
1140 return NULL;
1141 }
1142
1143 entry->page = page;
1144 entry->order = order;
1145 list_add_tail(&entry->list, &snp_hv_fixed_pages);
1146
1147 return page;
1148 }
1149
snp_free_hv_fixed_pages(struct page * page)1150 void snp_free_hv_fixed_pages(struct page *page)
1151 {
1152 struct psp_device *psp_master = psp_get_master_device();
1153 struct snp_hv_fixed_pages_entry *entry, *nentry;
1154
1155 if (!psp_master)
1156 return;
1157
1158 /*
1159 * SNP_INIT_EX is protected by sev_cmd_mutex, therefore this list
1160 * also needs to be protected using the same mutex.
1161 */
1162 guard(mutex)(&sev_cmd_mutex);
1163
1164 list_for_each_entry_safe(entry, nentry, &snp_hv_fixed_pages, list) {
1165 if (entry->page != page)
1166 continue;
1167
1168 /*
1169 * HV_FIXED page state cannot be changed until reboot
1170 * and they cannot be used by an SNP guest, so they cannot
1171 * be returned back to the page allocator.
1172 * Mark the pages as free internally to allow possible re-use.
1173 */
1174 if (entry->page_state == HV_FIXED) {
1175 entry->free = true;
1176 } else {
1177 __free_pages(page, entry->order);
1178 list_del(&entry->list);
1179 kfree(entry);
1180 }
1181 return;
1182 }
1183 }
1184
snp_add_hv_fixed_pages(struct sev_device * sev,struct sev_data_range_list * range_list)1185 static void snp_add_hv_fixed_pages(struct sev_device *sev, struct sev_data_range_list *range_list)
1186 {
1187 struct snp_hv_fixed_pages_entry *entry;
1188 struct sev_data_range *range;
1189 int num_elements;
1190
1191 lockdep_assert_held(&sev_cmd_mutex);
1192
1193 if (list_empty(&snp_hv_fixed_pages))
1194 return;
1195
1196 num_elements = list_count_nodes(&snp_hv_fixed_pages) +
1197 range_list->num_elements;
1198
1199 /*
1200 * Ensure the list of HV_FIXED pages that will be passed to firmware
1201 * do not exceed the page-sized argument buffer.
1202 */
1203 if (num_elements * sizeof(*range) + sizeof(*range_list) > PAGE_SIZE) {
1204 dev_warn(sev->dev, "Additional HV_Fixed pages cannot be accommodated, omitting\n");
1205 return;
1206 }
1207
1208 range = &range_list->ranges[range_list->num_elements];
1209 list_for_each_entry(entry, &snp_hv_fixed_pages, list) {
1210 range->base = page_to_pfn(entry->page) << PAGE_SHIFT;
1211 range->page_count = 1 << entry->order;
1212 range++;
1213 }
1214 range_list->num_elements = num_elements;
1215 }
1216
snp_leak_hv_fixed_pages(void)1217 static void snp_leak_hv_fixed_pages(void)
1218 {
1219 struct snp_hv_fixed_pages_entry *entry, *nentry;
1220
1221 /* List is protected by sev_cmd_mutex */
1222 lockdep_assert_held(&sev_cmd_mutex);
1223
1224 if (list_empty(&snp_hv_fixed_pages))
1225 return;
1226
1227 list_for_each_entry_safe(entry, nentry, &snp_hv_fixed_pages, list) {
1228 if (entry->free && entry->page_state != HV_FIXED)
1229 __free_pages(entry->page, entry->order);
1230 else
1231 __snp_leak_pages(page_to_pfn(entry->page),
1232 1 << entry->order, false);
1233
1234 list_del(&entry->list);
1235 kfree(entry);
1236 }
1237 }
1238
sev_is_snp_ciphertext_hiding_supported(void)1239 bool sev_is_snp_ciphertext_hiding_supported(void)
1240 {
1241 struct psp_device *psp = psp_master;
1242 struct sev_device *sev;
1243
1244 if (!psp || !psp->sev_data)
1245 return false;
1246
1247 sev = psp->sev_data;
1248
1249 /*
1250 * Feature information indicates if CipherTextHiding feature is
1251 * supported by the SEV firmware and additionally platform status
1252 * indicates if CipherTextHiding feature is enabled in the
1253 * Platform BIOS.
1254 */
1255 return ((sev->snp_feat_info_0.ecx & SNP_CIPHER_TEXT_HIDING_SUPPORTED) &&
1256 sev->snp_plat_status.ciphertext_hiding_cap);
1257 }
1258 EXPORT_SYMBOL_GPL(sev_is_snp_ciphertext_hiding_supported);
1259
snp_get_platform_data(struct sev_device * sev,int * error)1260 static int snp_get_platform_data(struct sev_device *sev, int *error)
1261 {
1262 struct sev_data_snp_feature_info snp_feat_info;
1263 struct snp_feature_info *feat_info;
1264 struct sev_data_snp_addr buf;
1265 struct page *page;
1266 int rc;
1267
1268 /*
1269 * This function is expected to be called before SNP is
1270 * initialized.
1271 */
1272 if (sev->snp_initialized)
1273 return -EINVAL;
1274
1275 buf.address = __psp_pa(&sev->snp_plat_status);
1276 rc = sev_do_cmd(SEV_CMD_SNP_PLATFORM_STATUS, &buf, error);
1277 if (rc) {
1278 dev_err(sev->dev, "SNP PLATFORM_STATUS command failed, ret = %d, error = %#x\n",
1279 rc, *error);
1280 return rc;
1281 }
1282
1283 sev->api_major = sev->snp_plat_status.api_major;
1284 sev->api_minor = sev->snp_plat_status.api_minor;
1285 sev->build = sev->snp_plat_status.build_id;
1286
1287 /*
1288 * Do feature discovery of the currently loaded firmware,
1289 * and cache feature information from CPUID 0x8000_0024,
1290 * sub-function 0.
1291 */
1292 if (!sev->snp_plat_status.feature_info)
1293 return 0;
1294
1295 /*
1296 * Use dynamically allocated structure for the SNP_FEATURE_INFO
1297 * command to ensure structure is 8-byte aligned, and does not
1298 * cross a page boundary.
1299 */
1300 page = alloc_page(GFP_KERNEL);
1301 if (!page)
1302 return -ENOMEM;
1303
1304 feat_info = page_address(page);
1305 snp_feat_info.length = sizeof(snp_feat_info);
1306 snp_feat_info.ecx_in = 0;
1307 snp_feat_info.feature_info_paddr = __psp_pa(feat_info);
1308
1309 rc = sev_do_cmd(SEV_CMD_SNP_FEATURE_INFO, &snp_feat_info, error);
1310 if (!rc)
1311 sev->snp_feat_info_0 = *feat_info;
1312 else
1313 dev_err(sev->dev, "SNP FEATURE_INFO command failed, ret = %d, error = %#x\n",
1314 rc, *error);
1315
1316 __free_page(page);
1317
1318 return rc;
1319 }
1320
snp_filter_reserved_mem_regions(struct resource * rs,void * arg)1321 static int snp_filter_reserved_mem_regions(struct resource *rs, void *arg)
1322 {
1323 struct sev_data_range_list *range_list = arg;
1324 struct sev_data_range *range = &range_list->ranges[range_list->num_elements];
1325 size_t size;
1326
1327 /*
1328 * Ensure the list of HV_FIXED pages passed to the firmware including
1329 * the one about to be written to do not exceed the page-sized argument
1330 * buffer.
1331 */
1332 if (((range_list->num_elements + 1) * sizeof(struct sev_data_range) +
1333 sizeof(struct sev_data_range_list)) > PAGE_SIZE)
1334 return -E2BIG;
1335
1336 switch (rs->desc) {
1337 case E820_TYPE_RESERVED:
1338 case E820_TYPE_PMEM:
1339 case E820_TYPE_ACPI:
1340 range->base = rs->start & PAGE_MASK;
1341 size = PAGE_ALIGN((rs->end + 1) - rs->start);
1342 range->page_count = size >> PAGE_SHIFT;
1343 range_list->num_elements++;
1344 break;
1345 default:
1346 break;
1347 }
1348
1349 return 0;
1350 }
1351
1352 #ifdef CONFIG_SYSFS
snp_verify_mitigation(u16 command,u64 vector,struct sev_data_snp_verify_mitigation_dst * dst)1353 static int snp_verify_mitigation(u16 command, u64 vector,
1354 struct sev_data_snp_verify_mitigation_dst *dst)
1355 {
1356 struct sev_data_snp_verify_mitigation_dst *mit_dst = NULL;
1357 struct sev_data_snp_verify_mitigation data = {0};
1358 struct sev_device *sev = psp_master->sev_data;
1359 int ret, error = 0;
1360
1361 mit_dst = snp_alloc_firmware_page(GFP_KERNEL | __GFP_ZERO);
1362 if (!mit_dst)
1363 return -ENOMEM;
1364
1365 data.length = sizeof(data);
1366 data.subcommand = command;
1367 data.vector = vector;
1368 data.dst_paddr = __psp_pa(mit_dst);
1369 data.dst_paddr_en = true;
1370
1371 ret = sev_do_cmd(SEV_CMD_SNP_VERIFY_MITIGATION, &data, &error);
1372 if (!ret)
1373 memcpy(dst, mit_dst, sizeof(*mit_dst));
1374 else
1375 dev_err(sev->dev, "SNP_VERIFY_MITIGATION command failed, ret = %d, error = %#x\n",
1376 ret, error);
1377
1378 snp_free_firmware_page(mit_dst);
1379
1380 return ret;
1381 }
1382
supported_mitigations_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)1383 static ssize_t supported_mitigations_show(struct kobject *kobj,
1384 struct kobj_attribute *attr, char *buf)
1385 {
1386 struct sev_data_snp_verify_mitigation_dst dst;
1387 int ret;
1388
1389 ret = snp_verify_mitigation(SNP_MIT_SUBCMD_REQ_STATUS, 0, &dst);
1390 if (ret)
1391 return ret;
1392
1393 return sysfs_emit(buf, "0x%llx\n", dst.mit_supported_vector);
1394 }
1395
1396 static struct kobj_attribute supported_attr =
1397 __ATTR_RO_MODE(supported_mitigations, 0400);
1398
verified_mitigations_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)1399 static ssize_t verified_mitigations_show(struct kobject *kobj,
1400 struct kobj_attribute *attr, char *buf)
1401 {
1402 struct sev_data_snp_verify_mitigation_dst dst;
1403 int ret;
1404
1405 ret = snp_verify_mitigation(SNP_MIT_SUBCMD_REQ_STATUS, 0, &dst);
1406 if (ret)
1407 return ret;
1408
1409 return sysfs_emit(buf, "0x%llx\n", dst.mit_verified_vector);
1410 }
1411
verified_mitigations_store(struct kobject * kobj,struct kobj_attribute * attr,const char * buf,size_t count)1412 static ssize_t verified_mitigations_store(struct kobject *kobj,
1413 struct kobj_attribute *attr,
1414 const char *buf, size_t count)
1415 {
1416 struct sev_data_snp_verify_mitigation_dst dst;
1417 struct sev_device *sev = psp_master->sev_data;
1418 u64 vector;
1419 int ret;
1420
1421 ret = kstrtoull(buf, 0, &vector);
1422 if (ret)
1423 return ret;
1424
1425 /*
1426 * The firmware verifies a single mitigation per call. Reject vectors
1427 * with more than one bit set early to avoid a guaranteed-to-fail call
1428 */
1429 if (hweight64(vector) != 1)
1430 return -EINVAL;
1431
1432 ret = snp_verify_mitigation(SNP_MIT_SUBCMD_REQ_VERIFY, vector, &dst);
1433 if (ret)
1434 return ret;
1435
1436 if (dst.mit_failure_status) {
1437 dev_err(sev->dev, "Verify Mitigation - failure status: 0x%x\n",
1438 dst.mit_failure_status);
1439 return -EINVAL;
1440 }
1441
1442 return count;
1443 }
1444
1445 static struct kobj_attribute verified_attr =
1446 __ATTR_RW_MODE(verified_mitigations, 0600);
1447
1448 static struct attribute *mitigation_attrs[] = {
1449 &supported_attr.attr,
1450 &verified_attr.attr,
1451 NULL
1452 };
1453
1454 static const struct attribute_group mit_attr_group = {
1455 .attrs = mitigation_attrs,
1456 };
1457
sev_snp_register_verify_mitigation(struct sev_device * sev)1458 static void sev_snp_register_verify_mitigation(struct sev_device *sev)
1459 {
1460 int rc;
1461
1462 if (!(sev->snp_feat_info_0.ecx & SNP_VERIFY_MITIGATION_SUPPORTED) ||
1463 sev->verify_mit)
1464 return;
1465
1466 if (!sev->sev_kobj) {
1467 sev->sev_kobj = kobject_create_and_add("sev", firmware_kobj);
1468 if (!sev->sev_kobj)
1469 return;
1470 }
1471
1472 sev->verify_mit = kobject_create_and_add("vulnerabilities", sev->sev_kobj);
1473 if (!sev->verify_mit)
1474 goto err_sev_kobj;
1475
1476 rc = sysfs_create_group(sev->verify_mit, &mit_attr_group);
1477 if (rc)
1478 goto err_verify_mit;
1479
1480 return;
1481
1482 err_verify_mit:
1483 kobject_put(sev->verify_mit);
1484 sev->verify_mit = NULL;
1485 err_sev_kobj:
1486 kobject_put(sev->sev_kobj);
1487 sev->sev_kobj = NULL;
1488 }
1489
sev_snp_unregister_verify_mitigation(struct sev_device * sev)1490 static void sev_snp_unregister_verify_mitigation(struct sev_device *sev)
1491 {
1492 if (sev->verify_mit) {
1493 sysfs_remove_group(sev->verify_mit, &mit_attr_group);
1494 kobject_put(sev->verify_mit);
1495 sev->verify_mit = NULL;
1496 }
1497
1498 if (sev->sev_kobj) {
1499 kobject_put(sev->sev_kobj);
1500 sev->sev_kobj = NULL;
1501 }
1502 }
1503 #else // CONFIG_SYSFS
sev_snp_register_verify_mitigation(struct sev_device * sev)1504 static void sev_snp_register_verify_mitigation(struct sev_device *sev) { }
sev_snp_unregister_verify_mitigation(struct sev_device * sev)1505 static void sev_snp_unregister_verify_mitigation(struct sev_device *sev) { }
1506 #endif // CONFIG_SYSFS
1507
__sev_snp_init_locked(int * error,unsigned int max_snp_asid)1508 static int __sev_snp_init_locked(int *error, unsigned int max_snp_asid)
1509 {
1510 struct sev_data_range_list *snp_range_list __free(kfree) = NULL;
1511 struct psp_device *psp = psp_master;
1512 struct sev_data_snp_init_ex data = {};
1513 struct sev_device *sev;
1514 void *arg = &data;
1515 int cmd, rc = 0;
1516
1517 if (!cc_platform_has(CC_ATTR_HOST_SEV_SNP))
1518 return -ENODEV;
1519
1520 sev = psp->sev_data;
1521
1522 if (sev->snp_initialized)
1523 return 0;
1524
1525 if (!sev_version_greater_or_equal(SNP_MIN_API_MAJOR, SNP_MIN_API_MINOR)) {
1526 dev_dbg(sev->dev, "SEV-SNP support requires firmware version >= %d:%d\n",
1527 SNP_MIN_API_MAJOR, SNP_MIN_API_MINOR);
1528 return -EOPNOTSUPP;
1529 }
1530
1531 rc = snp_prepare();
1532 if (rc)
1533 return rc;
1534
1535 /*
1536 * Starting in SNP firmware v1.52, the SNP_INIT_EX command takes a list
1537 * of system physical address ranges to convert into HV-fixed page
1538 * states during the RMP initialization. For instance, the memory that
1539 * UEFI reserves should be included in the that list. This allows system
1540 * components that occasionally write to memory (e.g. logging to UEFI
1541 * reserved regions) to not fail due to RMP initialization and SNP
1542 * enablement.
1543 *
1544 */
1545 if (sev_version_greater_or_equal(SNP_MIN_API_MAJOR, 52)) {
1546 bool tio_supp = !!(sev->snp_feat_info_0.ebx & SNP_SEV_TIO_SUPPORTED);
1547
1548 /*
1549 * Firmware checks that the pages containing the ranges enumerated
1550 * in the RANGES structure are either in the default page state or in the
1551 * firmware page state.
1552 */
1553 snp_range_list = kzalloc(PAGE_SIZE, GFP_KERNEL);
1554 if (!snp_range_list) {
1555 dev_err(sev->dev,
1556 "SEV: SNP_INIT_EX range list memory allocation failed\n");
1557 return -ENOMEM;
1558 }
1559
1560 /*
1561 * Retrieve all reserved memory regions from the e820 memory map
1562 * to be setup as HV-fixed pages.
1563 */
1564 rc = walk_iomem_res_desc(IORES_DESC_NONE, IORESOURCE_MEM, 0, ~0,
1565 snp_range_list, snp_filter_reserved_mem_regions);
1566 if (rc) {
1567 dev_err(sev->dev,
1568 "SEV: SNP_INIT_EX walk_iomem_res_desc failed rc = %d\n", rc);
1569 return rc;
1570 }
1571
1572 /*
1573 * Add HV_Fixed pages from other PSP sub-devices, such as SFS to the
1574 * HV_Fixed page list.
1575 */
1576 snp_add_hv_fixed_pages(sev, snp_range_list);
1577
1578 if (max_snp_asid) {
1579 data.ciphertext_hiding_en = 1;
1580 data.max_snp_asid = max_snp_asid;
1581 }
1582
1583 data.init_rmp = 1;
1584 data.list_paddr_en = 1;
1585 data.list_paddr = __psp_pa(snp_range_list);
1586
1587 data.tio_en = tio_supp && sev_tio_enabled && amd_iommu_sev_tio_supported();
1588
1589 /*
1590 * When psp_init_on_probe is disabled, the userspace calling
1591 * SEV ioctl can inadvertently shut down SNP and SEV-TIO causing
1592 * unexpected state loss.
1593 */
1594 if (data.tio_en && !psp_init_on_probe)
1595 dev_warn(sev->dev, "SEV-TIO as incompatible with psp_init_on_probe=0\n");
1596
1597 cmd = SEV_CMD_SNP_INIT_EX;
1598 } else {
1599 cmd = SEV_CMD_SNP_INIT;
1600 arg = NULL;
1601 }
1602
1603 /*
1604 * The following sequence must be issued before launching the first SNP
1605 * guest to ensure all dirty cache lines are flushed, including from
1606 * updates to the RMP table itself via the RMPUPDATE instruction:
1607 *
1608 * - WBINVD on all running CPUs
1609 * - SEV_CMD_SNP_INIT[_EX] firmware command
1610 * - WBINVD on all running CPUs
1611 * - SEV_CMD_SNP_DF_FLUSH firmware command
1612 */
1613 wbinvd_on_all_cpus();
1614
1615 rc = __sev_do_cmd_locked(cmd, arg, error);
1616 if (rc) {
1617 dev_err(sev->dev, "SEV-SNP: %s failed rc %d, error %#x\n",
1618 cmd == SEV_CMD_SNP_INIT_EX ? "SNP_INIT_EX" : "SNP_INIT",
1619 rc, *error);
1620 return rc;
1621 }
1622
1623 /* Prepare for first SNP guest launch after INIT. */
1624 wbinvd_on_all_cpus();
1625 rc = __sev_do_cmd_locked(SEV_CMD_SNP_DF_FLUSH, NULL, error);
1626 if (rc) {
1627 dev_err(sev->dev, "SEV-SNP: SNP_DF_FLUSH failed rc %d, error %#x\n",
1628 rc, *error);
1629 return rc;
1630 }
1631
1632 snp_hv_fixed_pages_state_update(sev, HV_FIXED);
1633 sev->snp_initialized = true;
1634 dev_dbg(sev->dev, "SEV-SNP firmware initialized, SEV-TIO is %s\n",
1635 data.tio_en ? "enabled" : "disabled");
1636
1637 dev_info(sev->dev, "SEV-SNP API:%d.%d build:%d\n", sev->api_major,
1638 sev->api_minor, sev->build);
1639
1640 atomic_notifier_chain_register(&panic_notifier_list,
1641 &snp_panic_notifier);
1642
1643 if (data.tio_en) {
1644 struct page *page;
1645
1646 /*
1647 * This executes with the sev_cmd_mutex held so down the stack
1648 * snp_reclaim_pages(locked=false) might be needed (which is extremely
1649 * unlikely) but will cause a deadlock.
1650 * Instead of exporting __snp_alloc_firmware_pages(), allocate a page
1651 * for this one call here.
1652 */
1653 page = __snp_alloc_firmware_pages(GFP_KERNEL_ACCOUNT | __GFP_ZERO,
1654 0, true);
1655 if (page) {
1656 void *tio_status = page_address(page);
1657
1658 sev_tsm_init_locked(sev, tio_status);
1659
1660 __snp_free_firmware_pages(page, 0, true);
1661 }
1662 }
1663
1664 sev_es_tmr_size = SNP_TMR_SIZE;
1665
1666 snp_enable_rmpopt();
1667
1668 return 0;
1669 }
1670
__sev_platform_init_handle_tmr(struct sev_device * sev)1671 static void __sev_platform_init_handle_tmr(struct sev_device *sev)
1672 {
1673 if (sev_es_tmr)
1674 return;
1675
1676 /* Obtain the TMR memory area for SEV-ES use */
1677 sev_es_tmr = sev_fw_alloc(sev_es_tmr_size);
1678 if (sev_es_tmr) {
1679 /* Must flush the cache before giving it to the firmware */
1680 if (!sev->snp_initialized)
1681 clflush_cache_range(sev_es_tmr, sev_es_tmr_size);
1682 } else {
1683 dev_warn(sev->dev, "SEV: TMR allocation failed, SEV-ES support unavailable\n");
1684 }
1685 }
1686
1687 /*
1688 * If an init_ex_path is provided allocate a buffer for the file and
1689 * read in the contents. Additionally, if SNP is initialized, convert
1690 * the buffer pages to firmware pages.
1691 */
__sev_platform_init_handle_init_ex_path(struct sev_device * sev)1692 static int __sev_platform_init_handle_init_ex_path(struct sev_device *sev)
1693 {
1694 struct page *page;
1695 int rc;
1696
1697 if (!init_ex_path)
1698 return 0;
1699
1700 if (sev_init_ex_buffer)
1701 return 0;
1702
1703 page = alloc_pages(GFP_KERNEL | __GFP_ZERO, get_order(NV_LENGTH));
1704 if (!page) {
1705 dev_err(sev->dev, "SEV: INIT_EX NV memory allocation failed\n");
1706 return -ENOMEM;
1707 }
1708
1709 sev_init_ex_buffer = page_address(page);
1710
1711 rc = sev_read_init_ex_file();
1712 if (rc)
1713 goto err_free;
1714
1715 /* If SEV-SNP is initialized, transition to firmware page. */
1716 if (sev->snp_initialized) {
1717 unsigned long npages;
1718
1719 npages = 1UL << get_order(NV_LENGTH);
1720 if (rmp_mark_pages_firmware(__pa(sev_init_ex_buffer), npages, true)) {
1721 dev_err(sev->dev, "SEV: INIT_EX NV memory page state change failed.\n");
1722 rc = -ENOMEM;
1723 /*
1724 * Pages can be in an inconsistent state, don't release them back to the
1725 * system.
1726 */
1727 goto err_reset;
1728 }
1729 }
1730
1731 return 0;
1732
1733 err_free:
1734 __free_pages(page, get_order(NV_LENGTH));
1735 err_reset:
1736 sev_init_ex_buffer = NULL;
1737 return rc;
1738 }
1739
__sev_platform_init_locked(int * error)1740 static int __sev_platform_init_locked(int *error)
1741 {
1742 int rc, psp_ret, dfflush_error;
1743 struct sev_device *sev;
1744
1745 psp_ret = dfflush_error = SEV_RET_NO_FW_CALL;
1746
1747 if (!psp_master || !psp_master->sev_data)
1748 return -ENODEV;
1749
1750 sev = psp_master->sev_data;
1751
1752 if (sev->sev_plat_status.state == SEV_STATE_INIT)
1753 return 0;
1754
1755 __sev_platform_init_handle_tmr(sev);
1756
1757 rc = __sev_platform_init_handle_init_ex_path(sev);
1758 if (rc)
1759 return rc;
1760
1761 rc = __sev_do_init_locked(&psp_ret);
1762 if (rc && psp_ret == SEV_RET_SECURE_DATA_INVALID) {
1763 /*
1764 * Initialization command returned an integrity check failure
1765 * status code, meaning that firmware load and validation of SEV
1766 * related persistent data has failed. Retrying the
1767 * initialization function should succeed by replacing the state
1768 * with a reset state.
1769 */
1770 dev_err(sev->dev,
1771 "SEV: retrying INIT command because of SECURE_DATA_INVALID error. Retrying once to reset PSP SEV state.");
1772 rc = __sev_do_init_locked(&psp_ret);
1773 }
1774
1775 if (error)
1776 *error = psp_ret;
1777
1778 if (rc) {
1779 dev_err(sev->dev, "SEV: %s failed %#x, rc %d\n",
1780 sev_init_ex_buffer ? "INIT_EX" : "INIT", psp_ret, rc);
1781 return rc;
1782 }
1783
1784 sev->sev_plat_status.state = SEV_STATE_INIT;
1785
1786 /* Prepare for first SEV guest launch after INIT */
1787 wbinvd_on_all_cpus();
1788 rc = __sev_do_cmd_locked(SEV_CMD_DF_FLUSH, NULL, &dfflush_error);
1789 if (rc) {
1790 dev_err(sev->dev, "SEV: DF_FLUSH failed %#x, rc %d\n",
1791 dfflush_error, rc);
1792 return rc;
1793 }
1794
1795 dev_dbg(sev->dev, "SEV firmware initialized\n");
1796
1797 dev_info(sev->dev, "SEV API:%d.%d build:%d\n", sev->api_major,
1798 sev->api_minor, sev->build);
1799
1800 return 0;
1801 }
1802
_sev_platform_init_locked(struct sev_platform_init_args * args)1803 static int _sev_platform_init_locked(struct sev_platform_init_args *args)
1804 {
1805 struct sev_device *sev;
1806 int rc;
1807
1808 if (!psp_master || !psp_master->sev_data)
1809 return -ENODEV;
1810
1811 /*
1812 * Skip SNP/SEV initialization under a kdump kernel as SEV/SNP
1813 * may already be initialized in the previous kernel. Since no
1814 * SNP/SEV guests are run under a kdump kernel, there is no
1815 * need to initialize SNP or SEV during kdump boot.
1816 */
1817 if (is_kdump_kernel())
1818 return 0;
1819
1820 sev = psp_master->sev_data;
1821
1822 if (sev->sev_plat_status.state == SEV_STATE_INIT)
1823 return 0;
1824
1825 rc = __sev_snp_init_locked(&args->error, args->max_snp_asid);
1826 if (rc && rc != -ENODEV)
1827 return rc;
1828
1829 /* Defer legacy SEV/SEV-ES support if allowed by caller/module. */
1830 if (args->probe && !psp_init_on_probe)
1831 return 0;
1832
1833 return __sev_platform_init_locked(&args->error);
1834 }
1835
sev_platform_init(struct sev_platform_init_args * args)1836 int sev_platform_init(struct sev_platform_init_args *args)
1837 {
1838 int rc;
1839
1840 mutex_lock(&sev_cmd_mutex);
1841 rc = _sev_platform_init_locked(args);
1842 mutex_unlock(&sev_cmd_mutex);
1843
1844 /*
1845 * Register the sysfs interface outside the sev_cmd_mutex. The
1846 * _show()/_store() handlers issue SEV commands that acquire the
1847 * sev_cmd_mutex, so creating (and on the shutdown path, removing) the
1848 * sysfs group must stay outside that lock. sysfs provides its own
1849 * synchronization between group creation/removal and concurrent
1850 * attribute access.
1851 */
1852 if (!rc)
1853 sev_snp_register_verify_mitigation(psp_master->sev_data);
1854
1855 return rc;
1856 }
1857 EXPORT_SYMBOL_GPL(sev_platform_init);
1858
__sev_platform_shutdown_locked(int * error)1859 static int __sev_platform_shutdown_locked(int *error)
1860 {
1861 struct psp_device *psp = psp_master;
1862 struct sev_device *sev;
1863 int ret;
1864
1865 if (!psp || !psp->sev_data)
1866 return 0;
1867
1868 sev = psp->sev_data;
1869
1870 if (sev->sev_plat_status.state == SEV_STATE_UNINIT)
1871 return 0;
1872
1873 ret = __sev_do_cmd_locked(SEV_CMD_SHUTDOWN, NULL, error);
1874 if (ret) {
1875 dev_err(sev->dev, "SEV: failed to SHUTDOWN error %#x, rc %d\n",
1876 *error, ret);
1877 return ret;
1878 }
1879
1880 sev->sev_plat_status.state = SEV_STATE_UNINIT;
1881 dev_dbg(sev->dev, "SEV firmware shutdown\n");
1882
1883 return ret;
1884 }
1885
sev_get_platform_state(int * state,int * error)1886 static int sev_get_platform_state(int *state, int *error)
1887 {
1888 struct sev_user_data_status data;
1889 int rc;
1890
1891 rc = __sev_do_cmd_locked(SEV_CMD_PLATFORM_STATUS, &data, error);
1892 if (rc)
1893 return rc;
1894
1895 *state = data.state;
1896 return rc;
1897 }
1898
sev_move_to_init_state(struct sev_issue_cmd * argp,bool * shutdown_required)1899 static int sev_move_to_init_state(struct sev_issue_cmd *argp, bool *shutdown_required)
1900 {
1901 int rc;
1902
1903 rc = __sev_platform_init_locked(&argp->error);
1904 if (rc)
1905 return rc;
1906
1907 *shutdown_required = true;
1908
1909 return 0;
1910 }
1911
sev_ioctl_do_reset(struct sev_issue_cmd * argp,bool writable)1912 static int sev_ioctl_do_reset(struct sev_issue_cmd *argp, bool writable)
1913 {
1914 int state, rc;
1915
1916 if (!writable)
1917 return -EPERM;
1918
1919 /*
1920 * The SEV spec requires that FACTORY_RESET must be issued in
1921 * UNINIT state. Before we go further lets check if any guest is
1922 * active.
1923 *
1924 * If FW is in WORKING state then deny the request otherwise issue
1925 * SHUTDOWN command do INIT -> UNINIT before issuing the FACTORY_RESET.
1926 *
1927 */
1928 rc = sev_get_platform_state(&state, &argp->error);
1929 if (rc)
1930 return rc;
1931
1932 if (state == SEV_STATE_WORKING)
1933 return -EBUSY;
1934
1935 if (state == SEV_STATE_INIT) {
1936 rc = __sev_platform_shutdown_locked(&argp->error);
1937 if (rc)
1938 return rc;
1939 }
1940
1941 return __sev_do_cmd_locked(SEV_CMD_FACTORY_RESET, NULL, &argp->error);
1942 }
1943
sev_ioctl_do_platform_status(struct sev_issue_cmd * argp)1944 static int sev_ioctl_do_platform_status(struct sev_issue_cmd *argp)
1945 {
1946 struct sev_user_data_status data;
1947 int ret;
1948
1949 memset(&data, 0, sizeof(data));
1950
1951 ret = __sev_do_cmd_locked(SEV_CMD_PLATFORM_STATUS, &data, &argp->error);
1952 if (ret)
1953 return ret;
1954
1955 if (copy_to_user((void __user *)argp->data, &data, sizeof(data)))
1956 ret = -EFAULT;
1957
1958 return ret;
1959 }
1960
sev_ioctl_do_pek_pdh_gen(int cmd,struct sev_issue_cmd * argp,bool writable)1961 static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool writable)
1962 {
1963 struct sev_device *sev = psp_master->sev_data;
1964 bool shutdown_required = false;
1965 int rc;
1966
1967 if (!writable)
1968 return -EPERM;
1969
1970 if (sev->sev_plat_status.state == SEV_STATE_UNINIT) {
1971 rc = sev_move_to_init_state(argp, &shutdown_required);
1972 if (rc)
1973 return rc;
1974 }
1975
1976 rc = __sev_do_cmd_locked(cmd, NULL, &argp->error);
1977
1978 if (shutdown_required)
1979 __sev_firmware_shutdown(sev, false);
1980
1981 return rc;
1982 }
1983
sev_ioctl_do_pek_csr(struct sev_issue_cmd * argp,bool writable)1984 static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
1985 {
1986 struct sev_device *sev = psp_master->sev_data;
1987 struct sev_user_data_pek_csr input;
1988 bool shutdown_required = false;
1989 struct sev_data_pek_csr data;
1990 void __user *input_address;
1991 void *blob = NULL;
1992 int ret;
1993
1994 if (!writable)
1995 return -EPERM;
1996
1997 if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
1998 return -EFAULT;
1999
2000 memset(&data, 0, sizeof(data));
2001
2002 /* userspace wants to query CSR length */
2003 if (!input.address || !input.length)
2004 goto cmd;
2005
2006 /* allocate a physically contiguous buffer to store the CSR blob */
2007 input_address = (void __user *)input.address;
2008 if (input.length > SEV_FW_BLOB_MAX_SIZE)
2009 return -EFAULT;
2010
2011 blob = kzalloc(input.length, GFP_KERNEL);
2012 if (!blob)
2013 return -ENOMEM;
2014
2015 data.address = __psp_pa(blob);
2016 data.len = input.length;
2017
2018 cmd:
2019 if (sev->sev_plat_status.state == SEV_STATE_UNINIT) {
2020 ret = sev_move_to_init_state(argp, &shutdown_required);
2021 if (ret)
2022 goto e_free_blob;
2023 }
2024
2025 ret = __sev_do_cmd_locked(SEV_CMD_PEK_CSR, &data, &argp->error);
2026
2027 /*
2028 * Firmware will returns the length of the CSR blob (either the minimum
2029 * required length or the actual length written), return it to the user.
2030 */
2031 input.length = data.len;
2032
2033 if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) {
2034 ret = -EFAULT;
2035 goto e_free_blob;
2036 }
2037
2038 if (ret || WARN_ON_ONCE(argp->error))
2039 goto e_free_blob;
2040
2041 if (blob) {
2042 if (copy_to_user(input_address, blob, input.length))
2043 ret = -EFAULT;
2044 }
2045
2046 e_free_blob:
2047 if (shutdown_required)
2048 __sev_firmware_shutdown(sev, false);
2049
2050 kfree(blob);
2051 return ret;
2052 }
2053
psp_copy_user_blob(u64 uaddr,u32 len)2054 void *psp_copy_user_blob(u64 uaddr, u32 len)
2055 {
2056 if (!uaddr || !len)
2057 return ERR_PTR(-EINVAL);
2058
2059 /* verify that blob length does not exceed our limit */
2060 if (len > SEV_FW_BLOB_MAX_SIZE)
2061 return ERR_PTR(-EINVAL);
2062
2063 return memdup_user((void __user *)uaddr, len);
2064 }
2065 EXPORT_SYMBOL_GPL(psp_copy_user_blob);
2066
sev_get_api_version(void)2067 static int sev_get_api_version(void)
2068 {
2069 struct sev_device *sev = psp_master->sev_data;
2070 struct sev_user_data_status status;
2071 int error = 0, ret;
2072
2073 /*
2074 * Cache SNP platform status and SNP feature information
2075 * if SNP is available.
2076 */
2077 if (cc_platform_has(CC_ATTR_HOST_SEV_SNP)) {
2078 ret = snp_get_platform_data(sev, &error);
2079 if (ret)
2080 return 1;
2081 }
2082
2083 ret = sev_platform_status(&status, &error);
2084 if (ret) {
2085 dev_err(sev->dev,
2086 "SEV: failed to get status. Error: %#x\n", error);
2087 return 1;
2088 }
2089
2090 /* Cache SEV platform status */
2091 sev->sev_plat_status = status;
2092
2093 sev->api_major = status.api_major;
2094 sev->api_minor = status.api_minor;
2095 sev->build = status.build;
2096
2097 return 0;
2098 }
2099
sev_get_firmware(struct device * dev,const struct firmware ** firmware)2100 static int sev_get_firmware(struct device *dev,
2101 const struct firmware **firmware)
2102 {
2103 char fw_name_specific[SEV_FW_NAME_SIZE];
2104 char fw_name_subset[SEV_FW_NAME_SIZE];
2105
2106 snprintf(fw_name_specific, sizeof(fw_name_specific),
2107 "amd/amd_sev_fam%.2xh_model%.2xh.sbin",
2108 boot_cpu_data.x86, boot_cpu_data.x86_model);
2109
2110 snprintf(fw_name_subset, sizeof(fw_name_subset),
2111 "amd/amd_sev_fam%.2xh_model%.1xxh.sbin",
2112 boot_cpu_data.x86, (boot_cpu_data.x86_model & 0xf0) >> 4);
2113
2114 /* Check for SEV FW for a particular model.
2115 * Ex. amd_sev_fam17h_model00h.sbin for Family 17h Model 00h
2116 *
2117 * or
2118 *
2119 * Check for SEV FW common to a subset of models.
2120 * Ex. amd_sev_fam17h_model0xh.sbin for
2121 * Family 17h Model 00h -- Family 17h Model 0Fh
2122 *
2123 * or
2124 *
2125 * Fall-back to using generic name: sev.fw
2126 */
2127 if ((firmware_request_nowarn(firmware, fw_name_specific, dev) >= 0) ||
2128 (firmware_request_nowarn(firmware, fw_name_subset, dev) >= 0) ||
2129 (firmware_request_nowarn(firmware, SEV_FW_FILE, dev) >= 0))
2130 return 0;
2131
2132 return -ENOENT;
2133 }
2134
2135 /* Don't fail if SEV FW couldn't be updated. Continue with existing SEV FW */
sev_update_firmware(struct device * dev)2136 static int sev_update_firmware(struct device *dev)
2137 {
2138 struct sev_data_download_firmware data;
2139 const struct firmware *firmware;
2140 int ret, error, order;
2141 struct page *p;
2142 void *fw_blob;
2143
2144 if (!sev_version_greater_or_equal(0, 15)) {
2145 dev_dbg(dev, "DOWNLOAD_FIRMWARE not supported\n");
2146 return -1;
2147 }
2148
2149 if (sev_get_firmware(dev, &firmware) == -ENOENT) {
2150 dev_dbg(dev, "No SEV firmware file present\n");
2151 return -1;
2152 }
2153
2154 order = get_order(firmware->size);
2155 p = alloc_pages(GFP_KERNEL, order);
2156 if (!p) {
2157 ret = -1;
2158 goto fw_err;
2159 }
2160
2161 /*
2162 * Copy firmware data to a kernel allocated contiguous
2163 * memory region.
2164 */
2165 fw_blob = page_address(p);
2166 memcpy(fw_blob, firmware->data, firmware->size);
2167
2168 data.address = __psp_pa(fw_blob);
2169 data.len = firmware->size;
2170
2171 ret = sev_do_cmd(SEV_CMD_DOWNLOAD_FIRMWARE, &data, &error);
2172
2173 /*
2174 * A quirk for fixing the committed TCB version, when upgrading from
2175 * earlier firmware version than 1.50.
2176 */
2177 if (!ret && !sev_version_greater_or_equal(1, 50))
2178 ret = sev_do_cmd(SEV_CMD_DOWNLOAD_FIRMWARE, &data, &error);
2179
2180 if (ret)
2181 dev_dbg(dev, "Failed to update SEV firmware: %#x\n", error);
2182
2183 __free_pages(p, order);
2184
2185 fw_err:
2186 release_firmware(firmware);
2187
2188 return ret;
2189 }
2190
__sev_snp_shutdown_locked(int * error,bool panic)2191 static int __sev_snp_shutdown_locked(int *error, bool panic)
2192 {
2193 struct psp_device *psp = psp_master;
2194 struct sev_device *sev;
2195 struct sev_data_snp_shutdown_ex data;
2196 int ret;
2197
2198 if (!psp || !psp->sev_data)
2199 return 0;
2200
2201 sev = psp->sev_data;
2202
2203 if (!sev->snp_initialized)
2204 return 0;
2205
2206 memset(&data, 0, sizeof(data));
2207 data.len = sizeof(data);
2208 data.iommu_snp_shutdown = 1;
2209 if (sev->snp_feat_info_0.ecx & SNP_X86_SHUTDOWN_SUPPORTED)
2210 data.x86_snp_shutdown = 1;
2211
2212 /*
2213 * If invoked during panic handling, local interrupts are disabled
2214 * and all CPUs are stopped, so wbinvd_on_all_cpus() can't be called.
2215 * In that case, a wbinvd() is done on remote CPUs via the NMI
2216 * callback, so only a local wbinvd() is needed here.
2217 */
2218 if (!panic)
2219 wbinvd_on_all_cpus();
2220 else
2221 wbinvd();
2222
2223 ret = __sev_do_cmd_locked(SEV_CMD_SNP_SHUTDOWN_EX, &data, error);
2224 /* SHUTDOWN may require DF_FLUSH */
2225 if (*error == SEV_RET_DFFLUSH_REQUIRED) {
2226 int dfflush_error = SEV_RET_NO_FW_CALL;
2227
2228 ret = __sev_do_cmd_locked(SEV_CMD_SNP_DF_FLUSH, NULL, &dfflush_error);
2229 if (ret) {
2230 dev_err(sev->dev, "SEV-SNP DF_FLUSH failed, ret = %d, error = %#x\n",
2231 ret, dfflush_error);
2232 return ret;
2233 }
2234 /* reissue the shutdown command */
2235 ret = __sev_do_cmd_locked(SEV_CMD_SNP_SHUTDOWN_EX, &data,
2236 error);
2237 }
2238 if (ret) {
2239 dev_err(sev->dev, "SEV-SNP firmware shutdown failed, rc %d, error %#x\n",
2240 ret, *error);
2241 return ret;
2242 }
2243
2244 if (data.x86_snp_shutdown) {
2245 if (!panic)
2246 snp_shutdown();
2247 snp_hv_fixed_pages_state_update(sev, ALLOCATED);
2248 } else {
2249 /*
2250 * SNP_SHUTDOWN_EX with IOMMU_SNP_SHUTDOWN set to 1 disables SNP
2251 * enforcement by the IOMMU and also transitions all pages
2252 * associated with the IOMMU to the Reclaim state.
2253 * Firmware was transitioning the IOMMU pages to Hypervisor state
2254 * before version 1.53. But, accounting for the number of assigned
2255 * 4kB pages in a 2M page was done incorrectly by not transitioning
2256 * to the Reclaim state. This resulted in RMP #PF when later accessing
2257 * the 2M page containing those pages during kexec boot. Hence, the
2258 * firmware now transitions these pages to Reclaim state and hypervisor
2259 * needs to transition these pages to shared state. SNP Firmware
2260 * version 1.53 and above are needed for kexec boot.
2261 */
2262 ret = amd_iommu_snp_disable();
2263 if (ret) {
2264 dev_err(sev->dev, "SNP IOMMU shutdown failed\n");
2265 return ret;
2266 }
2267 }
2268
2269 snp_leak_hv_fixed_pages();
2270 sev->snp_initialized = false;
2271 dev_dbg(sev->dev, "SEV-SNP firmware shutdown\n");
2272
2273 /*
2274 * __sev_snp_shutdown_locked() deadlocks when it tries to unregister
2275 * itself during panic as the panic notifier is called with RCU read
2276 * lock held and notifier unregistration does RCU synchronization.
2277 */
2278 if (!panic)
2279 atomic_notifier_chain_unregister(&panic_notifier_list,
2280 &snp_panic_notifier);
2281
2282 /* Reset TMR size back to default */
2283 sev_es_tmr_size = SEV_TMR_SIZE;
2284
2285 return ret;
2286 }
2287
sev_ioctl_do_pek_import(struct sev_issue_cmd * argp,bool writable)2288 static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
2289 {
2290 struct sev_device *sev = psp_master->sev_data;
2291 struct sev_user_data_pek_cert_import input;
2292 struct sev_data_pek_cert_import data;
2293 bool shutdown_required = false;
2294 void *pek_blob, *oca_blob;
2295 int ret;
2296
2297 if (!writable)
2298 return -EPERM;
2299
2300 if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
2301 return -EFAULT;
2302
2303 /* copy PEK certificate blobs from userspace */
2304 pek_blob = psp_copy_user_blob(input.pek_cert_address, input.pek_cert_len);
2305 if (IS_ERR(pek_blob))
2306 return PTR_ERR(pek_blob);
2307
2308 data.reserved = 0;
2309 data.pek_cert_address = __psp_pa(pek_blob);
2310 data.pek_cert_len = input.pek_cert_len;
2311
2312 /* copy PEK certificate blobs from userspace */
2313 oca_blob = psp_copy_user_blob(input.oca_cert_address, input.oca_cert_len);
2314 if (IS_ERR(oca_blob)) {
2315 ret = PTR_ERR(oca_blob);
2316 goto e_free_pek;
2317 }
2318
2319 data.oca_cert_address = __psp_pa(oca_blob);
2320 data.oca_cert_len = input.oca_cert_len;
2321
2322 /* If platform is not in INIT state then transition it to INIT */
2323 if (sev->sev_plat_status.state != SEV_STATE_INIT) {
2324 ret = sev_move_to_init_state(argp, &shutdown_required);
2325 if (ret)
2326 goto e_free_oca;
2327 }
2328
2329 ret = __sev_do_cmd_locked(SEV_CMD_PEK_CERT_IMPORT, &data, &argp->error);
2330
2331 e_free_oca:
2332 if (shutdown_required)
2333 __sev_firmware_shutdown(sev, false);
2334
2335 kfree(oca_blob);
2336 e_free_pek:
2337 kfree(pek_blob);
2338 return ret;
2339 }
2340
sev_ioctl_do_get_id2(struct sev_issue_cmd * argp)2341 static int sev_ioctl_do_get_id2(struct sev_issue_cmd *argp)
2342 {
2343 struct sev_user_data_get_id2 input;
2344 struct sev_data_get_id data;
2345 void __user *input_address;
2346 void *id_blob = NULL;
2347 int ret;
2348
2349 /* SEV GET_ID is available from SEV API v0.16 and up */
2350 if (!sev_version_greater_or_equal(0, 16))
2351 return -ENOTSUPP;
2352
2353 if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
2354 return -EFAULT;
2355
2356 input_address = (void __user *)input.address;
2357
2358 if (input.address && input.length) {
2359 /*
2360 * The length of the ID shouldn't be assumed by software since
2361 * it may change in the future. The allocation size is limited
2362 * to 1 << (PAGE_SHIFT + MAX_PAGE_ORDER) by the page allocator.
2363 * If the allocation fails, simply return ENOMEM rather than
2364 * warning in the kernel log.
2365 */
2366 id_blob = kzalloc(input.length, GFP_KERNEL | __GFP_NOWARN);
2367 if (!id_blob)
2368 return -ENOMEM;
2369
2370 data.address = __psp_pa(id_blob);
2371 data.len = input.length;
2372 } else {
2373 data.address = 0;
2374 data.len = 0;
2375 }
2376
2377 ret = __sev_do_cmd_locked(SEV_CMD_GET_ID, &data, &argp->error);
2378
2379 /*
2380 * Firmware will return the length of the ID value (either the minimum
2381 * required length or the actual length written), return it to the user.
2382 */
2383 input.length = data.len;
2384
2385 if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) {
2386 ret = -EFAULT;
2387 goto e_free;
2388 }
2389
2390 if (ret || WARN_ON_ONCE(argp->error))
2391 goto e_free;
2392
2393 if (id_blob) {
2394 if (copy_to_user(input_address, id_blob, data.len)) {
2395 ret = -EFAULT;
2396 goto e_free;
2397 }
2398 }
2399
2400 e_free:
2401 kfree(id_blob);
2402
2403 return ret;
2404 }
2405
sev_ioctl_do_get_id(struct sev_issue_cmd * argp)2406 static int sev_ioctl_do_get_id(struct sev_issue_cmd *argp)
2407 {
2408 struct sev_data_get_id *data;
2409 u64 data_size, user_size;
2410 void *id_blob, *mem;
2411 int ret;
2412
2413 /* SEV GET_ID available from SEV API v0.16 and up */
2414 if (!sev_version_greater_or_equal(0, 16))
2415 return -ENOTSUPP;
2416
2417 /* SEV FW expects the buffer it fills with the ID to be
2418 * 8-byte aligned. Memory allocated should be enough to
2419 * hold data structure + alignment padding + memory
2420 * where SEV FW writes the ID.
2421 */
2422 data_size = ALIGN(sizeof(struct sev_data_get_id), 8);
2423 user_size = sizeof(struct sev_user_data_get_id);
2424
2425 mem = kzalloc(data_size + user_size, GFP_KERNEL);
2426 if (!mem)
2427 return -ENOMEM;
2428
2429 data = mem;
2430 id_blob = mem + data_size;
2431
2432 data->address = __psp_pa(id_blob);
2433 data->len = user_size;
2434
2435 ret = __sev_do_cmd_locked(SEV_CMD_GET_ID, data, &argp->error);
2436 if (!ret) {
2437 if (copy_to_user((void __user *)argp->data, id_blob, data->len))
2438 ret = -EFAULT;
2439 }
2440
2441 kfree(mem);
2442
2443 return ret;
2444 }
2445
sev_ioctl_do_pdh_export(struct sev_issue_cmd * argp,bool writable)2446 static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
2447 {
2448 struct sev_device *sev = psp_master->sev_data;
2449 struct sev_user_data_pdh_cert_export input;
2450 void *pdh_blob = NULL, *cert_blob = NULL;
2451 struct sev_data_pdh_cert_export data;
2452 void __user *input_cert_chain_address;
2453 void __user *input_pdh_cert_address;
2454 bool shutdown_required = false;
2455 int ret;
2456
2457 if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
2458 return -EFAULT;
2459
2460 memset(&data, 0, sizeof(data));
2461
2462 input_pdh_cert_address = (void __user *)input.pdh_cert_address;
2463 input_cert_chain_address = (void __user *)input.cert_chain_address;
2464
2465 /* Userspace wants to query the certificate length. */
2466 if (!input.pdh_cert_address ||
2467 !input.pdh_cert_len ||
2468 !input.cert_chain_address ||
2469 !input.cert_chain_len)
2470 goto cmd;
2471
2472 /* Allocate a physically contiguous buffer to store the PDH blob. */
2473 if (input.pdh_cert_len > SEV_FW_BLOB_MAX_SIZE)
2474 return -EFAULT;
2475
2476 /* Allocate a physically contiguous buffer to store the cert chain blob. */
2477 if (input.cert_chain_len > SEV_FW_BLOB_MAX_SIZE)
2478 return -EFAULT;
2479
2480 pdh_blob = kzalloc(input.pdh_cert_len, GFP_KERNEL);
2481 if (!pdh_blob)
2482 return -ENOMEM;
2483
2484 data.pdh_cert_address = __psp_pa(pdh_blob);
2485 data.pdh_cert_len = input.pdh_cert_len;
2486
2487 cert_blob = kzalloc(input.cert_chain_len, GFP_KERNEL);
2488 if (!cert_blob) {
2489 ret = -ENOMEM;
2490 goto e_free_pdh;
2491 }
2492
2493 data.cert_chain_address = __psp_pa(cert_blob);
2494 data.cert_chain_len = input.cert_chain_len;
2495
2496 cmd:
2497 /* If platform is not in INIT state then transition it to INIT. */
2498 if (sev->sev_plat_status.state != SEV_STATE_INIT) {
2499 if (!writable) {
2500 ret = -EPERM;
2501 goto e_free_cert;
2502 }
2503 ret = sev_move_to_init_state(argp, &shutdown_required);
2504 if (ret)
2505 goto e_free_cert;
2506 }
2507
2508 ret = __sev_do_cmd_locked(SEV_CMD_PDH_CERT_EXPORT, &data, &argp->error);
2509
2510 /*
2511 * Firmware will return the length of the blobs (either the minimum
2512 * required length or the actual length written), return 'em to the user.
2513 */
2514 input.cert_chain_len = data.cert_chain_len;
2515 input.pdh_cert_len = data.pdh_cert_len;
2516
2517 if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) {
2518 ret = -EFAULT;
2519 goto e_free_cert;
2520 }
2521
2522 if (ret || WARN_ON_ONCE(argp->error))
2523 goto e_free_cert;
2524
2525 if (pdh_blob) {
2526 if (copy_to_user(input_pdh_cert_address,
2527 pdh_blob, input.pdh_cert_len)) {
2528 ret = -EFAULT;
2529 goto e_free_cert;
2530 }
2531 }
2532
2533 if (cert_blob) {
2534 if (copy_to_user(input_cert_chain_address,
2535 cert_blob, input.cert_chain_len))
2536 ret = -EFAULT;
2537 }
2538
2539 e_free_cert:
2540 if (shutdown_required)
2541 __sev_firmware_shutdown(sev, false);
2542
2543 kfree(cert_blob);
2544 e_free_pdh:
2545 kfree(pdh_blob);
2546 return ret;
2547 }
2548
__sev_do_snp_platform_status(struct sev_user_data_snp_status * status,int * error)2549 static int __sev_do_snp_platform_status(struct sev_user_data_snp_status *status,
2550 int *error)
2551 {
2552 struct sev_device *sev = psp_master->sev_data;
2553 struct sev_data_snp_addr buf;
2554 struct page *status_page;
2555 void *data;
2556 int ret;
2557
2558 status_page = alloc_page(GFP_KERNEL_ACCOUNT);
2559 if (!status_page)
2560 return -ENOMEM;
2561
2562 data = page_address(status_page);
2563
2564 /*
2565 * SNP_PLATFORM_STATUS can be executed in any SNP state. But if executed
2566 * when SNP has been initialized, the status page must be firmware-owned.
2567 */
2568 if (sev->snp_initialized) {
2569 /*
2570 * Firmware expects the status page to be in Firmware state,
2571 * otherwise it will report an error INVALID_PAGE_STATE.
2572 */
2573 if (rmp_mark_pages_firmware(__pa(data), 1, true)) {
2574 ret = -EFAULT;
2575 goto cleanup;
2576 }
2577 }
2578
2579 buf.address = __psp_pa(data);
2580 ret = __sev_do_cmd_locked(SEV_CMD_SNP_PLATFORM_STATUS, &buf, error);
2581
2582 if (sev->snp_initialized) {
2583 /*
2584 * The status page will be in Reclaim state on success, or left
2585 * in Firmware state on failure. Use snp_reclaim_pages() to
2586 * transition either case back to Hypervisor-owned state.
2587 */
2588 if (snp_reclaim_pages(__pa(data), 1, true))
2589 return -EFAULT;
2590 }
2591
2592 if (ret)
2593 goto cleanup;
2594
2595 memcpy(status, data, sizeof(*status));
2596
2597 cleanup:
2598 __free_pages(status_page, 0);
2599 return ret;
2600 }
2601
sev_ioctl_do_snp_platform_status(struct sev_issue_cmd * argp)2602 static int sev_ioctl_do_snp_platform_status(struct sev_issue_cmd *argp)
2603 {
2604 struct sev_user_data_snp_status status;
2605 int ret;
2606
2607 if (!argp->data)
2608 return -EINVAL;
2609
2610 ret = __sev_do_snp_platform_status(&status, &argp->error);
2611 if (ret < 0)
2612 return ret;
2613
2614 if (copy_to_user((void __user *)argp->data, &status,
2615 sizeof(struct sev_user_data_snp_status)))
2616 ret = -EFAULT;
2617
2618 return ret;
2619 }
2620
sev_ioctl_do_snp_commit(struct sev_issue_cmd * argp)2621 static int sev_ioctl_do_snp_commit(struct sev_issue_cmd *argp)
2622 {
2623 struct sev_data_snp_commit buf;
2624 int ret;
2625
2626 buf.len = sizeof(buf);
2627
2628 ret = __sev_do_cmd_locked(SEV_CMD_SNP_COMMIT, &buf, &argp->error);
2629
2630 return ret;
2631 }
2632
sev_ioctl_do_snp_set_config(struct sev_issue_cmd * argp,bool writable)2633 static int sev_ioctl_do_snp_set_config(struct sev_issue_cmd *argp, bool writable)
2634 {
2635 struct sev_device *sev = psp_master->sev_data;
2636 struct sev_user_data_snp_config config;
2637
2638 if (!argp->data)
2639 return -EINVAL;
2640
2641 if (!writable)
2642 return -EPERM;
2643
2644 if (!sev->snp_initialized)
2645 return -ENODEV;
2646
2647 if (copy_from_user(&config, (void __user *)argp->data, sizeof(config)))
2648 return -EFAULT;
2649
2650 return __sev_do_cmd_locked(SEV_CMD_SNP_CONFIG, &config, &argp->error);
2651 }
2652
sev_ioctl_do_snp_vlek_load(struct sev_issue_cmd * argp,bool writable)2653 static int sev_ioctl_do_snp_vlek_load(struct sev_issue_cmd *argp, bool writable)
2654 {
2655 struct sev_device *sev = psp_master->sev_data;
2656 struct sev_user_data_snp_vlek_load input;
2657 void *blob;
2658 int ret;
2659
2660 if (!argp->data)
2661 return -EINVAL;
2662
2663 if (!writable)
2664 return -EPERM;
2665
2666 if (!sev->snp_initialized)
2667 return -ENODEV;
2668
2669 if (copy_from_user(&input, u64_to_user_ptr(argp->data), sizeof(input)))
2670 return -EFAULT;
2671
2672 if (input.len != sizeof(input) || input.vlek_wrapped_version != 0)
2673 return -EINVAL;
2674
2675 blob = psp_copy_user_blob(input.vlek_wrapped_address,
2676 sizeof(struct sev_user_data_snp_wrapped_vlek_hashstick));
2677 if (IS_ERR(blob))
2678 return PTR_ERR(blob);
2679
2680 input.vlek_wrapped_address = __psp_pa(blob);
2681
2682 ret = __sev_do_cmd_locked(SEV_CMD_SNP_VLEK_LOAD, &input, &argp->error);
2683 kfree(blob);
2684
2685 return ret;
2686 }
2687
sev_ioctl(struct file * file,unsigned int ioctl,unsigned long arg)2688 static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
2689 {
2690 void __user *argp = (void __user *)arg;
2691 struct sev_issue_cmd input;
2692 int ret = -EFAULT;
2693 bool writable = file->f_mode & FMODE_WRITE;
2694
2695 if (!psp_master || !psp_master->sev_data)
2696 return -ENODEV;
2697
2698 if (ioctl != SEV_ISSUE_CMD)
2699 return -EINVAL;
2700
2701 if (copy_from_user(&input, argp, sizeof(struct sev_issue_cmd)))
2702 return -EFAULT;
2703
2704 if (input.cmd > SEV_MAX)
2705 return -EINVAL;
2706
2707 mutex_lock(&sev_cmd_mutex);
2708
2709 switch (input.cmd) {
2710
2711 case SEV_FACTORY_RESET:
2712 ret = sev_ioctl_do_reset(&input, writable);
2713 break;
2714 case SEV_PLATFORM_STATUS:
2715 ret = sev_ioctl_do_platform_status(&input);
2716 break;
2717 case SEV_PEK_GEN:
2718 ret = sev_ioctl_do_pek_pdh_gen(SEV_CMD_PEK_GEN, &input, writable);
2719 break;
2720 case SEV_PDH_GEN:
2721 ret = sev_ioctl_do_pek_pdh_gen(SEV_CMD_PDH_GEN, &input, writable);
2722 break;
2723 case SEV_PEK_CSR:
2724 ret = sev_ioctl_do_pek_csr(&input, writable);
2725 break;
2726 case SEV_PEK_CERT_IMPORT:
2727 ret = sev_ioctl_do_pek_import(&input, writable);
2728 break;
2729 case SEV_PDH_CERT_EXPORT:
2730 ret = sev_ioctl_do_pdh_export(&input, writable);
2731 break;
2732 case SEV_GET_ID:
2733 pr_warn_once("SEV_GET_ID command is deprecated, use SEV_GET_ID2\n");
2734 ret = sev_ioctl_do_get_id(&input);
2735 break;
2736 case SEV_GET_ID2:
2737 ret = sev_ioctl_do_get_id2(&input);
2738 break;
2739 case SNP_PLATFORM_STATUS:
2740 ret = sev_ioctl_do_snp_platform_status(&input);
2741 break;
2742 case SNP_COMMIT:
2743 ret = sev_ioctl_do_snp_commit(&input);
2744 break;
2745 case SNP_SET_CONFIG:
2746 ret = sev_ioctl_do_snp_set_config(&input, writable);
2747 break;
2748 case SNP_VLEK_LOAD:
2749 ret = sev_ioctl_do_snp_vlek_load(&input, writable);
2750 break;
2751 default:
2752 ret = -EINVAL;
2753 goto out;
2754 }
2755
2756 if (copy_to_user(argp, &input, sizeof(struct sev_issue_cmd)))
2757 ret = -EFAULT;
2758 out:
2759 mutex_unlock(&sev_cmd_mutex);
2760
2761 return ret;
2762 }
2763
2764 static const struct file_operations sev_fops = {
2765 .owner = THIS_MODULE,
2766 .unlocked_ioctl = sev_ioctl,
2767 };
2768
sev_platform_status(struct sev_user_data_status * data,int * error)2769 int sev_platform_status(struct sev_user_data_status *data, int *error)
2770 {
2771 return sev_do_cmd(SEV_CMD_PLATFORM_STATUS, data, error);
2772 }
2773 EXPORT_SYMBOL_GPL(sev_platform_status);
2774
sev_guest_deactivate(struct sev_data_deactivate * data,int * error)2775 int sev_guest_deactivate(struct sev_data_deactivate *data, int *error)
2776 {
2777 return sev_do_cmd(SEV_CMD_DEACTIVATE, data, error);
2778 }
2779 EXPORT_SYMBOL_GPL(sev_guest_deactivate);
2780
sev_guest_activate(struct sev_data_activate * data,int * error)2781 int sev_guest_activate(struct sev_data_activate *data, int *error)
2782 {
2783 return sev_do_cmd(SEV_CMD_ACTIVATE, data, error);
2784 }
2785 EXPORT_SYMBOL_GPL(sev_guest_activate);
2786
sev_guest_decommission(struct sev_data_decommission * data,int * error)2787 int sev_guest_decommission(struct sev_data_decommission *data, int *error)
2788 {
2789 return sev_do_cmd(SEV_CMD_DECOMMISSION, data, error);
2790 }
2791 EXPORT_SYMBOL_GPL(sev_guest_decommission);
2792
sev_guest_df_flush(int * error)2793 int sev_guest_df_flush(int *error)
2794 {
2795 return sev_do_cmd(SEV_CMD_DF_FLUSH, NULL, error);
2796 }
2797 EXPORT_SYMBOL_GPL(sev_guest_df_flush);
2798
sev_exit(struct kref * ref)2799 static void sev_exit(struct kref *ref)
2800 {
2801 misc_deregister(&misc_dev->misc);
2802 kfree(misc_dev);
2803 misc_dev = NULL;
2804 }
2805
sev_misc_init(struct sev_device * sev)2806 static int sev_misc_init(struct sev_device *sev)
2807 {
2808 struct device *dev = sev->dev;
2809 int ret;
2810
2811 /*
2812 * SEV feature support can be detected on multiple devices but the SEV
2813 * FW commands must be issued on the master. During probe, we do not
2814 * know the master hence we create /dev/sev on the first device probe.
2815 * sev_do_cmd() finds the right master device to which to issue the
2816 * command to the firmware.
2817 */
2818 if (!misc_dev) {
2819 struct miscdevice *misc;
2820
2821 misc_dev = kzalloc_obj(*misc_dev);
2822 if (!misc_dev)
2823 return -ENOMEM;
2824
2825 misc = &misc_dev->misc;
2826 misc->minor = MISC_DYNAMIC_MINOR;
2827 misc->name = DEVICE_NAME;
2828 misc->fops = &sev_fops;
2829
2830 ret = misc_register(misc);
2831 if (ret)
2832 return ret;
2833
2834 kref_init(&misc_dev->refcount);
2835 } else {
2836 kref_get(&misc_dev->refcount);
2837 }
2838
2839 init_waitqueue_head(&sev->int_queue);
2840 sev->misc = misc_dev;
2841 dev_dbg(dev, "registered SEV device\n");
2842
2843 return 0;
2844 }
2845
sev_dev_init(struct psp_device * psp)2846 int sev_dev_init(struct psp_device *psp)
2847 {
2848 struct device *dev = psp->dev;
2849 struct sev_device *sev;
2850 int ret = -ENOMEM;
2851
2852 if (!boot_cpu_has(X86_FEATURE_SEV)) {
2853 dev_info_once(dev, "SEV: memory encryption not enabled by BIOS\n");
2854 return 0;
2855 }
2856
2857 sev = devm_kzalloc(dev, sizeof(*sev), GFP_KERNEL);
2858 if (!sev)
2859 goto e_err;
2860
2861 sev->cmd_buf = (void *)devm_get_free_pages(dev, GFP_KERNEL, 1);
2862 if (!sev->cmd_buf)
2863 goto e_sev;
2864
2865 sev->cmd_buf_backup = (uint8_t *)sev->cmd_buf + PAGE_SIZE;
2866
2867 psp->sev_data = sev;
2868
2869 sev->dev = dev;
2870 sev->psp = psp;
2871
2872 sev->io_regs = psp->io_regs;
2873
2874 sev->vdata = (struct sev_vdata *)psp->vdata->sev;
2875 if (!sev->vdata) {
2876 ret = -ENODEV;
2877 dev_err(dev, "sev: missing driver data\n");
2878 goto e_buf;
2879 }
2880
2881 psp_set_sev_irq_handler(psp, sev_irq_handler, sev);
2882
2883 ret = sev_misc_init(sev);
2884 if (ret)
2885 goto e_irq;
2886
2887 dev_notice(dev, "sev enabled\n");
2888
2889 return 0;
2890
2891 e_irq:
2892 psp_clear_sev_irq_handler(psp);
2893 e_buf:
2894 devm_free_pages(dev, (unsigned long)sev->cmd_buf);
2895 e_sev:
2896 devm_kfree(dev, sev);
2897 e_err:
2898 psp->sev_data = NULL;
2899
2900 dev_notice(dev, "sev initialization failed\n");
2901
2902 return ret;
2903 }
2904
__sev_firmware_shutdown(struct sev_device * sev,bool panic)2905 static void __sev_firmware_shutdown(struct sev_device *sev, bool panic)
2906 {
2907 int error;
2908
2909 __sev_platform_shutdown_locked(&error);
2910
2911 if (sev_es_tmr) {
2912 /*
2913 * The TMR area was encrypted, flush it from the cache.
2914 *
2915 * If invoked during panic handling, local interrupts are
2916 * disabled and all CPUs are stopped, so wbinvd_on_all_cpus()
2917 * can't be used. In that case, wbinvd() is done on remote CPUs
2918 * via the NMI callback, and done for this CPU later during
2919 * SNP shutdown, so wbinvd_on_all_cpus() can be skipped.
2920 */
2921 if (!panic)
2922 wbinvd_on_all_cpus();
2923
2924 __snp_free_firmware_pages(virt_to_page(sev_es_tmr),
2925 get_order(sev_es_tmr_size),
2926 true);
2927 sev_es_tmr = NULL;
2928 }
2929
2930 if (sev_init_ex_buffer) {
2931 __snp_free_firmware_pages(virt_to_page(sev_init_ex_buffer),
2932 get_order(NV_LENGTH),
2933 true);
2934 sev_init_ex_buffer = NULL;
2935 }
2936
2937 __sev_snp_shutdown_locked(&error, panic);
2938 }
2939
sev_firmware_shutdown(struct sev_device * sev)2940 static void sev_firmware_shutdown(struct sev_device *sev)
2941 {
2942 /*
2943 * Calling without sev_cmd_mutex held as TSM will likely try disconnecting
2944 * IDE and this ends up calling sev_do_cmd() which locks sev_cmd_mutex.
2945 */
2946 if (sev->tio_status)
2947 sev_tsm_uninit(sev);
2948
2949 /*
2950 * Remove the sysfs interface before taking the sev_cmd_mutex.
2951 * sysfs_remove_group() waits for in-flight _show()/_store() handlers
2952 * to drain, and those handlers issue SNP_VERIFY_MITIGATION via
2953 * sev_do_cmd() which acquires the sev_cmd_mutex. Removing the group
2954 * while holding the mutex could therefore deadlock.
2955 */
2956 sev_snp_unregister_verify_mitigation(sev);
2957
2958 mutex_lock(&sev_cmd_mutex);
2959
2960 __sev_firmware_shutdown(sev, false);
2961
2962 kfree(sev->tio_status);
2963 sev->tio_status = NULL;
2964
2965 mutex_unlock(&sev_cmd_mutex);
2966 }
2967
sev_platform_shutdown(void)2968 void sev_platform_shutdown(void)
2969 {
2970 if (!psp_master || !psp_master->sev_data)
2971 return;
2972
2973 sev_firmware_shutdown(psp_master->sev_data);
2974 }
2975 EXPORT_SYMBOL_GPL(sev_platform_shutdown);
2976
sev_get_snp_policy_bits(void)2977 u64 sev_get_snp_policy_bits(void)
2978 {
2979 struct psp_device *psp = psp_master;
2980 struct sev_device *sev;
2981 u64 policy_bits;
2982
2983 if (!cc_platform_has(CC_ATTR_HOST_SEV_SNP))
2984 return 0;
2985
2986 if (!psp || !psp->sev_data)
2987 return 0;
2988
2989 sev = psp->sev_data;
2990
2991 policy_bits = SNP_POLICY_MASK_BASE;
2992
2993 if (sev->snp_plat_status.feature_info) {
2994 if (sev->snp_feat_info_0.ecx & SNP_RAPL_DISABLE_SUPPORTED)
2995 policy_bits |= SNP_POLICY_MASK_RAPL_DIS;
2996
2997 if (sev->snp_feat_info_0.ecx & SNP_CIPHER_TEXT_HIDING_SUPPORTED)
2998 policy_bits |= SNP_POLICY_MASK_CIPHERTEXT_HIDING_DRAM;
2999
3000 if (sev->snp_feat_info_0.ecx & SNP_AES_256_XTS_POLICY_SUPPORTED)
3001 policy_bits |= SNP_POLICY_MASK_MEM_AES_256_XTS;
3002
3003 if (sev->snp_feat_info_0.ecx & SNP_CXL_ALLOW_POLICY_SUPPORTED)
3004 policy_bits |= SNP_POLICY_MASK_CXL_ALLOW;
3005
3006 if (sev_version_greater_or_equal(1, 58))
3007 policy_bits |= SNP_POLICY_MASK_PAGE_SWAP_DISABLE;
3008 }
3009
3010 return policy_bits;
3011 }
3012 EXPORT_SYMBOL_GPL(sev_get_snp_policy_bits);
3013
sev_dev_destroy(struct psp_device * psp)3014 void sev_dev_destroy(struct psp_device *psp)
3015 {
3016 struct sev_device *sev = psp->sev_data;
3017
3018 if (!sev)
3019 return;
3020
3021 sev_firmware_shutdown(sev);
3022
3023 if (sev->misc)
3024 kref_put(&misc_dev->refcount, sev_exit);
3025
3026 psp_clear_sev_irq_handler(psp);
3027 }
3028
snp_shutdown_on_panic(struct notifier_block * nb,unsigned long reason,void * arg)3029 static int snp_shutdown_on_panic(struct notifier_block *nb,
3030 unsigned long reason, void *arg)
3031 {
3032 struct sev_device *sev = psp_master->sev_data;
3033
3034 /*
3035 * If sev_cmd_mutex is already acquired, then it's likely
3036 * another PSP command is in flight and issuing a shutdown
3037 * would fail in unexpected ways. Rather than create even
3038 * more confusion during a panic, just bail out here.
3039 */
3040 if (mutex_is_locked(&sev_cmd_mutex))
3041 return NOTIFY_DONE;
3042
3043 __sev_firmware_shutdown(sev, true);
3044
3045 return NOTIFY_DONE;
3046 }
3047
sev_issue_cmd_external_user(struct file * filep,unsigned int cmd,void * data,int * error)3048 int sev_issue_cmd_external_user(struct file *filep, unsigned int cmd,
3049 void *data, int *error)
3050 {
3051 if (!filep || filep->f_op != &sev_fops)
3052 return -EBADF;
3053
3054 return sev_do_cmd(cmd, data, error);
3055 }
3056 EXPORT_SYMBOL_GPL(sev_issue_cmd_external_user);
3057
sev_pci_init(void)3058 void sev_pci_init(void)
3059 {
3060 struct sev_device *sev = psp_master->sev_data;
3061 u8 api_major, api_minor, build;
3062
3063 if (!sev)
3064 return;
3065
3066 psp_timeout = psp_probe_timeout;
3067
3068 if (sev_get_api_version())
3069 goto err;
3070
3071 api_major = sev->api_major;
3072 api_minor = sev->api_minor;
3073 build = sev->build;
3074
3075 if (sev_update_firmware(sev->dev) == 0)
3076 sev_get_api_version();
3077
3078 if (api_major != sev->api_major || api_minor != sev->api_minor ||
3079 build != sev->build)
3080 dev_info(sev->dev, "SEV firmware updated from %d.%d.%d to %d.%d.%d\n",
3081 api_major, api_minor, build,
3082 sev->api_major, sev->api_minor, sev->build);
3083
3084 return;
3085
3086 err:
3087 sev_dev_destroy(psp_master);
3088
3089 psp_master->sev_data = NULL;
3090 }
3091
sev_pci_exit(void)3092 void sev_pci_exit(void)
3093 {
3094 struct sev_device *sev = psp_master->sev_data;
3095
3096 if (!sev)
3097 return;
3098
3099 sev_firmware_shutdown(sev);
3100 }
3101
get_v1_svn(struct sev_device * sev)3102 static int get_v1_svn(struct sev_device *sev)
3103 {
3104 struct sev_snp_tcb_version_genoa_milan *tcb;
3105 struct sev_user_data_snp_status status;
3106 int ret, error = 0;
3107
3108 mutex_lock(&sev_cmd_mutex);
3109 ret = __sev_do_snp_platform_status(&status, &error);
3110 mutex_unlock(&sev_cmd_mutex);
3111 if (ret < 0)
3112 return ret;
3113
3114 tcb = (struct sev_snp_tcb_version_genoa_milan *)&status
3115 .current_tcb_version;
3116 return tcb->snp;
3117 }
3118
get_v2_svn(struct sev_device * sev)3119 static int get_v2_svn(struct sev_device *sev)
3120 {
3121 struct sev_user_data_snp_status status;
3122 struct sev_snp_tcb_version_turin *tcb;
3123 int ret, error = 0;
3124
3125 mutex_lock(&sev_cmd_mutex);
3126 ret = __sev_do_snp_platform_status(&status, &error);
3127 mutex_unlock(&sev_cmd_mutex);
3128 if (ret < 0)
3129 return ret;
3130
3131 tcb = (struct sev_snp_tcb_version_turin *)&status
3132 .current_tcb_version;
3133 return tcb->snp;
3134 }
3135
sev_firmware_allows_es(struct sev_device * sev)3136 static bool sev_firmware_allows_es(struct sev_device *sev)
3137 {
3138 /* Documented in AMD-SB-3023 */
3139 if (boot_cpu_has(X86_FEATURE_ZEN4) || boot_cpu_has(X86_FEATURE_ZEN3))
3140 return get_v1_svn(sev) < 0x1b;
3141 else if (boot_cpu_has(X86_FEATURE_ZEN5))
3142 return get_v2_svn(sev) < 0x4;
3143 else
3144 return true;
3145 }
3146
sev_firmware_supported_vm_types(void)3147 int sev_firmware_supported_vm_types(void)
3148 {
3149 int supported_vm_types = 0;
3150 struct sev_device *sev;
3151
3152 if (!psp_master || !psp_master->sev_data)
3153 return supported_vm_types;
3154 sev = psp_master->sev_data;
3155
3156 supported_vm_types |= BIT(KVM_X86_SEV_VM);
3157 supported_vm_types |= BIT(KVM_X86_SEV_ES_VM);
3158
3159 if (!sev->snp_initialized)
3160 return supported_vm_types;
3161
3162 supported_vm_types |= BIT(KVM_X86_SNP_VM);
3163
3164 if (!sev_firmware_allows_es(sev))
3165 supported_vm_types &= ~BIT(KVM_X86_SEV_ES_VM);
3166
3167 return supported_vm_types;
3168
3169 }
3170 EXPORT_SYMBOL_FOR_MODULES(sev_firmware_supported_vm_types, "kvm-amd");
3171