1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * AMD Secure Encrypted Virtualization (SEV) guest driver interface
4 *
5 * Copyright (C) 2021-2024 Advanced Micro Devices, Inc.
6 *
7 * Author: Brijesh Singh <brijesh.singh@amd.com>
8 */
9
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/types.h>
13 #include <linux/mutex.h>
14 #include <linux/io.h>
15 #include <linux/platform_device.h>
16 #include <linux/miscdevice.h>
17 #include <linux/set_memory.h>
18 #include <linux/fs.h>
19 #include <linux/tsm.h>
20 #include <crypto/gcm.h>
21 #include <linux/psp-sev.h>
22 #include <linux/sockptr.h>
23 #include <linux/cleanup.h>
24 #include <linux/uuid.h>
25 #include <linux/configfs.h>
26 #include <linux/mm.h>
27 #include <uapi/linux/sev-guest.h>
28 #include <uapi/linux/psp-sev.h>
29
30 #include <asm/svm.h>
31 #include <asm/sev.h>
32
33 #define DEVICE_NAME "sev-guest"
34
35 #define SVSM_MAX_RETRIES 3
36
37 struct snp_guest_dev {
38 struct device *dev;
39 struct miscdevice misc;
40
41 struct snp_msg_desc *msg_desc;
42 };
43
44 /*
45 * The VMPCK ID represents the key used by the SNP guest to communicate with the
46 * SEV firmware in the AMD Secure Processor (ASP, aka PSP). By default, the key
47 * used will be the key associated with the VMPL at which the guest is running.
48 * Should the default key be wiped (see snp_disable_vmpck()), this parameter
49 * allows for using one of the remaining VMPCKs.
50 */
51 static int vmpck_id = -1;
52 module_param(vmpck_id, int, 0444);
53 MODULE_PARM_DESC(vmpck_id, "The VMPCK ID to use when communicating with the PSP.");
54
to_snp_dev(struct file * file)55 static inline struct snp_guest_dev *to_snp_dev(struct file *file)
56 {
57 struct miscdevice *dev = file->private_data;
58
59 return container_of(dev, struct snp_guest_dev, misc);
60 }
61
62 struct snp_req_resp {
63 sockptr_t req_data;
64 sockptr_t resp_data;
65 };
66
get_report(struct snp_guest_dev * snp_dev,struct snp_guest_request_ioctl * arg)67 static int get_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_ioctl *arg)
68 {
69 struct snp_report_req *report_req __free(kfree) = NULL;
70 struct snp_msg_desc *mdesc = snp_dev->msg_desc;
71 struct snp_report_resp *report_resp;
72 struct snp_guest_req req = {};
73 int rc, resp_len;
74
75 if (!arg->req_data || !arg->resp_data)
76 return -EINVAL;
77
78 report_req = kzalloc_obj(*report_req, GFP_KERNEL_ACCOUNT);
79 if (!report_req)
80 return -ENOMEM;
81
82 if (copy_from_user(report_req, (void __user *)arg->req_data, sizeof(*report_req)))
83 return -EFAULT;
84
85 /*
86 * The intermediate response buffer is used while decrypting the
87 * response payload. Make sure that it has enough space to cover the
88 * authtag.
89 */
90 resp_len = sizeof(report_resp->data) + mdesc->ctx->authsize;
91 report_resp = kzalloc(resp_len, GFP_KERNEL_ACCOUNT);
92 if (!report_resp)
93 return -ENOMEM;
94
95 req.msg_version = arg->msg_version;
96 req.msg_type = SNP_MSG_REPORT_REQ;
97 req.vmpck_id = mdesc->vmpck_id;
98 req.req_buf = report_req;
99 req.req_sz = sizeof(*report_req);
100 req.resp_buf = report_resp->data;
101 req.resp_sz = resp_len;
102 req.exit_code = SVM_VMGEXIT_GUEST_REQUEST;
103
104 rc = snp_send_guest_request(mdesc, &req);
105 arg->exitinfo2 = req.exitinfo2;
106 if (rc)
107 goto e_free;
108
109 if (copy_to_user((void __user *)arg->resp_data, report_resp, sizeof(*report_resp)))
110 rc = -EFAULT;
111
112 e_free:
113 kfree(report_resp);
114 return rc;
115 }
116
get_derived_key(struct snp_guest_dev * snp_dev,struct snp_guest_request_ioctl * arg)117 static int get_derived_key(struct snp_guest_dev *snp_dev, struct snp_guest_request_ioctl *arg)
118 {
119 struct snp_derived_key_resp *derived_key_resp __free(kfree) = NULL;
120 struct snp_derived_key_req *derived_key_req __free(kfree) = NULL;
121 struct snp_msg_desc *mdesc = snp_dev->msg_desc;
122 struct snp_guest_req req = {};
123 int rc, resp_len;
124
125 if (!arg->req_data || !arg->resp_data)
126 return -EINVAL;
127
128 /*
129 * The intermediate response buffer is used while decrypting the
130 * response payload. Make sure that it has enough space to cover the
131 * authtag.
132 */
133 resp_len = sizeof(derived_key_resp->data) + mdesc->ctx->authsize;
134 derived_key_resp = kzalloc(resp_len, GFP_KERNEL_ACCOUNT);
135 if (!derived_key_resp)
136 return -ENOMEM;
137
138 derived_key_req = kzalloc_obj(*derived_key_req, GFP_KERNEL_ACCOUNT);
139 if (!derived_key_req)
140 return -ENOMEM;
141
142 if (copy_from_user(derived_key_req, (void __user *)arg->req_data,
143 sizeof(*derived_key_req)))
144 return -EFAULT;
145
146 req.msg_version = arg->msg_version;
147 req.msg_type = SNP_MSG_KEY_REQ;
148 req.vmpck_id = mdesc->vmpck_id;
149 req.req_buf = derived_key_req;
150 req.req_sz = sizeof(*derived_key_req);
151 req.resp_buf = derived_key_resp;
152 req.resp_sz = resp_len;
153 req.exit_code = SVM_VMGEXIT_GUEST_REQUEST;
154
155 rc = snp_send_guest_request(mdesc, &req);
156 arg->exitinfo2 = req.exitinfo2;
157 if (!rc) {
158 if (copy_to_user((void __user *)arg->resp_data, derived_key_resp,
159 sizeof(derived_key_resp->data)))
160 rc = -EFAULT;
161 }
162
163 /* The response buffer contains the sensitive data, explicitly clear it. */
164 memzero_explicit(derived_key_resp, sizeof(*derived_key_resp));
165
166 return rc;
167 }
168
get_ext_report(struct snp_guest_dev * snp_dev,struct snp_guest_request_ioctl * arg,struct snp_req_resp * io)169 static int get_ext_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_ioctl *arg,
170 struct snp_req_resp *io)
171
172 {
173 struct snp_ext_report_req *report_req __free(kfree) = NULL;
174 struct snp_msg_desc *mdesc = snp_dev->msg_desc;
175 struct snp_report_resp *report_resp;
176 struct snp_guest_req req = {};
177 int ret, npages = 0, resp_len;
178 sockptr_t certs_address;
179 u64 pfn;
180
181 if (sockptr_is_null(io->req_data) || sockptr_is_null(io->resp_data))
182 return -EINVAL;
183
184 report_req = kzalloc_obj(*report_req, GFP_KERNEL_ACCOUNT);
185 if (!report_req)
186 return -ENOMEM;
187
188 if (copy_from_sockptr(report_req, io->req_data, sizeof(*report_req)))
189 return -EFAULT;
190
191 /* caller does not want certificate data */
192 if (!report_req->certs_len || !report_req->certs_address)
193 goto cmd;
194
195 if (report_req->certs_len > SEV_FW_BLOB_MAX_SIZE ||
196 !IS_ALIGNED(report_req->certs_len, PAGE_SIZE))
197 return -EINVAL;
198
199 if (sockptr_is_kernel(io->resp_data)) {
200 certs_address = KERNEL_SOCKPTR((void *)report_req->certs_address);
201 } else {
202 certs_address = USER_SOCKPTR((void __user *)report_req->certs_address);
203 if (!access_ok(certs_address.user, report_req->certs_len))
204 return -EFAULT;
205 }
206
207 /*
208 * Initialize the intermediate buffer with all zeros. This buffer
209 * is used in the guest request message to get the certs blob from
210 * the host. If host does not supply any certs in it, then copy
211 * zeros to indicate that certificate data was not provided.
212 */
213 npages = report_req->certs_len >> PAGE_SHIFT;
214 req.certs_data = alloc_pages_exact(npages << PAGE_SHIFT,
215 GFP_KERNEL_ACCOUNT | __GFP_ZERO);
216 if (!req.certs_data)
217 return -ENOMEM;
218
219 pfn = PHYS_PFN(virt_to_phys(req.certs_data));
220 ret = set_memory_decrypted((unsigned long)req.certs_data, npages);
221 if (ret) {
222 pr_err("failed to mark page shared, ret=%d\n", ret);
223 snp_leak_pages(pfn, npages);
224 return -EFAULT;
225 }
226
227 cmd:
228 /*
229 * The intermediate response buffer is used while decrypting the
230 * response payload. Make sure that it has enough space to cover the
231 * authtag.
232 */
233 resp_len = sizeof(report_resp->data) + mdesc->ctx->authsize;
234 report_resp = kzalloc(resp_len, GFP_KERNEL_ACCOUNT);
235 if (!report_resp) {
236 ret = -ENOMEM;
237 goto e_free_data;
238 }
239
240 req.input.data_npages = npages;
241
242 req.msg_version = arg->msg_version;
243 req.msg_type = SNP_MSG_REPORT_REQ;
244 req.vmpck_id = mdesc->vmpck_id;
245 req.req_buf = &report_req->data;
246 req.req_sz = sizeof(report_req->data);
247 req.resp_buf = report_resp->data;
248 req.resp_sz = resp_len;
249 req.exit_code = SVM_VMGEXIT_EXT_GUEST_REQUEST;
250
251 ret = snp_send_guest_request(mdesc, &req);
252 arg->exitinfo2 = req.exitinfo2;
253
254 /* If certs length is invalid then copy the returned length */
255 if (arg->vmm_error == SNP_GUEST_VMM_ERR_INVALID_LEN) {
256 report_req->certs_len = req.input.data_npages << PAGE_SHIFT;
257
258 if (copy_to_sockptr(io->req_data, report_req, sizeof(*report_req)))
259 ret = -EFAULT;
260 }
261
262 if (ret)
263 goto e_free;
264
265 if (npages && copy_to_sockptr(certs_address, req.certs_data, report_req->certs_len)) {
266 ret = -EFAULT;
267 goto e_free;
268 }
269
270 if (copy_to_sockptr(io->resp_data, report_resp, sizeof(*report_resp)))
271 ret = -EFAULT;
272
273 e_free:
274 kfree(report_resp);
275 e_free_data:
276 if (npages) {
277 if (set_memory_encrypted((unsigned long)req.certs_data, npages)) {
278 WARN_ONCE(ret, "failed to restore encryption mask (leak it)\n");
279 snp_leak_pages(pfn, npages);
280 } else {
281 free_pages_exact(req.certs_data, npages << PAGE_SHIFT);
282 }
283 }
284 return ret;
285 }
286
snp_guest_ioctl(struct file * file,unsigned int ioctl,unsigned long arg)287 static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
288 {
289 struct snp_guest_dev *snp_dev = to_snp_dev(file);
290 void __user *argp = (void __user *)arg;
291 struct snp_guest_request_ioctl input;
292 struct snp_req_resp io;
293 int ret = -ENOTTY;
294
295 if (copy_from_user(&input, argp, sizeof(input)))
296 return -EFAULT;
297
298 input.exitinfo2 = 0xff;
299
300 /* Message version must be non-zero */
301 if (!input.msg_version)
302 return -EINVAL;
303
304 switch (ioctl) {
305 case SNP_GET_REPORT:
306 ret = get_report(snp_dev, &input);
307 break;
308 case SNP_GET_DERIVED_KEY:
309 ret = get_derived_key(snp_dev, &input);
310 break;
311 case SNP_GET_EXT_REPORT:
312 /*
313 * As get_ext_report() may be called from the ioctl() path and a
314 * kernel internal path (configfs-tsm), decorate the passed
315 * buffers as user pointers.
316 */
317 io.req_data = USER_SOCKPTR((void __user *)input.req_data);
318 io.resp_data = USER_SOCKPTR((void __user *)input.resp_data);
319 ret = get_ext_report(snp_dev, &input, &io);
320 break;
321 default:
322 break;
323 }
324
325 if (input.exitinfo2 && copy_to_user(argp, &input, sizeof(input)))
326 return -EFAULT;
327
328 return ret;
329 }
330
331 static const struct file_operations snp_guest_fops = {
332 .owner = THIS_MODULE,
333 .unlocked_ioctl = snp_guest_ioctl,
334 };
335
336 struct snp_msg_report_resp_hdr {
337 u32 status;
338 u32 report_size;
339 u8 rsvd[24];
340 };
341
342 struct snp_msg_cert_entry {
343 guid_t guid;
344 u32 offset;
345 u32 length;
346 };
347
sev_svsm_report_new(struct tsm_report * report,void * data)348 static int sev_svsm_report_new(struct tsm_report *report, void *data)
349 {
350 unsigned int rep_len, man_len, certs_len;
351 struct tsm_report_desc *desc = &report->desc;
352 struct svsm_attest_call ac = {};
353 unsigned int retry_count;
354 void *rep, *man, *certs;
355 struct svsm_call call;
356 unsigned int size;
357 bool try_again;
358 void *buffer;
359 u64 call_id;
360 int ret;
361
362 /*
363 * Allocate pages for the request:
364 * - Report blob (4K)
365 * - Manifest blob (4K)
366 * - Certificate blob (16K)
367 *
368 * Above addresses must be 4K aligned
369 */
370 rep_len = SZ_4K;
371 man_len = SZ_4K;
372 certs_len = SEV_FW_BLOB_MAX_SIZE;
373
374 if (guid_is_null(&desc->service_guid)) {
375 call_id = SVSM_ATTEST_CALL(SVSM_ATTEST_SERVICES);
376 } else {
377 export_guid(ac.service_guid, &desc->service_guid);
378 ac.service_manifest_ver = desc->service_manifest_version;
379
380 call_id = SVSM_ATTEST_CALL(SVSM_ATTEST_SINGLE_SERVICE);
381 }
382
383 retry_count = 0;
384
385 retry:
386 memset(&call, 0, sizeof(call));
387
388 size = rep_len + man_len + certs_len;
389 buffer = alloc_pages_exact(size, __GFP_ZERO);
390 if (!buffer)
391 return -ENOMEM;
392
393 rep = buffer;
394 ac.report_buf.pa = __pa(rep);
395 ac.report_buf.len = rep_len;
396
397 man = rep + rep_len;
398 ac.manifest_buf.pa = __pa(man);
399 ac.manifest_buf.len = man_len;
400
401 certs = man + man_len;
402 ac.certificates_buf.pa = __pa(certs);
403 ac.certificates_buf.len = certs_len;
404
405 ac.nonce.pa = __pa(desc->inblob);
406 ac.nonce.len = desc->inblob_len;
407
408 ret = snp_issue_svsm_attest_req(call_id, &call, &ac);
409 if (ret) {
410 free_pages_exact(buffer, size);
411
412 switch (call.rax_out) {
413 case SVSM_ERR_INVALID_PARAMETER:
414 try_again = false;
415
416 if (ac.report_buf.len > rep_len) {
417 rep_len = PAGE_ALIGN(ac.report_buf.len);
418 try_again = true;
419 }
420
421 if (ac.manifest_buf.len > man_len) {
422 man_len = PAGE_ALIGN(ac.manifest_buf.len);
423 try_again = true;
424 }
425
426 if (ac.certificates_buf.len > certs_len) {
427 certs_len = PAGE_ALIGN(ac.certificates_buf.len);
428 try_again = true;
429 }
430
431 /* If one of the buffers wasn't large enough, retry the request */
432 if (try_again && retry_count < SVSM_MAX_RETRIES) {
433 retry_count++;
434 goto retry;
435 }
436
437 return -EINVAL;
438 default:
439 pr_err_ratelimited("SVSM attestation request failed (%d / 0x%llx)\n",
440 ret, call.rax_out);
441 return -EINVAL;
442 }
443 }
444
445 /*
446 * Allocate all the blob memory buffers at once so that the cleanup is
447 * done for errors that occur after the first allocation (i.e. before
448 * using no_free_ptr()).
449 */
450 rep_len = ac.report_buf.len;
451 void *rbuf __free(kvfree) = kvzalloc(rep_len, GFP_KERNEL);
452
453 man_len = ac.manifest_buf.len;
454 void *mbuf __free(kvfree) = kvzalloc(man_len, GFP_KERNEL);
455
456 certs_len = ac.certificates_buf.len;
457 void *cbuf __free(kvfree) = certs_len ? kvzalloc(certs_len, GFP_KERNEL) : NULL;
458
459 if (!rbuf || !mbuf || (certs_len && !cbuf)) {
460 free_pages_exact(buffer, size);
461 return -ENOMEM;
462 }
463
464 memcpy(rbuf, rep, rep_len);
465 report->outblob = no_free_ptr(rbuf);
466 report->outblob_len = rep_len;
467
468 memcpy(mbuf, man, man_len);
469 report->manifestblob = no_free_ptr(mbuf);
470 report->manifestblob_len = man_len;
471
472 if (certs_len) {
473 memcpy(cbuf, certs, certs_len);
474 report->auxblob = no_free_ptr(cbuf);
475 report->auxblob_len = certs_len;
476 }
477
478 free_pages_exact(buffer, size);
479
480 return 0;
481 }
482
sev_report_new(struct tsm_report * report,void * data)483 static int sev_report_new(struct tsm_report *report, void *data)
484 {
485 struct snp_msg_cert_entry *cert_table;
486 struct tsm_report_desc *desc = &report->desc;
487 struct snp_guest_dev *snp_dev = data;
488 struct snp_msg_report_resp_hdr hdr;
489 const u32 report_size = SZ_4K;
490 const u32 ext_size = SEV_FW_BLOB_MAX_SIZE;
491 u32 certs_size, i, size = report_size + ext_size;
492 int ret;
493
494 if (desc->inblob_len != SNP_REPORT_USER_DATA_SIZE)
495 return -EINVAL;
496
497 if (desc->service_provider) {
498 if (strcmp(desc->service_provider, "svsm"))
499 return -EINVAL;
500
501 return sev_svsm_report_new(report, data);
502 }
503
504 void *buf __free(kvfree) = kvzalloc(size, GFP_KERNEL);
505 if (!buf)
506 return -ENOMEM;
507
508 cert_table = buf + report_size;
509 struct snp_ext_report_req ext_req = {
510 .data = { .vmpl = desc->privlevel },
511 .certs_address = (__u64)cert_table,
512 .certs_len = ext_size,
513 };
514 memcpy(&ext_req.data.user_data, desc->inblob, desc->inblob_len);
515
516 struct snp_guest_request_ioctl input = {
517 .msg_version = 1,
518 .req_data = (__u64)&ext_req,
519 .resp_data = (__u64)buf,
520 .exitinfo2 = 0xff,
521 };
522 struct snp_req_resp io = {
523 .req_data = KERNEL_SOCKPTR(&ext_req),
524 .resp_data = KERNEL_SOCKPTR(buf),
525 };
526
527 ret = get_ext_report(snp_dev, &input, &io);
528 if (ret)
529 return ret;
530
531 memcpy(&hdr, buf, sizeof(hdr));
532 if (hdr.status == SEV_RET_INVALID_PARAM)
533 return -EINVAL;
534 if (hdr.status == SEV_RET_INVALID_KEY)
535 return -EINVAL;
536 if (hdr.status)
537 return -ENXIO;
538 if ((hdr.report_size + sizeof(hdr)) > report_size)
539 return -ENOMEM;
540
541 void *rbuf __free(kvfree) = kvzalloc(hdr.report_size, GFP_KERNEL);
542 if (!rbuf)
543 return -ENOMEM;
544
545 memcpy(rbuf, buf + sizeof(hdr), hdr.report_size);
546 report->outblob = no_free_ptr(rbuf);
547 report->outblob_len = hdr.report_size;
548
549 certs_size = 0;
550 for (i = 0; i < ext_size / sizeof(struct snp_msg_cert_entry); i++) {
551 struct snp_msg_cert_entry *ent = &cert_table[i];
552
553 if (guid_is_null(&ent->guid) && !ent->offset && !ent->length)
554 break;
555 certs_size = max(certs_size, ent->offset + ent->length);
556 }
557
558 /* Suspicious that the response populated entries without populating size */
559 if (!certs_size && i)
560 dev_warn_ratelimited(snp_dev->dev, "certificate slots conveyed without size\n");
561
562 /* No certs to report */
563 if (!certs_size)
564 return 0;
565
566 /* Suspicious that the certificate blob size contract was violated
567 */
568 if (certs_size > ext_size) {
569 dev_warn_ratelimited(snp_dev->dev, "certificate data truncated\n");
570 certs_size = ext_size;
571 }
572
573 void *cbuf __free(kvfree) = kvzalloc(certs_size, GFP_KERNEL);
574 if (!cbuf)
575 return -ENOMEM;
576
577 memcpy(cbuf, cert_table, certs_size);
578 report->auxblob = no_free_ptr(cbuf);
579 report->auxblob_len = certs_size;
580
581 return 0;
582 }
583
sev_report_attr_visible(int n)584 static bool sev_report_attr_visible(int n)
585 {
586 switch (n) {
587 case TSM_REPORT_GENERATION:
588 case TSM_REPORT_PROVIDER:
589 case TSM_REPORT_PRIVLEVEL:
590 case TSM_REPORT_PRIVLEVEL_FLOOR:
591 return true;
592 case TSM_REPORT_SERVICE_PROVIDER:
593 case TSM_REPORT_SERVICE_GUID:
594 case TSM_REPORT_SERVICE_MANIFEST_VER:
595 return snp_vmpl;
596 }
597
598 return false;
599 }
600
sev_report_bin_attr_visible(int n)601 static bool sev_report_bin_attr_visible(int n)
602 {
603 switch (n) {
604 case TSM_REPORT_INBLOB:
605 case TSM_REPORT_OUTBLOB:
606 case TSM_REPORT_AUXBLOB:
607 return true;
608 case TSM_REPORT_MANIFESTBLOB:
609 return snp_vmpl;
610 }
611
612 return false;
613 }
614
615 static struct tsm_report_ops sev_tsm_report_ops = {
616 .name = KBUILD_MODNAME,
617 .report_new = sev_report_new,
618 .report_attr_visible = sev_report_attr_visible,
619 .report_bin_attr_visible = sev_report_bin_attr_visible,
620 };
621
unregister_sev_tsm(void * data)622 static void unregister_sev_tsm(void *data)
623 {
624 tsm_report_unregister(&sev_tsm_report_ops);
625 }
626
sev_guest_probe(struct platform_device * pdev)627 static int __init sev_guest_probe(struct platform_device *pdev)
628 {
629 struct device *dev = &pdev->dev;
630 struct snp_guest_dev *snp_dev;
631 struct snp_msg_desc *mdesc;
632 struct miscdevice *misc;
633 int ret;
634
635 BUILD_BUG_ON(sizeof(struct snp_guest_msg) > PAGE_SIZE);
636
637 if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
638 return -ENODEV;
639
640 snp_dev = devm_kzalloc(&pdev->dev, sizeof(struct snp_guest_dev), GFP_KERNEL);
641 if (!snp_dev)
642 return -ENOMEM;
643
644 mdesc = snp_msg_alloc();
645 if (IS_ERR_OR_NULL(mdesc))
646 return -ENOMEM;
647
648 ret = snp_msg_init(mdesc, vmpck_id);
649 if (ret)
650 goto e_msg_init;
651
652 platform_set_drvdata(pdev, snp_dev);
653 snp_dev->dev = dev;
654
655 misc = &snp_dev->misc;
656 misc->minor = MISC_DYNAMIC_MINOR;
657 misc->name = DEVICE_NAME;
658 misc->fops = &snp_guest_fops;
659
660 /* Set the privlevel_floor attribute based on the vmpck_id */
661 sev_tsm_report_ops.privlevel_floor = mdesc->vmpck_id;
662
663 ret = tsm_report_register(&sev_tsm_report_ops, snp_dev);
664 if (ret)
665 goto e_msg_init;
666
667 ret = devm_add_action_or_reset(&pdev->dev, unregister_sev_tsm, NULL);
668 if (ret)
669 goto e_msg_init;
670
671 ret = misc_register(misc);
672 if (ret)
673 goto e_msg_init;
674
675 snp_dev->msg_desc = mdesc;
676 dev_info(dev, "Initialized SEV guest driver (using VMPCK%d communication key)\n",
677 mdesc->vmpck_id);
678 return 0;
679
680 e_msg_init:
681 snp_msg_free(mdesc);
682
683 return ret;
684 }
685
sev_guest_remove(struct platform_device * pdev)686 static void __exit sev_guest_remove(struct platform_device *pdev)
687 {
688 struct snp_guest_dev *snp_dev = platform_get_drvdata(pdev);
689
690 snp_msg_free(snp_dev->msg_desc);
691 misc_deregister(&snp_dev->misc);
692 }
693
694 /*
695 * This driver is meant to be a common SEV guest interface driver and to
696 * support any SEV guest API. As such, even though it has been introduced
697 * with the SEV-SNP support, it is named "sev-guest".
698 *
699 * sev_guest_remove() lives in .exit.text. For drivers registered via
700 * module_platform_driver_probe() this is ok because they cannot get unbound
701 * at runtime. So mark the driver struct with __refdata to prevent modpost
702 * triggering a section mismatch warning.
703 */
704 static struct platform_driver sev_guest_driver __refdata = {
705 .remove = __exit_p(sev_guest_remove),
706 .driver = {
707 .name = "sev-guest",
708 },
709 };
710
711 module_platform_driver_probe(sev_guest_driver, sev_guest_probe);
712
713 MODULE_AUTHOR("Brijesh Singh <brijesh.singh@amd.com>");
714 MODULE_LICENSE("GPL");
715 MODULE_VERSION("1.0.0");
716 MODULE_DESCRIPTION("AMD SEV Guest Driver");
717 MODULE_ALIAS("platform:sev-guest");
718