1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Kernel-based Virtual Machine driver for Linux
4  *
5  * AMD SVM-SEV support
6  *
7  * Copyright 2010 Red Hat, Inc. and/or its affiliates.
8  */
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10 
11 #include <linux/kvm_types.h>
12 #include <linux/kvm_host.h>
13 #include <linux/kernel.h>
14 #include <linux/highmem.h>
15 #include <linux/psp.h>
16 #include <linux/psp-sev.h>
17 #include <linux/pagemap.h>
18 #include <linux/swap.h>
19 #include <linux/misc_cgroup.h>
20 #include <linux/processor.h>
21 #include <linux/trace_events.h>
22 
23 #include <asm/pkru.h>
24 #include <asm/trapnr.h>
25 #include <asm/fpu/xcr.h>
26 #include <asm/debugreg.h>
27 
28 #include "mmu.h"
29 #include "x86.h"
30 #include "svm.h"
31 #include "svm_ops.h"
32 #include "cpuid.h"
33 #include "trace.h"
34 
35 #ifndef CONFIG_KVM_AMD_SEV
36 /*
37  * When this config is not defined, SEV feature is not supported and APIs in
38  * this file are not used but this file still gets compiled into the KVM AMD
39  * module.
40  *
41  * We will not have MISC_CG_RES_SEV and MISC_CG_RES_SEV_ES entries in the enum
42  * misc_res_type {} defined in linux/misc_cgroup.h.
43  *
44  * Below macros allow compilation to succeed.
45  */
46 #define MISC_CG_RES_SEV MISC_CG_RES_TYPES
47 #define MISC_CG_RES_SEV_ES MISC_CG_RES_TYPES
48 #endif
49 
50 #ifdef CONFIG_KVM_AMD_SEV
51 /* enable/disable SEV support */
52 static bool sev_enabled = true;
53 module_param_named(sev, sev_enabled, bool, 0444);
54 
55 /* enable/disable SEV-ES support */
56 static bool sev_es_enabled = true;
57 module_param_named(sev_es, sev_es_enabled, bool, 0444);
58 
59 /* enable/disable SEV-ES DebugSwap support */
60 static bool sev_es_debug_swap_enabled = false;
61 module_param_named(debug_swap, sev_es_debug_swap_enabled, bool, 0444);
62 #else
63 #define sev_enabled false
64 #define sev_es_enabled false
65 #define sev_es_debug_swap_enabled false
66 #endif /* CONFIG_KVM_AMD_SEV */
67 
68 static u8 sev_enc_bit;
69 static DECLARE_RWSEM(sev_deactivate_lock);
70 static DEFINE_MUTEX(sev_bitmap_lock);
71 unsigned int max_sev_asid;
72 static unsigned int min_sev_asid;
73 static unsigned long sev_me_mask;
74 static unsigned int nr_asids;
75 static unsigned long *sev_asid_bitmap;
76 static unsigned long *sev_reclaim_asid_bitmap;
77 
78 struct enc_region {
79 	struct list_head list;
80 	unsigned long npages;
81 	struct page **pages;
82 	unsigned long uaddr;
83 	unsigned long size;
84 };
85 
86 /* Called with the sev_bitmap_lock held, or on shutdown  */
sev_flush_asids(int min_asid,int max_asid)87 static int sev_flush_asids(int min_asid, int max_asid)
88 {
89 	int ret, asid, error = 0;
90 
91 	/* Check if there are any ASIDs to reclaim before performing a flush */
92 	asid = find_next_bit(sev_reclaim_asid_bitmap, nr_asids, min_asid);
93 	if (asid > max_asid)
94 		return -EBUSY;
95 
96 	/*
97 	 * DEACTIVATE will clear the WBINVD indicator causing DF_FLUSH to fail,
98 	 * so it must be guarded.
99 	 */
100 	down_write(&sev_deactivate_lock);
101 
102 	wbinvd_on_all_cpus();
103 	ret = sev_guest_df_flush(&error);
104 
105 	up_write(&sev_deactivate_lock);
106 
107 	if (ret)
108 		pr_err("SEV: DF_FLUSH failed, ret=%d, error=%#x\n", ret, error);
109 
110 	return ret;
111 }
112 
is_mirroring_enc_context(struct kvm * kvm)113 static inline bool is_mirroring_enc_context(struct kvm *kvm)
114 {
115 	return !!to_kvm_svm(kvm)->sev_info.enc_context_owner;
116 }
117 
118 /* Must be called with the sev_bitmap_lock held */
__sev_recycle_asids(int min_asid,int max_asid)119 static bool __sev_recycle_asids(int min_asid, int max_asid)
120 {
121 	if (sev_flush_asids(min_asid, max_asid))
122 		return false;
123 
124 	/* The flush process will flush all reclaimable SEV and SEV-ES ASIDs */
125 	bitmap_xor(sev_asid_bitmap, sev_asid_bitmap, sev_reclaim_asid_bitmap,
126 		   nr_asids);
127 	bitmap_zero(sev_reclaim_asid_bitmap, nr_asids);
128 
129 	return true;
130 }
131 
sev_misc_cg_try_charge(struct kvm_sev_info * sev)132 static int sev_misc_cg_try_charge(struct kvm_sev_info *sev)
133 {
134 	enum misc_res_type type = sev->es_active ? MISC_CG_RES_SEV_ES : MISC_CG_RES_SEV;
135 	return misc_cg_try_charge(type, sev->misc_cg, 1);
136 }
137 
sev_misc_cg_uncharge(struct kvm_sev_info * sev)138 static void sev_misc_cg_uncharge(struct kvm_sev_info *sev)
139 {
140 	enum misc_res_type type = sev->es_active ? MISC_CG_RES_SEV_ES : MISC_CG_RES_SEV;
141 	misc_cg_uncharge(type, sev->misc_cg, 1);
142 }
143 
sev_asid_new(struct kvm_sev_info * sev)144 static int sev_asid_new(struct kvm_sev_info *sev)
145 {
146 	int asid, min_asid, max_asid, ret;
147 	bool retry = true;
148 
149 	WARN_ON(sev->misc_cg);
150 	sev->misc_cg = get_current_misc_cg();
151 	ret = sev_misc_cg_try_charge(sev);
152 	if (ret) {
153 		put_misc_cg(sev->misc_cg);
154 		sev->misc_cg = NULL;
155 		return ret;
156 	}
157 
158 	mutex_lock(&sev_bitmap_lock);
159 
160 	/*
161 	 * SEV-enabled guests must use asid from min_sev_asid to max_sev_asid.
162 	 * SEV-ES-enabled guest can use from 1 to min_sev_asid - 1.
163 	 */
164 	min_asid = sev->es_active ? 1 : min_sev_asid;
165 	max_asid = sev->es_active ? min_sev_asid - 1 : max_sev_asid;
166 again:
167 	asid = find_next_zero_bit(sev_asid_bitmap, max_asid + 1, min_asid);
168 	if (asid > max_asid) {
169 		if (retry && __sev_recycle_asids(min_asid, max_asid)) {
170 			retry = false;
171 			goto again;
172 		}
173 		mutex_unlock(&sev_bitmap_lock);
174 		ret = -EBUSY;
175 		goto e_uncharge;
176 	}
177 
178 	__set_bit(asid, sev_asid_bitmap);
179 
180 	mutex_unlock(&sev_bitmap_lock);
181 
182 	return asid;
183 e_uncharge:
184 	sev_misc_cg_uncharge(sev);
185 	put_misc_cg(sev->misc_cg);
186 	sev->misc_cg = NULL;
187 	return ret;
188 }
189 
sev_get_asid(struct kvm * kvm)190 static int sev_get_asid(struct kvm *kvm)
191 {
192 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
193 
194 	return sev->asid;
195 }
196 
sev_asid_free(struct kvm_sev_info * sev)197 static void sev_asid_free(struct kvm_sev_info *sev)
198 {
199 	struct svm_cpu_data *sd;
200 	int cpu;
201 
202 	mutex_lock(&sev_bitmap_lock);
203 
204 	__set_bit(sev->asid, sev_reclaim_asid_bitmap);
205 
206 	for_each_possible_cpu(cpu) {
207 		sd = per_cpu_ptr(&svm_data, cpu);
208 		sd->sev_vmcbs[sev->asid] = NULL;
209 	}
210 
211 	mutex_unlock(&sev_bitmap_lock);
212 
213 	sev_misc_cg_uncharge(sev);
214 	put_misc_cg(sev->misc_cg);
215 	sev->misc_cg = NULL;
216 }
217 
sev_decommission(unsigned int handle)218 static void sev_decommission(unsigned int handle)
219 {
220 	struct sev_data_decommission decommission;
221 
222 	if (!handle)
223 		return;
224 
225 	decommission.handle = handle;
226 	sev_guest_decommission(&decommission, NULL);
227 }
228 
sev_unbind_asid(struct kvm * kvm,unsigned int handle)229 static void sev_unbind_asid(struct kvm *kvm, unsigned int handle)
230 {
231 	struct sev_data_deactivate deactivate;
232 
233 	if (!handle)
234 		return;
235 
236 	deactivate.handle = handle;
237 
238 	/* Guard DEACTIVATE against WBINVD/DF_FLUSH used in ASID recycling */
239 	down_read(&sev_deactivate_lock);
240 	sev_guest_deactivate(&deactivate, NULL);
241 	up_read(&sev_deactivate_lock);
242 
243 	sev_decommission(handle);
244 }
245 
sev_guest_init(struct kvm * kvm,struct kvm_sev_cmd * argp)246 static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
247 {
248 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
249 	int asid, ret;
250 
251 	if (kvm->created_vcpus)
252 		return -EINVAL;
253 
254 	ret = -EBUSY;
255 	if (unlikely(sev->active))
256 		return ret;
257 
258 	sev->active = true;
259 	sev->es_active = argp->id == KVM_SEV_ES_INIT;
260 	asid = sev_asid_new(sev);
261 	if (asid < 0)
262 		goto e_no_asid;
263 	sev->asid = asid;
264 
265 	ret = sev_platform_init(&argp->error);
266 	if (ret)
267 		goto e_free;
268 
269 	INIT_LIST_HEAD(&sev->regions_list);
270 	INIT_LIST_HEAD(&sev->mirror_vms);
271 
272 	kvm_set_apicv_inhibit(kvm, APICV_INHIBIT_REASON_SEV);
273 
274 	return 0;
275 
276 e_free:
277 	sev_asid_free(sev);
278 	sev->asid = 0;
279 e_no_asid:
280 	sev->es_active = false;
281 	sev->active = false;
282 	return ret;
283 }
284 
sev_bind_asid(struct kvm * kvm,unsigned int handle,int * error)285 static int sev_bind_asid(struct kvm *kvm, unsigned int handle, int *error)
286 {
287 	struct sev_data_activate activate;
288 	int asid = sev_get_asid(kvm);
289 	int ret;
290 
291 	/* activate ASID on the given handle */
292 	activate.handle = handle;
293 	activate.asid   = asid;
294 	ret = sev_guest_activate(&activate, error);
295 
296 	return ret;
297 }
298 
__sev_issue_cmd(int fd,int id,void * data,int * error)299 static int __sev_issue_cmd(int fd, int id, void *data, int *error)
300 {
301 	struct fd f;
302 	int ret;
303 
304 	f = fdget(fd);
305 	if (!f.file)
306 		return -EBADF;
307 
308 	ret = sev_issue_cmd_external_user(f.file, id, data, error);
309 
310 	fdput(f);
311 	return ret;
312 }
313 
sev_issue_cmd(struct kvm * kvm,int id,void * data,int * error)314 static int sev_issue_cmd(struct kvm *kvm, int id, void *data, int *error)
315 {
316 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
317 
318 	return __sev_issue_cmd(sev->fd, id, data, error);
319 }
320 
sev_launch_start(struct kvm * kvm,struct kvm_sev_cmd * argp)321 static int sev_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
322 {
323 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
324 	struct sev_data_launch_start start;
325 	struct kvm_sev_launch_start params;
326 	void *dh_blob, *session_blob;
327 	int *error = &argp->error;
328 	int ret;
329 
330 	if (!sev_guest(kvm))
331 		return -ENOTTY;
332 
333 	if (copy_from_user(&params, (void __user *)(uintptr_t)argp->data, sizeof(params)))
334 		return -EFAULT;
335 
336 	memset(&start, 0, sizeof(start));
337 
338 	dh_blob = NULL;
339 	if (params.dh_uaddr) {
340 		dh_blob = psp_copy_user_blob(params.dh_uaddr, params.dh_len);
341 		if (IS_ERR(dh_blob))
342 			return PTR_ERR(dh_blob);
343 
344 		start.dh_cert_address = __sme_set(__pa(dh_blob));
345 		start.dh_cert_len = params.dh_len;
346 	}
347 
348 	session_blob = NULL;
349 	if (params.session_uaddr) {
350 		session_blob = psp_copy_user_blob(params.session_uaddr, params.session_len);
351 		if (IS_ERR(session_blob)) {
352 			ret = PTR_ERR(session_blob);
353 			goto e_free_dh;
354 		}
355 
356 		start.session_address = __sme_set(__pa(session_blob));
357 		start.session_len = params.session_len;
358 	}
359 
360 	start.handle = params.handle;
361 	start.policy = params.policy;
362 
363 	/* create memory encryption context */
364 	ret = __sev_issue_cmd(argp->sev_fd, SEV_CMD_LAUNCH_START, &start, error);
365 	if (ret)
366 		goto e_free_session;
367 
368 	/* Bind ASID to this guest */
369 	ret = sev_bind_asid(kvm, start.handle, error);
370 	if (ret) {
371 		sev_decommission(start.handle);
372 		goto e_free_session;
373 	}
374 
375 	/* return handle to userspace */
376 	params.handle = start.handle;
377 	if (copy_to_user((void __user *)(uintptr_t)argp->data, &params, sizeof(params))) {
378 		sev_unbind_asid(kvm, start.handle);
379 		ret = -EFAULT;
380 		goto e_free_session;
381 	}
382 
383 	sev->handle = start.handle;
384 	sev->fd = argp->sev_fd;
385 
386 e_free_session:
387 	kfree(session_blob);
388 e_free_dh:
389 	kfree(dh_blob);
390 	return ret;
391 }
392 
sev_pin_memory(struct kvm * kvm,unsigned long uaddr,unsigned long ulen,unsigned long * n,int write)393 static struct page **sev_pin_memory(struct kvm *kvm, unsigned long uaddr,
394 				    unsigned long ulen, unsigned long *n,
395 				    int write)
396 {
397 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
398 	unsigned long npages, size;
399 	int npinned;
400 	unsigned long locked, lock_limit;
401 	struct page **pages;
402 	unsigned long first, last;
403 	int ret;
404 
405 	lockdep_assert_held(&kvm->lock);
406 
407 	if (ulen == 0 || uaddr + ulen < uaddr)
408 		return ERR_PTR(-EINVAL);
409 
410 	/* Calculate number of pages. */
411 	first = (uaddr & PAGE_MASK) >> PAGE_SHIFT;
412 	last = ((uaddr + ulen - 1) & PAGE_MASK) >> PAGE_SHIFT;
413 	npages = (last - first + 1);
414 
415 	locked = sev->pages_locked + npages;
416 	lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
417 	if (locked > lock_limit && !capable(CAP_IPC_LOCK)) {
418 		pr_err("SEV: %lu locked pages exceed the lock limit of %lu.\n", locked, lock_limit);
419 		return ERR_PTR(-ENOMEM);
420 	}
421 
422 	if (WARN_ON_ONCE(npages > INT_MAX))
423 		return ERR_PTR(-EINVAL);
424 
425 	/* Avoid using vmalloc for smaller buffers. */
426 	size = npages * sizeof(struct page *);
427 	if (size > PAGE_SIZE)
428 		pages = __vmalloc(size, GFP_KERNEL_ACCOUNT | __GFP_ZERO);
429 	else
430 		pages = kmalloc(size, GFP_KERNEL_ACCOUNT);
431 
432 	if (!pages)
433 		return ERR_PTR(-ENOMEM);
434 
435 	/* Pin the user virtual address. */
436 	npinned = pin_user_pages_fast(uaddr, npages, write ? FOLL_WRITE : 0, pages);
437 	if (npinned != npages) {
438 		pr_err("SEV: Failure locking %lu pages.\n", npages);
439 		ret = -ENOMEM;
440 		goto err;
441 	}
442 
443 	*n = npages;
444 	sev->pages_locked = locked;
445 
446 	return pages;
447 
448 err:
449 	if (npinned > 0)
450 		unpin_user_pages(pages, npinned);
451 
452 	kvfree(pages);
453 	return ERR_PTR(ret);
454 }
455 
sev_unpin_memory(struct kvm * kvm,struct page ** pages,unsigned long npages)456 static void sev_unpin_memory(struct kvm *kvm, struct page **pages,
457 			     unsigned long npages)
458 {
459 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
460 
461 	unpin_user_pages(pages, npages);
462 	kvfree(pages);
463 	sev->pages_locked -= npages;
464 }
465 
sev_clflush_pages(struct page * pages[],unsigned long npages)466 static void sev_clflush_pages(struct page *pages[], unsigned long npages)
467 {
468 	uint8_t *page_virtual;
469 	unsigned long i;
470 
471 	if (this_cpu_has(X86_FEATURE_SME_COHERENT) || npages == 0 ||
472 	    pages == NULL)
473 		return;
474 
475 	for (i = 0; i < npages; i++) {
476 		page_virtual = kmap_local_page(pages[i]);
477 		clflush_cache_range(page_virtual, PAGE_SIZE);
478 		kunmap_local(page_virtual);
479 		cond_resched();
480 	}
481 }
482 
get_num_contig_pages(unsigned long idx,struct page ** inpages,unsigned long npages)483 static unsigned long get_num_contig_pages(unsigned long idx,
484 				struct page **inpages, unsigned long npages)
485 {
486 	unsigned long paddr, next_paddr;
487 	unsigned long i = idx + 1, pages = 1;
488 
489 	/* find the number of contiguous pages starting from idx */
490 	paddr = __sme_page_pa(inpages[idx]);
491 	while (i < npages) {
492 		next_paddr = __sme_page_pa(inpages[i++]);
493 		if ((paddr + PAGE_SIZE) == next_paddr) {
494 			pages++;
495 			paddr = next_paddr;
496 			continue;
497 		}
498 		break;
499 	}
500 
501 	return pages;
502 }
503 
sev_launch_update_data(struct kvm * kvm,struct kvm_sev_cmd * argp)504 static int sev_launch_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
505 {
506 	unsigned long vaddr, vaddr_end, next_vaddr, npages, pages, size, i;
507 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
508 	struct kvm_sev_launch_update_data params;
509 	struct sev_data_launch_update_data data;
510 	struct page **inpages;
511 	int ret;
512 
513 	if (!sev_guest(kvm))
514 		return -ENOTTY;
515 
516 	if (copy_from_user(&params, (void __user *)(uintptr_t)argp->data, sizeof(params)))
517 		return -EFAULT;
518 
519 	vaddr = params.uaddr;
520 	size = params.len;
521 	vaddr_end = vaddr + size;
522 
523 	/* Lock the user memory. */
524 	inpages = sev_pin_memory(kvm, vaddr, size, &npages, 1);
525 	if (IS_ERR(inpages))
526 		return PTR_ERR(inpages);
527 
528 	/*
529 	 * Flush (on non-coherent CPUs) before LAUNCH_UPDATE encrypts pages in
530 	 * place; the cache may contain the data that was written unencrypted.
531 	 */
532 	sev_clflush_pages(inpages, npages);
533 
534 	data.reserved = 0;
535 	data.handle = sev->handle;
536 
537 	for (i = 0; vaddr < vaddr_end; vaddr = next_vaddr, i += pages) {
538 		int offset, len;
539 
540 		/*
541 		 * If the user buffer is not page-aligned, calculate the offset
542 		 * within the page.
543 		 */
544 		offset = vaddr & (PAGE_SIZE - 1);
545 
546 		/* Calculate the number of pages that can be encrypted in one go. */
547 		pages = get_num_contig_pages(i, inpages, npages);
548 
549 		len = min_t(size_t, ((pages * PAGE_SIZE) - offset), size);
550 
551 		data.len = len;
552 		data.address = __sme_page_pa(inpages[i]) + offset;
553 		ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_UPDATE_DATA, &data, &argp->error);
554 		if (ret)
555 			goto e_unpin;
556 
557 		size -= len;
558 		next_vaddr = vaddr + len;
559 	}
560 
561 e_unpin:
562 	/* content of memory is updated, mark pages dirty */
563 	for (i = 0; i < npages; i++) {
564 		set_page_dirty_lock(inpages[i]);
565 		mark_page_accessed(inpages[i]);
566 	}
567 	/* unlock the user pages */
568 	sev_unpin_memory(kvm, inpages, npages);
569 	return ret;
570 }
571 
sev_es_sync_vmsa(struct vcpu_svm * svm)572 static int sev_es_sync_vmsa(struct vcpu_svm *svm)
573 {
574 	struct sev_es_save_area *save = svm->sev_es.vmsa;
575 
576 	/* Check some debug related fields before encrypting the VMSA */
577 	if (svm->vcpu.guest_debug || (svm->vmcb->save.dr7 & ~DR7_FIXED_1))
578 		return -EINVAL;
579 
580 	/*
581 	 * SEV-ES will use a VMSA that is pointed to by the VMCB, not
582 	 * the traditional VMSA that is part of the VMCB. Copy the
583 	 * traditional VMSA as it has been built so far (in prep
584 	 * for LAUNCH_UPDATE_VMSA) to be the initial SEV-ES state.
585 	 */
586 	memcpy(save, &svm->vmcb->save, sizeof(svm->vmcb->save));
587 
588 	/* Sync registgers */
589 	save->rax = svm->vcpu.arch.regs[VCPU_REGS_RAX];
590 	save->rbx = svm->vcpu.arch.regs[VCPU_REGS_RBX];
591 	save->rcx = svm->vcpu.arch.regs[VCPU_REGS_RCX];
592 	save->rdx = svm->vcpu.arch.regs[VCPU_REGS_RDX];
593 	save->rsp = svm->vcpu.arch.regs[VCPU_REGS_RSP];
594 	save->rbp = svm->vcpu.arch.regs[VCPU_REGS_RBP];
595 	save->rsi = svm->vcpu.arch.regs[VCPU_REGS_RSI];
596 	save->rdi = svm->vcpu.arch.regs[VCPU_REGS_RDI];
597 #ifdef CONFIG_X86_64
598 	save->r8  = svm->vcpu.arch.regs[VCPU_REGS_R8];
599 	save->r9  = svm->vcpu.arch.regs[VCPU_REGS_R9];
600 	save->r10 = svm->vcpu.arch.regs[VCPU_REGS_R10];
601 	save->r11 = svm->vcpu.arch.regs[VCPU_REGS_R11];
602 	save->r12 = svm->vcpu.arch.regs[VCPU_REGS_R12];
603 	save->r13 = svm->vcpu.arch.regs[VCPU_REGS_R13];
604 	save->r14 = svm->vcpu.arch.regs[VCPU_REGS_R14];
605 	save->r15 = svm->vcpu.arch.regs[VCPU_REGS_R15];
606 #endif
607 	save->rip = svm->vcpu.arch.regs[VCPU_REGS_RIP];
608 
609 	/* Sync some non-GPR registers before encrypting */
610 	save->xcr0 = svm->vcpu.arch.xcr0;
611 	save->pkru = svm->vcpu.arch.pkru;
612 	save->xss  = svm->vcpu.arch.ia32_xss;
613 	save->dr6  = svm->vcpu.arch.dr6;
614 
615 	if (sev_es_debug_swap_enabled) {
616 		save->sev_features |= SVM_SEV_FEAT_DEBUG_SWAP;
617 		pr_warn_once("Enabling DebugSwap with KVM_SEV_ES_INIT. "
618 			     "This will not work starting with Linux 6.10\n");
619 	}
620 
621 	pr_debug("Virtual Machine Save Area (VMSA):\n");
622 	print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, save, sizeof(*save), false);
623 
624 	return 0;
625 }
626 
__sev_launch_update_vmsa(struct kvm * kvm,struct kvm_vcpu * vcpu,int * error)627 static int __sev_launch_update_vmsa(struct kvm *kvm, struct kvm_vcpu *vcpu,
628 				    int *error)
629 {
630 	struct sev_data_launch_update_vmsa vmsa;
631 	struct vcpu_svm *svm = to_svm(vcpu);
632 	int ret;
633 
634 	if (vcpu->guest_debug) {
635 		pr_warn_once("KVM_SET_GUEST_DEBUG for SEV-ES guest is not supported");
636 		return -EINVAL;
637 	}
638 
639 	/* Perform some pre-encryption checks against the VMSA */
640 	ret = sev_es_sync_vmsa(svm);
641 	if (ret)
642 		return ret;
643 
644 	/*
645 	 * The LAUNCH_UPDATE_VMSA command will perform in-place encryption of
646 	 * the VMSA memory content (i.e it will write the same memory region
647 	 * with the guest's key), so invalidate it first.
648 	 */
649 	clflush_cache_range(svm->sev_es.vmsa, PAGE_SIZE);
650 
651 	vmsa.reserved = 0;
652 	vmsa.handle = to_kvm_svm(kvm)->sev_info.handle;
653 	vmsa.address = __sme_pa(svm->sev_es.vmsa);
654 	vmsa.len = PAGE_SIZE;
655 	ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_UPDATE_VMSA, &vmsa, error);
656 	if (ret)
657 	  return ret;
658 
659 	vcpu->arch.guest_state_protected = true;
660 	return 0;
661 }
662 
sev_launch_update_vmsa(struct kvm * kvm,struct kvm_sev_cmd * argp)663 static int sev_launch_update_vmsa(struct kvm *kvm, struct kvm_sev_cmd *argp)
664 {
665 	struct kvm_vcpu *vcpu;
666 	unsigned long i;
667 	int ret;
668 
669 	if (!sev_es_guest(kvm))
670 		return -ENOTTY;
671 
672 	kvm_for_each_vcpu(i, vcpu, kvm) {
673 		ret = mutex_lock_killable(&vcpu->mutex);
674 		if (ret)
675 			return ret;
676 
677 		ret = __sev_launch_update_vmsa(kvm, vcpu, &argp->error);
678 
679 		mutex_unlock(&vcpu->mutex);
680 		if (ret)
681 			return ret;
682 	}
683 
684 	return 0;
685 }
686 
sev_launch_measure(struct kvm * kvm,struct kvm_sev_cmd * argp)687 static int sev_launch_measure(struct kvm *kvm, struct kvm_sev_cmd *argp)
688 {
689 	void __user *measure = (void __user *)(uintptr_t)argp->data;
690 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
691 	struct sev_data_launch_measure data;
692 	struct kvm_sev_launch_measure params;
693 	void __user *p = NULL;
694 	void *blob = NULL;
695 	int ret;
696 
697 	if (!sev_guest(kvm))
698 		return -ENOTTY;
699 
700 	if (copy_from_user(&params, measure, sizeof(params)))
701 		return -EFAULT;
702 
703 	memset(&data, 0, sizeof(data));
704 
705 	/* User wants to query the blob length */
706 	if (!params.len)
707 		goto cmd;
708 
709 	p = (void __user *)(uintptr_t)params.uaddr;
710 	if (p) {
711 		if (params.len > SEV_FW_BLOB_MAX_SIZE)
712 			return -EINVAL;
713 
714 		blob = kzalloc(params.len, GFP_KERNEL_ACCOUNT);
715 		if (!blob)
716 			return -ENOMEM;
717 
718 		data.address = __psp_pa(blob);
719 		data.len = params.len;
720 	}
721 
722 cmd:
723 	data.handle = sev->handle;
724 	ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_MEASURE, &data, &argp->error);
725 
726 	/*
727 	 * If we query the session length, FW responded with expected data.
728 	 */
729 	if (!params.len)
730 		goto done;
731 
732 	if (ret)
733 		goto e_free_blob;
734 
735 	if (blob) {
736 		if (copy_to_user(p, blob, params.len))
737 			ret = -EFAULT;
738 	}
739 
740 done:
741 	params.len = data.len;
742 	if (copy_to_user(measure, &params, sizeof(params)))
743 		ret = -EFAULT;
744 e_free_blob:
745 	kfree(blob);
746 	return ret;
747 }
748 
sev_launch_finish(struct kvm * kvm,struct kvm_sev_cmd * argp)749 static int sev_launch_finish(struct kvm *kvm, struct kvm_sev_cmd *argp)
750 {
751 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
752 	struct sev_data_launch_finish data;
753 
754 	if (!sev_guest(kvm))
755 		return -ENOTTY;
756 
757 	data.handle = sev->handle;
758 	return sev_issue_cmd(kvm, SEV_CMD_LAUNCH_FINISH, &data, &argp->error);
759 }
760 
sev_guest_status(struct kvm * kvm,struct kvm_sev_cmd * argp)761 static int sev_guest_status(struct kvm *kvm, struct kvm_sev_cmd *argp)
762 {
763 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
764 	struct kvm_sev_guest_status params;
765 	struct sev_data_guest_status data;
766 	int ret;
767 
768 	if (!sev_guest(kvm))
769 		return -ENOTTY;
770 
771 	memset(&data, 0, sizeof(data));
772 
773 	data.handle = sev->handle;
774 	ret = sev_issue_cmd(kvm, SEV_CMD_GUEST_STATUS, &data, &argp->error);
775 	if (ret)
776 		return ret;
777 
778 	params.policy = data.policy;
779 	params.state = data.state;
780 	params.handle = data.handle;
781 
782 	if (copy_to_user((void __user *)(uintptr_t)argp->data, &params, sizeof(params)))
783 		ret = -EFAULT;
784 
785 	return ret;
786 }
787 
__sev_issue_dbg_cmd(struct kvm * kvm,unsigned long src,unsigned long dst,int size,int * error,bool enc)788 static int __sev_issue_dbg_cmd(struct kvm *kvm, unsigned long src,
789 			       unsigned long dst, int size,
790 			       int *error, bool enc)
791 {
792 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
793 	struct sev_data_dbg data;
794 
795 	data.reserved = 0;
796 	data.handle = sev->handle;
797 	data.dst_addr = dst;
798 	data.src_addr = src;
799 	data.len = size;
800 
801 	return sev_issue_cmd(kvm,
802 			     enc ? SEV_CMD_DBG_ENCRYPT : SEV_CMD_DBG_DECRYPT,
803 			     &data, error);
804 }
805 
__sev_dbg_decrypt(struct kvm * kvm,unsigned long src_paddr,unsigned long dst_paddr,int sz,int * err)806 static int __sev_dbg_decrypt(struct kvm *kvm, unsigned long src_paddr,
807 			     unsigned long dst_paddr, int sz, int *err)
808 {
809 	int offset;
810 
811 	/*
812 	 * Its safe to read more than we are asked, caller should ensure that
813 	 * destination has enough space.
814 	 */
815 	offset = src_paddr & 15;
816 	src_paddr = round_down(src_paddr, 16);
817 	sz = round_up(sz + offset, 16);
818 
819 	return __sev_issue_dbg_cmd(kvm, src_paddr, dst_paddr, sz, err, false);
820 }
821 
__sev_dbg_decrypt_user(struct kvm * kvm,unsigned long paddr,void __user * dst_uaddr,unsigned long dst_paddr,int size,int * err)822 static int __sev_dbg_decrypt_user(struct kvm *kvm, unsigned long paddr,
823 				  void __user *dst_uaddr,
824 				  unsigned long dst_paddr,
825 				  int size, int *err)
826 {
827 	struct page *tpage = NULL;
828 	int ret, offset;
829 
830 	/* if inputs are not 16-byte then use intermediate buffer */
831 	if (!IS_ALIGNED(dst_paddr, 16) ||
832 	    !IS_ALIGNED(paddr,     16) ||
833 	    !IS_ALIGNED(size,      16)) {
834 		tpage = (void *)alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
835 		if (!tpage)
836 			return -ENOMEM;
837 
838 		dst_paddr = __sme_page_pa(tpage);
839 	}
840 
841 	ret = __sev_dbg_decrypt(kvm, paddr, dst_paddr, size, err);
842 	if (ret)
843 		goto e_free;
844 
845 	if (tpage) {
846 		offset = paddr & 15;
847 		if (copy_to_user(dst_uaddr, page_address(tpage) + offset, size))
848 			ret = -EFAULT;
849 	}
850 
851 e_free:
852 	if (tpage)
853 		__free_page(tpage);
854 
855 	return ret;
856 }
857 
__sev_dbg_encrypt_user(struct kvm * kvm,unsigned long paddr,void __user * vaddr,unsigned long dst_paddr,void __user * dst_vaddr,int size,int * error)858 static int __sev_dbg_encrypt_user(struct kvm *kvm, unsigned long paddr,
859 				  void __user *vaddr,
860 				  unsigned long dst_paddr,
861 				  void __user *dst_vaddr,
862 				  int size, int *error)
863 {
864 	struct page *src_tpage = NULL;
865 	struct page *dst_tpage = NULL;
866 	int ret, len = size;
867 
868 	/* If source buffer is not aligned then use an intermediate buffer */
869 	if (!IS_ALIGNED((unsigned long)vaddr, 16)) {
870 		src_tpage = alloc_page(GFP_KERNEL_ACCOUNT);
871 		if (!src_tpage)
872 			return -ENOMEM;
873 
874 		if (copy_from_user(page_address(src_tpage), vaddr, size)) {
875 			__free_page(src_tpage);
876 			return -EFAULT;
877 		}
878 
879 		paddr = __sme_page_pa(src_tpage);
880 	}
881 
882 	/*
883 	 *  If destination buffer or length is not aligned then do read-modify-write:
884 	 *   - decrypt destination in an intermediate buffer
885 	 *   - copy the source buffer in an intermediate buffer
886 	 *   - use the intermediate buffer as source buffer
887 	 */
888 	if (!IS_ALIGNED((unsigned long)dst_vaddr, 16) || !IS_ALIGNED(size, 16)) {
889 		int dst_offset;
890 
891 		dst_tpage = alloc_page(GFP_KERNEL_ACCOUNT);
892 		if (!dst_tpage) {
893 			ret = -ENOMEM;
894 			goto e_free;
895 		}
896 
897 		ret = __sev_dbg_decrypt(kvm, dst_paddr,
898 					__sme_page_pa(dst_tpage), size, error);
899 		if (ret)
900 			goto e_free;
901 
902 		/*
903 		 *  If source is kernel buffer then use memcpy() otherwise
904 		 *  copy_from_user().
905 		 */
906 		dst_offset = dst_paddr & 15;
907 
908 		if (src_tpage)
909 			memcpy(page_address(dst_tpage) + dst_offset,
910 			       page_address(src_tpage), size);
911 		else {
912 			if (copy_from_user(page_address(dst_tpage) + dst_offset,
913 					   vaddr, size)) {
914 				ret = -EFAULT;
915 				goto e_free;
916 			}
917 		}
918 
919 		paddr = __sme_page_pa(dst_tpage);
920 		dst_paddr = round_down(dst_paddr, 16);
921 		len = round_up(size, 16);
922 	}
923 
924 	ret = __sev_issue_dbg_cmd(kvm, paddr, dst_paddr, len, error, true);
925 
926 e_free:
927 	if (src_tpage)
928 		__free_page(src_tpage);
929 	if (dst_tpage)
930 		__free_page(dst_tpage);
931 	return ret;
932 }
933 
sev_dbg_crypt(struct kvm * kvm,struct kvm_sev_cmd * argp,bool dec)934 static int sev_dbg_crypt(struct kvm *kvm, struct kvm_sev_cmd *argp, bool dec)
935 {
936 	unsigned long vaddr, vaddr_end, next_vaddr;
937 	unsigned long dst_vaddr;
938 	struct page **src_p, **dst_p;
939 	struct kvm_sev_dbg debug;
940 	unsigned long n;
941 	unsigned int size;
942 	int ret;
943 
944 	if (!sev_guest(kvm))
945 		return -ENOTTY;
946 
947 	if (copy_from_user(&debug, (void __user *)(uintptr_t)argp->data, sizeof(debug)))
948 		return -EFAULT;
949 
950 	if (!debug.len || debug.src_uaddr + debug.len < debug.src_uaddr)
951 		return -EINVAL;
952 	if (!debug.dst_uaddr)
953 		return -EINVAL;
954 
955 	vaddr = debug.src_uaddr;
956 	size = debug.len;
957 	vaddr_end = vaddr + size;
958 	dst_vaddr = debug.dst_uaddr;
959 
960 	for (; vaddr < vaddr_end; vaddr = next_vaddr) {
961 		int len, s_off, d_off;
962 
963 		/* lock userspace source and destination page */
964 		src_p = sev_pin_memory(kvm, vaddr & PAGE_MASK, PAGE_SIZE, &n, 0);
965 		if (IS_ERR(src_p))
966 			return PTR_ERR(src_p);
967 
968 		dst_p = sev_pin_memory(kvm, dst_vaddr & PAGE_MASK, PAGE_SIZE, &n, 1);
969 		if (IS_ERR(dst_p)) {
970 			sev_unpin_memory(kvm, src_p, n);
971 			return PTR_ERR(dst_p);
972 		}
973 
974 		/*
975 		 * Flush (on non-coherent CPUs) before DBG_{DE,EN}CRYPT read or modify
976 		 * the pages; flush the destination too so that future accesses do not
977 		 * see stale data.
978 		 */
979 		sev_clflush_pages(src_p, 1);
980 		sev_clflush_pages(dst_p, 1);
981 
982 		/*
983 		 * Since user buffer may not be page aligned, calculate the
984 		 * offset within the page.
985 		 */
986 		s_off = vaddr & ~PAGE_MASK;
987 		d_off = dst_vaddr & ~PAGE_MASK;
988 		len = min_t(size_t, (PAGE_SIZE - s_off), size);
989 
990 		if (dec)
991 			ret = __sev_dbg_decrypt_user(kvm,
992 						     __sme_page_pa(src_p[0]) + s_off,
993 						     (void __user *)dst_vaddr,
994 						     __sme_page_pa(dst_p[0]) + d_off,
995 						     len, &argp->error);
996 		else
997 			ret = __sev_dbg_encrypt_user(kvm,
998 						     __sme_page_pa(src_p[0]) + s_off,
999 						     (void __user *)vaddr,
1000 						     __sme_page_pa(dst_p[0]) + d_off,
1001 						     (void __user *)dst_vaddr,
1002 						     len, &argp->error);
1003 
1004 		sev_unpin_memory(kvm, src_p, n);
1005 		sev_unpin_memory(kvm, dst_p, n);
1006 
1007 		if (ret)
1008 			goto err;
1009 
1010 		next_vaddr = vaddr + len;
1011 		dst_vaddr = dst_vaddr + len;
1012 		size -= len;
1013 	}
1014 err:
1015 	return ret;
1016 }
1017 
sev_launch_secret(struct kvm * kvm,struct kvm_sev_cmd * argp)1018 static int sev_launch_secret(struct kvm *kvm, struct kvm_sev_cmd *argp)
1019 {
1020 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1021 	struct sev_data_launch_secret data;
1022 	struct kvm_sev_launch_secret params;
1023 	struct page **pages;
1024 	void *blob, *hdr;
1025 	unsigned long n, i;
1026 	int ret, offset;
1027 
1028 	if (!sev_guest(kvm))
1029 		return -ENOTTY;
1030 
1031 	if (copy_from_user(&params, (void __user *)(uintptr_t)argp->data, sizeof(params)))
1032 		return -EFAULT;
1033 
1034 	pages = sev_pin_memory(kvm, params.guest_uaddr, params.guest_len, &n, 1);
1035 	if (IS_ERR(pages))
1036 		return PTR_ERR(pages);
1037 
1038 	/*
1039 	 * Flush (on non-coherent CPUs) before LAUNCH_SECRET encrypts pages in
1040 	 * place; the cache may contain the data that was written unencrypted.
1041 	 */
1042 	sev_clflush_pages(pages, n);
1043 
1044 	/*
1045 	 * The secret must be copied into contiguous memory region, lets verify
1046 	 * that userspace memory pages are contiguous before we issue command.
1047 	 */
1048 	if (get_num_contig_pages(0, pages, n) != n) {
1049 		ret = -EINVAL;
1050 		goto e_unpin_memory;
1051 	}
1052 
1053 	memset(&data, 0, sizeof(data));
1054 
1055 	offset = params.guest_uaddr & (PAGE_SIZE - 1);
1056 	data.guest_address = __sme_page_pa(pages[0]) + offset;
1057 	data.guest_len = params.guest_len;
1058 
1059 	blob = psp_copy_user_blob(params.trans_uaddr, params.trans_len);
1060 	if (IS_ERR(blob)) {
1061 		ret = PTR_ERR(blob);
1062 		goto e_unpin_memory;
1063 	}
1064 
1065 	data.trans_address = __psp_pa(blob);
1066 	data.trans_len = params.trans_len;
1067 
1068 	hdr = psp_copy_user_blob(params.hdr_uaddr, params.hdr_len);
1069 	if (IS_ERR(hdr)) {
1070 		ret = PTR_ERR(hdr);
1071 		goto e_free_blob;
1072 	}
1073 	data.hdr_address = __psp_pa(hdr);
1074 	data.hdr_len = params.hdr_len;
1075 
1076 	data.handle = sev->handle;
1077 	ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_UPDATE_SECRET, &data, &argp->error);
1078 
1079 	kfree(hdr);
1080 
1081 e_free_blob:
1082 	kfree(blob);
1083 e_unpin_memory:
1084 	/* content of memory is updated, mark pages dirty */
1085 	for (i = 0; i < n; i++) {
1086 		set_page_dirty_lock(pages[i]);
1087 		mark_page_accessed(pages[i]);
1088 	}
1089 	sev_unpin_memory(kvm, pages, n);
1090 	return ret;
1091 }
1092 
sev_get_attestation_report(struct kvm * kvm,struct kvm_sev_cmd * argp)1093 static int sev_get_attestation_report(struct kvm *kvm, struct kvm_sev_cmd *argp)
1094 {
1095 	void __user *report = (void __user *)(uintptr_t)argp->data;
1096 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1097 	struct sev_data_attestation_report data;
1098 	struct kvm_sev_attestation_report params;
1099 	void __user *p;
1100 	void *blob = NULL;
1101 	int ret;
1102 
1103 	if (!sev_guest(kvm))
1104 		return -ENOTTY;
1105 
1106 	if (copy_from_user(&params, (void __user *)(uintptr_t)argp->data, sizeof(params)))
1107 		return -EFAULT;
1108 
1109 	memset(&data, 0, sizeof(data));
1110 
1111 	/* User wants to query the blob length */
1112 	if (!params.len)
1113 		goto cmd;
1114 
1115 	p = (void __user *)(uintptr_t)params.uaddr;
1116 	if (p) {
1117 		if (params.len > SEV_FW_BLOB_MAX_SIZE)
1118 			return -EINVAL;
1119 
1120 		blob = kzalloc(params.len, GFP_KERNEL_ACCOUNT);
1121 		if (!blob)
1122 			return -ENOMEM;
1123 
1124 		data.address = __psp_pa(blob);
1125 		data.len = params.len;
1126 		memcpy(data.mnonce, params.mnonce, sizeof(params.mnonce));
1127 	}
1128 cmd:
1129 	data.handle = sev->handle;
1130 	ret = sev_issue_cmd(kvm, SEV_CMD_ATTESTATION_REPORT, &data, &argp->error);
1131 	/*
1132 	 * If we query the session length, FW responded with expected data.
1133 	 */
1134 	if (!params.len)
1135 		goto done;
1136 
1137 	if (ret)
1138 		goto e_free_blob;
1139 
1140 	if (blob) {
1141 		if (copy_to_user(p, blob, params.len))
1142 			ret = -EFAULT;
1143 	}
1144 
1145 done:
1146 	params.len = data.len;
1147 	if (copy_to_user(report, &params, sizeof(params)))
1148 		ret = -EFAULT;
1149 e_free_blob:
1150 	kfree(blob);
1151 	return ret;
1152 }
1153 
1154 /* Userspace wants to query session length. */
1155 static int
__sev_send_start_query_session_length(struct kvm * kvm,struct kvm_sev_cmd * argp,struct kvm_sev_send_start * params)1156 __sev_send_start_query_session_length(struct kvm *kvm, struct kvm_sev_cmd *argp,
1157 				      struct kvm_sev_send_start *params)
1158 {
1159 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1160 	struct sev_data_send_start data;
1161 	int ret;
1162 
1163 	memset(&data, 0, sizeof(data));
1164 	data.handle = sev->handle;
1165 	ret = sev_issue_cmd(kvm, SEV_CMD_SEND_START, &data, &argp->error);
1166 
1167 	params->session_len = data.session_len;
1168 	if (copy_to_user((void __user *)(uintptr_t)argp->data, params,
1169 				sizeof(struct kvm_sev_send_start)))
1170 		ret = -EFAULT;
1171 
1172 	return ret;
1173 }
1174 
sev_send_start(struct kvm * kvm,struct kvm_sev_cmd * argp)1175 static int sev_send_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
1176 {
1177 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1178 	struct sev_data_send_start data;
1179 	struct kvm_sev_send_start params;
1180 	void *amd_certs, *session_data;
1181 	void *pdh_cert, *plat_certs;
1182 	int ret;
1183 
1184 	if (!sev_guest(kvm))
1185 		return -ENOTTY;
1186 
1187 	if (copy_from_user(&params, (void __user *)(uintptr_t)argp->data,
1188 				sizeof(struct kvm_sev_send_start)))
1189 		return -EFAULT;
1190 
1191 	/* if session_len is zero, userspace wants to query the session length */
1192 	if (!params.session_len)
1193 		return __sev_send_start_query_session_length(kvm, argp,
1194 				&params);
1195 
1196 	/* some sanity checks */
1197 	if (!params.pdh_cert_uaddr || !params.pdh_cert_len ||
1198 	    !params.session_uaddr || params.session_len > SEV_FW_BLOB_MAX_SIZE)
1199 		return -EINVAL;
1200 
1201 	/* allocate the memory to hold the session data blob */
1202 	session_data = kzalloc(params.session_len, GFP_KERNEL_ACCOUNT);
1203 	if (!session_data)
1204 		return -ENOMEM;
1205 
1206 	/* copy the certificate blobs from userspace */
1207 	pdh_cert = psp_copy_user_blob(params.pdh_cert_uaddr,
1208 				params.pdh_cert_len);
1209 	if (IS_ERR(pdh_cert)) {
1210 		ret = PTR_ERR(pdh_cert);
1211 		goto e_free_session;
1212 	}
1213 
1214 	plat_certs = psp_copy_user_blob(params.plat_certs_uaddr,
1215 				params.plat_certs_len);
1216 	if (IS_ERR(plat_certs)) {
1217 		ret = PTR_ERR(plat_certs);
1218 		goto e_free_pdh;
1219 	}
1220 
1221 	amd_certs = psp_copy_user_blob(params.amd_certs_uaddr,
1222 				params.amd_certs_len);
1223 	if (IS_ERR(amd_certs)) {
1224 		ret = PTR_ERR(amd_certs);
1225 		goto e_free_plat_cert;
1226 	}
1227 
1228 	/* populate the FW SEND_START field with system physical address */
1229 	memset(&data, 0, sizeof(data));
1230 	data.pdh_cert_address = __psp_pa(pdh_cert);
1231 	data.pdh_cert_len = params.pdh_cert_len;
1232 	data.plat_certs_address = __psp_pa(plat_certs);
1233 	data.plat_certs_len = params.plat_certs_len;
1234 	data.amd_certs_address = __psp_pa(amd_certs);
1235 	data.amd_certs_len = params.amd_certs_len;
1236 	data.session_address = __psp_pa(session_data);
1237 	data.session_len = params.session_len;
1238 	data.handle = sev->handle;
1239 
1240 	ret = sev_issue_cmd(kvm, SEV_CMD_SEND_START, &data, &argp->error);
1241 
1242 	if (!ret && copy_to_user((void __user *)(uintptr_t)params.session_uaddr,
1243 			session_data, params.session_len)) {
1244 		ret = -EFAULT;
1245 		goto e_free_amd_cert;
1246 	}
1247 
1248 	params.policy = data.policy;
1249 	params.session_len = data.session_len;
1250 	if (copy_to_user((void __user *)(uintptr_t)argp->data, &params,
1251 				sizeof(struct kvm_sev_send_start)))
1252 		ret = -EFAULT;
1253 
1254 e_free_amd_cert:
1255 	kfree(amd_certs);
1256 e_free_plat_cert:
1257 	kfree(plat_certs);
1258 e_free_pdh:
1259 	kfree(pdh_cert);
1260 e_free_session:
1261 	kfree(session_data);
1262 	return ret;
1263 }
1264 
1265 /* Userspace wants to query either header or trans length. */
1266 static int
__sev_send_update_data_query_lengths(struct kvm * kvm,struct kvm_sev_cmd * argp,struct kvm_sev_send_update_data * params)1267 __sev_send_update_data_query_lengths(struct kvm *kvm, struct kvm_sev_cmd *argp,
1268 				     struct kvm_sev_send_update_data *params)
1269 {
1270 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1271 	struct sev_data_send_update_data data;
1272 	int ret;
1273 
1274 	memset(&data, 0, sizeof(data));
1275 	data.handle = sev->handle;
1276 	ret = sev_issue_cmd(kvm, SEV_CMD_SEND_UPDATE_DATA, &data, &argp->error);
1277 
1278 	params->hdr_len = data.hdr_len;
1279 	params->trans_len = data.trans_len;
1280 
1281 	if (copy_to_user((void __user *)(uintptr_t)argp->data, params,
1282 			 sizeof(struct kvm_sev_send_update_data)))
1283 		ret = -EFAULT;
1284 
1285 	return ret;
1286 }
1287 
sev_send_update_data(struct kvm * kvm,struct kvm_sev_cmd * argp)1288 static int sev_send_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
1289 {
1290 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1291 	struct sev_data_send_update_data data;
1292 	struct kvm_sev_send_update_data params;
1293 	void *hdr, *trans_data;
1294 	struct page **guest_page;
1295 	unsigned long n;
1296 	int ret, offset;
1297 
1298 	if (!sev_guest(kvm))
1299 		return -ENOTTY;
1300 
1301 	if (copy_from_user(&params, (void __user *)(uintptr_t)argp->data,
1302 			sizeof(struct kvm_sev_send_update_data)))
1303 		return -EFAULT;
1304 
1305 	/* userspace wants to query either header or trans length */
1306 	if (!params.trans_len || !params.hdr_len)
1307 		return __sev_send_update_data_query_lengths(kvm, argp, &params);
1308 
1309 	if (!params.trans_uaddr || !params.guest_uaddr ||
1310 	    !params.guest_len || !params.hdr_uaddr)
1311 		return -EINVAL;
1312 
1313 	/* Check if we are crossing the page boundary */
1314 	offset = params.guest_uaddr & (PAGE_SIZE - 1);
1315 	if (params.guest_len > PAGE_SIZE || (params.guest_len + offset) > PAGE_SIZE)
1316 		return -EINVAL;
1317 
1318 	/* Pin guest memory */
1319 	guest_page = sev_pin_memory(kvm, params.guest_uaddr & PAGE_MASK,
1320 				    PAGE_SIZE, &n, 0);
1321 	if (IS_ERR(guest_page))
1322 		return PTR_ERR(guest_page);
1323 
1324 	/* allocate memory for header and transport buffer */
1325 	ret = -ENOMEM;
1326 	hdr = kzalloc(params.hdr_len, GFP_KERNEL_ACCOUNT);
1327 	if (!hdr)
1328 		goto e_unpin;
1329 
1330 	trans_data = kzalloc(params.trans_len, GFP_KERNEL_ACCOUNT);
1331 	if (!trans_data)
1332 		goto e_free_hdr;
1333 
1334 	memset(&data, 0, sizeof(data));
1335 	data.hdr_address = __psp_pa(hdr);
1336 	data.hdr_len = params.hdr_len;
1337 	data.trans_address = __psp_pa(trans_data);
1338 	data.trans_len = params.trans_len;
1339 
1340 	/* The SEND_UPDATE_DATA command requires C-bit to be always set. */
1341 	data.guest_address = (page_to_pfn(guest_page[0]) << PAGE_SHIFT) + offset;
1342 	data.guest_address |= sev_me_mask;
1343 	data.guest_len = params.guest_len;
1344 	data.handle = sev->handle;
1345 
1346 	ret = sev_issue_cmd(kvm, SEV_CMD_SEND_UPDATE_DATA, &data, &argp->error);
1347 
1348 	if (ret)
1349 		goto e_free_trans_data;
1350 
1351 	/* copy transport buffer to user space */
1352 	if (copy_to_user((void __user *)(uintptr_t)params.trans_uaddr,
1353 			 trans_data, params.trans_len)) {
1354 		ret = -EFAULT;
1355 		goto e_free_trans_data;
1356 	}
1357 
1358 	/* Copy packet header to userspace. */
1359 	if (copy_to_user((void __user *)(uintptr_t)params.hdr_uaddr, hdr,
1360 			 params.hdr_len))
1361 		ret = -EFAULT;
1362 
1363 e_free_trans_data:
1364 	kfree(trans_data);
1365 e_free_hdr:
1366 	kfree(hdr);
1367 e_unpin:
1368 	sev_unpin_memory(kvm, guest_page, n);
1369 
1370 	return ret;
1371 }
1372 
sev_send_finish(struct kvm * kvm,struct kvm_sev_cmd * argp)1373 static int sev_send_finish(struct kvm *kvm, struct kvm_sev_cmd *argp)
1374 {
1375 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1376 	struct sev_data_send_finish data;
1377 
1378 	if (!sev_guest(kvm))
1379 		return -ENOTTY;
1380 
1381 	data.handle = sev->handle;
1382 	return sev_issue_cmd(kvm, SEV_CMD_SEND_FINISH, &data, &argp->error);
1383 }
1384 
sev_send_cancel(struct kvm * kvm,struct kvm_sev_cmd * argp)1385 static int sev_send_cancel(struct kvm *kvm, struct kvm_sev_cmd *argp)
1386 {
1387 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1388 	struct sev_data_send_cancel data;
1389 
1390 	if (!sev_guest(kvm))
1391 		return -ENOTTY;
1392 
1393 	data.handle = sev->handle;
1394 	return sev_issue_cmd(kvm, SEV_CMD_SEND_CANCEL, &data, &argp->error);
1395 }
1396 
sev_receive_start(struct kvm * kvm,struct kvm_sev_cmd * argp)1397 static int sev_receive_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
1398 {
1399 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1400 	struct sev_data_receive_start start;
1401 	struct kvm_sev_receive_start params;
1402 	int *error = &argp->error;
1403 	void *session_data;
1404 	void *pdh_data;
1405 	int ret;
1406 
1407 	if (!sev_guest(kvm))
1408 		return -ENOTTY;
1409 
1410 	/* Get parameter from the userspace */
1411 	if (copy_from_user(&params, (void __user *)(uintptr_t)argp->data,
1412 			sizeof(struct kvm_sev_receive_start)))
1413 		return -EFAULT;
1414 
1415 	/* some sanity checks */
1416 	if (!params.pdh_uaddr || !params.pdh_len ||
1417 	    !params.session_uaddr || !params.session_len)
1418 		return -EINVAL;
1419 
1420 	pdh_data = psp_copy_user_blob(params.pdh_uaddr, params.pdh_len);
1421 	if (IS_ERR(pdh_data))
1422 		return PTR_ERR(pdh_data);
1423 
1424 	session_data = psp_copy_user_blob(params.session_uaddr,
1425 			params.session_len);
1426 	if (IS_ERR(session_data)) {
1427 		ret = PTR_ERR(session_data);
1428 		goto e_free_pdh;
1429 	}
1430 
1431 	memset(&start, 0, sizeof(start));
1432 	start.handle = params.handle;
1433 	start.policy = params.policy;
1434 	start.pdh_cert_address = __psp_pa(pdh_data);
1435 	start.pdh_cert_len = params.pdh_len;
1436 	start.session_address = __psp_pa(session_data);
1437 	start.session_len = params.session_len;
1438 
1439 	/* create memory encryption context */
1440 	ret = __sev_issue_cmd(argp->sev_fd, SEV_CMD_RECEIVE_START, &start,
1441 				error);
1442 	if (ret)
1443 		goto e_free_session;
1444 
1445 	/* Bind ASID to this guest */
1446 	ret = sev_bind_asid(kvm, start.handle, error);
1447 	if (ret) {
1448 		sev_decommission(start.handle);
1449 		goto e_free_session;
1450 	}
1451 
1452 	params.handle = start.handle;
1453 	if (copy_to_user((void __user *)(uintptr_t)argp->data,
1454 			 &params, sizeof(struct kvm_sev_receive_start))) {
1455 		ret = -EFAULT;
1456 		sev_unbind_asid(kvm, start.handle);
1457 		goto e_free_session;
1458 	}
1459 
1460     	sev->handle = start.handle;
1461 	sev->fd = argp->sev_fd;
1462 
1463 e_free_session:
1464 	kfree(session_data);
1465 e_free_pdh:
1466 	kfree(pdh_data);
1467 
1468 	return ret;
1469 }
1470 
sev_receive_update_data(struct kvm * kvm,struct kvm_sev_cmd * argp)1471 static int sev_receive_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
1472 {
1473 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1474 	struct kvm_sev_receive_update_data params;
1475 	struct sev_data_receive_update_data data;
1476 	void *hdr = NULL, *trans = NULL;
1477 	struct page **guest_page;
1478 	unsigned long n;
1479 	int ret, offset;
1480 
1481 	if (!sev_guest(kvm))
1482 		return -EINVAL;
1483 
1484 	if (copy_from_user(&params, (void __user *)(uintptr_t)argp->data,
1485 			sizeof(struct kvm_sev_receive_update_data)))
1486 		return -EFAULT;
1487 
1488 	if (!params.hdr_uaddr || !params.hdr_len ||
1489 	    !params.guest_uaddr || !params.guest_len ||
1490 	    !params.trans_uaddr || !params.trans_len)
1491 		return -EINVAL;
1492 
1493 	/* Check if we are crossing the page boundary */
1494 	offset = params.guest_uaddr & (PAGE_SIZE - 1);
1495 	if (params.guest_len > PAGE_SIZE || (params.guest_len + offset) > PAGE_SIZE)
1496 		return -EINVAL;
1497 
1498 	hdr = psp_copy_user_blob(params.hdr_uaddr, params.hdr_len);
1499 	if (IS_ERR(hdr))
1500 		return PTR_ERR(hdr);
1501 
1502 	trans = psp_copy_user_blob(params.trans_uaddr, params.trans_len);
1503 	if (IS_ERR(trans)) {
1504 		ret = PTR_ERR(trans);
1505 		goto e_free_hdr;
1506 	}
1507 
1508 	memset(&data, 0, sizeof(data));
1509 	data.hdr_address = __psp_pa(hdr);
1510 	data.hdr_len = params.hdr_len;
1511 	data.trans_address = __psp_pa(trans);
1512 	data.trans_len = params.trans_len;
1513 
1514 	/* Pin guest memory */
1515 	guest_page = sev_pin_memory(kvm, params.guest_uaddr & PAGE_MASK,
1516 				    PAGE_SIZE, &n, 1);
1517 	if (IS_ERR(guest_page)) {
1518 		ret = PTR_ERR(guest_page);
1519 		goto e_free_trans;
1520 	}
1521 
1522 	/*
1523 	 * Flush (on non-coherent CPUs) before RECEIVE_UPDATE_DATA, the PSP
1524 	 * encrypts the written data with the guest's key, and the cache may
1525 	 * contain dirty, unencrypted data.
1526 	 */
1527 	sev_clflush_pages(guest_page, n);
1528 
1529 	/* The RECEIVE_UPDATE_DATA command requires C-bit to be always set. */
1530 	data.guest_address = (page_to_pfn(guest_page[0]) << PAGE_SHIFT) + offset;
1531 	data.guest_address |= sev_me_mask;
1532 	data.guest_len = params.guest_len;
1533 	data.handle = sev->handle;
1534 
1535 	ret = sev_issue_cmd(kvm, SEV_CMD_RECEIVE_UPDATE_DATA, &data,
1536 				&argp->error);
1537 
1538 	sev_unpin_memory(kvm, guest_page, n);
1539 
1540 e_free_trans:
1541 	kfree(trans);
1542 e_free_hdr:
1543 	kfree(hdr);
1544 
1545 	return ret;
1546 }
1547 
sev_receive_finish(struct kvm * kvm,struct kvm_sev_cmd * argp)1548 static int sev_receive_finish(struct kvm *kvm, struct kvm_sev_cmd *argp)
1549 {
1550 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1551 	struct sev_data_receive_finish data;
1552 
1553 	if (!sev_guest(kvm))
1554 		return -ENOTTY;
1555 
1556 	data.handle = sev->handle;
1557 	return sev_issue_cmd(kvm, SEV_CMD_RECEIVE_FINISH, &data, &argp->error);
1558 }
1559 
is_cmd_allowed_from_mirror(u32 cmd_id)1560 static bool is_cmd_allowed_from_mirror(u32 cmd_id)
1561 {
1562 	/*
1563 	 * Allow mirrors VM to call KVM_SEV_LAUNCH_UPDATE_VMSA to enable SEV-ES
1564 	 * active mirror VMs. Also allow the debugging and status commands.
1565 	 */
1566 	if (cmd_id == KVM_SEV_LAUNCH_UPDATE_VMSA ||
1567 	    cmd_id == KVM_SEV_GUEST_STATUS || cmd_id == KVM_SEV_DBG_DECRYPT ||
1568 	    cmd_id == KVM_SEV_DBG_ENCRYPT)
1569 		return true;
1570 
1571 	return false;
1572 }
1573 
sev_lock_two_vms(struct kvm * dst_kvm,struct kvm * src_kvm)1574 static int sev_lock_two_vms(struct kvm *dst_kvm, struct kvm *src_kvm)
1575 {
1576 	struct kvm_sev_info *dst_sev = &to_kvm_svm(dst_kvm)->sev_info;
1577 	struct kvm_sev_info *src_sev = &to_kvm_svm(src_kvm)->sev_info;
1578 	int r = -EBUSY;
1579 
1580 	if (dst_kvm == src_kvm)
1581 		return -EINVAL;
1582 
1583 	/*
1584 	 * Bail if these VMs are already involved in a migration to avoid
1585 	 * deadlock between two VMs trying to migrate to/from each other.
1586 	 */
1587 	if (atomic_cmpxchg_acquire(&dst_sev->migration_in_progress, 0, 1))
1588 		return -EBUSY;
1589 
1590 	if (atomic_cmpxchg_acquire(&src_sev->migration_in_progress, 0, 1))
1591 		goto release_dst;
1592 
1593 	r = -EINTR;
1594 	if (mutex_lock_killable(&dst_kvm->lock))
1595 		goto release_src;
1596 	if (mutex_lock_killable_nested(&src_kvm->lock, SINGLE_DEPTH_NESTING))
1597 		goto unlock_dst;
1598 	return 0;
1599 
1600 unlock_dst:
1601 	mutex_unlock(&dst_kvm->lock);
1602 release_src:
1603 	atomic_set_release(&src_sev->migration_in_progress, 0);
1604 release_dst:
1605 	atomic_set_release(&dst_sev->migration_in_progress, 0);
1606 	return r;
1607 }
1608 
sev_unlock_two_vms(struct kvm * dst_kvm,struct kvm * src_kvm)1609 static void sev_unlock_two_vms(struct kvm *dst_kvm, struct kvm *src_kvm)
1610 {
1611 	struct kvm_sev_info *dst_sev = &to_kvm_svm(dst_kvm)->sev_info;
1612 	struct kvm_sev_info *src_sev = &to_kvm_svm(src_kvm)->sev_info;
1613 
1614 	mutex_unlock(&dst_kvm->lock);
1615 	mutex_unlock(&src_kvm->lock);
1616 	atomic_set_release(&dst_sev->migration_in_progress, 0);
1617 	atomic_set_release(&src_sev->migration_in_progress, 0);
1618 }
1619 
1620 /* vCPU mutex subclasses.  */
1621 enum sev_migration_role {
1622 	SEV_MIGRATION_SOURCE = 0,
1623 	SEV_MIGRATION_TARGET,
1624 	SEV_NR_MIGRATION_ROLES,
1625 };
1626 
sev_lock_vcpus_for_migration(struct kvm * kvm,enum sev_migration_role role)1627 static int sev_lock_vcpus_for_migration(struct kvm *kvm,
1628 					enum sev_migration_role role)
1629 {
1630 	struct kvm_vcpu *vcpu;
1631 	unsigned long i, j;
1632 
1633 	kvm_for_each_vcpu(i, vcpu, kvm) {
1634 		if (mutex_lock_killable_nested(&vcpu->mutex, role))
1635 			goto out_unlock;
1636 
1637 #ifdef CONFIG_PROVE_LOCKING
1638 		if (!i)
1639 			/*
1640 			 * Reset the role to one that avoids colliding with
1641 			 * the role used for the first vcpu mutex.
1642 			 */
1643 			role = SEV_NR_MIGRATION_ROLES;
1644 		else
1645 			mutex_release(&vcpu->mutex.dep_map, _THIS_IP_);
1646 #endif
1647 	}
1648 
1649 	return 0;
1650 
1651 out_unlock:
1652 
1653 	kvm_for_each_vcpu(j, vcpu, kvm) {
1654 		if (i == j)
1655 			break;
1656 
1657 #ifdef CONFIG_PROVE_LOCKING
1658 		if (j)
1659 			mutex_acquire(&vcpu->mutex.dep_map, role, 0, _THIS_IP_);
1660 #endif
1661 
1662 		mutex_unlock(&vcpu->mutex);
1663 	}
1664 	return -EINTR;
1665 }
1666 
sev_unlock_vcpus_for_migration(struct kvm * kvm)1667 static void sev_unlock_vcpus_for_migration(struct kvm *kvm)
1668 {
1669 	struct kvm_vcpu *vcpu;
1670 	unsigned long i;
1671 	bool first = true;
1672 
1673 	kvm_for_each_vcpu(i, vcpu, kvm) {
1674 		if (first)
1675 			first = false;
1676 		else
1677 			mutex_acquire(&vcpu->mutex.dep_map,
1678 				      SEV_NR_MIGRATION_ROLES, 0, _THIS_IP_);
1679 
1680 		mutex_unlock(&vcpu->mutex);
1681 	}
1682 }
1683 
sev_migrate_from(struct kvm * dst_kvm,struct kvm * src_kvm)1684 static void sev_migrate_from(struct kvm *dst_kvm, struct kvm *src_kvm)
1685 {
1686 	struct kvm_sev_info *dst = &to_kvm_svm(dst_kvm)->sev_info;
1687 	struct kvm_sev_info *src = &to_kvm_svm(src_kvm)->sev_info;
1688 	struct kvm_vcpu *dst_vcpu, *src_vcpu;
1689 	struct vcpu_svm *dst_svm, *src_svm;
1690 	struct kvm_sev_info *mirror;
1691 	unsigned long i;
1692 
1693 	dst->active = true;
1694 	dst->asid = src->asid;
1695 	dst->handle = src->handle;
1696 	dst->pages_locked = src->pages_locked;
1697 	dst->enc_context_owner = src->enc_context_owner;
1698 	dst->es_active = src->es_active;
1699 
1700 	src->asid = 0;
1701 	src->active = false;
1702 	src->handle = 0;
1703 	src->pages_locked = 0;
1704 	src->enc_context_owner = NULL;
1705 	src->es_active = false;
1706 
1707 	list_cut_before(&dst->regions_list, &src->regions_list, &src->regions_list);
1708 
1709 	/*
1710 	 * If this VM has mirrors, "transfer" each mirror's refcount of the
1711 	 * source to the destination (this KVM).  The caller holds a reference
1712 	 * to the source, so there's no danger of use-after-free.
1713 	 */
1714 	list_cut_before(&dst->mirror_vms, &src->mirror_vms, &src->mirror_vms);
1715 	list_for_each_entry(mirror, &dst->mirror_vms, mirror_entry) {
1716 		kvm_get_kvm(dst_kvm);
1717 		kvm_put_kvm(src_kvm);
1718 		mirror->enc_context_owner = dst_kvm;
1719 	}
1720 
1721 	/*
1722 	 * If this VM is a mirror, remove the old mirror from the owners list
1723 	 * and add the new mirror to the list.
1724 	 */
1725 	if (is_mirroring_enc_context(dst_kvm)) {
1726 		struct kvm_sev_info *owner_sev_info =
1727 			&to_kvm_svm(dst->enc_context_owner)->sev_info;
1728 
1729 		list_del(&src->mirror_entry);
1730 		list_add_tail(&dst->mirror_entry, &owner_sev_info->mirror_vms);
1731 	}
1732 
1733 	kvm_for_each_vcpu(i, dst_vcpu, dst_kvm) {
1734 		dst_svm = to_svm(dst_vcpu);
1735 
1736 		sev_init_vmcb(dst_svm);
1737 
1738 		if (!dst->es_active)
1739 			continue;
1740 
1741 		/*
1742 		 * Note, the source is not required to have the same number of
1743 		 * vCPUs as the destination when migrating a vanilla SEV VM.
1744 		 */
1745 		src_vcpu = kvm_get_vcpu(src_kvm, i);
1746 		src_svm = to_svm(src_vcpu);
1747 
1748 		/*
1749 		 * Transfer VMSA and GHCB state to the destination.  Nullify and
1750 		 * clear source fields as appropriate, the state now belongs to
1751 		 * the destination.
1752 		 */
1753 		memcpy(&dst_svm->sev_es, &src_svm->sev_es, sizeof(src_svm->sev_es));
1754 		dst_svm->vmcb->control.ghcb_gpa = src_svm->vmcb->control.ghcb_gpa;
1755 		dst_svm->vmcb->control.vmsa_pa = src_svm->vmcb->control.vmsa_pa;
1756 		dst_vcpu->arch.guest_state_protected = true;
1757 
1758 		memset(&src_svm->sev_es, 0, sizeof(src_svm->sev_es));
1759 		src_svm->vmcb->control.ghcb_gpa = INVALID_PAGE;
1760 		src_svm->vmcb->control.vmsa_pa = INVALID_PAGE;
1761 		src_vcpu->arch.guest_state_protected = false;
1762 	}
1763 }
1764 
sev_check_source_vcpus(struct kvm * dst,struct kvm * src)1765 static int sev_check_source_vcpus(struct kvm *dst, struct kvm *src)
1766 {
1767 	struct kvm_vcpu *src_vcpu;
1768 	unsigned long i;
1769 
1770 	if (!sev_es_guest(src))
1771 		return 0;
1772 
1773 	if (atomic_read(&src->online_vcpus) != atomic_read(&dst->online_vcpus))
1774 		return -EINVAL;
1775 
1776 	kvm_for_each_vcpu(i, src_vcpu, src) {
1777 		if (!src_vcpu->arch.guest_state_protected)
1778 			return -EINVAL;
1779 	}
1780 
1781 	return 0;
1782 }
1783 
sev_vm_move_enc_context_from(struct kvm * kvm,unsigned int source_fd)1784 int sev_vm_move_enc_context_from(struct kvm *kvm, unsigned int source_fd)
1785 {
1786 	struct kvm_sev_info *dst_sev = &to_kvm_svm(kvm)->sev_info;
1787 	struct kvm_sev_info *src_sev, *cg_cleanup_sev;
1788 	struct fd f = fdget(source_fd);
1789 	struct kvm *source_kvm;
1790 	bool charged = false;
1791 	int ret;
1792 
1793 	if (!f.file)
1794 		return -EBADF;
1795 
1796 	if (!file_is_kvm(f.file)) {
1797 		ret = -EBADF;
1798 		goto out_fput;
1799 	}
1800 
1801 	source_kvm = f.file->private_data;
1802 	ret = sev_lock_two_vms(kvm, source_kvm);
1803 	if (ret)
1804 		goto out_fput;
1805 
1806 	if (sev_guest(kvm) || !sev_guest(source_kvm)) {
1807 		ret = -EINVAL;
1808 		goto out_unlock;
1809 	}
1810 
1811 	src_sev = &to_kvm_svm(source_kvm)->sev_info;
1812 
1813 	dst_sev->misc_cg = get_current_misc_cg();
1814 	cg_cleanup_sev = dst_sev;
1815 	if (dst_sev->misc_cg != src_sev->misc_cg) {
1816 		ret = sev_misc_cg_try_charge(dst_sev);
1817 		if (ret)
1818 			goto out_dst_cgroup;
1819 		charged = true;
1820 	}
1821 
1822 	ret = sev_lock_vcpus_for_migration(kvm, SEV_MIGRATION_SOURCE);
1823 	if (ret)
1824 		goto out_dst_cgroup;
1825 	ret = sev_lock_vcpus_for_migration(source_kvm, SEV_MIGRATION_TARGET);
1826 	if (ret)
1827 		goto out_dst_vcpu;
1828 
1829 	ret = sev_check_source_vcpus(kvm, source_kvm);
1830 	if (ret)
1831 		goto out_source_vcpu;
1832 
1833 	sev_migrate_from(kvm, source_kvm);
1834 	kvm_vm_dead(source_kvm);
1835 	cg_cleanup_sev = src_sev;
1836 	ret = 0;
1837 
1838 out_source_vcpu:
1839 	sev_unlock_vcpus_for_migration(source_kvm);
1840 out_dst_vcpu:
1841 	sev_unlock_vcpus_for_migration(kvm);
1842 out_dst_cgroup:
1843 	/* Operates on the source on success, on the destination on failure.  */
1844 	if (charged)
1845 		sev_misc_cg_uncharge(cg_cleanup_sev);
1846 	put_misc_cg(cg_cleanup_sev->misc_cg);
1847 	cg_cleanup_sev->misc_cg = NULL;
1848 out_unlock:
1849 	sev_unlock_two_vms(kvm, source_kvm);
1850 out_fput:
1851 	fdput(f);
1852 	return ret;
1853 }
1854 
sev_mem_enc_ioctl(struct kvm * kvm,void __user * argp)1855 int sev_mem_enc_ioctl(struct kvm *kvm, void __user *argp)
1856 {
1857 	struct kvm_sev_cmd sev_cmd;
1858 	int r;
1859 
1860 	if (!sev_enabled)
1861 		return -ENOTTY;
1862 
1863 	if (!argp)
1864 		return 0;
1865 
1866 	if (copy_from_user(&sev_cmd, argp, sizeof(struct kvm_sev_cmd)))
1867 		return -EFAULT;
1868 
1869 	mutex_lock(&kvm->lock);
1870 
1871 	/* Only the enc_context_owner handles some memory enc operations. */
1872 	if (is_mirroring_enc_context(kvm) &&
1873 	    !is_cmd_allowed_from_mirror(sev_cmd.id)) {
1874 		r = -EINVAL;
1875 		goto out;
1876 	}
1877 
1878 	switch (sev_cmd.id) {
1879 	case KVM_SEV_ES_INIT:
1880 		if (!sev_es_enabled) {
1881 			r = -ENOTTY;
1882 			goto out;
1883 		}
1884 		fallthrough;
1885 	case KVM_SEV_INIT:
1886 		r = sev_guest_init(kvm, &sev_cmd);
1887 		break;
1888 	case KVM_SEV_LAUNCH_START:
1889 		r = sev_launch_start(kvm, &sev_cmd);
1890 		break;
1891 	case KVM_SEV_LAUNCH_UPDATE_DATA:
1892 		r = sev_launch_update_data(kvm, &sev_cmd);
1893 		break;
1894 	case KVM_SEV_LAUNCH_UPDATE_VMSA:
1895 		r = sev_launch_update_vmsa(kvm, &sev_cmd);
1896 		break;
1897 	case KVM_SEV_LAUNCH_MEASURE:
1898 		r = sev_launch_measure(kvm, &sev_cmd);
1899 		break;
1900 	case KVM_SEV_LAUNCH_FINISH:
1901 		r = sev_launch_finish(kvm, &sev_cmd);
1902 		break;
1903 	case KVM_SEV_GUEST_STATUS:
1904 		r = sev_guest_status(kvm, &sev_cmd);
1905 		break;
1906 	case KVM_SEV_DBG_DECRYPT:
1907 		r = sev_dbg_crypt(kvm, &sev_cmd, true);
1908 		break;
1909 	case KVM_SEV_DBG_ENCRYPT:
1910 		r = sev_dbg_crypt(kvm, &sev_cmd, false);
1911 		break;
1912 	case KVM_SEV_LAUNCH_SECRET:
1913 		r = sev_launch_secret(kvm, &sev_cmd);
1914 		break;
1915 	case KVM_SEV_GET_ATTESTATION_REPORT:
1916 		r = sev_get_attestation_report(kvm, &sev_cmd);
1917 		break;
1918 	case KVM_SEV_SEND_START:
1919 		r = sev_send_start(kvm, &sev_cmd);
1920 		break;
1921 	case KVM_SEV_SEND_UPDATE_DATA:
1922 		r = sev_send_update_data(kvm, &sev_cmd);
1923 		break;
1924 	case KVM_SEV_SEND_FINISH:
1925 		r = sev_send_finish(kvm, &sev_cmd);
1926 		break;
1927 	case KVM_SEV_SEND_CANCEL:
1928 		r = sev_send_cancel(kvm, &sev_cmd);
1929 		break;
1930 	case KVM_SEV_RECEIVE_START:
1931 		r = sev_receive_start(kvm, &sev_cmd);
1932 		break;
1933 	case KVM_SEV_RECEIVE_UPDATE_DATA:
1934 		r = sev_receive_update_data(kvm, &sev_cmd);
1935 		break;
1936 	case KVM_SEV_RECEIVE_FINISH:
1937 		r = sev_receive_finish(kvm, &sev_cmd);
1938 		break;
1939 	default:
1940 		r = -EINVAL;
1941 		goto out;
1942 	}
1943 
1944 	if (copy_to_user(argp, &sev_cmd, sizeof(struct kvm_sev_cmd)))
1945 		r = -EFAULT;
1946 
1947 out:
1948 	mutex_unlock(&kvm->lock);
1949 	return r;
1950 }
1951 
sev_mem_enc_register_region(struct kvm * kvm,struct kvm_enc_region * range)1952 int sev_mem_enc_register_region(struct kvm *kvm,
1953 				struct kvm_enc_region *range)
1954 {
1955 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1956 	struct enc_region *region;
1957 	int ret = 0;
1958 
1959 	if (!sev_guest(kvm))
1960 		return -ENOTTY;
1961 
1962 	/* If kvm is mirroring encryption context it isn't responsible for it */
1963 	if (is_mirroring_enc_context(kvm))
1964 		return -EINVAL;
1965 
1966 	if (range->addr > ULONG_MAX || range->size > ULONG_MAX)
1967 		return -EINVAL;
1968 
1969 	region = kzalloc(sizeof(*region), GFP_KERNEL_ACCOUNT);
1970 	if (!region)
1971 		return -ENOMEM;
1972 
1973 	mutex_lock(&kvm->lock);
1974 	region->pages = sev_pin_memory(kvm, range->addr, range->size, &region->npages, 1);
1975 	if (IS_ERR(region->pages)) {
1976 		ret = PTR_ERR(region->pages);
1977 		mutex_unlock(&kvm->lock);
1978 		goto e_free;
1979 	}
1980 
1981 	/*
1982 	 * The guest may change the memory encryption attribute from C=0 -> C=1
1983 	 * or vice versa for this memory range. Lets make sure caches are
1984 	 * flushed to ensure that guest data gets written into memory with
1985 	 * correct C-bit.  Note, this must be done before dropping kvm->lock,
1986 	 * as region and its array of pages can be freed by a different task
1987 	 * once kvm->lock is released.
1988 	 */
1989 	sev_clflush_pages(region->pages, region->npages);
1990 
1991 	region->uaddr = range->addr;
1992 	region->size = range->size;
1993 
1994 	list_add_tail(&region->list, &sev->regions_list);
1995 	mutex_unlock(&kvm->lock);
1996 
1997 	return ret;
1998 
1999 e_free:
2000 	kfree(region);
2001 	return ret;
2002 }
2003 
2004 static struct enc_region *
find_enc_region(struct kvm * kvm,struct kvm_enc_region * range)2005 find_enc_region(struct kvm *kvm, struct kvm_enc_region *range)
2006 {
2007 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
2008 	struct list_head *head = &sev->regions_list;
2009 	struct enc_region *i;
2010 
2011 	list_for_each_entry(i, head, list) {
2012 		if (i->uaddr == range->addr &&
2013 		    i->size == range->size)
2014 			return i;
2015 	}
2016 
2017 	return NULL;
2018 }
2019 
__unregister_enc_region_locked(struct kvm * kvm,struct enc_region * region)2020 static void __unregister_enc_region_locked(struct kvm *kvm,
2021 					   struct enc_region *region)
2022 {
2023 	sev_unpin_memory(kvm, region->pages, region->npages);
2024 	list_del(&region->list);
2025 	kfree(region);
2026 }
2027 
sev_mem_enc_unregister_region(struct kvm * kvm,struct kvm_enc_region * range)2028 int sev_mem_enc_unregister_region(struct kvm *kvm,
2029 				  struct kvm_enc_region *range)
2030 {
2031 	struct enc_region *region;
2032 	int ret;
2033 
2034 	/* If kvm is mirroring encryption context it isn't responsible for it */
2035 	if (is_mirroring_enc_context(kvm))
2036 		return -EINVAL;
2037 
2038 	mutex_lock(&kvm->lock);
2039 
2040 	if (!sev_guest(kvm)) {
2041 		ret = -ENOTTY;
2042 		goto failed;
2043 	}
2044 
2045 	region = find_enc_region(kvm, range);
2046 	if (!region) {
2047 		ret = -EINVAL;
2048 		goto failed;
2049 	}
2050 
2051 	/*
2052 	 * Ensure that all guest tagged cache entries are flushed before
2053 	 * releasing the pages back to the system for use. CLFLUSH will
2054 	 * not do this, so issue a WBINVD.
2055 	 */
2056 	wbinvd_on_all_cpus();
2057 
2058 	__unregister_enc_region_locked(kvm, region);
2059 
2060 	mutex_unlock(&kvm->lock);
2061 	return 0;
2062 
2063 failed:
2064 	mutex_unlock(&kvm->lock);
2065 	return ret;
2066 }
2067 
sev_vm_copy_enc_context_from(struct kvm * kvm,unsigned int source_fd)2068 int sev_vm_copy_enc_context_from(struct kvm *kvm, unsigned int source_fd)
2069 {
2070 	struct fd f = fdget(source_fd);
2071 	struct kvm *source_kvm;
2072 	struct kvm_sev_info *source_sev, *mirror_sev;
2073 	int ret;
2074 
2075 	if (!f.file)
2076 		return -EBADF;
2077 
2078 	if (!file_is_kvm(f.file)) {
2079 		ret = -EBADF;
2080 		goto e_source_fput;
2081 	}
2082 
2083 	source_kvm = f.file->private_data;
2084 	ret = sev_lock_two_vms(kvm, source_kvm);
2085 	if (ret)
2086 		goto e_source_fput;
2087 
2088 	/*
2089 	 * Mirrors of mirrors should work, but let's not get silly.  Also
2090 	 * disallow out-of-band SEV/SEV-ES init if the target is already an
2091 	 * SEV guest, or if vCPUs have been created.  KVM relies on vCPUs being
2092 	 * created after SEV/SEV-ES initialization, e.g. to init intercepts.
2093 	 */
2094 	if (sev_guest(kvm) || !sev_guest(source_kvm) ||
2095 	    is_mirroring_enc_context(source_kvm) || kvm->created_vcpus) {
2096 		ret = -EINVAL;
2097 		goto e_unlock;
2098 	}
2099 
2100 	/*
2101 	 * The mirror kvm holds an enc_context_owner ref so its asid can't
2102 	 * disappear until we're done with it
2103 	 */
2104 	source_sev = &to_kvm_svm(source_kvm)->sev_info;
2105 	kvm_get_kvm(source_kvm);
2106 	mirror_sev = &to_kvm_svm(kvm)->sev_info;
2107 	list_add_tail(&mirror_sev->mirror_entry, &source_sev->mirror_vms);
2108 
2109 	/* Set enc_context_owner and copy its encryption context over */
2110 	mirror_sev->enc_context_owner = source_kvm;
2111 	mirror_sev->active = true;
2112 	mirror_sev->asid = source_sev->asid;
2113 	mirror_sev->fd = source_sev->fd;
2114 	mirror_sev->es_active = source_sev->es_active;
2115 	mirror_sev->handle = source_sev->handle;
2116 	INIT_LIST_HEAD(&mirror_sev->regions_list);
2117 	INIT_LIST_HEAD(&mirror_sev->mirror_vms);
2118 	ret = 0;
2119 
2120 	/*
2121 	 * Do not copy ap_jump_table. Since the mirror does not share the same
2122 	 * KVM contexts as the original, and they may have different
2123 	 * memory-views.
2124 	 */
2125 
2126 e_unlock:
2127 	sev_unlock_two_vms(kvm, source_kvm);
2128 e_source_fput:
2129 	fdput(f);
2130 	return ret;
2131 }
2132 
sev_vm_destroy(struct kvm * kvm)2133 void sev_vm_destroy(struct kvm *kvm)
2134 {
2135 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
2136 	struct list_head *head = &sev->regions_list;
2137 	struct list_head *pos, *q;
2138 
2139 	if (!sev_guest(kvm))
2140 		return;
2141 
2142 	WARN_ON(!list_empty(&sev->mirror_vms));
2143 
2144 	/* If this is a mirror_kvm release the enc_context_owner and skip sev cleanup */
2145 	if (is_mirroring_enc_context(kvm)) {
2146 		struct kvm *owner_kvm = sev->enc_context_owner;
2147 
2148 		mutex_lock(&owner_kvm->lock);
2149 		list_del(&sev->mirror_entry);
2150 		mutex_unlock(&owner_kvm->lock);
2151 		kvm_put_kvm(owner_kvm);
2152 		return;
2153 	}
2154 
2155 	/*
2156 	 * Ensure that all guest tagged cache entries are flushed before
2157 	 * releasing the pages back to the system for use. CLFLUSH will
2158 	 * not do this, so issue a WBINVD.
2159 	 */
2160 	wbinvd_on_all_cpus();
2161 
2162 	/*
2163 	 * if userspace was terminated before unregistering the memory regions
2164 	 * then lets unpin all the registered memory.
2165 	 */
2166 	if (!list_empty(head)) {
2167 		list_for_each_safe(pos, q, head) {
2168 			__unregister_enc_region_locked(kvm,
2169 				list_entry(pos, struct enc_region, list));
2170 			cond_resched();
2171 		}
2172 	}
2173 
2174 	sev_unbind_asid(kvm, sev->handle);
2175 	sev_asid_free(sev);
2176 }
2177 
sev_set_cpu_caps(void)2178 void __init sev_set_cpu_caps(void)
2179 {
2180 	if (!sev_enabled)
2181 		kvm_cpu_cap_clear(X86_FEATURE_SEV);
2182 	if (!sev_es_enabled)
2183 		kvm_cpu_cap_clear(X86_FEATURE_SEV_ES);
2184 }
2185 
sev_hardware_setup(void)2186 void __init sev_hardware_setup(void)
2187 {
2188 #ifdef CONFIG_KVM_AMD_SEV
2189 	unsigned int eax, ebx, ecx, edx, sev_asid_count, sev_es_asid_count;
2190 	bool sev_es_supported = false;
2191 	bool sev_supported = false;
2192 
2193 	if (!sev_enabled || !npt_enabled || !nrips)
2194 		goto out;
2195 
2196 	/*
2197 	 * SEV must obviously be supported in hardware.  Sanity check that the
2198 	 * CPU supports decode assists, which is mandatory for SEV guests to
2199 	 * support instruction emulation.  Ditto for flushing by ASID, as SEV
2200 	 * guests are bound to a single ASID, i.e. KVM can't rotate to a new
2201 	 * ASID to effect a TLB flush.
2202 	 */
2203 	if (!boot_cpu_has(X86_FEATURE_SEV) ||
2204 	    WARN_ON_ONCE(!boot_cpu_has(X86_FEATURE_DECODEASSISTS)) ||
2205 	    WARN_ON_ONCE(!boot_cpu_has(X86_FEATURE_FLUSHBYASID)))
2206 		goto out;
2207 
2208 	/* Retrieve SEV CPUID information */
2209 	cpuid(0x8000001f, &eax, &ebx, &ecx, &edx);
2210 
2211 	/* Set encryption bit location for SEV-ES guests */
2212 	sev_enc_bit = ebx & 0x3f;
2213 
2214 	/* Maximum number of encrypted guests supported simultaneously */
2215 	max_sev_asid = ecx;
2216 	if (!max_sev_asid)
2217 		goto out;
2218 
2219 	/* Minimum ASID value that should be used for SEV guest */
2220 	min_sev_asid = edx;
2221 	sev_me_mask = 1UL << (ebx & 0x3f);
2222 
2223 	/*
2224 	 * Initialize SEV ASID bitmaps. Allocate space for ASID 0 in the bitmap,
2225 	 * even though it's never used, so that the bitmap is indexed by the
2226 	 * actual ASID.
2227 	 */
2228 	nr_asids = max_sev_asid + 1;
2229 	sev_asid_bitmap = bitmap_zalloc(nr_asids, GFP_KERNEL);
2230 	if (!sev_asid_bitmap)
2231 		goto out;
2232 
2233 	sev_reclaim_asid_bitmap = bitmap_zalloc(nr_asids, GFP_KERNEL);
2234 	if (!sev_reclaim_asid_bitmap) {
2235 		bitmap_free(sev_asid_bitmap);
2236 		sev_asid_bitmap = NULL;
2237 		goto out;
2238 	}
2239 
2240 	sev_asid_count = max_sev_asid - min_sev_asid + 1;
2241 	WARN_ON_ONCE(misc_cg_set_capacity(MISC_CG_RES_SEV, sev_asid_count));
2242 	sev_supported = true;
2243 
2244 	/* SEV-ES support requested? */
2245 	if (!sev_es_enabled)
2246 		goto out;
2247 
2248 	/*
2249 	 * SEV-ES requires MMIO caching as KVM doesn't have access to the guest
2250 	 * instruction stream, i.e. can't emulate in response to a #NPF and
2251 	 * instead relies on #NPF(RSVD) being reflected into the guest as #VC
2252 	 * (the guest can then do a #VMGEXIT to request MMIO emulation).
2253 	 */
2254 	if (!enable_mmio_caching)
2255 		goto out;
2256 
2257 	/* Does the CPU support SEV-ES? */
2258 	if (!boot_cpu_has(X86_FEATURE_SEV_ES))
2259 		goto out;
2260 
2261 	/* Has the system been allocated ASIDs for SEV-ES? */
2262 	if (min_sev_asid == 1)
2263 		goto out;
2264 
2265 	sev_es_asid_count = min_sev_asid - 1;
2266 	WARN_ON_ONCE(misc_cg_set_capacity(MISC_CG_RES_SEV_ES, sev_es_asid_count));
2267 	sev_es_supported = true;
2268 
2269 out:
2270 	if (boot_cpu_has(X86_FEATURE_SEV))
2271 		pr_info("SEV %s (ASIDs %u - %u)\n",
2272 			sev_supported ? "enabled" : "disabled",
2273 			min_sev_asid, max_sev_asid);
2274 	if (boot_cpu_has(X86_FEATURE_SEV_ES))
2275 		pr_info("SEV-ES %s (ASIDs %u - %u)\n",
2276 			sev_es_supported ? "enabled" : "disabled",
2277 			min_sev_asid > 1 ? 1 : 0, min_sev_asid - 1);
2278 
2279 	sev_enabled = sev_supported;
2280 	sev_es_enabled = sev_es_supported;
2281 	if (!sev_es_enabled || !cpu_feature_enabled(X86_FEATURE_DEBUG_SWAP) ||
2282 	    !cpu_feature_enabled(X86_FEATURE_NO_NESTED_DATA_BP))
2283 		sev_es_debug_swap_enabled = false;
2284 #endif
2285 }
2286 
sev_hardware_unsetup(void)2287 void sev_hardware_unsetup(void)
2288 {
2289 	if (!sev_enabled)
2290 		return;
2291 
2292 	/* No need to take sev_bitmap_lock, all VMs have been destroyed. */
2293 	sev_flush_asids(1, max_sev_asid);
2294 
2295 	bitmap_free(sev_asid_bitmap);
2296 	bitmap_free(sev_reclaim_asid_bitmap);
2297 
2298 	misc_cg_set_capacity(MISC_CG_RES_SEV, 0);
2299 	misc_cg_set_capacity(MISC_CG_RES_SEV_ES, 0);
2300 }
2301 
sev_cpu_init(struct svm_cpu_data * sd)2302 int sev_cpu_init(struct svm_cpu_data *sd)
2303 {
2304 	if (!sev_enabled)
2305 		return 0;
2306 
2307 	sd->sev_vmcbs = kcalloc(nr_asids, sizeof(void *), GFP_KERNEL);
2308 	if (!sd->sev_vmcbs)
2309 		return -ENOMEM;
2310 
2311 	return 0;
2312 }
2313 
2314 /*
2315  * Pages used by hardware to hold guest encrypted state must be flushed before
2316  * returning them to the system.
2317  */
sev_flush_encrypted_page(struct kvm_vcpu * vcpu,void * va)2318 static void sev_flush_encrypted_page(struct kvm_vcpu *vcpu, void *va)
2319 {
2320 	int asid = to_kvm_svm(vcpu->kvm)->sev_info.asid;
2321 
2322 	/*
2323 	 * Note!  The address must be a kernel address, as regular page walk
2324 	 * checks are performed by VM_PAGE_FLUSH, i.e. operating on a user
2325 	 * address is non-deterministic and unsafe.  This function deliberately
2326 	 * takes a pointer to deter passing in a user address.
2327 	 */
2328 	unsigned long addr = (unsigned long)va;
2329 
2330 	/*
2331 	 * If CPU enforced cache coherency for encrypted mappings of the
2332 	 * same physical page is supported, use CLFLUSHOPT instead. NOTE: cache
2333 	 * flush is still needed in order to work properly with DMA devices.
2334 	 */
2335 	if (boot_cpu_has(X86_FEATURE_SME_COHERENT)) {
2336 		clflush_cache_range(va, PAGE_SIZE);
2337 		return;
2338 	}
2339 
2340 	/*
2341 	 * VM Page Flush takes a host virtual address and a guest ASID.  Fall
2342 	 * back to WBINVD if this faults so as not to make any problems worse
2343 	 * by leaving stale encrypted data in the cache.
2344 	 */
2345 	if (WARN_ON_ONCE(wrmsrl_safe(MSR_AMD64_VM_PAGE_FLUSH, addr | asid)))
2346 		goto do_wbinvd;
2347 
2348 	return;
2349 
2350 do_wbinvd:
2351 	wbinvd_on_all_cpus();
2352 }
2353 
sev_guest_memory_reclaimed(struct kvm * kvm)2354 void sev_guest_memory_reclaimed(struct kvm *kvm)
2355 {
2356 	if (!sev_guest(kvm))
2357 		return;
2358 
2359 	wbinvd_on_all_cpus();
2360 }
2361 
sev_free_vcpu(struct kvm_vcpu * vcpu)2362 void sev_free_vcpu(struct kvm_vcpu *vcpu)
2363 {
2364 	struct vcpu_svm *svm;
2365 
2366 	if (!sev_es_guest(vcpu->kvm))
2367 		return;
2368 
2369 	svm = to_svm(vcpu);
2370 
2371 	if (vcpu->arch.guest_state_protected)
2372 		sev_flush_encrypted_page(vcpu, svm->sev_es.vmsa);
2373 
2374 	__free_page(virt_to_page(svm->sev_es.vmsa));
2375 
2376 	if (svm->sev_es.ghcb_sa_free)
2377 		kvfree(svm->sev_es.ghcb_sa);
2378 }
2379 
dump_ghcb(struct vcpu_svm * svm)2380 static void dump_ghcb(struct vcpu_svm *svm)
2381 {
2382 	struct ghcb *ghcb = svm->sev_es.ghcb;
2383 	unsigned int nbits;
2384 
2385 	/* Re-use the dump_invalid_vmcb module parameter */
2386 	if (!dump_invalid_vmcb) {
2387 		pr_warn_ratelimited("set kvm_amd.dump_invalid_vmcb=1 to dump internal KVM state.\n");
2388 		return;
2389 	}
2390 
2391 	nbits = sizeof(ghcb->save.valid_bitmap) * 8;
2392 
2393 	pr_err("GHCB (GPA=%016llx):\n", svm->vmcb->control.ghcb_gpa);
2394 	pr_err("%-20s%016llx is_valid: %u\n", "sw_exit_code",
2395 	       ghcb->save.sw_exit_code, ghcb_sw_exit_code_is_valid(ghcb));
2396 	pr_err("%-20s%016llx is_valid: %u\n", "sw_exit_info_1",
2397 	       ghcb->save.sw_exit_info_1, ghcb_sw_exit_info_1_is_valid(ghcb));
2398 	pr_err("%-20s%016llx is_valid: %u\n", "sw_exit_info_2",
2399 	       ghcb->save.sw_exit_info_2, ghcb_sw_exit_info_2_is_valid(ghcb));
2400 	pr_err("%-20s%016llx is_valid: %u\n", "sw_scratch",
2401 	       ghcb->save.sw_scratch, ghcb_sw_scratch_is_valid(ghcb));
2402 	pr_err("%-20s%*pb\n", "valid_bitmap", nbits, ghcb->save.valid_bitmap);
2403 }
2404 
sev_es_sync_to_ghcb(struct vcpu_svm * svm)2405 static void sev_es_sync_to_ghcb(struct vcpu_svm *svm)
2406 {
2407 	struct kvm_vcpu *vcpu = &svm->vcpu;
2408 	struct ghcb *ghcb = svm->sev_es.ghcb;
2409 
2410 	/*
2411 	 * The GHCB protocol so far allows for the following data
2412 	 * to be returned:
2413 	 *   GPRs RAX, RBX, RCX, RDX
2414 	 *
2415 	 * Copy their values, even if they may not have been written during the
2416 	 * VM-Exit.  It's the guest's responsibility to not consume random data.
2417 	 */
2418 	ghcb_set_rax(ghcb, vcpu->arch.regs[VCPU_REGS_RAX]);
2419 	ghcb_set_rbx(ghcb, vcpu->arch.regs[VCPU_REGS_RBX]);
2420 	ghcb_set_rcx(ghcb, vcpu->arch.regs[VCPU_REGS_RCX]);
2421 	ghcb_set_rdx(ghcb, vcpu->arch.regs[VCPU_REGS_RDX]);
2422 }
2423 
sev_es_sync_from_ghcb(struct vcpu_svm * svm)2424 static void sev_es_sync_from_ghcb(struct vcpu_svm *svm)
2425 {
2426 	struct vmcb_control_area *control = &svm->vmcb->control;
2427 	struct kvm_vcpu *vcpu = &svm->vcpu;
2428 	struct ghcb *ghcb = svm->sev_es.ghcb;
2429 	u64 exit_code;
2430 
2431 	/*
2432 	 * The GHCB protocol so far allows for the following data
2433 	 * to be supplied:
2434 	 *   GPRs RAX, RBX, RCX, RDX
2435 	 *   XCR0
2436 	 *   CPL
2437 	 *
2438 	 * VMMCALL allows the guest to provide extra registers. KVM also
2439 	 * expects RSI for hypercalls, so include that, too.
2440 	 *
2441 	 * Copy their values to the appropriate location if supplied.
2442 	 */
2443 	memset(vcpu->arch.regs, 0, sizeof(vcpu->arch.regs));
2444 
2445 	BUILD_BUG_ON(sizeof(svm->sev_es.valid_bitmap) != sizeof(ghcb->save.valid_bitmap));
2446 	memcpy(&svm->sev_es.valid_bitmap, &ghcb->save.valid_bitmap, sizeof(ghcb->save.valid_bitmap));
2447 
2448 	vcpu->arch.regs[VCPU_REGS_RAX] = kvm_ghcb_get_rax_if_valid(svm, ghcb);
2449 	vcpu->arch.regs[VCPU_REGS_RBX] = kvm_ghcb_get_rbx_if_valid(svm, ghcb);
2450 	vcpu->arch.regs[VCPU_REGS_RCX] = kvm_ghcb_get_rcx_if_valid(svm, ghcb);
2451 	vcpu->arch.regs[VCPU_REGS_RDX] = kvm_ghcb_get_rdx_if_valid(svm, ghcb);
2452 	vcpu->arch.regs[VCPU_REGS_RSI] = kvm_ghcb_get_rsi_if_valid(svm, ghcb);
2453 
2454 	svm->vmcb->save.cpl = kvm_ghcb_get_cpl_if_valid(svm, ghcb);
2455 
2456 	if (kvm_ghcb_xcr0_is_valid(svm)) {
2457 		vcpu->arch.xcr0 = ghcb_get_xcr0(ghcb);
2458 		kvm_update_cpuid_runtime(vcpu);
2459 	}
2460 
2461 	/* Copy the GHCB exit information into the VMCB fields */
2462 	exit_code = ghcb_get_sw_exit_code(ghcb);
2463 	control->exit_code = lower_32_bits(exit_code);
2464 	control->exit_code_hi = upper_32_bits(exit_code);
2465 	control->exit_info_1 = ghcb_get_sw_exit_info_1(ghcb);
2466 	control->exit_info_2 = ghcb_get_sw_exit_info_2(ghcb);
2467 	svm->sev_es.sw_scratch = kvm_ghcb_get_sw_scratch_if_valid(svm, ghcb);
2468 
2469 	/* Clear the valid entries fields */
2470 	memset(ghcb->save.valid_bitmap, 0, sizeof(ghcb->save.valid_bitmap));
2471 }
2472 
kvm_ghcb_get_sw_exit_code(struct vmcb_control_area * control)2473 static u64 kvm_ghcb_get_sw_exit_code(struct vmcb_control_area *control)
2474 {
2475 	return (((u64)control->exit_code_hi) << 32) | control->exit_code;
2476 }
2477 
sev_es_validate_vmgexit(struct vcpu_svm * svm)2478 static int sev_es_validate_vmgexit(struct vcpu_svm *svm)
2479 {
2480 	struct vmcb_control_area *control = &svm->vmcb->control;
2481 	struct kvm_vcpu *vcpu = &svm->vcpu;
2482 	u64 exit_code;
2483 	u64 reason;
2484 
2485 	/*
2486 	 * Retrieve the exit code now even though it may not be marked valid
2487 	 * as it could help with debugging.
2488 	 */
2489 	exit_code = kvm_ghcb_get_sw_exit_code(control);
2490 
2491 	/* Only GHCB Usage code 0 is supported */
2492 	if (svm->sev_es.ghcb->ghcb_usage) {
2493 		reason = GHCB_ERR_INVALID_USAGE;
2494 		goto vmgexit_err;
2495 	}
2496 
2497 	reason = GHCB_ERR_MISSING_INPUT;
2498 
2499 	if (!kvm_ghcb_sw_exit_code_is_valid(svm) ||
2500 	    !kvm_ghcb_sw_exit_info_1_is_valid(svm) ||
2501 	    !kvm_ghcb_sw_exit_info_2_is_valid(svm))
2502 		goto vmgexit_err;
2503 
2504 	switch (exit_code) {
2505 	case SVM_EXIT_READ_DR7:
2506 		break;
2507 	case SVM_EXIT_WRITE_DR7:
2508 		if (!kvm_ghcb_rax_is_valid(svm))
2509 			goto vmgexit_err;
2510 		break;
2511 	case SVM_EXIT_RDTSC:
2512 		break;
2513 	case SVM_EXIT_RDPMC:
2514 		if (!kvm_ghcb_rcx_is_valid(svm))
2515 			goto vmgexit_err;
2516 		break;
2517 	case SVM_EXIT_CPUID:
2518 		if (!kvm_ghcb_rax_is_valid(svm) ||
2519 		    !kvm_ghcb_rcx_is_valid(svm))
2520 			goto vmgexit_err;
2521 		if (vcpu->arch.regs[VCPU_REGS_RAX] == 0xd)
2522 			if (!kvm_ghcb_xcr0_is_valid(svm))
2523 				goto vmgexit_err;
2524 		break;
2525 	case SVM_EXIT_INVD:
2526 		break;
2527 	case SVM_EXIT_IOIO:
2528 		if (control->exit_info_1 & SVM_IOIO_STR_MASK) {
2529 			if (!kvm_ghcb_sw_scratch_is_valid(svm))
2530 				goto vmgexit_err;
2531 		} else {
2532 			if (!(control->exit_info_1 & SVM_IOIO_TYPE_MASK))
2533 				if (!kvm_ghcb_rax_is_valid(svm))
2534 					goto vmgexit_err;
2535 		}
2536 		break;
2537 	case SVM_EXIT_MSR:
2538 		if (!kvm_ghcb_rcx_is_valid(svm))
2539 			goto vmgexit_err;
2540 		if (control->exit_info_1) {
2541 			if (!kvm_ghcb_rax_is_valid(svm) ||
2542 			    !kvm_ghcb_rdx_is_valid(svm))
2543 				goto vmgexit_err;
2544 		}
2545 		break;
2546 	case SVM_EXIT_VMMCALL:
2547 		if (!kvm_ghcb_rax_is_valid(svm) ||
2548 		    !kvm_ghcb_cpl_is_valid(svm))
2549 			goto vmgexit_err;
2550 		break;
2551 	case SVM_EXIT_RDTSCP:
2552 		break;
2553 	case SVM_EXIT_WBINVD:
2554 		break;
2555 	case SVM_EXIT_MONITOR:
2556 		if (!kvm_ghcb_rax_is_valid(svm) ||
2557 		    !kvm_ghcb_rcx_is_valid(svm) ||
2558 		    !kvm_ghcb_rdx_is_valid(svm))
2559 			goto vmgexit_err;
2560 		break;
2561 	case SVM_EXIT_MWAIT:
2562 		if (!kvm_ghcb_rax_is_valid(svm) ||
2563 		    !kvm_ghcb_rcx_is_valid(svm))
2564 			goto vmgexit_err;
2565 		break;
2566 	case SVM_VMGEXIT_MMIO_READ:
2567 	case SVM_VMGEXIT_MMIO_WRITE:
2568 		if (!kvm_ghcb_sw_scratch_is_valid(svm))
2569 			goto vmgexit_err;
2570 		break;
2571 	case SVM_VMGEXIT_NMI_COMPLETE:
2572 	case SVM_VMGEXIT_AP_HLT_LOOP:
2573 	case SVM_VMGEXIT_AP_JUMP_TABLE:
2574 	case SVM_VMGEXIT_UNSUPPORTED_EVENT:
2575 		break;
2576 	default:
2577 		reason = GHCB_ERR_INVALID_EVENT;
2578 		goto vmgexit_err;
2579 	}
2580 
2581 	return 0;
2582 
2583 vmgexit_err:
2584 	if (reason == GHCB_ERR_INVALID_USAGE) {
2585 		vcpu_unimpl(vcpu, "vmgexit: ghcb usage %#x is not valid\n",
2586 			    svm->sev_es.ghcb->ghcb_usage);
2587 	} else if (reason == GHCB_ERR_INVALID_EVENT) {
2588 		vcpu_unimpl(vcpu, "vmgexit: exit code %#llx is not valid\n",
2589 			    exit_code);
2590 	} else {
2591 		vcpu_unimpl(vcpu, "vmgexit: exit code %#llx input is not valid\n",
2592 			    exit_code);
2593 		dump_ghcb(svm);
2594 	}
2595 
2596 	ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2);
2597 	ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, reason);
2598 
2599 	/* Resume the guest to "return" the error code. */
2600 	return 1;
2601 }
2602 
sev_es_unmap_ghcb(struct vcpu_svm * svm)2603 void sev_es_unmap_ghcb(struct vcpu_svm *svm)
2604 {
2605 	if (!svm->sev_es.ghcb)
2606 		return;
2607 
2608 	if (svm->sev_es.ghcb_sa_free) {
2609 		/*
2610 		 * The scratch area lives outside the GHCB, so there is a
2611 		 * buffer that, depending on the operation performed, may
2612 		 * need to be synced, then freed.
2613 		 */
2614 		if (svm->sev_es.ghcb_sa_sync) {
2615 			kvm_write_guest(svm->vcpu.kvm,
2616 					svm->sev_es.sw_scratch,
2617 					svm->sev_es.ghcb_sa,
2618 					svm->sev_es.ghcb_sa_len);
2619 			svm->sev_es.ghcb_sa_sync = false;
2620 		}
2621 
2622 		kvfree(svm->sev_es.ghcb_sa);
2623 		svm->sev_es.ghcb_sa = NULL;
2624 		svm->sev_es.ghcb_sa_free = false;
2625 	}
2626 
2627 	trace_kvm_vmgexit_exit(svm->vcpu.vcpu_id, svm->sev_es.ghcb);
2628 
2629 	sev_es_sync_to_ghcb(svm);
2630 
2631 	kvm_vcpu_unmap(&svm->vcpu, &svm->sev_es.ghcb_map, true);
2632 	svm->sev_es.ghcb = NULL;
2633 }
2634 
pre_sev_run(struct vcpu_svm * svm,int cpu)2635 void pre_sev_run(struct vcpu_svm *svm, int cpu)
2636 {
2637 	struct svm_cpu_data *sd = per_cpu_ptr(&svm_data, cpu);
2638 	int asid = sev_get_asid(svm->vcpu.kvm);
2639 
2640 	/* Assign the asid allocated with this SEV guest */
2641 	svm->asid = asid;
2642 
2643 	/*
2644 	 * Flush guest TLB:
2645 	 *
2646 	 * 1) when different VMCB for the same ASID is to be run on the same host CPU.
2647 	 * 2) or this VMCB was executed on different host CPU in previous VMRUNs.
2648 	 */
2649 	if (sd->sev_vmcbs[asid] == svm->vmcb &&
2650 	    svm->vcpu.arch.last_vmentry_cpu == cpu)
2651 		return;
2652 
2653 	sd->sev_vmcbs[asid] = svm->vmcb;
2654 	svm->vmcb->control.tlb_ctl = TLB_CONTROL_FLUSH_ASID;
2655 	vmcb_mark_dirty(svm->vmcb, VMCB_ASID);
2656 }
2657 
2658 #define GHCB_SCRATCH_AREA_LIMIT		(16ULL * PAGE_SIZE)
setup_vmgexit_scratch(struct vcpu_svm * svm,bool sync,u64 len)2659 static int setup_vmgexit_scratch(struct vcpu_svm *svm, bool sync, u64 len)
2660 {
2661 	struct vmcb_control_area *control = &svm->vmcb->control;
2662 	u64 ghcb_scratch_beg, ghcb_scratch_end;
2663 	u64 scratch_gpa_beg, scratch_gpa_end;
2664 	void *scratch_va;
2665 
2666 	scratch_gpa_beg = svm->sev_es.sw_scratch;
2667 	if (!scratch_gpa_beg) {
2668 		pr_err("vmgexit: scratch gpa not provided\n");
2669 		goto e_scratch;
2670 	}
2671 
2672 	scratch_gpa_end = scratch_gpa_beg + len;
2673 	if (scratch_gpa_end < scratch_gpa_beg) {
2674 		pr_err("vmgexit: scratch length (%#llx) not valid for scratch address (%#llx)\n",
2675 		       len, scratch_gpa_beg);
2676 		goto e_scratch;
2677 	}
2678 
2679 	if ((scratch_gpa_beg & PAGE_MASK) == control->ghcb_gpa) {
2680 		/* Scratch area begins within GHCB */
2681 		ghcb_scratch_beg = control->ghcb_gpa +
2682 				   offsetof(struct ghcb, shared_buffer);
2683 		ghcb_scratch_end = control->ghcb_gpa +
2684 				   offsetof(struct ghcb, reserved_0xff0);
2685 
2686 		/*
2687 		 * If the scratch area begins within the GHCB, it must be
2688 		 * completely contained in the GHCB shared buffer area.
2689 		 */
2690 		if (scratch_gpa_beg < ghcb_scratch_beg ||
2691 		    scratch_gpa_end > ghcb_scratch_end) {
2692 			pr_err("vmgexit: scratch area is outside of GHCB shared buffer area (%#llx - %#llx)\n",
2693 			       scratch_gpa_beg, scratch_gpa_end);
2694 			goto e_scratch;
2695 		}
2696 
2697 		scratch_va = (void *)svm->sev_es.ghcb;
2698 		scratch_va += (scratch_gpa_beg - control->ghcb_gpa);
2699 	} else {
2700 		/*
2701 		 * The guest memory must be read into a kernel buffer, so
2702 		 * limit the size
2703 		 */
2704 		if (len > GHCB_SCRATCH_AREA_LIMIT) {
2705 			pr_err("vmgexit: scratch area exceeds KVM limits (%#llx requested, %#llx limit)\n",
2706 			       len, GHCB_SCRATCH_AREA_LIMIT);
2707 			goto e_scratch;
2708 		}
2709 		scratch_va = kvzalloc(len, GFP_KERNEL_ACCOUNT);
2710 		if (!scratch_va)
2711 			return -ENOMEM;
2712 
2713 		if (kvm_read_guest(svm->vcpu.kvm, scratch_gpa_beg, scratch_va, len)) {
2714 			/* Unable to copy scratch area from guest */
2715 			pr_err("vmgexit: kvm_read_guest for scratch area failed\n");
2716 
2717 			kvfree(scratch_va);
2718 			return -EFAULT;
2719 		}
2720 
2721 		/*
2722 		 * The scratch area is outside the GHCB. The operation will
2723 		 * dictate whether the buffer needs to be synced before running
2724 		 * the vCPU next time (i.e. a read was requested so the data
2725 		 * must be written back to the guest memory).
2726 		 */
2727 		svm->sev_es.ghcb_sa_sync = sync;
2728 		svm->sev_es.ghcb_sa_free = true;
2729 	}
2730 
2731 	svm->sev_es.ghcb_sa = scratch_va;
2732 	svm->sev_es.ghcb_sa_len = len;
2733 
2734 	return 0;
2735 
2736 e_scratch:
2737 	ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2);
2738 	ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_ERR_INVALID_SCRATCH_AREA);
2739 
2740 	return 1;
2741 }
2742 
set_ghcb_msr_bits(struct vcpu_svm * svm,u64 value,u64 mask,unsigned int pos)2743 static void set_ghcb_msr_bits(struct vcpu_svm *svm, u64 value, u64 mask,
2744 			      unsigned int pos)
2745 {
2746 	svm->vmcb->control.ghcb_gpa &= ~(mask << pos);
2747 	svm->vmcb->control.ghcb_gpa |= (value & mask) << pos;
2748 }
2749 
get_ghcb_msr_bits(struct vcpu_svm * svm,u64 mask,unsigned int pos)2750 static u64 get_ghcb_msr_bits(struct vcpu_svm *svm, u64 mask, unsigned int pos)
2751 {
2752 	return (svm->vmcb->control.ghcb_gpa >> pos) & mask;
2753 }
2754 
set_ghcb_msr(struct vcpu_svm * svm,u64 value)2755 static void set_ghcb_msr(struct vcpu_svm *svm, u64 value)
2756 {
2757 	svm->vmcb->control.ghcb_gpa = value;
2758 }
2759 
sev_handle_vmgexit_msr_protocol(struct vcpu_svm * svm)2760 static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm)
2761 {
2762 	struct vmcb_control_area *control = &svm->vmcb->control;
2763 	struct kvm_vcpu *vcpu = &svm->vcpu;
2764 	u64 ghcb_info;
2765 	int ret = 1;
2766 
2767 	ghcb_info = control->ghcb_gpa & GHCB_MSR_INFO_MASK;
2768 
2769 	trace_kvm_vmgexit_msr_protocol_enter(svm->vcpu.vcpu_id,
2770 					     control->ghcb_gpa);
2771 
2772 	switch (ghcb_info) {
2773 	case GHCB_MSR_SEV_INFO_REQ:
2774 		set_ghcb_msr(svm, GHCB_MSR_SEV_INFO(GHCB_VERSION_MAX,
2775 						    GHCB_VERSION_MIN,
2776 						    sev_enc_bit));
2777 		break;
2778 	case GHCB_MSR_CPUID_REQ: {
2779 		u64 cpuid_fn, cpuid_reg, cpuid_value;
2780 
2781 		cpuid_fn = get_ghcb_msr_bits(svm,
2782 					     GHCB_MSR_CPUID_FUNC_MASK,
2783 					     GHCB_MSR_CPUID_FUNC_POS);
2784 
2785 		/* Initialize the registers needed by the CPUID intercept */
2786 		vcpu->arch.regs[VCPU_REGS_RAX] = cpuid_fn;
2787 		vcpu->arch.regs[VCPU_REGS_RCX] = 0;
2788 
2789 		ret = svm_invoke_exit_handler(vcpu, SVM_EXIT_CPUID);
2790 		if (!ret) {
2791 			/* Error, keep GHCB MSR value as-is */
2792 			break;
2793 		}
2794 
2795 		cpuid_reg = get_ghcb_msr_bits(svm,
2796 					      GHCB_MSR_CPUID_REG_MASK,
2797 					      GHCB_MSR_CPUID_REG_POS);
2798 		if (cpuid_reg == 0)
2799 			cpuid_value = vcpu->arch.regs[VCPU_REGS_RAX];
2800 		else if (cpuid_reg == 1)
2801 			cpuid_value = vcpu->arch.regs[VCPU_REGS_RBX];
2802 		else if (cpuid_reg == 2)
2803 			cpuid_value = vcpu->arch.regs[VCPU_REGS_RCX];
2804 		else
2805 			cpuid_value = vcpu->arch.regs[VCPU_REGS_RDX];
2806 
2807 		set_ghcb_msr_bits(svm, cpuid_value,
2808 				  GHCB_MSR_CPUID_VALUE_MASK,
2809 				  GHCB_MSR_CPUID_VALUE_POS);
2810 
2811 		set_ghcb_msr_bits(svm, GHCB_MSR_CPUID_RESP,
2812 				  GHCB_MSR_INFO_MASK,
2813 				  GHCB_MSR_INFO_POS);
2814 		break;
2815 	}
2816 	case GHCB_MSR_TERM_REQ: {
2817 		u64 reason_set, reason_code;
2818 
2819 		reason_set = get_ghcb_msr_bits(svm,
2820 					       GHCB_MSR_TERM_REASON_SET_MASK,
2821 					       GHCB_MSR_TERM_REASON_SET_POS);
2822 		reason_code = get_ghcb_msr_bits(svm,
2823 						GHCB_MSR_TERM_REASON_MASK,
2824 						GHCB_MSR_TERM_REASON_POS);
2825 		pr_info("SEV-ES guest requested termination: %#llx:%#llx\n",
2826 			reason_set, reason_code);
2827 
2828 		vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
2829 		vcpu->run->system_event.type = KVM_SYSTEM_EVENT_SEV_TERM;
2830 		vcpu->run->system_event.ndata = 1;
2831 		vcpu->run->system_event.data[0] = control->ghcb_gpa;
2832 
2833 		return 0;
2834 	}
2835 	default:
2836 		/* Error, keep GHCB MSR value as-is */
2837 		break;
2838 	}
2839 
2840 	trace_kvm_vmgexit_msr_protocol_exit(svm->vcpu.vcpu_id,
2841 					    control->ghcb_gpa, ret);
2842 
2843 	return ret;
2844 }
2845 
sev_handle_vmgexit(struct kvm_vcpu * vcpu)2846 int sev_handle_vmgexit(struct kvm_vcpu *vcpu)
2847 {
2848 	struct vcpu_svm *svm = to_svm(vcpu);
2849 	struct vmcb_control_area *control = &svm->vmcb->control;
2850 	u64 ghcb_gpa, exit_code;
2851 	int ret;
2852 
2853 	/* Validate the GHCB */
2854 	ghcb_gpa = control->ghcb_gpa;
2855 	if (ghcb_gpa & GHCB_MSR_INFO_MASK)
2856 		return sev_handle_vmgexit_msr_protocol(svm);
2857 
2858 	if (!ghcb_gpa) {
2859 		vcpu_unimpl(vcpu, "vmgexit: GHCB gpa is not set\n");
2860 
2861 		/* Without a GHCB, just return right back to the guest */
2862 		return 1;
2863 	}
2864 
2865 	if (kvm_vcpu_map(vcpu, ghcb_gpa >> PAGE_SHIFT, &svm->sev_es.ghcb_map)) {
2866 		/* Unable to map GHCB from guest */
2867 		vcpu_unimpl(vcpu, "vmgexit: error mapping GHCB [%#llx] from guest\n",
2868 			    ghcb_gpa);
2869 
2870 		/* Without a GHCB, just return right back to the guest */
2871 		return 1;
2872 	}
2873 
2874 	svm->sev_es.ghcb = svm->sev_es.ghcb_map.hva;
2875 
2876 	trace_kvm_vmgexit_enter(vcpu->vcpu_id, svm->sev_es.ghcb);
2877 
2878 	sev_es_sync_from_ghcb(svm);
2879 	ret = sev_es_validate_vmgexit(svm);
2880 	if (ret)
2881 		return ret;
2882 
2883 	ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 0);
2884 	ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, 0);
2885 
2886 	exit_code = kvm_ghcb_get_sw_exit_code(control);
2887 	switch (exit_code) {
2888 	case SVM_VMGEXIT_MMIO_READ:
2889 		ret = setup_vmgexit_scratch(svm, true, control->exit_info_2);
2890 		if (ret)
2891 			break;
2892 
2893 		ret = kvm_sev_es_mmio_read(vcpu,
2894 					   control->exit_info_1,
2895 					   control->exit_info_2,
2896 					   svm->sev_es.ghcb_sa);
2897 		break;
2898 	case SVM_VMGEXIT_MMIO_WRITE:
2899 		ret = setup_vmgexit_scratch(svm, false, control->exit_info_2);
2900 		if (ret)
2901 			break;
2902 
2903 		ret = kvm_sev_es_mmio_write(vcpu,
2904 					    control->exit_info_1,
2905 					    control->exit_info_2,
2906 					    svm->sev_es.ghcb_sa);
2907 		break;
2908 	case SVM_VMGEXIT_NMI_COMPLETE:
2909 		++vcpu->stat.nmi_window_exits;
2910 		svm->nmi_masked = false;
2911 		kvm_make_request(KVM_REQ_EVENT, vcpu);
2912 		ret = 1;
2913 		break;
2914 	case SVM_VMGEXIT_AP_HLT_LOOP:
2915 		ret = kvm_emulate_ap_reset_hold(vcpu);
2916 		break;
2917 	case SVM_VMGEXIT_AP_JUMP_TABLE: {
2918 		struct kvm_sev_info *sev = &to_kvm_svm(vcpu->kvm)->sev_info;
2919 
2920 		switch (control->exit_info_1) {
2921 		case 0:
2922 			/* Set AP jump table address */
2923 			sev->ap_jump_table = control->exit_info_2;
2924 			break;
2925 		case 1:
2926 			/* Get AP jump table address */
2927 			ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, sev->ap_jump_table);
2928 			break;
2929 		default:
2930 			pr_err("svm: vmgexit: unsupported AP jump table request - exit_info_1=%#llx\n",
2931 			       control->exit_info_1);
2932 			ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2);
2933 			ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_ERR_INVALID_INPUT);
2934 		}
2935 
2936 		ret = 1;
2937 		break;
2938 	}
2939 	case SVM_VMGEXIT_UNSUPPORTED_EVENT:
2940 		vcpu_unimpl(vcpu,
2941 			    "vmgexit: unsupported event - exit_info_1=%#llx, exit_info_2=%#llx\n",
2942 			    control->exit_info_1, control->exit_info_2);
2943 		ret = -EINVAL;
2944 		break;
2945 	default:
2946 		ret = svm_invoke_exit_handler(vcpu, exit_code);
2947 	}
2948 
2949 	return ret;
2950 }
2951 
sev_es_string_io(struct vcpu_svm * svm,int size,unsigned int port,int in)2952 int sev_es_string_io(struct vcpu_svm *svm, int size, unsigned int port, int in)
2953 {
2954 	int count;
2955 	int bytes;
2956 	int r;
2957 
2958 	if (svm->vmcb->control.exit_info_2 > INT_MAX)
2959 		return -EINVAL;
2960 
2961 	count = svm->vmcb->control.exit_info_2;
2962 	if (unlikely(check_mul_overflow(count, size, &bytes)))
2963 		return -EINVAL;
2964 
2965 	r = setup_vmgexit_scratch(svm, in, bytes);
2966 	if (r)
2967 		return r;
2968 
2969 	return kvm_sev_es_string_io(&svm->vcpu, size, port, svm->sev_es.ghcb_sa,
2970 				    count, in);
2971 }
2972 
sev_es_vcpu_after_set_cpuid(struct vcpu_svm * svm)2973 static void sev_es_vcpu_after_set_cpuid(struct vcpu_svm *svm)
2974 {
2975 	struct kvm_vcpu *vcpu = &svm->vcpu;
2976 
2977 	if (boot_cpu_has(X86_FEATURE_V_TSC_AUX)) {
2978 		bool v_tsc_aux = guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP) ||
2979 				 guest_cpuid_has(vcpu, X86_FEATURE_RDPID);
2980 
2981 		set_msr_interception(vcpu, svm->msrpm, MSR_TSC_AUX, v_tsc_aux, v_tsc_aux);
2982 	}
2983 
2984 	/*
2985 	 * For SEV-ES, accesses to MSR_IA32_XSS should not be intercepted if
2986 	 * the host/guest supports its use.
2987 	 *
2988 	 * guest_can_use() checks a number of requirements on the host/guest to
2989 	 * ensure that MSR_IA32_XSS is available, but it might report true even
2990 	 * if X86_FEATURE_XSAVES isn't configured in the guest to ensure host
2991 	 * MSR_IA32_XSS is always properly restored. For SEV-ES, it is better
2992 	 * to further check that the guest CPUID actually supports
2993 	 * X86_FEATURE_XSAVES so that accesses to MSR_IA32_XSS by misbehaved
2994 	 * guests will still get intercepted and caught in the normal
2995 	 * kvm_emulate_rdmsr()/kvm_emulated_wrmsr() paths.
2996 	 */
2997 	if (guest_can_use(vcpu, X86_FEATURE_XSAVES) &&
2998 	    guest_cpuid_has(vcpu, X86_FEATURE_XSAVES))
2999 		set_msr_interception(vcpu, svm->msrpm, MSR_IA32_XSS, 1, 1);
3000 	else
3001 		set_msr_interception(vcpu, svm->msrpm, MSR_IA32_XSS, 0, 0);
3002 }
3003 
sev_vcpu_after_set_cpuid(struct vcpu_svm * svm)3004 void sev_vcpu_after_set_cpuid(struct vcpu_svm *svm)
3005 {
3006 	struct kvm_vcpu *vcpu = &svm->vcpu;
3007 	struct kvm_cpuid_entry2 *best;
3008 
3009 	/* For sev guests, the memory encryption bit is not reserved in CR3.  */
3010 	best = kvm_find_cpuid_entry(vcpu, 0x8000001F);
3011 	if (best)
3012 		vcpu->arch.reserved_gpa_bits &= ~(1UL << (best->ebx & 0x3f));
3013 
3014 	if (sev_es_guest(svm->vcpu.kvm))
3015 		sev_es_vcpu_after_set_cpuid(svm);
3016 }
3017 
sev_es_init_vmcb(struct vcpu_svm * svm)3018 static void sev_es_init_vmcb(struct vcpu_svm *svm)
3019 {
3020 	struct vmcb *vmcb = svm->vmcb01.ptr;
3021 	struct kvm_vcpu *vcpu = &svm->vcpu;
3022 
3023 	svm->vmcb->control.nested_ctl |= SVM_NESTED_CTL_SEV_ES_ENABLE;
3024 	svm->vmcb->control.virt_ext |= LBR_CTL_ENABLE_MASK;
3025 
3026 	/*
3027 	 * An SEV-ES guest requires a VMSA area that is a separate from the
3028 	 * VMCB page. Do not include the encryption mask on the VMSA physical
3029 	 * address since hardware will access it using the guest key.  Note,
3030 	 * the VMSA will be NULL if this vCPU is the destination for intrahost
3031 	 * migration, and will be copied later.
3032 	 */
3033 	if (svm->sev_es.vmsa)
3034 		svm->vmcb->control.vmsa_pa = __pa(svm->sev_es.vmsa);
3035 
3036 	/* Can't intercept CR register access, HV can't modify CR registers */
3037 	svm_clr_intercept(svm, INTERCEPT_CR0_READ);
3038 	svm_clr_intercept(svm, INTERCEPT_CR4_READ);
3039 	svm_clr_intercept(svm, INTERCEPT_CR8_READ);
3040 	svm_clr_intercept(svm, INTERCEPT_CR0_WRITE);
3041 	svm_clr_intercept(svm, INTERCEPT_CR4_WRITE);
3042 	svm_clr_intercept(svm, INTERCEPT_CR8_WRITE);
3043 
3044 	svm_clr_intercept(svm, INTERCEPT_SELECTIVE_CR0);
3045 
3046 	/* Track EFER/CR register changes */
3047 	svm_set_intercept(svm, TRAP_EFER_WRITE);
3048 	svm_set_intercept(svm, TRAP_CR0_WRITE);
3049 	svm_set_intercept(svm, TRAP_CR4_WRITE);
3050 	svm_set_intercept(svm, TRAP_CR8_WRITE);
3051 
3052 	vmcb->control.intercepts[INTERCEPT_DR] = 0;
3053 	if (!sev_es_debug_swap_enabled) {
3054 		vmcb_set_intercept(&vmcb->control, INTERCEPT_DR7_READ);
3055 		vmcb_set_intercept(&vmcb->control, INTERCEPT_DR7_WRITE);
3056 		recalc_intercepts(svm);
3057 	} else {
3058 		/*
3059 		 * Disable #DB intercept iff DebugSwap is enabled.  KVM doesn't
3060 		 * allow debugging SEV-ES guests, and enables DebugSwap iff
3061 		 * NO_NESTED_DATA_BP is supported, so there's no reason to
3062 		 * intercept #DB when DebugSwap is enabled.  For simplicity
3063 		 * with respect to guest debug, intercept #DB for other VMs
3064 		 * even if NO_NESTED_DATA_BP is supported, i.e. even if the
3065 		 * guest can't DoS the CPU with infinite #DB vectoring.
3066 		 */
3067 		clr_exception_intercept(svm, DB_VECTOR);
3068 	}
3069 
3070 	/* Can't intercept XSETBV, HV can't modify XCR0 directly */
3071 	svm_clr_intercept(svm, INTERCEPT_XSETBV);
3072 
3073 	/* Clear intercepts on selected MSRs */
3074 	set_msr_interception(vcpu, svm->msrpm, MSR_EFER, 1, 1);
3075 	set_msr_interception(vcpu, svm->msrpm, MSR_IA32_CR_PAT, 1, 1);
3076 	set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTBRANCHFROMIP, 1, 1);
3077 	set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTBRANCHTOIP, 1, 1);
3078 	set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTINTFROMIP, 1, 1);
3079 	set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTINTTOIP, 1, 1);
3080 }
3081 
sev_init_vmcb(struct vcpu_svm * svm)3082 void sev_init_vmcb(struct vcpu_svm *svm)
3083 {
3084 	svm->vmcb->control.nested_ctl |= SVM_NESTED_CTL_SEV_ENABLE;
3085 	clr_exception_intercept(svm, UD_VECTOR);
3086 
3087 	/*
3088 	 * Don't intercept #GP for SEV guests, e.g. for the VMware backdoor, as
3089 	 * KVM can't decrypt guest memory to decode the faulting instruction.
3090 	 */
3091 	clr_exception_intercept(svm, GP_VECTOR);
3092 
3093 	if (sev_es_guest(svm->vcpu.kvm))
3094 		sev_es_init_vmcb(svm);
3095 }
3096 
sev_es_vcpu_reset(struct vcpu_svm * svm)3097 void sev_es_vcpu_reset(struct vcpu_svm *svm)
3098 {
3099 	/*
3100 	 * Set the GHCB MSR value as per the GHCB specification when emulating
3101 	 * vCPU RESET for an SEV-ES guest.
3102 	 */
3103 	set_ghcb_msr(svm, GHCB_MSR_SEV_INFO(GHCB_VERSION_MAX,
3104 					    GHCB_VERSION_MIN,
3105 					    sev_enc_bit));
3106 }
3107 
sev_es_prepare_switch_to_guest(struct sev_es_save_area * hostsa)3108 void sev_es_prepare_switch_to_guest(struct sev_es_save_area *hostsa)
3109 {
3110 	/*
3111 	 * All host state for SEV-ES guests is categorized into three swap types
3112 	 * based on how it is handled by hardware during a world switch:
3113 	 *
3114 	 * A: VMRUN:   Host state saved in host save area
3115 	 *    VMEXIT:  Host state loaded from host save area
3116 	 *
3117 	 * B: VMRUN:   Host state _NOT_ saved in host save area
3118 	 *    VMEXIT:  Host state loaded from host save area
3119 	 *
3120 	 * C: VMRUN:   Host state _NOT_ saved in host save area
3121 	 *    VMEXIT:  Host state initialized to default(reset) values
3122 	 *
3123 	 * Manually save type-B state, i.e. state that is loaded by VMEXIT but
3124 	 * isn't saved by VMRUN, that isn't already saved by VMSAVE (performed
3125 	 * by common SVM code).
3126 	 */
3127 	hostsa->xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
3128 	hostsa->pkru = read_pkru();
3129 	hostsa->xss = host_xss;
3130 
3131 	/*
3132 	 * If DebugSwap is enabled, debug registers are loaded but NOT saved by
3133 	 * the CPU (Type-B). If DebugSwap is disabled/unsupported, the CPU both
3134 	 * saves and loads debug registers (Type-A).
3135 	 */
3136 	if (sev_es_debug_swap_enabled) {
3137 		hostsa->dr0 = native_get_debugreg(0);
3138 		hostsa->dr1 = native_get_debugreg(1);
3139 		hostsa->dr2 = native_get_debugreg(2);
3140 		hostsa->dr3 = native_get_debugreg(3);
3141 		hostsa->dr0_addr_mask = amd_get_dr_addr_mask(0);
3142 		hostsa->dr1_addr_mask = amd_get_dr_addr_mask(1);
3143 		hostsa->dr2_addr_mask = amd_get_dr_addr_mask(2);
3144 		hostsa->dr3_addr_mask = amd_get_dr_addr_mask(3);
3145 	}
3146 }
3147 
sev_vcpu_deliver_sipi_vector(struct kvm_vcpu * vcpu,u8 vector)3148 void sev_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector)
3149 {
3150 	struct vcpu_svm *svm = to_svm(vcpu);
3151 
3152 	/* First SIPI: Use the values as initially set by the VMM */
3153 	if (!svm->sev_es.received_first_sipi) {
3154 		svm->sev_es.received_first_sipi = true;
3155 		return;
3156 	}
3157 
3158 	/*
3159 	 * Subsequent SIPI: Return from an AP Reset Hold VMGEXIT, where
3160 	 * the guest will set the CS and RIP. Set SW_EXIT_INFO_2 to a
3161 	 * non-zero value.
3162 	 */
3163 	if (!svm->sev_es.ghcb)
3164 		return;
3165 
3166 	ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, 1);
3167 }
3168