xref: /linux/drivers/crypto/ccp/sev-dev.c (revision 10ef74c06bb1f51e706018f2939722e881192eff)
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 MODULE_FIRMWARE("amd/amd_sev_fam17h_model0xh.sbin"); /* 1st gen EPYC */
79 MODULE_FIRMWARE("amd/amd_sev_fam17h_model3xh.sbin"); /* 2nd gen EPYC */
80 MODULE_FIRMWARE("amd/amd_sev_fam19h_model0xh.sbin"); /* 3rd gen EPYC */
81 MODULE_FIRMWARE("amd/amd_sev_fam19h_model1xh.sbin"); /* 4th gen EPYC */
82 
83 static bool psp_dead;
84 static int psp_timeout;
85 
86 enum snp_hv_fixed_pages_state {
87 	ALLOCATED,
88 	HV_FIXED,
89 };
90 
91 struct snp_hv_fixed_pages_entry {
92 	struct list_head list;
93 	struct page *page;
94 	unsigned int order;
95 	bool free;
96 	enum snp_hv_fixed_pages_state page_state;
97 };
98 
99 static LIST_HEAD(snp_hv_fixed_pages);
100 
101 /* Trusted Memory Region (TMR):
102  *   The TMR is a 1MB area that must be 1MB aligned.  Use the page allocator
103  *   to allocate the memory, which will return aligned memory for the specified
104  *   allocation order.
105  *
106  * When SEV-SNP is enabled the TMR needs to be 2MB aligned and 2MB sized.
107  */
108 #define SEV_TMR_SIZE		(1024 * 1024)
109 #define SNP_TMR_SIZE		(2 * 1024 * 1024)
110 
111 static void *sev_es_tmr;
112 static size_t sev_es_tmr_size = SEV_TMR_SIZE;
113 
114 /* INIT_EX NV Storage:
115  *   The NV Storage is a 32Kb area and must be 4Kb page aligned.  Use the page
116  *   allocator to allocate the memory, which will return aligned memory for the
117  *   specified allocation order.
118  */
119 #define NV_LENGTH (32 * 1024)
120 static void *sev_init_ex_buffer;
121 
122 /*
123  * SEV_DATA_RANGE_LIST:
124  *   Array containing range of pages that firmware transitions to HV-fixed
125  *   page state.
126  */
127 static struct sev_data_range_list *snp_range_list;
128 
129 static void __sev_firmware_shutdown(struct sev_device *sev, bool panic);
130 
131 static int snp_shutdown_on_panic(struct notifier_block *nb,
132 				 unsigned long reason, void *arg);
133 
134 static struct notifier_block snp_panic_notifier = {
135 	.notifier_call = snp_shutdown_on_panic,
136 };
137 
sev_version_greater_or_equal(u8 maj,u8 min)138 static inline bool sev_version_greater_or_equal(u8 maj, u8 min)
139 {
140 	struct sev_device *sev = psp_master->sev_data;
141 
142 	if (sev->api_major > maj)
143 		return true;
144 
145 	if (sev->api_major == maj && sev->api_minor >= min)
146 		return true;
147 
148 	return false;
149 }
150 
sev_irq_handler(int irq,void * data,unsigned int status)151 static void sev_irq_handler(int irq, void *data, unsigned int status)
152 {
153 	struct sev_device *sev = data;
154 	int reg;
155 
156 	/* Check if it is command completion: */
157 	if (!(status & SEV_CMD_COMPLETE))
158 		return;
159 
160 	/* Check if it is SEV command completion: */
161 	reg = ioread32(sev->io_regs + sev->vdata->cmdresp_reg);
162 	if (FIELD_GET(PSP_CMDRESP_RESP, reg)) {
163 		sev->int_rcvd = 1;
164 		wake_up(&sev->int_queue);
165 	}
166 }
167 
sev_wait_cmd_ioc(struct sev_device * sev,unsigned int * reg,unsigned int timeout)168 static int sev_wait_cmd_ioc(struct sev_device *sev,
169 			    unsigned int *reg, unsigned int timeout)
170 {
171 	int ret;
172 
173 	/*
174 	 * If invoked during panic handling, local interrupts are disabled,
175 	 * so the PSP command completion interrupt can't be used. Poll for
176 	 * PSP command completion instead.
177 	 */
178 	if (irqs_disabled()) {
179 		unsigned long timeout_usecs = (timeout * USEC_PER_SEC) / 10;
180 
181 		/* Poll for SEV command completion: */
182 		while (timeout_usecs--) {
183 			*reg = ioread32(sev->io_regs + sev->vdata->cmdresp_reg);
184 			if (*reg & PSP_CMDRESP_RESP)
185 				return 0;
186 
187 			udelay(10);
188 		}
189 		return -ETIMEDOUT;
190 	}
191 
192 	ret = wait_event_timeout(sev->int_queue,
193 			sev->int_rcvd, timeout * HZ);
194 	if (!ret)
195 		return -ETIMEDOUT;
196 
197 	*reg = ioread32(sev->io_regs + sev->vdata->cmdresp_reg);
198 
199 	return 0;
200 }
201 
sev_cmd_buffer_len(int cmd)202 static int sev_cmd_buffer_len(int cmd)
203 {
204 	switch (cmd) {
205 	case SEV_CMD_INIT:			return sizeof(struct sev_data_init);
206 	case SEV_CMD_INIT_EX:                   return sizeof(struct sev_data_init_ex);
207 	case SEV_CMD_SNP_SHUTDOWN_EX:		return sizeof(struct sev_data_snp_shutdown_ex);
208 	case SEV_CMD_SNP_INIT_EX:		return sizeof(struct sev_data_snp_init_ex);
209 	case SEV_CMD_PLATFORM_STATUS:		return sizeof(struct sev_user_data_status);
210 	case SEV_CMD_PEK_CSR:			return sizeof(struct sev_data_pek_csr);
211 	case SEV_CMD_PEK_CERT_IMPORT:		return sizeof(struct sev_data_pek_cert_import);
212 	case SEV_CMD_PDH_CERT_EXPORT:		return sizeof(struct sev_data_pdh_cert_export);
213 	case SEV_CMD_LAUNCH_START:		return sizeof(struct sev_data_launch_start);
214 	case SEV_CMD_LAUNCH_UPDATE_DATA:	return sizeof(struct sev_data_launch_update_data);
215 	case SEV_CMD_LAUNCH_UPDATE_VMSA:	return sizeof(struct sev_data_launch_update_vmsa);
216 	case SEV_CMD_LAUNCH_FINISH:		return sizeof(struct sev_data_launch_finish);
217 	case SEV_CMD_LAUNCH_MEASURE:		return sizeof(struct sev_data_launch_measure);
218 	case SEV_CMD_ACTIVATE:			return sizeof(struct sev_data_activate);
219 	case SEV_CMD_DEACTIVATE:		return sizeof(struct sev_data_deactivate);
220 	case SEV_CMD_DECOMMISSION:		return sizeof(struct sev_data_decommission);
221 	case SEV_CMD_GUEST_STATUS:		return sizeof(struct sev_data_guest_status);
222 	case SEV_CMD_DBG_DECRYPT:		return sizeof(struct sev_data_dbg);
223 	case SEV_CMD_DBG_ENCRYPT:		return sizeof(struct sev_data_dbg);
224 	case SEV_CMD_SEND_START:		return sizeof(struct sev_data_send_start);
225 	case SEV_CMD_SEND_UPDATE_DATA:		return sizeof(struct sev_data_send_update_data);
226 	case SEV_CMD_SEND_UPDATE_VMSA:		return sizeof(struct sev_data_send_update_vmsa);
227 	case SEV_CMD_SEND_FINISH:		return sizeof(struct sev_data_send_finish);
228 	case SEV_CMD_RECEIVE_START:		return sizeof(struct sev_data_receive_start);
229 	case SEV_CMD_RECEIVE_FINISH:		return sizeof(struct sev_data_receive_finish);
230 	case SEV_CMD_RECEIVE_UPDATE_DATA:	return sizeof(struct sev_data_receive_update_data);
231 	case SEV_CMD_RECEIVE_UPDATE_VMSA:	return sizeof(struct sev_data_receive_update_vmsa);
232 	case SEV_CMD_LAUNCH_UPDATE_SECRET:	return sizeof(struct sev_data_launch_secret);
233 	case SEV_CMD_DOWNLOAD_FIRMWARE:		return sizeof(struct sev_data_download_firmware);
234 	case SEV_CMD_GET_ID:			return sizeof(struct sev_data_get_id);
235 	case SEV_CMD_ATTESTATION_REPORT:	return sizeof(struct sev_data_attestation_report);
236 	case SEV_CMD_SEND_CANCEL:		return sizeof(struct sev_data_send_cancel);
237 	case SEV_CMD_SNP_GCTX_CREATE:		return sizeof(struct sev_data_snp_addr);
238 	case SEV_CMD_SNP_LAUNCH_START:		return sizeof(struct sev_data_snp_launch_start);
239 	case SEV_CMD_SNP_LAUNCH_UPDATE:		return sizeof(struct sev_data_snp_launch_update);
240 	case SEV_CMD_SNP_ACTIVATE:		return sizeof(struct sev_data_snp_activate);
241 	case SEV_CMD_SNP_DECOMMISSION:		return sizeof(struct sev_data_snp_addr);
242 	case SEV_CMD_SNP_PAGE_RECLAIM:		return sizeof(struct sev_data_snp_page_reclaim);
243 	case SEV_CMD_SNP_GUEST_STATUS:		return sizeof(struct sev_data_snp_guest_status);
244 	case SEV_CMD_SNP_LAUNCH_FINISH:		return sizeof(struct sev_data_snp_launch_finish);
245 	case SEV_CMD_SNP_DBG_DECRYPT:		return sizeof(struct sev_data_snp_dbg);
246 	case SEV_CMD_SNP_DBG_ENCRYPT:		return sizeof(struct sev_data_snp_dbg);
247 	case SEV_CMD_SNP_PAGE_UNSMASH:		return sizeof(struct sev_data_snp_page_unsmash);
248 	case SEV_CMD_SNP_PLATFORM_STATUS:	return sizeof(struct sev_data_snp_addr);
249 	case SEV_CMD_SNP_GUEST_REQUEST:		return sizeof(struct sev_data_snp_guest_request);
250 	case SEV_CMD_SNP_CONFIG:		return sizeof(struct sev_user_data_snp_config);
251 	case SEV_CMD_SNP_COMMIT:		return sizeof(struct sev_data_snp_commit);
252 	case SEV_CMD_SNP_FEATURE_INFO:		return sizeof(struct sev_data_snp_feature_info);
253 	case SEV_CMD_SNP_VLEK_LOAD:		return sizeof(struct sev_user_data_snp_vlek_load);
254 	default:				return 0;
255 	}
256 
257 	return 0;
258 }
259 
open_file_as_root(const char * filename,int flags,umode_t mode)260 static struct file *open_file_as_root(const char *filename, int flags, umode_t mode)
261 {
262 	struct file *fp;
263 	struct path root;
264 	struct cred *cred;
265 	const struct cred *old_cred;
266 
267 	task_lock(&init_task);
268 	get_fs_root(init_task.fs, &root);
269 	task_unlock(&init_task);
270 
271 	cred = prepare_creds();
272 	if (!cred)
273 		return ERR_PTR(-ENOMEM);
274 	cred->fsuid = GLOBAL_ROOT_UID;
275 	old_cred = override_creds(cred);
276 
277 	fp = file_open_root(&root, filename, flags, mode);
278 	path_put(&root);
279 
280 	put_cred(revert_creds(old_cred));
281 
282 	return fp;
283 }
284 
sev_read_init_ex_file(void)285 static int sev_read_init_ex_file(void)
286 {
287 	struct sev_device *sev = psp_master->sev_data;
288 	struct file *fp;
289 	ssize_t nread;
290 
291 	lockdep_assert_held(&sev_cmd_mutex);
292 
293 	if (!sev_init_ex_buffer)
294 		return -EOPNOTSUPP;
295 
296 	fp = open_file_as_root(init_ex_path, O_RDONLY, 0);
297 	if (IS_ERR(fp)) {
298 		int ret = PTR_ERR(fp);
299 
300 		if (ret == -ENOENT) {
301 			dev_info(sev->dev,
302 				"SEV: %s does not exist and will be created later.\n",
303 				init_ex_path);
304 			ret = 0;
305 		} else {
306 			dev_err(sev->dev,
307 				"SEV: could not open %s for read, error %d\n",
308 				init_ex_path, ret);
309 		}
310 		return ret;
311 	}
312 
313 	nread = kernel_read(fp, sev_init_ex_buffer, NV_LENGTH, NULL);
314 	if (nread != NV_LENGTH) {
315 		dev_info(sev->dev,
316 			"SEV: could not read %u bytes to non volatile memory area, ret %ld\n",
317 			NV_LENGTH, nread);
318 	}
319 
320 	dev_dbg(sev->dev, "SEV: read %ld bytes from NV file\n", nread);
321 	filp_close(fp, NULL);
322 
323 	return 0;
324 }
325 
sev_write_init_ex_file(void)326 static int sev_write_init_ex_file(void)
327 {
328 	struct sev_device *sev = psp_master->sev_data;
329 	struct file *fp;
330 	loff_t offset = 0;
331 	ssize_t nwrite;
332 
333 	lockdep_assert_held(&sev_cmd_mutex);
334 
335 	if (!sev_init_ex_buffer)
336 		return 0;
337 
338 	fp = open_file_as_root(init_ex_path, O_CREAT | O_WRONLY, 0600);
339 	if (IS_ERR(fp)) {
340 		int ret = PTR_ERR(fp);
341 
342 		dev_err(sev->dev,
343 			"SEV: could not open file for write, error %d\n",
344 			ret);
345 		return ret;
346 	}
347 
348 	nwrite = kernel_write(fp, sev_init_ex_buffer, NV_LENGTH, &offset);
349 	vfs_fsync(fp, 0);
350 	filp_close(fp, NULL);
351 
352 	if (nwrite != NV_LENGTH) {
353 		dev_err(sev->dev,
354 			"SEV: failed to write %u bytes to non volatile memory area, ret %ld\n",
355 			NV_LENGTH, nwrite);
356 		return -EIO;
357 	}
358 
359 	dev_dbg(sev->dev, "SEV: write successful to NV file\n");
360 
361 	return 0;
362 }
363 
sev_write_init_ex_file_if_required(int cmd_id)364 static int sev_write_init_ex_file_if_required(int cmd_id)
365 {
366 	lockdep_assert_held(&sev_cmd_mutex);
367 
368 	if (!sev_init_ex_buffer)
369 		return 0;
370 
371 	/*
372 	 * Only a few platform commands modify the SPI/NV area, but none of the
373 	 * non-platform commands do. Only INIT(_EX), PLATFORM_RESET, PEK_GEN,
374 	 * PEK_CERT_IMPORT, and PDH_GEN do.
375 	 */
376 	switch (cmd_id) {
377 	case SEV_CMD_FACTORY_RESET:
378 	case SEV_CMD_INIT_EX:
379 	case SEV_CMD_PDH_GEN:
380 	case SEV_CMD_PEK_CERT_IMPORT:
381 	case SEV_CMD_PEK_GEN:
382 		break;
383 	default:
384 		return 0;
385 	}
386 
387 	return sev_write_init_ex_file();
388 }
389 
390 /*
391  * snp_reclaim_pages() needs __sev_do_cmd_locked(), and __sev_do_cmd_locked()
392  * needs snp_reclaim_pages(), so a forward declaration is needed.
393  */
394 static int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret);
395 
snp_reclaim_pages(unsigned long paddr,unsigned int npages,bool locked)396 static int snp_reclaim_pages(unsigned long paddr, unsigned int npages, bool locked)
397 {
398 	int ret, err, i;
399 
400 	paddr = __sme_clr(ALIGN_DOWN(paddr, PAGE_SIZE));
401 
402 	for (i = 0; i < npages; i++, paddr += PAGE_SIZE) {
403 		struct sev_data_snp_page_reclaim data = {0};
404 
405 		data.paddr = paddr;
406 
407 		if (locked)
408 			ret = __sev_do_cmd_locked(SEV_CMD_SNP_PAGE_RECLAIM, &data, &err);
409 		else
410 			ret = sev_do_cmd(SEV_CMD_SNP_PAGE_RECLAIM, &data, &err);
411 
412 		if (ret)
413 			goto cleanup;
414 
415 		ret = rmp_make_shared(__phys_to_pfn(paddr), PG_LEVEL_4K);
416 		if (ret)
417 			goto cleanup;
418 	}
419 
420 	return 0;
421 
422 cleanup:
423 	/*
424 	 * If there was a failure reclaiming the page then it is no longer safe
425 	 * to release it back to the system; leak it instead.
426 	 */
427 	snp_leak_pages(__phys_to_pfn(paddr), npages - i);
428 	return ret;
429 }
430 
rmp_mark_pages_firmware(unsigned long paddr,unsigned int npages,bool locked)431 static int rmp_mark_pages_firmware(unsigned long paddr, unsigned int npages, bool locked)
432 {
433 	unsigned long pfn = __sme_clr(paddr) >> PAGE_SHIFT;
434 	int rc, i;
435 
436 	for (i = 0; i < npages; i++, pfn++) {
437 		rc = rmp_make_private(pfn, 0, PG_LEVEL_4K, 0, true);
438 		if (rc)
439 			goto cleanup;
440 	}
441 
442 	return 0;
443 
444 cleanup:
445 	/*
446 	 * Try unrolling the firmware state changes by
447 	 * reclaiming the pages which were already changed to the
448 	 * firmware state.
449 	 */
450 	snp_reclaim_pages(paddr, i, locked);
451 
452 	return rc;
453 }
454 
__snp_alloc_firmware_pages(gfp_t gfp_mask,int order,bool locked)455 static struct page *__snp_alloc_firmware_pages(gfp_t gfp_mask, int order, bool locked)
456 {
457 	unsigned long npages = 1ul << order, paddr;
458 	struct sev_device *sev;
459 	struct page *page;
460 
461 	if (!psp_master || !psp_master->sev_data)
462 		return NULL;
463 
464 	page = alloc_pages(gfp_mask, order);
465 	if (!page)
466 		return NULL;
467 
468 	/* If SEV-SNP is initialized then add the page in RMP table. */
469 	sev = psp_master->sev_data;
470 	if (!sev->snp_initialized)
471 		return page;
472 
473 	paddr = __pa((unsigned long)page_address(page));
474 	if (rmp_mark_pages_firmware(paddr, npages, locked))
475 		return NULL;
476 
477 	return page;
478 }
479 
snp_alloc_firmware_page(gfp_t gfp_mask)480 void *snp_alloc_firmware_page(gfp_t gfp_mask)
481 {
482 	struct page *page;
483 
484 	page = __snp_alloc_firmware_pages(gfp_mask, 0, false);
485 
486 	return page ? page_address(page) : NULL;
487 }
488 EXPORT_SYMBOL_GPL(snp_alloc_firmware_page);
489 
__snp_free_firmware_pages(struct page * page,int order,bool locked)490 static void __snp_free_firmware_pages(struct page *page, int order, bool locked)
491 {
492 	struct sev_device *sev = psp_master->sev_data;
493 	unsigned long paddr, npages = 1ul << order;
494 
495 	if (!page)
496 		return;
497 
498 	paddr = __pa((unsigned long)page_address(page));
499 	if (sev->snp_initialized &&
500 	    snp_reclaim_pages(paddr, npages, locked))
501 		return;
502 
503 	__free_pages(page, order);
504 }
505 
snp_free_firmware_page(void * addr)506 void snp_free_firmware_page(void *addr)
507 {
508 	if (!addr)
509 		return;
510 
511 	__snp_free_firmware_pages(virt_to_page(addr), 0, false);
512 }
513 EXPORT_SYMBOL_GPL(snp_free_firmware_page);
514 
sev_fw_alloc(unsigned long len)515 static void *sev_fw_alloc(unsigned long len)
516 {
517 	struct page *page;
518 
519 	page = __snp_alloc_firmware_pages(GFP_KERNEL, get_order(len), true);
520 	if (!page)
521 		return NULL;
522 
523 	return page_address(page);
524 }
525 
526 /**
527  * struct cmd_buf_desc - descriptors for managing legacy SEV command address
528  * parameters corresponding to buffers that may be written to by firmware.
529  *
530  * @paddr_ptr:  pointer to the address parameter in the command buffer which may
531  *              need to be saved/restored depending on whether a bounce buffer
532  *              is used. In the case of a bounce buffer, the command buffer
533  *              needs to be updated with the address of the new bounce buffer
534  *              snp_map_cmd_buf_desc() has allocated specifically for it. Must
535  *              be NULL if this descriptor is only an end-of-list indicator.
536  *
537  * @paddr_orig: storage for the original address parameter, which can be used to
538  *              restore the original value in @paddr_ptr in cases where it is
539  *              replaced with the address of a bounce buffer.
540  *
541  * @len: length of buffer located at the address originally stored at @paddr_ptr
542  *
543  * @guest_owned: true if the address corresponds to guest-owned pages, in which
544  *               case bounce buffers are not needed.
545  */
546 struct cmd_buf_desc {
547 	u64 *paddr_ptr;
548 	u64 paddr_orig;
549 	u32 len;
550 	bool guest_owned;
551 };
552 
553 /*
554  * If a legacy SEV command parameter is a memory address, those pages in
555  * turn need to be transitioned to/from firmware-owned before/after
556  * executing the firmware command.
557  *
558  * Additionally, in cases where those pages are not guest-owned, a bounce
559  * buffer is needed in place of the original memory address parameter.
560  *
561  * A set of descriptors are used to keep track of this handling, and
562  * initialized here based on the specific commands being executed.
563  */
snp_populate_cmd_buf_desc_list(int cmd,void * cmd_buf,struct cmd_buf_desc * desc_list)564 static void snp_populate_cmd_buf_desc_list(int cmd, void *cmd_buf,
565 					   struct cmd_buf_desc *desc_list)
566 {
567 	switch (cmd) {
568 	case SEV_CMD_PDH_CERT_EXPORT: {
569 		struct sev_data_pdh_cert_export *data = cmd_buf;
570 
571 		desc_list[0].paddr_ptr = &data->pdh_cert_address;
572 		desc_list[0].len = data->pdh_cert_len;
573 		desc_list[1].paddr_ptr = &data->cert_chain_address;
574 		desc_list[1].len = data->cert_chain_len;
575 		break;
576 	}
577 	case SEV_CMD_GET_ID: {
578 		struct sev_data_get_id *data = cmd_buf;
579 
580 		desc_list[0].paddr_ptr = &data->address;
581 		desc_list[0].len = data->len;
582 		break;
583 	}
584 	case SEV_CMD_PEK_CSR: {
585 		struct sev_data_pek_csr *data = cmd_buf;
586 
587 		desc_list[0].paddr_ptr = &data->address;
588 		desc_list[0].len = data->len;
589 		break;
590 	}
591 	case SEV_CMD_LAUNCH_UPDATE_DATA: {
592 		struct sev_data_launch_update_data *data = cmd_buf;
593 
594 		desc_list[0].paddr_ptr = &data->address;
595 		desc_list[0].len = data->len;
596 		desc_list[0].guest_owned = true;
597 		break;
598 	}
599 	case SEV_CMD_LAUNCH_UPDATE_VMSA: {
600 		struct sev_data_launch_update_vmsa *data = cmd_buf;
601 
602 		desc_list[0].paddr_ptr = &data->address;
603 		desc_list[0].len = data->len;
604 		desc_list[0].guest_owned = true;
605 		break;
606 	}
607 	case SEV_CMD_LAUNCH_MEASURE: {
608 		struct sev_data_launch_measure *data = cmd_buf;
609 
610 		desc_list[0].paddr_ptr = &data->address;
611 		desc_list[0].len = data->len;
612 		break;
613 	}
614 	case SEV_CMD_LAUNCH_UPDATE_SECRET: {
615 		struct sev_data_launch_secret *data = cmd_buf;
616 
617 		desc_list[0].paddr_ptr = &data->guest_address;
618 		desc_list[0].len = data->guest_len;
619 		desc_list[0].guest_owned = true;
620 		break;
621 	}
622 	case SEV_CMD_DBG_DECRYPT: {
623 		struct sev_data_dbg *data = cmd_buf;
624 
625 		desc_list[0].paddr_ptr = &data->dst_addr;
626 		desc_list[0].len = data->len;
627 		desc_list[0].guest_owned = true;
628 		break;
629 	}
630 	case SEV_CMD_DBG_ENCRYPT: {
631 		struct sev_data_dbg *data = cmd_buf;
632 
633 		desc_list[0].paddr_ptr = &data->dst_addr;
634 		desc_list[0].len = data->len;
635 		desc_list[0].guest_owned = true;
636 		break;
637 	}
638 	case SEV_CMD_ATTESTATION_REPORT: {
639 		struct sev_data_attestation_report *data = cmd_buf;
640 
641 		desc_list[0].paddr_ptr = &data->address;
642 		desc_list[0].len = data->len;
643 		break;
644 	}
645 	case SEV_CMD_SEND_START: {
646 		struct sev_data_send_start *data = cmd_buf;
647 
648 		desc_list[0].paddr_ptr = &data->session_address;
649 		desc_list[0].len = data->session_len;
650 		break;
651 	}
652 	case SEV_CMD_SEND_UPDATE_DATA: {
653 		struct sev_data_send_update_data *data = cmd_buf;
654 
655 		desc_list[0].paddr_ptr = &data->hdr_address;
656 		desc_list[0].len = data->hdr_len;
657 		desc_list[1].paddr_ptr = &data->trans_address;
658 		desc_list[1].len = data->trans_len;
659 		break;
660 	}
661 	case SEV_CMD_SEND_UPDATE_VMSA: {
662 		struct sev_data_send_update_vmsa *data = cmd_buf;
663 
664 		desc_list[0].paddr_ptr = &data->hdr_address;
665 		desc_list[0].len = data->hdr_len;
666 		desc_list[1].paddr_ptr = &data->trans_address;
667 		desc_list[1].len = data->trans_len;
668 		break;
669 	}
670 	case SEV_CMD_RECEIVE_UPDATE_DATA: {
671 		struct sev_data_receive_update_data *data = cmd_buf;
672 
673 		desc_list[0].paddr_ptr = &data->guest_address;
674 		desc_list[0].len = data->guest_len;
675 		desc_list[0].guest_owned = true;
676 		break;
677 	}
678 	case SEV_CMD_RECEIVE_UPDATE_VMSA: {
679 		struct sev_data_receive_update_vmsa *data = cmd_buf;
680 
681 		desc_list[0].paddr_ptr = &data->guest_address;
682 		desc_list[0].len = data->guest_len;
683 		desc_list[0].guest_owned = true;
684 		break;
685 	}
686 	default:
687 		break;
688 	}
689 }
690 
snp_map_cmd_buf_desc(struct cmd_buf_desc * desc)691 static int snp_map_cmd_buf_desc(struct cmd_buf_desc *desc)
692 {
693 	unsigned int npages;
694 
695 	if (!desc->len)
696 		return 0;
697 
698 	/* Allocate a bounce buffer if this isn't a guest owned page. */
699 	if (!desc->guest_owned) {
700 		struct page *page;
701 
702 		page = alloc_pages(GFP_KERNEL_ACCOUNT, get_order(desc->len));
703 		if (!page) {
704 			pr_warn("Failed to allocate bounce buffer for SEV legacy command.\n");
705 			return -ENOMEM;
706 		}
707 
708 		desc->paddr_orig = *desc->paddr_ptr;
709 		*desc->paddr_ptr = __psp_pa(page_to_virt(page));
710 	}
711 
712 	npages = PAGE_ALIGN(desc->len) >> PAGE_SHIFT;
713 
714 	/* Transition the buffer to firmware-owned. */
715 	if (rmp_mark_pages_firmware(*desc->paddr_ptr, npages, true)) {
716 		pr_warn("Error moving pages to firmware-owned state for SEV legacy command.\n");
717 		return -EFAULT;
718 	}
719 
720 	return 0;
721 }
722 
snp_unmap_cmd_buf_desc(struct cmd_buf_desc * desc)723 static int snp_unmap_cmd_buf_desc(struct cmd_buf_desc *desc)
724 {
725 	unsigned int npages;
726 
727 	if (!desc->len)
728 		return 0;
729 
730 	npages = PAGE_ALIGN(desc->len) >> PAGE_SHIFT;
731 
732 	/* Transition the buffers back to hypervisor-owned. */
733 	if (snp_reclaim_pages(*desc->paddr_ptr, npages, true)) {
734 		pr_warn("Failed to reclaim firmware-owned pages while issuing SEV legacy command.\n");
735 		return -EFAULT;
736 	}
737 
738 	/* Copy data from bounce buffer and then free it. */
739 	if (!desc->guest_owned) {
740 		void *bounce_buf = __va(__sme_clr(*desc->paddr_ptr));
741 		void *dst_buf = __va(__sme_clr(desc->paddr_orig));
742 
743 		memcpy(dst_buf, bounce_buf, desc->len);
744 		__free_pages(virt_to_page(bounce_buf), get_order(desc->len));
745 
746 		/* Restore the original address in the command buffer. */
747 		*desc->paddr_ptr = desc->paddr_orig;
748 	}
749 
750 	return 0;
751 }
752 
snp_map_cmd_buf_desc_list(int cmd,void * cmd_buf,struct cmd_buf_desc * desc_list)753 static int snp_map_cmd_buf_desc_list(int cmd, void *cmd_buf, struct cmd_buf_desc *desc_list)
754 {
755 	int i;
756 
757 	snp_populate_cmd_buf_desc_list(cmd, cmd_buf, desc_list);
758 
759 	for (i = 0; i < CMD_BUF_DESC_MAX; i++) {
760 		struct cmd_buf_desc *desc = &desc_list[i];
761 
762 		if (!desc->paddr_ptr)
763 			break;
764 
765 		if (snp_map_cmd_buf_desc(desc))
766 			goto err_unmap;
767 	}
768 
769 	return 0;
770 
771 err_unmap:
772 	for (i--; i >= 0; i--)
773 		snp_unmap_cmd_buf_desc(&desc_list[i]);
774 
775 	return -EFAULT;
776 }
777 
snp_unmap_cmd_buf_desc_list(struct cmd_buf_desc * desc_list)778 static int snp_unmap_cmd_buf_desc_list(struct cmd_buf_desc *desc_list)
779 {
780 	int i, ret = 0;
781 
782 	for (i = 0; i < CMD_BUF_DESC_MAX; i++) {
783 		struct cmd_buf_desc *desc = &desc_list[i];
784 
785 		if (!desc->paddr_ptr)
786 			break;
787 
788 		if (snp_unmap_cmd_buf_desc(&desc_list[i]))
789 			ret = -EFAULT;
790 	}
791 
792 	return ret;
793 }
794 
sev_cmd_buf_writable(int cmd)795 static bool sev_cmd_buf_writable(int cmd)
796 {
797 	switch (cmd) {
798 	case SEV_CMD_PLATFORM_STATUS:
799 	case SEV_CMD_GUEST_STATUS:
800 	case SEV_CMD_LAUNCH_START:
801 	case SEV_CMD_RECEIVE_START:
802 	case SEV_CMD_LAUNCH_MEASURE:
803 	case SEV_CMD_SEND_START:
804 	case SEV_CMD_SEND_UPDATE_DATA:
805 	case SEV_CMD_SEND_UPDATE_VMSA:
806 	case SEV_CMD_PEK_CSR:
807 	case SEV_CMD_PDH_CERT_EXPORT:
808 	case SEV_CMD_GET_ID:
809 	case SEV_CMD_ATTESTATION_REPORT:
810 		return true;
811 	default:
812 		return false;
813 	}
814 }
815 
816 /* After SNP is INIT'ed, the behavior of legacy SEV commands is changed. */
snp_legacy_handling_needed(int cmd)817 static bool snp_legacy_handling_needed(int cmd)
818 {
819 	struct sev_device *sev = psp_master->sev_data;
820 
821 	return cmd < SEV_CMD_SNP_INIT && sev->snp_initialized;
822 }
823 
snp_prep_cmd_buf(int cmd,void * cmd_buf,struct cmd_buf_desc * desc_list)824 static int snp_prep_cmd_buf(int cmd, void *cmd_buf, struct cmd_buf_desc *desc_list)
825 {
826 	if (!snp_legacy_handling_needed(cmd))
827 		return 0;
828 
829 	if (snp_map_cmd_buf_desc_list(cmd, cmd_buf, desc_list))
830 		return -EFAULT;
831 
832 	/*
833 	 * Before command execution, the command buffer needs to be put into
834 	 * the firmware-owned state.
835 	 */
836 	if (sev_cmd_buf_writable(cmd)) {
837 		if (rmp_mark_pages_firmware(__pa(cmd_buf), 1, true))
838 			return -EFAULT;
839 	}
840 
841 	return 0;
842 }
843 
snp_reclaim_cmd_buf(int cmd,void * cmd_buf)844 static int snp_reclaim_cmd_buf(int cmd, void *cmd_buf)
845 {
846 	if (!snp_legacy_handling_needed(cmd))
847 		return 0;
848 
849 	/*
850 	 * After command completion, the command buffer needs to be put back
851 	 * into the hypervisor-owned state.
852 	 */
853 	if (sev_cmd_buf_writable(cmd))
854 		if (snp_reclaim_pages(__pa(cmd_buf), 1, true))
855 			return -EFAULT;
856 
857 	return 0;
858 }
859 
__sev_do_cmd_locked(int cmd,void * data,int * psp_ret)860 static int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret)
861 {
862 	struct cmd_buf_desc desc_list[CMD_BUF_DESC_MAX] = {0};
863 	struct psp_device *psp = psp_master;
864 	struct sev_device *sev;
865 	unsigned int cmdbuff_hi, cmdbuff_lo;
866 	unsigned int phys_lsb, phys_msb;
867 	unsigned int reg;
868 	void *cmd_buf;
869 	int buf_len;
870 	int ret = 0;
871 
872 	if (!psp || !psp->sev_data)
873 		return -ENODEV;
874 
875 	if (psp_dead)
876 		return -EBUSY;
877 
878 	sev = psp->sev_data;
879 
880 	buf_len = sev_cmd_buffer_len(cmd);
881 	if (WARN_ON_ONCE(!data != !buf_len))
882 		return -EINVAL;
883 
884 	/*
885 	 * Copy the incoming data to driver's scratch buffer as __pa() will not
886 	 * work for some memory, e.g. vmalloc'd addresses, and @data may not be
887 	 * physically contiguous.
888 	 */
889 	if (data) {
890 		/*
891 		 * Commands are generally issued one at a time and require the
892 		 * sev_cmd_mutex, but there could be recursive firmware requests
893 		 * due to SEV_CMD_SNP_PAGE_RECLAIM needing to be issued while
894 		 * preparing buffers for another command. This is the only known
895 		 * case of nesting in the current code, so exactly one
896 		 * additional command buffer is available for that purpose.
897 		 */
898 		if (!sev->cmd_buf_active) {
899 			cmd_buf = sev->cmd_buf;
900 			sev->cmd_buf_active = true;
901 		} else if (!sev->cmd_buf_backup_active) {
902 			cmd_buf = sev->cmd_buf_backup;
903 			sev->cmd_buf_backup_active = true;
904 		} else {
905 			dev_err(sev->dev,
906 				"SEV: too many firmware commands in progress, no command buffers available.\n");
907 			return -EBUSY;
908 		}
909 
910 		memcpy(cmd_buf, data, buf_len);
911 
912 		/*
913 		 * The behavior of the SEV-legacy commands is altered when the
914 		 * SNP firmware is in the INIT state.
915 		 */
916 		ret = snp_prep_cmd_buf(cmd, cmd_buf, desc_list);
917 		if (ret) {
918 			dev_err(sev->dev,
919 				"SEV: failed to prepare buffer for legacy command 0x%x. Error: %d\n",
920 				cmd, ret);
921 			return ret;
922 		}
923 	} else {
924 		cmd_buf = sev->cmd_buf;
925 	}
926 
927 	/* Get the physical address of the command buffer */
928 	phys_lsb = data ? lower_32_bits(__psp_pa(cmd_buf)) : 0;
929 	phys_msb = data ? upper_32_bits(__psp_pa(cmd_buf)) : 0;
930 
931 	dev_dbg(sev->dev, "sev command id %#x buffer 0x%08x%08x timeout %us\n",
932 		cmd, phys_msb, phys_lsb, psp_timeout);
933 
934 	print_hex_dump_debug("(in):  ", DUMP_PREFIX_OFFSET, 16, 2, data,
935 			     buf_len, false);
936 
937 	iowrite32(phys_lsb, sev->io_regs + sev->vdata->cmdbuff_addr_lo_reg);
938 	iowrite32(phys_msb, sev->io_regs + sev->vdata->cmdbuff_addr_hi_reg);
939 
940 	sev->int_rcvd = 0;
941 
942 	reg = FIELD_PREP(SEV_CMDRESP_CMD, cmd);
943 
944 	/*
945 	 * If invoked during panic handling, local interrupts are disabled so
946 	 * the PSP command completion interrupt can't be used.
947 	 * sev_wait_cmd_ioc() already checks for interrupts disabled and
948 	 * polls for PSP command completion.  Ensure we do not request an
949 	 * interrupt from the PSP if irqs disabled.
950 	 */
951 	if (!irqs_disabled())
952 		reg |= SEV_CMDRESP_IOC;
953 
954 	iowrite32(reg, sev->io_regs + sev->vdata->cmdresp_reg);
955 
956 	/* wait for command completion */
957 	ret = sev_wait_cmd_ioc(sev, &reg, psp_timeout);
958 	if (ret) {
959 		if (psp_ret)
960 			*psp_ret = 0;
961 
962 		dev_err(sev->dev, "sev command %#x timed out, disabling PSP\n", cmd);
963 		psp_dead = true;
964 
965 		return ret;
966 	}
967 
968 	psp_timeout = psp_cmd_timeout;
969 
970 	if (psp_ret)
971 		*psp_ret = FIELD_GET(PSP_CMDRESP_STS, reg);
972 
973 	if (FIELD_GET(PSP_CMDRESP_STS, reg)) {
974 		dev_dbg(sev->dev, "sev command %#x failed (%#010lx)\n",
975 			cmd, FIELD_GET(PSP_CMDRESP_STS, reg));
976 
977 		/*
978 		 * PSP firmware may report additional error information in the
979 		 * command buffer registers on error. Print contents of command
980 		 * buffer registers if they changed.
981 		 */
982 		cmdbuff_hi = ioread32(sev->io_regs + sev->vdata->cmdbuff_addr_hi_reg);
983 		cmdbuff_lo = ioread32(sev->io_regs + sev->vdata->cmdbuff_addr_lo_reg);
984 		if (cmdbuff_hi != phys_msb || cmdbuff_lo != phys_lsb) {
985 			dev_dbg(sev->dev, "Additional error information reported in cmdbuff:");
986 			dev_dbg(sev->dev, "  cmdbuff hi: %#010x\n", cmdbuff_hi);
987 			dev_dbg(sev->dev, "  cmdbuff lo: %#010x\n", cmdbuff_lo);
988 		}
989 		ret = -EIO;
990 	} else {
991 		ret = sev_write_init_ex_file_if_required(cmd);
992 	}
993 
994 	/*
995 	 * Copy potential output from the PSP back to data.  Do this even on
996 	 * failure in case the caller wants to glean something from the error.
997 	 */
998 	if (data) {
999 		int ret_reclaim;
1000 		/*
1001 		 * Restore the page state after the command completes.
1002 		 */
1003 		ret_reclaim = snp_reclaim_cmd_buf(cmd, cmd_buf);
1004 		if (ret_reclaim) {
1005 			dev_err(sev->dev,
1006 				"SEV: failed to reclaim buffer for legacy command %#x. Error: %d\n",
1007 				cmd, ret_reclaim);
1008 			return ret_reclaim;
1009 		}
1010 
1011 		memcpy(data, cmd_buf, buf_len);
1012 
1013 		if (sev->cmd_buf_backup_active)
1014 			sev->cmd_buf_backup_active = false;
1015 		else
1016 			sev->cmd_buf_active = false;
1017 
1018 		if (snp_unmap_cmd_buf_desc_list(desc_list))
1019 			return -EFAULT;
1020 	}
1021 
1022 	print_hex_dump_debug("(out): ", DUMP_PREFIX_OFFSET, 16, 2, data,
1023 			     buf_len, false);
1024 
1025 	return ret;
1026 }
1027 
sev_do_cmd(int cmd,void * data,int * psp_ret)1028 int sev_do_cmd(int cmd, void *data, int *psp_ret)
1029 {
1030 	int rc;
1031 
1032 	mutex_lock(&sev_cmd_mutex);
1033 	rc = __sev_do_cmd_locked(cmd, data, psp_ret);
1034 	mutex_unlock(&sev_cmd_mutex);
1035 
1036 	return rc;
1037 }
1038 EXPORT_SYMBOL_GPL(sev_do_cmd);
1039 
__sev_init_locked(int * error)1040 static int __sev_init_locked(int *error)
1041 {
1042 	struct sev_data_init data;
1043 
1044 	memset(&data, 0, sizeof(data));
1045 	if (sev_es_tmr) {
1046 		/*
1047 		 * Do not include the encryption mask on the physical
1048 		 * address of the TMR (firmware should clear it anyway).
1049 		 */
1050 		data.tmr_address = __pa(sev_es_tmr);
1051 
1052 		data.flags |= SEV_INIT_FLAGS_SEV_ES;
1053 		data.tmr_len = sev_es_tmr_size;
1054 	}
1055 
1056 	return __sev_do_cmd_locked(SEV_CMD_INIT, &data, error);
1057 }
1058 
__sev_init_ex_locked(int * error)1059 static int __sev_init_ex_locked(int *error)
1060 {
1061 	struct sev_data_init_ex data;
1062 
1063 	memset(&data, 0, sizeof(data));
1064 	data.length = sizeof(data);
1065 	data.nv_address = __psp_pa(sev_init_ex_buffer);
1066 	data.nv_len = NV_LENGTH;
1067 
1068 	if (sev_es_tmr) {
1069 		/*
1070 		 * Do not include the encryption mask on the physical
1071 		 * address of the TMR (firmware should clear it anyway).
1072 		 */
1073 		data.tmr_address = __pa(sev_es_tmr);
1074 
1075 		data.flags |= SEV_INIT_FLAGS_SEV_ES;
1076 		data.tmr_len = sev_es_tmr_size;
1077 	}
1078 
1079 	return __sev_do_cmd_locked(SEV_CMD_INIT_EX, &data, error);
1080 }
1081 
__sev_do_init_locked(int * psp_ret)1082 static inline int __sev_do_init_locked(int *psp_ret)
1083 {
1084 	if (sev_init_ex_buffer)
1085 		return __sev_init_ex_locked(psp_ret);
1086 	else
1087 		return __sev_init_locked(psp_ret);
1088 }
1089 
snp_set_hsave_pa(void * arg)1090 static void snp_set_hsave_pa(void *arg)
1091 {
1092 	wrmsrq(MSR_VM_HSAVE_PA, 0);
1093 }
1094 
1095 /* Hypervisor Fixed pages API interface */
snp_hv_fixed_pages_state_update(struct sev_device * sev,enum snp_hv_fixed_pages_state page_state)1096 static void snp_hv_fixed_pages_state_update(struct sev_device *sev,
1097 					    enum snp_hv_fixed_pages_state page_state)
1098 {
1099 	struct snp_hv_fixed_pages_entry *entry;
1100 
1101 	/* List is protected by sev_cmd_mutex */
1102 	lockdep_assert_held(&sev_cmd_mutex);
1103 
1104 	if (list_empty(&snp_hv_fixed_pages))
1105 		return;
1106 
1107 	list_for_each_entry(entry, &snp_hv_fixed_pages, list)
1108 		entry->page_state = page_state;
1109 }
1110 
1111 /*
1112  * Allocate HV_FIXED pages in 2MB aligned sizes to ensure the whole
1113  * 2MB pages are marked as HV_FIXED.
1114  */
snp_alloc_hv_fixed_pages(unsigned int num_2mb_pages)1115 struct page *snp_alloc_hv_fixed_pages(unsigned int num_2mb_pages)
1116 {
1117 	struct psp_device *psp_master = psp_get_master_device();
1118 	struct snp_hv_fixed_pages_entry *entry;
1119 	struct sev_device *sev;
1120 	unsigned int order;
1121 	struct page *page;
1122 
1123 	if (!psp_master || !psp_master->sev_data)
1124 		return NULL;
1125 
1126 	sev = psp_master->sev_data;
1127 
1128 	order = get_order(PMD_SIZE * num_2mb_pages);
1129 
1130 	/*
1131 	 * SNP_INIT_EX is protected by sev_cmd_mutex, therefore this list
1132 	 * also needs to be protected using the same mutex.
1133 	 */
1134 	guard(mutex)(&sev_cmd_mutex);
1135 
1136 	/*
1137 	 * This API uses SNP_INIT_EX to transition allocated pages to HV_Fixed
1138 	 * page state, fail if SNP is already initialized.
1139 	 */
1140 	if (sev->snp_initialized)
1141 		return NULL;
1142 
1143 	/* Re-use freed pages that match the request */
1144 	list_for_each_entry(entry, &snp_hv_fixed_pages, list) {
1145 		/* Hypervisor fixed page allocator implements exact fit policy */
1146 		if (entry->order == order && entry->free) {
1147 			entry->free = false;
1148 			memset(page_address(entry->page), 0,
1149 			       (1 << entry->order) * PAGE_SIZE);
1150 			return entry->page;
1151 		}
1152 	}
1153 
1154 	page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
1155 	if (!page)
1156 		return NULL;
1157 
1158 	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
1159 	if (!entry) {
1160 		__free_pages(page, order);
1161 		return NULL;
1162 	}
1163 
1164 	entry->page = page;
1165 	entry->order = order;
1166 	list_add_tail(&entry->list, &snp_hv_fixed_pages);
1167 
1168 	return page;
1169 }
1170 
snp_free_hv_fixed_pages(struct page * page)1171 void snp_free_hv_fixed_pages(struct page *page)
1172 {
1173 	struct psp_device *psp_master = psp_get_master_device();
1174 	struct snp_hv_fixed_pages_entry *entry, *nentry;
1175 
1176 	if (!psp_master || !psp_master->sev_data)
1177 		return;
1178 
1179 	/*
1180 	 * SNP_INIT_EX is protected by sev_cmd_mutex, therefore this list
1181 	 * also needs to be protected using the same mutex.
1182 	 */
1183 	guard(mutex)(&sev_cmd_mutex);
1184 
1185 	list_for_each_entry_safe(entry, nentry, &snp_hv_fixed_pages, list) {
1186 		if (entry->page != page)
1187 			continue;
1188 
1189 		/*
1190 		 * HV_FIXED page state cannot be changed until reboot
1191 		 * and they cannot be used by an SNP guest, so they cannot
1192 		 * be returned back to the page allocator.
1193 		 * Mark the pages as free internally to allow possible re-use.
1194 		 */
1195 		if (entry->page_state == HV_FIXED) {
1196 			entry->free = true;
1197 		} else {
1198 			__free_pages(page, entry->order);
1199 			list_del(&entry->list);
1200 			kfree(entry);
1201 		}
1202 		return;
1203 	}
1204 }
1205 
snp_add_hv_fixed_pages(struct sev_device * sev,struct sev_data_range_list * range_list)1206 static void snp_add_hv_fixed_pages(struct sev_device *sev, struct sev_data_range_list *range_list)
1207 {
1208 	struct snp_hv_fixed_pages_entry *entry;
1209 	struct sev_data_range *range;
1210 	int num_elements;
1211 
1212 	lockdep_assert_held(&sev_cmd_mutex);
1213 
1214 	if (list_empty(&snp_hv_fixed_pages))
1215 		return;
1216 
1217 	num_elements = list_count_nodes(&snp_hv_fixed_pages) +
1218 		       range_list->num_elements;
1219 
1220 	/*
1221 	 * Ensure the list of HV_FIXED pages that will be passed to firmware
1222 	 * do not exceed the page-sized argument buffer.
1223 	 */
1224 	if (num_elements * sizeof(*range) + sizeof(*range_list) > PAGE_SIZE) {
1225 		dev_warn(sev->dev, "Additional HV_Fixed pages cannot be accommodated, omitting\n");
1226 		return;
1227 	}
1228 
1229 	range = &range_list->ranges[range_list->num_elements];
1230 	list_for_each_entry(entry, &snp_hv_fixed_pages, list) {
1231 		range->base = page_to_pfn(entry->page) << PAGE_SHIFT;
1232 		range->page_count = 1 << entry->order;
1233 		range++;
1234 	}
1235 	range_list->num_elements = num_elements;
1236 }
1237 
snp_leak_hv_fixed_pages(void)1238 static void snp_leak_hv_fixed_pages(void)
1239 {
1240 	struct snp_hv_fixed_pages_entry *entry;
1241 
1242 	/* List is protected by sev_cmd_mutex */
1243 	lockdep_assert_held(&sev_cmd_mutex);
1244 
1245 	if (list_empty(&snp_hv_fixed_pages))
1246 		return;
1247 
1248 	list_for_each_entry(entry, &snp_hv_fixed_pages, list)
1249 		if (entry->page_state == HV_FIXED)
1250 			__snp_leak_pages(page_to_pfn(entry->page),
1251 					 1 << entry->order, false);
1252 }
1253 
sev_is_snp_ciphertext_hiding_supported(void)1254 bool sev_is_snp_ciphertext_hiding_supported(void)
1255 {
1256 	struct psp_device *psp = psp_master;
1257 	struct sev_device *sev;
1258 
1259 	if (!psp || !psp->sev_data)
1260 		return false;
1261 
1262 	sev = psp->sev_data;
1263 
1264 	/*
1265 	 * Feature information indicates if CipherTextHiding feature is
1266 	 * supported by the SEV firmware and additionally platform status
1267 	 * indicates if CipherTextHiding feature is enabled in the
1268 	 * Platform BIOS.
1269 	 */
1270 	return ((sev->snp_feat_info_0.ecx & SNP_CIPHER_TEXT_HIDING_SUPPORTED) &&
1271 		 sev->snp_plat_status.ciphertext_hiding_cap);
1272 }
1273 EXPORT_SYMBOL_GPL(sev_is_snp_ciphertext_hiding_supported);
1274 
snp_get_platform_data(struct sev_device * sev,int * error)1275 static int snp_get_platform_data(struct sev_device *sev, int *error)
1276 {
1277 	struct sev_data_snp_feature_info snp_feat_info;
1278 	struct snp_feature_info *feat_info;
1279 	struct sev_data_snp_addr buf;
1280 	struct page *page;
1281 	int rc;
1282 
1283 	/*
1284 	 * This function is expected to be called before SNP is
1285 	 * initialized.
1286 	 */
1287 	if (sev->snp_initialized)
1288 		return -EINVAL;
1289 
1290 	buf.address = __psp_pa(&sev->snp_plat_status);
1291 	rc = sev_do_cmd(SEV_CMD_SNP_PLATFORM_STATUS, &buf, error);
1292 	if (rc) {
1293 		dev_err(sev->dev, "SNP PLATFORM_STATUS command failed, ret = %d, error = %#x\n",
1294 			rc, *error);
1295 		return rc;
1296 	}
1297 
1298 	sev->api_major = sev->snp_plat_status.api_major;
1299 	sev->api_minor = sev->snp_plat_status.api_minor;
1300 	sev->build = sev->snp_plat_status.build_id;
1301 
1302 	/*
1303 	 * Do feature discovery of the currently loaded firmware,
1304 	 * and cache feature information from CPUID 0x8000_0024,
1305 	 * sub-function 0.
1306 	 */
1307 	if (!sev->snp_plat_status.feature_info)
1308 		return 0;
1309 
1310 	/*
1311 	 * Use dynamically allocated structure for the SNP_FEATURE_INFO
1312 	 * command to ensure structure is 8-byte aligned, and does not
1313 	 * cross a page boundary.
1314 	 */
1315 	page = alloc_page(GFP_KERNEL);
1316 	if (!page)
1317 		return -ENOMEM;
1318 
1319 	feat_info = page_address(page);
1320 	snp_feat_info.length = sizeof(snp_feat_info);
1321 	snp_feat_info.ecx_in = 0;
1322 	snp_feat_info.feature_info_paddr = __psp_pa(feat_info);
1323 
1324 	rc = sev_do_cmd(SEV_CMD_SNP_FEATURE_INFO, &snp_feat_info, error);
1325 	if (!rc)
1326 		sev->snp_feat_info_0 = *feat_info;
1327 	else
1328 		dev_err(sev->dev, "SNP FEATURE_INFO command failed, ret = %d, error = %#x\n",
1329 			rc, *error);
1330 
1331 	__free_page(page);
1332 
1333 	return rc;
1334 }
1335 
snp_filter_reserved_mem_regions(struct resource * rs,void * arg)1336 static int snp_filter_reserved_mem_regions(struct resource *rs, void *arg)
1337 {
1338 	struct sev_data_range_list *range_list = arg;
1339 	struct sev_data_range *range = &range_list->ranges[range_list->num_elements];
1340 	size_t size;
1341 
1342 	/*
1343 	 * Ensure the list of HV_FIXED pages that will be passed to firmware
1344 	 * do not exceed the page-sized argument buffer.
1345 	 */
1346 	if ((range_list->num_elements * sizeof(struct sev_data_range) +
1347 	     sizeof(struct sev_data_range_list)) > PAGE_SIZE)
1348 		return -E2BIG;
1349 
1350 	switch (rs->desc) {
1351 	case E820_TYPE_RESERVED:
1352 	case E820_TYPE_PMEM:
1353 	case E820_TYPE_ACPI:
1354 		range->base = rs->start & PAGE_MASK;
1355 		size = PAGE_ALIGN((rs->end + 1) - rs->start);
1356 		range->page_count = size >> PAGE_SHIFT;
1357 		range_list->num_elements++;
1358 		break;
1359 	default:
1360 		break;
1361 	}
1362 
1363 	return 0;
1364 }
1365 
__sev_snp_init_locked(int * error,unsigned int max_snp_asid)1366 static int __sev_snp_init_locked(int *error, unsigned int max_snp_asid)
1367 {
1368 	struct psp_device *psp = psp_master;
1369 	struct sev_data_snp_init_ex data;
1370 	struct sev_device *sev;
1371 	void *arg = &data;
1372 	int cmd, rc = 0;
1373 
1374 	if (!cc_platform_has(CC_ATTR_HOST_SEV_SNP))
1375 		return -ENODEV;
1376 
1377 	sev = psp->sev_data;
1378 
1379 	if (sev->snp_initialized)
1380 		return 0;
1381 
1382 	if (!sev_version_greater_or_equal(SNP_MIN_API_MAJOR, SNP_MIN_API_MINOR)) {
1383 		dev_dbg(sev->dev, "SEV-SNP support requires firmware version >= %d:%d\n",
1384 			SNP_MIN_API_MAJOR, SNP_MIN_API_MINOR);
1385 		return -EOPNOTSUPP;
1386 	}
1387 
1388 	/* SNP_INIT requires MSR_VM_HSAVE_PA to be cleared on all CPUs. */
1389 	on_each_cpu(snp_set_hsave_pa, NULL, 1);
1390 
1391 	/*
1392 	 * Starting in SNP firmware v1.52, the SNP_INIT_EX command takes a list
1393 	 * of system physical address ranges to convert into HV-fixed page
1394 	 * states during the RMP initialization.  For instance, the memory that
1395 	 * UEFI reserves should be included in the that list. This allows system
1396 	 * components that occasionally write to memory (e.g. logging to UEFI
1397 	 * reserved regions) to not fail due to RMP initialization and SNP
1398 	 * enablement.
1399 	 *
1400 	 */
1401 	if (sev_version_greater_or_equal(SNP_MIN_API_MAJOR, 52)) {
1402 		/*
1403 		 * Firmware checks that the pages containing the ranges enumerated
1404 		 * in the RANGES structure are either in the default page state or in the
1405 		 * firmware page state.
1406 		 */
1407 		snp_range_list = kzalloc(PAGE_SIZE, GFP_KERNEL);
1408 		if (!snp_range_list) {
1409 			dev_err(sev->dev,
1410 				"SEV: SNP_INIT_EX range list memory allocation failed\n");
1411 			return -ENOMEM;
1412 		}
1413 
1414 		/*
1415 		 * Retrieve all reserved memory regions from the e820 memory map
1416 		 * to be setup as HV-fixed pages.
1417 		 */
1418 		rc = walk_iomem_res_desc(IORES_DESC_NONE, IORESOURCE_MEM, 0, ~0,
1419 					 snp_range_list, snp_filter_reserved_mem_regions);
1420 		if (rc) {
1421 			dev_err(sev->dev,
1422 				"SEV: SNP_INIT_EX walk_iomem_res_desc failed rc = %d\n", rc);
1423 			return rc;
1424 		}
1425 
1426 		/*
1427 		 * Add HV_Fixed pages from other PSP sub-devices, such as SFS to the
1428 		 * HV_Fixed page list.
1429 		 */
1430 		snp_add_hv_fixed_pages(sev, snp_range_list);
1431 
1432 		memset(&data, 0, sizeof(data));
1433 
1434 		if (max_snp_asid) {
1435 			data.ciphertext_hiding_en = 1;
1436 			data.max_snp_asid = max_snp_asid;
1437 		}
1438 
1439 		data.init_rmp = 1;
1440 		data.list_paddr_en = 1;
1441 		data.list_paddr = __psp_pa(snp_range_list);
1442 		cmd = SEV_CMD_SNP_INIT_EX;
1443 	} else {
1444 		cmd = SEV_CMD_SNP_INIT;
1445 		arg = NULL;
1446 	}
1447 
1448 	/*
1449 	 * The following sequence must be issued before launching the first SNP
1450 	 * guest to ensure all dirty cache lines are flushed, including from
1451 	 * updates to the RMP table itself via the RMPUPDATE instruction:
1452 	 *
1453 	 * - WBINVD on all running CPUs
1454 	 * - SEV_CMD_SNP_INIT[_EX] firmware command
1455 	 * - WBINVD on all running CPUs
1456 	 * - SEV_CMD_SNP_DF_FLUSH firmware command
1457 	 */
1458 	wbinvd_on_all_cpus();
1459 
1460 	rc = __sev_do_cmd_locked(cmd, arg, error);
1461 	if (rc) {
1462 		dev_err(sev->dev, "SEV-SNP: %s failed rc %d, error %#x\n",
1463 			cmd == SEV_CMD_SNP_INIT_EX ? "SNP_INIT_EX" : "SNP_INIT",
1464 			rc, *error);
1465 		return rc;
1466 	}
1467 
1468 	/* Prepare for first SNP guest launch after INIT. */
1469 	wbinvd_on_all_cpus();
1470 	rc = __sev_do_cmd_locked(SEV_CMD_SNP_DF_FLUSH, NULL, error);
1471 	if (rc) {
1472 		dev_err(sev->dev, "SEV-SNP: SNP_DF_FLUSH failed rc %d, error %#x\n",
1473 			rc, *error);
1474 		return rc;
1475 	}
1476 
1477 	snp_hv_fixed_pages_state_update(sev, HV_FIXED);
1478 	sev->snp_initialized = true;
1479 	dev_dbg(sev->dev, "SEV-SNP firmware initialized\n");
1480 
1481 	dev_info(sev->dev, "SEV-SNP API:%d.%d build:%d\n", sev->api_major,
1482 		 sev->api_minor, sev->build);
1483 
1484 	atomic_notifier_chain_register(&panic_notifier_list,
1485 				       &snp_panic_notifier);
1486 
1487 	sev_es_tmr_size = SNP_TMR_SIZE;
1488 
1489 	return 0;
1490 }
1491 
__sev_platform_init_handle_tmr(struct sev_device * sev)1492 static void __sev_platform_init_handle_tmr(struct sev_device *sev)
1493 {
1494 	if (sev_es_tmr)
1495 		return;
1496 
1497 	/* Obtain the TMR memory area for SEV-ES use */
1498 	sev_es_tmr = sev_fw_alloc(sev_es_tmr_size);
1499 	if (sev_es_tmr) {
1500 		/* Must flush the cache before giving it to the firmware */
1501 		if (!sev->snp_initialized)
1502 			clflush_cache_range(sev_es_tmr, sev_es_tmr_size);
1503 	} else {
1504 			dev_warn(sev->dev, "SEV: TMR allocation failed, SEV-ES support unavailable\n");
1505 	}
1506 }
1507 
1508 /*
1509  * If an init_ex_path is provided allocate a buffer for the file and
1510  * read in the contents. Additionally, if SNP is initialized, convert
1511  * the buffer pages to firmware pages.
1512  */
__sev_platform_init_handle_init_ex_path(struct sev_device * sev)1513 static int __sev_platform_init_handle_init_ex_path(struct sev_device *sev)
1514 {
1515 	struct page *page;
1516 	int rc;
1517 
1518 	if (!init_ex_path)
1519 		return 0;
1520 
1521 	if (sev_init_ex_buffer)
1522 		return 0;
1523 
1524 	page = alloc_pages(GFP_KERNEL, get_order(NV_LENGTH));
1525 	if (!page) {
1526 		dev_err(sev->dev, "SEV: INIT_EX NV memory allocation failed\n");
1527 		return -ENOMEM;
1528 	}
1529 
1530 	sev_init_ex_buffer = page_address(page);
1531 
1532 	rc = sev_read_init_ex_file();
1533 	if (rc)
1534 		return rc;
1535 
1536 	/* If SEV-SNP is initialized, transition to firmware page. */
1537 	if (sev->snp_initialized) {
1538 		unsigned long npages;
1539 
1540 		npages = 1UL << get_order(NV_LENGTH);
1541 		if (rmp_mark_pages_firmware(__pa(sev_init_ex_buffer), npages, false)) {
1542 			dev_err(sev->dev, "SEV: INIT_EX NV memory page state change failed.\n");
1543 			return -ENOMEM;
1544 		}
1545 	}
1546 
1547 	return 0;
1548 }
1549 
__sev_platform_init_locked(int * error)1550 static int __sev_platform_init_locked(int *error)
1551 {
1552 	int rc, psp_ret, dfflush_error;
1553 	struct sev_device *sev;
1554 
1555 	psp_ret = dfflush_error = SEV_RET_NO_FW_CALL;
1556 
1557 	if (!psp_master || !psp_master->sev_data)
1558 		return -ENODEV;
1559 
1560 	sev = psp_master->sev_data;
1561 
1562 	if (sev->sev_plat_status.state == SEV_STATE_INIT)
1563 		return 0;
1564 
1565 	__sev_platform_init_handle_tmr(sev);
1566 
1567 	rc = __sev_platform_init_handle_init_ex_path(sev);
1568 	if (rc)
1569 		return rc;
1570 
1571 	rc = __sev_do_init_locked(&psp_ret);
1572 	if (rc && psp_ret == SEV_RET_SECURE_DATA_INVALID) {
1573 		/*
1574 		 * Initialization command returned an integrity check failure
1575 		 * status code, meaning that firmware load and validation of SEV
1576 		 * related persistent data has failed. Retrying the
1577 		 * initialization function should succeed by replacing the state
1578 		 * with a reset state.
1579 		 */
1580 		dev_err(sev->dev,
1581 "SEV: retrying INIT command because of SECURE_DATA_INVALID error. Retrying once to reset PSP SEV state.");
1582 		rc = __sev_do_init_locked(&psp_ret);
1583 	}
1584 
1585 	if (error)
1586 		*error = psp_ret;
1587 
1588 	if (rc) {
1589 		dev_err(sev->dev, "SEV: %s failed %#x, rc %d\n",
1590 			sev_init_ex_buffer ? "INIT_EX" : "INIT", psp_ret, rc);
1591 		return rc;
1592 	}
1593 
1594 	sev->sev_plat_status.state = SEV_STATE_INIT;
1595 
1596 	/* Prepare for first SEV guest launch after INIT */
1597 	wbinvd_on_all_cpus();
1598 	rc = __sev_do_cmd_locked(SEV_CMD_DF_FLUSH, NULL, &dfflush_error);
1599 	if (rc) {
1600 		dev_err(sev->dev, "SEV: DF_FLUSH failed %#x, rc %d\n",
1601 			dfflush_error, rc);
1602 		return rc;
1603 	}
1604 
1605 	dev_dbg(sev->dev, "SEV firmware initialized\n");
1606 
1607 	dev_info(sev->dev, "SEV API:%d.%d build:%d\n", sev->api_major,
1608 		 sev->api_minor, sev->build);
1609 
1610 	return 0;
1611 }
1612 
_sev_platform_init_locked(struct sev_platform_init_args * args)1613 static int _sev_platform_init_locked(struct sev_platform_init_args *args)
1614 {
1615 	struct sev_device *sev;
1616 	int rc;
1617 
1618 	if (!psp_master || !psp_master->sev_data)
1619 		return -ENODEV;
1620 
1621 	/*
1622 	 * Skip SNP/SEV initialization under a kdump kernel as SEV/SNP
1623 	 * may already be initialized in the previous kernel. Since no
1624 	 * SNP/SEV guests are run under a kdump kernel, there is no
1625 	 * need to initialize SNP or SEV during kdump boot.
1626 	 */
1627 	if (is_kdump_kernel())
1628 		return 0;
1629 
1630 	sev = psp_master->sev_data;
1631 
1632 	if (sev->sev_plat_status.state == SEV_STATE_INIT)
1633 		return 0;
1634 
1635 	rc = __sev_snp_init_locked(&args->error, args->max_snp_asid);
1636 	if (rc && rc != -ENODEV)
1637 		return rc;
1638 
1639 	/* Defer legacy SEV/SEV-ES support if allowed by caller/module. */
1640 	if (args->probe && !psp_init_on_probe)
1641 		return 0;
1642 
1643 	return __sev_platform_init_locked(&args->error);
1644 }
1645 
sev_platform_init(struct sev_platform_init_args * args)1646 int sev_platform_init(struct sev_platform_init_args *args)
1647 {
1648 	int rc;
1649 
1650 	mutex_lock(&sev_cmd_mutex);
1651 	rc = _sev_platform_init_locked(args);
1652 	mutex_unlock(&sev_cmd_mutex);
1653 
1654 	return rc;
1655 }
1656 EXPORT_SYMBOL_GPL(sev_platform_init);
1657 
__sev_platform_shutdown_locked(int * error)1658 static int __sev_platform_shutdown_locked(int *error)
1659 {
1660 	struct psp_device *psp = psp_master;
1661 	struct sev_device *sev;
1662 	int ret;
1663 
1664 	if (!psp || !psp->sev_data)
1665 		return 0;
1666 
1667 	sev = psp->sev_data;
1668 
1669 	if (sev->sev_plat_status.state == SEV_STATE_UNINIT)
1670 		return 0;
1671 
1672 	ret = __sev_do_cmd_locked(SEV_CMD_SHUTDOWN, NULL, error);
1673 	if (ret) {
1674 		dev_err(sev->dev, "SEV: failed to SHUTDOWN error %#x, rc %d\n",
1675 			*error, ret);
1676 		return ret;
1677 	}
1678 
1679 	sev->sev_plat_status.state = SEV_STATE_UNINIT;
1680 	dev_dbg(sev->dev, "SEV firmware shutdown\n");
1681 
1682 	return ret;
1683 }
1684 
sev_get_platform_state(int * state,int * error)1685 static int sev_get_platform_state(int *state, int *error)
1686 {
1687 	struct sev_user_data_status data;
1688 	int rc;
1689 
1690 	rc = __sev_do_cmd_locked(SEV_CMD_PLATFORM_STATUS, &data, error);
1691 	if (rc)
1692 		return rc;
1693 
1694 	*state = data.state;
1695 	return rc;
1696 }
1697 
sev_move_to_init_state(struct sev_issue_cmd * argp,bool * shutdown_required)1698 static int sev_move_to_init_state(struct sev_issue_cmd *argp, bool *shutdown_required)
1699 {
1700 	struct sev_platform_init_args init_args = {0};
1701 	int rc;
1702 
1703 	rc = _sev_platform_init_locked(&init_args);
1704 	if (rc) {
1705 		argp->error = SEV_RET_INVALID_PLATFORM_STATE;
1706 		return rc;
1707 	}
1708 
1709 	*shutdown_required = true;
1710 
1711 	return 0;
1712 }
1713 
snp_move_to_init_state(struct sev_issue_cmd * argp,bool * shutdown_required)1714 static int snp_move_to_init_state(struct sev_issue_cmd *argp, bool *shutdown_required)
1715 {
1716 	int error, rc;
1717 
1718 	rc = __sev_snp_init_locked(&error, 0);
1719 	if (rc) {
1720 		argp->error = SEV_RET_INVALID_PLATFORM_STATE;
1721 		return rc;
1722 	}
1723 
1724 	*shutdown_required = true;
1725 
1726 	return 0;
1727 }
1728 
sev_ioctl_do_reset(struct sev_issue_cmd * argp,bool writable)1729 static int sev_ioctl_do_reset(struct sev_issue_cmd *argp, bool writable)
1730 {
1731 	int state, rc;
1732 
1733 	if (!writable)
1734 		return -EPERM;
1735 
1736 	/*
1737 	 * The SEV spec requires that FACTORY_RESET must be issued in
1738 	 * UNINIT state. Before we go further lets check if any guest is
1739 	 * active.
1740 	 *
1741 	 * If FW is in WORKING state then deny the request otherwise issue
1742 	 * SHUTDOWN command do INIT -> UNINIT before issuing the FACTORY_RESET.
1743 	 *
1744 	 */
1745 	rc = sev_get_platform_state(&state, &argp->error);
1746 	if (rc)
1747 		return rc;
1748 
1749 	if (state == SEV_STATE_WORKING)
1750 		return -EBUSY;
1751 
1752 	if (state == SEV_STATE_INIT) {
1753 		rc = __sev_platform_shutdown_locked(&argp->error);
1754 		if (rc)
1755 			return rc;
1756 	}
1757 
1758 	return __sev_do_cmd_locked(SEV_CMD_FACTORY_RESET, NULL, &argp->error);
1759 }
1760 
sev_ioctl_do_platform_status(struct sev_issue_cmd * argp)1761 static int sev_ioctl_do_platform_status(struct sev_issue_cmd *argp)
1762 {
1763 	struct sev_user_data_status data;
1764 	int ret;
1765 
1766 	memset(&data, 0, sizeof(data));
1767 
1768 	ret = __sev_do_cmd_locked(SEV_CMD_PLATFORM_STATUS, &data, &argp->error);
1769 	if (ret)
1770 		return ret;
1771 
1772 	if (copy_to_user((void __user *)argp->data, &data, sizeof(data)))
1773 		ret = -EFAULT;
1774 
1775 	return ret;
1776 }
1777 
sev_ioctl_do_pek_pdh_gen(int cmd,struct sev_issue_cmd * argp,bool writable)1778 static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool writable)
1779 {
1780 	struct sev_device *sev = psp_master->sev_data;
1781 	bool shutdown_required = false;
1782 	int rc;
1783 
1784 	if (!writable)
1785 		return -EPERM;
1786 
1787 	if (sev->sev_plat_status.state == SEV_STATE_UNINIT) {
1788 		rc = sev_move_to_init_state(argp, &shutdown_required);
1789 		if (rc)
1790 			return rc;
1791 	}
1792 
1793 	rc = __sev_do_cmd_locked(cmd, NULL, &argp->error);
1794 
1795 	if (shutdown_required)
1796 		__sev_firmware_shutdown(sev, false);
1797 
1798 	return rc;
1799 }
1800 
sev_ioctl_do_pek_csr(struct sev_issue_cmd * argp,bool writable)1801 static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
1802 {
1803 	struct sev_device *sev = psp_master->sev_data;
1804 	struct sev_user_data_pek_csr input;
1805 	bool shutdown_required = false;
1806 	struct sev_data_pek_csr data;
1807 	void __user *input_address;
1808 	void *blob = NULL;
1809 	int ret;
1810 
1811 	if (!writable)
1812 		return -EPERM;
1813 
1814 	if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
1815 		return -EFAULT;
1816 
1817 	memset(&data, 0, sizeof(data));
1818 
1819 	/* userspace wants to query CSR length */
1820 	if (!input.address || !input.length)
1821 		goto cmd;
1822 
1823 	/* allocate a physically contiguous buffer to store the CSR blob */
1824 	input_address = (void __user *)input.address;
1825 	if (input.length > SEV_FW_BLOB_MAX_SIZE)
1826 		return -EFAULT;
1827 
1828 	blob = kzalloc(input.length, GFP_KERNEL);
1829 	if (!blob)
1830 		return -ENOMEM;
1831 
1832 	data.address = __psp_pa(blob);
1833 	data.len = input.length;
1834 
1835 cmd:
1836 	if (sev->sev_plat_status.state == SEV_STATE_UNINIT) {
1837 		ret = sev_move_to_init_state(argp, &shutdown_required);
1838 		if (ret)
1839 			goto e_free_blob;
1840 	}
1841 
1842 	ret = __sev_do_cmd_locked(SEV_CMD_PEK_CSR, &data, &argp->error);
1843 
1844 	 /* If we query the CSR length, FW responded with expected data. */
1845 	input.length = data.len;
1846 
1847 	if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) {
1848 		ret = -EFAULT;
1849 		goto e_free_blob;
1850 	}
1851 
1852 	if (blob) {
1853 		if (copy_to_user(input_address, blob, input.length))
1854 			ret = -EFAULT;
1855 	}
1856 
1857 e_free_blob:
1858 	if (shutdown_required)
1859 		__sev_firmware_shutdown(sev, false);
1860 
1861 	kfree(blob);
1862 	return ret;
1863 }
1864 
psp_copy_user_blob(u64 uaddr,u32 len)1865 void *psp_copy_user_blob(u64 uaddr, u32 len)
1866 {
1867 	if (!uaddr || !len)
1868 		return ERR_PTR(-EINVAL);
1869 
1870 	/* verify that blob length does not exceed our limit */
1871 	if (len > SEV_FW_BLOB_MAX_SIZE)
1872 		return ERR_PTR(-EINVAL);
1873 
1874 	return memdup_user((void __user *)uaddr, len);
1875 }
1876 EXPORT_SYMBOL_GPL(psp_copy_user_blob);
1877 
sev_get_api_version(void)1878 static int sev_get_api_version(void)
1879 {
1880 	struct sev_device *sev = psp_master->sev_data;
1881 	struct sev_user_data_status status;
1882 	int error = 0, ret;
1883 
1884 	/*
1885 	 * Cache SNP platform status and SNP feature information
1886 	 * if SNP is available.
1887 	 */
1888 	if (cc_platform_has(CC_ATTR_HOST_SEV_SNP)) {
1889 		ret = snp_get_platform_data(sev, &error);
1890 		if (ret)
1891 			return 1;
1892 	}
1893 
1894 	ret = sev_platform_status(&status, &error);
1895 	if (ret) {
1896 		dev_err(sev->dev,
1897 			"SEV: failed to get status. Error: %#x\n", error);
1898 		return 1;
1899 	}
1900 
1901 	/* Cache SEV platform status */
1902 	sev->sev_plat_status = status;
1903 
1904 	sev->api_major = status.api_major;
1905 	sev->api_minor = status.api_minor;
1906 	sev->build = status.build;
1907 
1908 	return 0;
1909 }
1910 
sev_get_firmware(struct device * dev,const struct firmware ** firmware)1911 static int sev_get_firmware(struct device *dev,
1912 			    const struct firmware **firmware)
1913 {
1914 	char fw_name_specific[SEV_FW_NAME_SIZE];
1915 	char fw_name_subset[SEV_FW_NAME_SIZE];
1916 
1917 	snprintf(fw_name_specific, sizeof(fw_name_specific),
1918 		 "amd/amd_sev_fam%.2xh_model%.2xh.sbin",
1919 		 boot_cpu_data.x86, boot_cpu_data.x86_model);
1920 
1921 	snprintf(fw_name_subset, sizeof(fw_name_subset),
1922 		 "amd/amd_sev_fam%.2xh_model%.1xxh.sbin",
1923 		 boot_cpu_data.x86, (boot_cpu_data.x86_model & 0xf0) >> 4);
1924 
1925 	/* Check for SEV FW for a particular model.
1926 	 * Ex. amd_sev_fam17h_model00h.sbin for Family 17h Model 00h
1927 	 *
1928 	 * or
1929 	 *
1930 	 * Check for SEV FW common to a subset of models.
1931 	 * Ex. amd_sev_fam17h_model0xh.sbin for
1932 	 *     Family 17h Model 00h -- Family 17h Model 0Fh
1933 	 *
1934 	 * or
1935 	 *
1936 	 * Fall-back to using generic name: sev.fw
1937 	 */
1938 	if ((firmware_request_nowarn(firmware, fw_name_specific, dev) >= 0) ||
1939 	    (firmware_request_nowarn(firmware, fw_name_subset, dev) >= 0) ||
1940 	    (firmware_request_nowarn(firmware, SEV_FW_FILE, dev) >= 0))
1941 		return 0;
1942 
1943 	return -ENOENT;
1944 }
1945 
1946 /* Don't fail if SEV FW couldn't be updated. Continue with existing SEV FW */
sev_update_firmware(struct device * dev)1947 static int sev_update_firmware(struct device *dev)
1948 {
1949 	struct sev_data_download_firmware *data;
1950 	const struct firmware *firmware;
1951 	int ret, error, order;
1952 	struct page *p;
1953 	u64 data_size;
1954 
1955 	if (!sev_version_greater_or_equal(0, 15)) {
1956 		dev_dbg(dev, "DOWNLOAD_FIRMWARE not supported\n");
1957 		return -1;
1958 	}
1959 
1960 	if (sev_get_firmware(dev, &firmware) == -ENOENT) {
1961 		dev_dbg(dev, "No SEV firmware file present\n");
1962 		return -1;
1963 	}
1964 
1965 	/*
1966 	 * SEV FW expects the physical address given to it to be 32
1967 	 * byte aligned. Memory allocated has structure placed at the
1968 	 * beginning followed by the firmware being passed to the SEV
1969 	 * FW. Allocate enough memory for data structure + alignment
1970 	 * padding + SEV FW.
1971 	 */
1972 	data_size = ALIGN(sizeof(struct sev_data_download_firmware), 32);
1973 
1974 	order = get_order(firmware->size + data_size);
1975 	p = alloc_pages(GFP_KERNEL, order);
1976 	if (!p) {
1977 		ret = -1;
1978 		goto fw_err;
1979 	}
1980 
1981 	/*
1982 	 * Copy firmware data to a kernel allocated contiguous
1983 	 * memory region.
1984 	 */
1985 	data = page_address(p);
1986 	memcpy(page_address(p) + data_size, firmware->data, firmware->size);
1987 
1988 	data->address = __psp_pa(page_address(p) + data_size);
1989 	data->len = firmware->size;
1990 
1991 	ret = sev_do_cmd(SEV_CMD_DOWNLOAD_FIRMWARE, data, &error);
1992 
1993 	/*
1994 	 * A quirk for fixing the committed TCB version, when upgrading from
1995 	 * earlier firmware version than 1.50.
1996 	 */
1997 	if (!ret && !sev_version_greater_or_equal(1, 50))
1998 		ret = sev_do_cmd(SEV_CMD_DOWNLOAD_FIRMWARE, data, &error);
1999 
2000 	if (ret)
2001 		dev_dbg(dev, "Failed to update SEV firmware: %#x\n", error);
2002 
2003 	__free_pages(p, order);
2004 
2005 fw_err:
2006 	release_firmware(firmware);
2007 
2008 	return ret;
2009 }
2010 
__sev_snp_shutdown_locked(int * error,bool panic)2011 static int __sev_snp_shutdown_locked(int *error, bool panic)
2012 {
2013 	struct psp_device *psp = psp_master;
2014 	struct sev_device *sev;
2015 	struct sev_data_snp_shutdown_ex data;
2016 	int ret;
2017 
2018 	if (!psp || !psp->sev_data)
2019 		return 0;
2020 
2021 	sev = psp->sev_data;
2022 
2023 	if (!sev->snp_initialized)
2024 		return 0;
2025 
2026 	memset(&data, 0, sizeof(data));
2027 	data.len = sizeof(data);
2028 	data.iommu_snp_shutdown = 1;
2029 
2030 	/*
2031 	 * If invoked during panic handling, local interrupts are disabled
2032 	 * and all CPUs are stopped, so wbinvd_on_all_cpus() can't be called.
2033 	 * In that case, a wbinvd() is done on remote CPUs via the NMI
2034 	 * callback, so only a local wbinvd() is needed here.
2035 	 */
2036 	if (!panic)
2037 		wbinvd_on_all_cpus();
2038 	else
2039 		wbinvd();
2040 
2041 	ret = __sev_do_cmd_locked(SEV_CMD_SNP_SHUTDOWN_EX, &data, error);
2042 	/* SHUTDOWN may require DF_FLUSH */
2043 	if (*error == SEV_RET_DFFLUSH_REQUIRED) {
2044 		int dfflush_error = SEV_RET_NO_FW_CALL;
2045 
2046 		ret = __sev_do_cmd_locked(SEV_CMD_SNP_DF_FLUSH, NULL, &dfflush_error);
2047 		if (ret) {
2048 			dev_err(sev->dev, "SEV-SNP DF_FLUSH failed, ret = %d, error = %#x\n",
2049 				ret, dfflush_error);
2050 			return ret;
2051 		}
2052 		/* reissue the shutdown command */
2053 		ret = __sev_do_cmd_locked(SEV_CMD_SNP_SHUTDOWN_EX, &data,
2054 					  error);
2055 	}
2056 	if (ret) {
2057 		dev_err(sev->dev, "SEV-SNP firmware shutdown failed, rc %d, error %#x\n",
2058 			ret, *error);
2059 		return ret;
2060 	}
2061 
2062 	/*
2063 	 * SNP_SHUTDOWN_EX with IOMMU_SNP_SHUTDOWN set to 1 disables SNP
2064 	 * enforcement by the IOMMU and also transitions all pages
2065 	 * associated with the IOMMU to the Reclaim state.
2066 	 * Firmware was transitioning the IOMMU pages to Hypervisor state
2067 	 * before version 1.53. But, accounting for the number of assigned
2068 	 * 4kB pages in a 2M page was done incorrectly by not transitioning
2069 	 * to the Reclaim state. This resulted in RMP #PF when later accessing
2070 	 * the 2M page containing those pages during kexec boot. Hence, the
2071 	 * firmware now transitions these pages to Reclaim state and hypervisor
2072 	 * needs to transition these pages to shared state. SNP Firmware
2073 	 * version 1.53 and above are needed for kexec boot.
2074 	 */
2075 	ret = amd_iommu_snp_disable();
2076 	if (ret) {
2077 		dev_err(sev->dev, "SNP IOMMU shutdown failed\n");
2078 		return ret;
2079 	}
2080 
2081 	snp_leak_hv_fixed_pages();
2082 	sev->snp_initialized = false;
2083 	dev_dbg(sev->dev, "SEV-SNP firmware shutdown\n");
2084 
2085 	/*
2086 	 * __sev_snp_shutdown_locked() deadlocks when it tries to unregister
2087 	 * itself during panic as the panic notifier is called with RCU read
2088 	 * lock held and notifier unregistration does RCU synchronization.
2089 	 */
2090 	if (!panic)
2091 		atomic_notifier_chain_unregister(&panic_notifier_list,
2092 						 &snp_panic_notifier);
2093 
2094 	/* Reset TMR size back to default */
2095 	sev_es_tmr_size = SEV_TMR_SIZE;
2096 
2097 	return ret;
2098 }
2099 
sev_ioctl_do_pek_import(struct sev_issue_cmd * argp,bool writable)2100 static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
2101 {
2102 	struct sev_device *sev = psp_master->sev_data;
2103 	struct sev_user_data_pek_cert_import input;
2104 	struct sev_data_pek_cert_import data;
2105 	bool shutdown_required = false;
2106 	void *pek_blob, *oca_blob;
2107 	int ret;
2108 
2109 	if (!writable)
2110 		return -EPERM;
2111 
2112 	if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
2113 		return -EFAULT;
2114 
2115 	/* copy PEK certificate blobs from userspace */
2116 	pek_blob = psp_copy_user_blob(input.pek_cert_address, input.pek_cert_len);
2117 	if (IS_ERR(pek_blob))
2118 		return PTR_ERR(pek_blob);
2119 
2120 	data.reserved = 0;
2121 	data.pek_cert_address = __psp_pa(pek_blob);
2122 	data.pek_cert_len = input.pek_cert_len;
2123 
2124 	/* copy PEK certificate blobs from userspace */
2125 	oca_blob = psp_copy_user_blob(input.oca_cert_address, input.oca_cert_len);
2126 	if (IS_ERR(oca_blob)) {
2127 		ret = PTR_ERR(oca_blob);
2128 		goto e_free_pek;
2129 	}
2130 
2131 	data.oca_cert_address = __psp_pa(oca_blob);
2132 	data.oca_cert_len = input.oca_cert_len;
2133 
2134 	/* If platform is not in INIT state then transition it to INIT */
2135 	if (sev->sev_plat_status.state != SEV_STATE_INIT) {
2136 		ret = sev_move_to_init_state(argp, &shutdown_required);
2137 		if (ret)
2138 			goto e_free_oca;
2139 	}
2140 
2141 	ret = __sev_do_cmd_locked(SEV_CMD_PEK_CERT_IMPORT, &data, &argp->error);
2142 
2143 e_free_oca:
2144 	if (shutdown_required)
2145 		__sev_firmware_shutdown(sev, false);
2146 
2147 	kfree(oca_blob);
2148 e_free_pek:
2149 	kfree(pek_blob);
2150 	return ret;
2151 }
2152 
sev_ioctl_do_get_id2(struct sev_issue_cmd * argp)2153 static int sev_ioctl_do_get_id2(struct sev_issue_cmd *argp)
2154 {
2155 	struct sev_user_data_get_id2 input;
2156 	struct sev_data_get_id data;
2157 	void __user *input_address;
2158 	void *id_blob = NULL;
2159 	int ret;
2160 
2161 	/* SEV GET_ID is available from SEV API v0.16 and up */
2162 	if (!sev_version_greater_or_equal(0, 16))
2163 		return -ENOTSUPP;
2164 
2165 	if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
2166 		return -EFAULT;
2167 
2168 	input_address = (void __user *)input.address;
2169 
2170 	if (input.address && input.length) {
2171 		/*
2172 		 * The length of the ID shouldn't be assumed by software since
2173 		 * it may change in the future.  The allocation size is limited
2174 		 * to 1 << (PAGE_SHIFT + MAX_PAGE_ORDER) by the page allocator.
2175 		 * If the allocation fails, simply return ENOMEM rather than
2176 		 * warning in the kernel log.
2177 		 */
2178 		id_blob = kzalloc(input.length, GFP_KERNEL | __GFP_NOWARN);
2179 		if (!id_blob)
2180 			return -ENOMEM;
2181 
2182 		data.address = __psp_pa(id_blob);
2183 		data.len = input.length;
2184 	} else {
2185 		data.address = 0;
2186 		data.len = 0;
2187 	}
2188 
2189 	ret = __sev_do_cmd_locked(SEV_CMD_GET_ID, &data, &argp->error);
2190 
2191 	/*
2192 	 * Firmware will return the length of the ID value (either the minimum
2193 	 * required length or the actual length written), return it to the user.
2194 	 */
2195 	input.length = data.len;
2196 
2197 	if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) {
2198 		ret = -EFAULT;
2199 		goto e_free;
2200 	}
2201 
2202 	if (id_blob) {
2203 		if (copy_to_user(input_address, id_blob, data.len)) {
2204 			ret = -EFAULT;
2205 			goto e_free;
2206 		}
2207 	}
2208 
2209 e_free:
2210 	kfree(id_blob);
2211 
2212 	return ret;
2213 }
2214 
sev_ioctl_do_get_id(struct sev_issue_cmd * argp)2215 static int sev_ioctl_do_get_id(struct sev_issue_cmd *argp)
2216 {
2217 	struct sev_data_get_id *data;
2218 	u64 data_size, user_size;
2219 	void *id_blob, *mem;
2220 	int ret;
2221 
2222 	/* SEV GET_ID available from SEV API v0.16 and up */
2223 	if (!sev_version_greater_or_equal(0, 16))
2224 		return -ENOTSUPP;
2225 
2226 	/* SEV FW expects the buffer it fills with the ID to be
2227 	 * 8-byte aligned. Memory allocated should be enough to
2228 	 * hold data structure + alignment padding + memory
2229 	 * where SEV FW writes the ID.
2230 	 */
2231 	data_size = ALIGN(sizeof(struct sev_data_get_id), 8);
2232 	user_size = sizeof(struct sev_user_data_get_id);
2233 
2234 	mem = kzalloc(data_size + user_size, GFP_KERNEL);
2235 	if (!mem)
2236 		return -ENOMEM;
2237 
2238 	data = mem;
2239 	id_blob = mem + data_size;
2240 
2241 	data->address = __psp_pa(id_blob);
2242 	data->len = user_size;
2243 
2244 	ret = __sev_do_cmd_locked(SEV_CMD_GET_ID, data, &argp->error);
2245 	if (!ret) {
2246 		if (copy_to_user((void __user *)argp->data, id_blob, data->len))
2247 			ret = -EFAULT;
2248 	}
2249 
2250 	kfree(mem);
2251 
2252 	return ret;
2253 }
2254 
sev_ioctl_do_pdh_export(struct sev_issue_cmd * argp,bool writable)2255 static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
2256 {
2257 	struct sev_device *sev = psp_master->sev_data;
2258 	struct sev_user_data_pdh_cert_export input;
2259 	void *pdh_blob = NULL, *cert_blob = NULL;
2260 	struct sev_data_pdh_cert_export data;
2261 	void __user *input_cert_chain_address;
2262 	void __user *input_pdh_cert_address;
2263 	bool shutdown_required = false;
2264 	int ret;
2265 
2266 	if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
2267 		return -EFAULT;
2268 
2269 	memset(&data, 0, sizeof(data));
2270 
2271 	input_pdh_cert_address = (void __user *)input.pdh_cert_address;
2272 	input_cert_chain_address = (void __user *)input.cert_chain_address;
2273 
2274 	/* Userspace wants to query the certificate length. */
2275 	if (!input.pdh_cert_address ||
2276 	    !input.pdh_cert_len ||
2277 	    !input.cert_chain_address)
2278 		goto cmd;
2279 
2280 	/* Allocate a physically contiguous buffer to store the PDH blob. */
2281 	if (input.pdh_cert_len > SEV_FW_BLOB_MAX_SIZE)
2282 		return -EFAULT;
2283 
2284 	/* Allocate a physically contiguous buffer to store the cert chain blob. */
2285 	if (input.cert_chain_len > SEV_FW_BLOB_MAX_SIZE)
2286 		return -EFAULT;
2287 
2288 	pdh_blob = kzalloc(input.pdh_cert_len, GFP_KERNEL);
2289 	if (!pdh_blob)
2290 		return -ENOMEM;
2291 
2292 	data.pdh_cert_address = __psp_pa(pdh_blob);
2293 	data.pdh_cert_len = input.pdh_cert_len;
2294 
2295 	cert_blob = kzalloc(input.cert_chain_len, GFP_KERNEL);
2296 	if (!cert_blob) {
2297 		ret = -ENOMEM;
2298 		goto e_free_pdh;
2299 	}
2300 
2301 	data.cert_chain_address = __psp_pa(cert_blob);
2302 	data.cert_chain_len = input.cert_chain_len;
2303 
2304 cmd:
2305 	/* If platform is not in INIT state then transition it to INIT. */
2306 	if (sev->sev_plat_status.state != SEV_STATE_INIT) {
2307 		if (!writable) {
2308 			ret = -EPERM;
2309 			goto e_free_cert;
2310 		}
2311 		ret = sev_move_to_init_state(argp, &shutdown_required);
2312 		if (ret)
2313 			goto e_free_cert;
2314 	}
2315 
2316 	ret = __sev_do_cmd_locked(SEV_CMD_PDH_CERT_EXPORT, &data, &argp->error);
2317 
2318 	/* If we query the length, FW responded with expected data. */
2319 	input.cert_chain_len = data.cert_chain_len;
2320 	input.pdh_cert_len = data.pdh_cert_len;
2321 
2322 	if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) {
2323 		ret = -EFAULT;
2324 		goto e_free_cert;
2325 	}
2326 
2327 	if (pdh_blob) {
2328 		if (copy_to_user(input_pdh_cert_address,
2329 				 pdh_blob, input.pdh_cert_len)) {
2330 			ret = -EFAULT;
2331 			goto e_free_cert;
2332 		}
2333 	}
2334 
2335 	if (cert_blob) {
2336 		if (copy_to_user(input_cert_chain_address,
2337 				 cert_blob, input.cert_chain_len))
2338 			ret = -EFAULT;
2339 	}
2340 
2341 e_free_cert:
2342 	if (shutdown_required)
2343 		__sev_firmware_shutdown(sev, false);
2344 
2345 	kfree(cert_blob);
2346 e_free_pdh:
2347 	kfree(pdh_blob);
2348 	return ret;
2349 }
2350 
sev_ioctl_do_snp_platform_status(struct sev_issue_cmd * argp)2351 static int sev_ioctl_do_snp_platform_status(struct sev_issue_cmd *argp)
2352 {
2353 	struct sev_device *sev = psp_master->sev_data;
2354 	bool shutdown_required = false;
2355 	struct sev_data_snp_addr buf;
2356 	struct page *status_page;
2357 	int ret, error;
2358 	void *data;
2359 
2360 	if (!argp->data)
2361 		return -EINVAL;
2362 
2363 	status_page = alloc_page(GFP_KERNEL_ACCOUNT);
2364 	if (!status_page)
2365 		return -ENOMEM;
2366 
2367 	data = page_address(status_page);
2368 
2369 	if (!sev->snp_initialized) {
2370 		ret = snp_move_to_init_state(argp, &shutdown_required);
2371 		if (ret)
2372 			goto cleanup;
2373 	}
2374 
2375 	/*
2376 	 * Firmware expects status page to be in firmware-owned state, otherwise
2377 	 * it will report firmware error code INVALID_PAGE_STATE (0x1A).
2378 	 */
2379 	if (rmp_mark_pages_firmware(__pa(data), 1, true)) {
2380 		ret = -EFAULT;
2381 		goto cleanup;
2382 	}
2383 
2384 	buf.address = __psp_pa(data);
2385 	ret = __sev_do_cmd_locked(SEV_CMD_SNP_PLATFORM_STATUS, &buf, &argp->error);
2386 
2387 	/*
2388 	 * Status page will be transitioned to Reclaim state upon success, or
2389 	 * left in Firmware state in failure. Use snp_reclaim_pages() to
2390 	 * transition either case back to Hypervisor-owned state.
2391 	 */
2392 	if (snp_reclaim_pages(__pa(data), 1, true))
2393 		return -EFAULT;
2394 
2395 	if (ret)
2396 		goto cleanup;
2397 
2398 	if (copy_to_user((void __user *)argp->data, data,
2399 			 sizeof(struct sev_user_data_snp_status)))
2400 		ret = -EFAULT;
2401 
2402 cleanup:
2403 	if (shutdown_required)
2404 		__sev_snp_shutdown_locked(&error, false);
2405 
2406 	__free_pages(status_page, 0);
2407 	return ret;
2408 }
2409 
sev_ioctl_do_snp_commit(struct sev_issue_cmd * argp)2410 static int sev_ioctl_do_snp_commit(struct sev_issue_cmd *argp)
2411 {
2412 	struct sev_device *sev = psp_master->sev_data;
2413 	struct sev_data_snp_commit buf;
2414 	bool shutdown_required = false;
2415 	int ret, error;
2416 
2417 	if (!sev->snp_initialized) {
2418 		ret = snp_move_to_init_state(argp, &shutdown_required);
2419 		if (ret)
2420 			return ret;
2421 	}
2422 
2423 	buf.len = sizeof(buf);
2424 
2425 	ret = __sev_do_cmd_locked(SEV_CMD_SNP_COMMIT, &buf, &argp->error);
2426 
2427 	if (shutdown_required)
2428 		__sev_snp_shutdown_locked(&error, false);
2429 
2430 	return ret;
2431 }
2432 
sev_ioctl_do_snp_set_config(struct sev_issue_cmd * argp,bool writable)2433 static int sev_ioctl_do_snp_set_config(struct sev_issue_cmd *argp, bool writable)
2434 {
2435 	struct sev_device *sev = psp_master->sev_data;
2436 	struct sev_user_data_snp_config config;
2437 	bool shutdown_required = false;
2438 	int ret, error;
2439 
2440 	if (!argp->data)
2441 		return -EINVAL;
2442 
2443 	if (!writable)
2444 		return -EPERM;
2445 
2446 	if (copy_from_user(&config, (void __user *)argp->data, sizeof(config)))
2447 		return -EFAULT;
2448 
2449 	if (!sev->snp_initialized) {
2450 		ret = snp_move_to_init_state(argp, &shutdown_required);
2451 		if (ret)
2452 			return ret;
2453 	}
2454 
2455 	ret = __sev_do_cmd_locked(SEV_CMD_SNP_CONFIG, &config, &argp->error);
2456 
2457 	if (shutdown_required)
2458 		__sev_snp_shutdown_locked(&error, false);
2459 
2460 	return ret;
2461 }
2462 
sev_ioctl_do_snp_vlek_load(struct sev_issue_cmd * argp,bool writable)2463 static int sev_ioctl_do_snp_vlek_load(struct sev_issue_cmd *argp, bool writable)
2464 {
2465 	struct sev_device *sev = psp_master->sev_data;
2466 	struct sev_user_data_snp_vlek_load input;
2467 	bool shutdown_required = false;
2468 	int ret, error;
2469 	void *blob;
2470 
2471 	if (!argp->data)
2472 		return -EINVAL;
2473 
2474 	if (!writable)
2475 		return -EPERM;
2476 
2477 	if (copy_from_user(&input, u64_to_user_ptr(argp->data), sizeof(input)))
2478 		return -EFAULT;
2479 
2480 	if (input.len != sizeof(input) || input.vlek_wrapped_version != 0)
2481 		return -EINVAL;
2482 
2483 	blob = psp_copy_user_blob(input.vlek_wrapped_address,
2484 				  sizeof(struct sev_user_data_snp_wrapped_vlek_hashstick));
2485 	if (IS_ERR(blob))
2486 		return PTR_ERR(blob);
2487 
2488 	input.vlek_wrapped_address = __psp_pa(blob);
2489 
2490 	if (!sev->snp_initialized) {
2491 		ret = snp_move_to_init_state(argp, &shutdown_required);
2492 		if (ret)
2493 			goto cleanup;
2494 	}
2495 
2496 	ret = __sev_do_cmd_locked(SEV_CMD_SNP_VLEK_LOAD, &input, &argp->error);
2497 
2498 	if (shutdown_required)
2499 		__sev_snp_shutdown_locked(&error, false);
2500 
2501 cleanup:
2502 	kfree(blob);
2503 
2504 	return ret;
2505 }
2506 
sev_ioctl(struct file * file,unsigned int ioctl,unsigned long arg)2507 static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
2508 {
2509 	void __user *argp = (void __user *)arg;
2510 	struct sev_issue_cmd input;
2511 	int ret = -EFAULT;
2512 	bool writable = file->f_mode & FMODE_WRITE;
2513 
2514 	if (!psp_master || !psp_master->sev_data)
2515 		return -ENODEV;
2516 
2517 	if (ioctl != SEV_ISSUE_CMD)
2518 		return -EINVAL;
2519 
2520 	if (copy_from_user(&input, argp, sizeof(struct sev_issue_cmd)))
2521 		return -EFAULT;
2522 
2523 	if (input.cmd > SEV_MAX)
2524 		return -EINVAL;
2525 
2526 	mutex_lock(&sev_cmd_mutex);
2527 
2528 	switch (input.cmd) {
2529 
2530 	case SEV_FACTORY_RESET:
2531 		ret = sev_ioctl_do_reset(&input, writable);
2532 		break;
2533 	case SEV_PLATFORM_STATUS:
2534 		ret = sev_ioctl_do_platform_status(&input);
2535 		break;
2536 	case SEV_PEK_GEN:
2537 		ret = sev_ioctl_do_pek_pdh_gen(SEV_CMD_PEK_GEN, &input, writable);
2538 		break;
2539 	case SEV_PDH_GEN:
2540 		ret = sev_ioctl_do_pek_pdh_gen(SEV_CMD_PDH_GEN, &input, writable);
2541 		break;
2542 	case SEV_PEK_CSR:
2543 		ret = sev_ioctl_do_pek_csr(&input, writable);
2544 		break;
2545 	case SEV_PEK_CERT_IMPORT:
2546 		ret = sev_ioctl_do_pek_import(&input, writable);
2547 		break;
2548 	case SEV_PDH_CERT_EXPORT:
2549 		ret = sev_ioctl_do_pdh_export(&input, writable);
2550 		break;
2551 	case SEV_GET_ID:
2552 		pr_warn_once("SEV_GET_ID command is deprecated, use SEV_GET_ID2\n");
2553 		ret = sev_ioctl_do_get_id(&input);
2554 		break;
2555 	case SEV_GET_ID2:
2556 		ret = sev_ioctl_do_get_id2(&input);
2557 		break;
2558 	case SNP_PLATFORM_STATUS:
2559 		ret = sev_ioctl_do_snp_platform_status(&input);
2560 		break;
2561 	case SNP_COMMIT:
2562 		ret = sev_ioctl_do_snp_commit(&input);
2563 		break;
2564 	case SNP_SET_CONFIG:
2565 		ret = sev_ioctl_do_snp_set_config(&input, writable);
2566 		break;
2567 	case SNP_VLEK_LOAD:
2568 		ret = sev_ioctl_do_snp_vlek_load(&input, writable);
2569 		break;
2570 	default:
2571 		ret = -EINVAL;
2572 		goto out;
2573 	}
2574 
2575 	if (copy_to_user(argp, &input, sizeof(struct sev_issue_cmd)))
2576 		ret = -EFAULT;
2577 out:
2578 	mutex_unlock(&sev_cmd_mutex);
2579 
2580 	return ret;
2581 }
2582 
2583 static const struct file_operations sev_fops = {
2584 	.owner	= THIS_MODULE,
2585 	.unlocked_ioctl = sev_ioctl,
2586 };
2587 
sev_platform_status(struct sev_user_data_status * data,int * error)2588 int sev_platform_status(struct sev_user_data_status *data, int *error)
2589 {
2590 	return sev_do_cmd(SEV_CMD_PLATFORM_STATUS, data, error);
2591 }
2592 EXPORT_SYMBOL_GPL(sev_platform_status);
2593 
sev_guest_deactivate(struct sev_data_deactivate * data,int * error)2594 int sev_guest_deactivate(struct sev_data_deactivate *data, int *error)
2595 {
2596 	return sev_do_cmd(SEV_CMD_DEACTIVATE, data, error);
2597 }
2598 EXPORT_SYMBOL_GPL(sev_guest_deactivate);
2599 
sev_guest_activate(struct sev_data_activate * data,int * error)2600 int sev_guest_activate(struct sev_data_activate *data, int *error)
2601 {
2602 	return sev_do_cmd(SEV_CMD_ACTIVATE, data, error);
2603 }
2604 EXPORT_SYMBOL_GPL(sev_guest_activate);
2605 
sev_guest_decommission(struct sev_data_decommission * data,int * error)2606 int sev_guest_decommission(struct sev_data_decommission *data, int *error)
2607 {
2608 	return sev_do_cmd(SEV_CMD_DECOMMISSION, data, error);
2609 }
2610 EXPORT_SYMBOL_GPL(sev_guest_decommission);
2611 
sev_guest_df_flush(int * error)2612 int sev_guest_df_flush(int *error)
2613 {
2614 	return sev_do_cmd(SEV_CMD_DF_FLUSH, NULL, error);
2615 }
2616 EXPORT_SYMBOL_GPL(sev_guest_df_flush);
2617 
sev_exit(struct kref * ref)2618 static void sev_exit(struct kref *ref)
2619 {
2620 	misc_deregister(&misc_dev->misc);
2621 	kfree(misc_dev);
2622 	misc_dev = NULL;
2623 }
2624 
sev_misc_init(struct sev_device * sev)2625 static int sev_misc_init(struct sev_device *sev)
2626 {
2627 	struct device *dev = sev->dev;
2628 	int ret;
2629 
2630 	/*
2631 	 * SEV feature support can be detected on multiple devices but the SEV
2632 	 * FW commands must be issued on the master. During probe, we do not
2633 	 * know the master hence we create /dev/sev on the first device probe.
2634 	 * sev_do_cmd() finds the right master device to which to issue the
2635 	 * command to the firmware.
2636 	 */
2637 	if (!misc_dev) {
2638 		struct miscdevice *misc;
2639 
2640 		misc_dev = kzalloc(sizeof(*misc_dev), GFP_KERNEL);
2641 		if (!misc_dev)
2642 			return -ENOMEM;
2643 
2644 		misc = &misc_dev->misc;
2645 		misc->minor = MISC_DYNAMIC_MINOR;
2646 		misc->name = DEVICE_NAME;
2647 		misc->fops = &sev_fops;
2648 
2649 		ret = misc_register(misc);
2650 		if (ret)
2651 			return ret;
2652 
2653 		kref_init(&misc_dev->refcount);
2654 	} else {
2655 		kref_get(&misc_dev->refcount);
2656 	}
2657 
2658 	init_waitqueue_head(&sev->int_queue);
2659 	sev->misc = misc_dev;
2660 	dev_dbg(dev, "registered SEV device\n");
2661 
2662 	return 0;
2663 }
2664 
sev_dev_init(struct psp_device * psp)2665 int sev_dev_init(struct psp_device *psp)
2666 {
2667 	struct device *dev = psp->dev;
2668 	struct sev_device *sev;
2669 	int ret = -ENOMEM;
2670 
2671 	if (!boot_cpu_has(X86_FEATURE_SEV)) {
2672 		dev_info_once(dev, "SEV: memory encryption not enabled by BIOS\n");
2673 		return 0;
2674 	}
2675 
2676 	sev = devm_kzalloc(dev, sizeof(*sev), GFP_KERNEL);
2677 	if (!sev)
2678 		goto e_err;
2679 
2680 	sev->cmd_buf = (void *)devm_get_free_pages(dev, GFP_KERNEL, 1);
2681 	if (!sev->cmd_buf)
2682 		goto e_sev;
2683 
2684 	sev->cmd_buf_backup = (uint8_t *)sev->cmd_buf + PAGE_SIZE;
2685 
2686 	psp->sev_data = sev;
2687 
2688 	sev->dev = dev;
2689 	sev->psp = psp;
2690 
2691 	sev->io_regs = psp->io_regs;
2692 
2693 	sev->vdata = (struct sev_vdata *)psp->vdata->sev;
2694 	if (!sev->vdata) {
2695 		ret = -ENODEV;
2696 		dev_err(dev, "sev: missing driver data\n");
2697 		goto e_buf;
2698 	}
2699 
2700 	psp_set_sev_irq_handler(psp, sev_irq_handler, sev);
2701 
2702 	ret = sev_misc_init(sev);
2703 	if (ret)
2704 		goto e_irq;
2705 
2706 	dev_notice(dev, "sev enabled\n");
2707 
2708 	return 0;
2709 
2710 e_irq:
2711 	psp_clear_sev_irq_handler(psp);
2712 e_buf:
2713 	devm_free_pages(dev, (unsigned long)sev->cmd_buf);
2714 e_sev:
2715 	devm_kfree(dev, sev);
2716 e_err:
2717 	psp->sev_data = NULL;
2718 
2719 	dev_notice(dev, "sev initialization failed\n");
2720 
2721 	return ret;
2722 }
2723 
__sev_firmware_shutdown(struct sev_device * sev,bool panic)2724 static void __sev_firmware_shutdown(struct sev_device *sev, bool panic)
2725 {
2726 	int error;
2727 
2728 	__sev_platform_shutdown_locked(&error);
2729 
2730 	if (sev_es_tmr) {
2731 		/*
2732 		 * The TMR area was encrypted, flush it from the cache.
2733 		 *
2734 		 * If invoked during panic handling, local interrupts are
2735 		 * disabled and all CPUs are stopped, so wbinvd_on_all_cpus()
2736 		 * can't be used. In that case, wbinvd() is done on remote CPUs
2737 		 * via the NMI callback, and done for this CPU later during
2738 		 * SNP shutdown, so wbinvd_on_all_cpus() can be skipped.
2739 		 */
2740 		if (!panic)
2741 			wbinvd_on_all_cpus();
2742 
2743 		__snp_free_firmware_pages(virt_to_page(sev_es_tmr),
2744 					  get_order(sev_es_tmr_size),
2745 					  true);
2746 		sev_es_tmr = NULL;
2747 	}
2748 
2749 	if (sev_init_ex_buffer) {
2750 		__snp_free_firmware_pages(virt_to_page(sev_init_ex_buffer),
2751 					  get_order(NV_LENGTH),
2752 					  true);
2753 		sev_init_ex_buffer = NULL;
2754 	}
2755 
2756 	if (snp_range_list) {
2757 		kfree(snp_range_list);
2758 		snp_range_list = NULL;
2759 	}
2760 
2761 	__sev_snp_shutdown_locked(&error, panic);
2762 }
2763 
sev_firmware_shutdown(struct sev_device * sev)2764 static void sev_firmware_shutdown(struct sev_device *sev)
2765 {
2766 	mutex_lock(&sev_cmd_mutex);
2767 	__sev_firmware_shutdown(sev, false);
2768 	mutex_unlock(&sev_cmd_mutex);
2769 }
2770 
sev_platform_shutdown(void)2771 void sev_platform_shutdown(void)
2772 {
2773 	if (!psp_master || !psp_master->sev_data)
2774 		return;
2775 
2776 	sev_firmware_shutdown(psp_master->sev_data);
2777 }
2778 EXPORT_SYMBOL_GPL(sev_platform_shutdown);
2779 
sev_dev_destroy(struct psp_device * psp)2780 void sev_dev_destroy(struct psp_device *psp)
2781 {
2782 	struct sev_device *sev = psp->sev_data;
2783 
2784 	if (!sev)
2785 		return;
2786 
2787 	sev_firmware_shutdown(sev);
2788 
2789 	if (sev->misc)
2790 		kref_put(&misc_dev->refcount, sev_exit);
2791 
2792 	psp_clear_sev_irq_handler(psp);
2793 }
2794 
snp_shutdown_on_panic(struct notifier_block * nb,unsigned long reason,void * arg)2795 static int snp_shutdown_on_panic(struct notifier_block *nb,
2796 				 unsigned long reason, void *arg)
2797 {
2798 	struct sev_device *sev = psp_master->sev_data;
2799 
2800 	/*
2801 	 * If sev_cmd_mutex is already acquired, then it's likely
2802 	 * another PSP command is in flight and issuing a shutdown
2803 	 * would fail in unexpected ways. Rather than create even
2804 	 * more confusion during a panic, just bail out here.
2805 	 */
2806 	if (mutex_is_locked(&sev_cmd_mutex))
2807 		return NOTIFY_DONE;
2808 
2809 	__sev_firmware_shutdown(sev, true);
2810 
2811 	return NOTIFY_DONE;
2812 }
2813 
sev_issue_cmd_external_user(struct file * filep,unsigned int cmd,void * data,int * error)2814 int sev_issue_cmd_external_user(struct file *filep, unsigned int cmd,
2815 				void *data, int *error)
2816 {
2817 	if (!filep || filep->f_op != &sev_fops)
2818 		return -EBADF;
2819 
2820 	return sev_do_cmd(cmd, data, error);
2821 }
2822 EXPORT_SYMBOL_GPL(sev_issue_cmd_external_user);
2823 
sev_pci_init(void)2824 void sev_pci_init(void)
2825 {
2826 	struct sev_device *sev = psp_master->sev_data;
2827 	u8 api_major, api_minor, build;
2828 
2829 	if (!sev)
2830 		return;
2831 
2832 	psp_timeout = psp_probe_timeout;
2833 
2834 	if (sev_get_api_version())
2835 		goto err;
2836 
2837 	api_major = sev->api_major;
2838 	api_minor = sev->api_minor;
2839 	build     = sev->build;
2840 
2841 	if (sev_update_firmware(sev->dev) == 0)
2842 		sev_get_api_version();
2843 
2844 	if (api_major != sev->api_major || api_minor != sev->api_minor ||
2845 	    build != sev->build)
2846 		dev_info(sev->dev, "SEV firmware updated from %d.%d.%d to %d.%d.%d\n",
2847 			 api_major, api_minor, build,
2848 			 sev->api_major, sev->api_minor, sev->build);
2849 
2850 	return;
2851 
2852 err:
2853 	sev_dev_destroy(psp_master);
2854 
2855 	psp_master->sev_data = NULL;
2856 }
2857 
sev_pci_exit(void)2858 void sev_pci_exit(void)
2859 {
2860 	struct sev_device *sev = psp_master->sev_data;
2861 
2862 	if (!sev)
2863 		return;
2864 
2865 	sev_firmware_shutdown(sev);
2866 }
2867