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(unsigned int min_asid,unsigned int max_asid)87 static int sev_flush_asids(unsigned int min_asid, unsigned int max_asid)
88 {
89 int ret, error = 0;
90 unsigned int asid;
91
92 /* Check if there are any ASIDs to reclaim before performing a flush */
93 asid = find_next_bit(sev_reclaim_asid_bitmap, nr_asids, min_asid);
94 if (asid > max_asid)
95 return -EBUSY;
96
97 /*
98 * DEACTIVATE will clear the WBINVD indicator causing DF_FLUSH to fail,
99 * so it must be guarded.
100 */
101 down_write(&sev_deactivate_lock);
102
103 wbinvd_on_all_cpus();
104 ret = sev_guest_df_flush(&error);
105
106 up_write(&sev_deactivate_lock);
107
108 if (ret)
109 pr_err("SEV: DF_FLUSH failed, ret=%d, error=%#x\n", ret, error);
110
111 return ret;
112 }
113
is_mirroring_enc_context(struct kvm * kvm)114 static inline bool is_mirroring_enc_context(struct kvm *kvm)
115 {
116 return !!to_kvm_svm(kvm)->sev_info.enc_context_owner;
117 }
118
119 /* Must be called with the sev_bitmap_lock held */
__sev_recycle_asids(unsigned int min_asid,unsigned int max_asid)120 static bool __sev_recycle_asids(unsigned int min_asid, unsigned int max_asid)
121 {
122 if (sev_flush_asids(min_asid, max_asid))
123 return false;
124
125 /* The flush process will flush all reclaimable SEV and SEV-ES ASIDs */
126 bitmap_xor(sev_asid_bitmap, sev_asid_bitmap, sev_reclaim_asid_bitmap,
127 nr_asids);
128 bitmap_zero(sev_reclaim_asid_bitmap, nr_asids);
129
130 return true;
131 }
132
sev_misc_cg_try_charge(struct kvm_sev_info * sev)133 static int sev_misc_cg_try_charge(struct kvm_sev_info *sev)
134 {
135 enum misc_res_type type = sev->es_active ? MISC_CG_RES_SEV_ES : MISC_CG_RES_SEV;
136 return misc_cg_try_charge(type, sev->misc_cg, 1);
137 }
138
sev_misc_cg_uncharge(struct kvm_sev_info * sev)139 static void sev_misc_cg_uncharge(struct kvm_sev_info *sev)
140 {
141 enum misc_res_type type = sev->es_active ? MISC_CG_RES_SEV_ES : MISC_CG_RES_SEV;
142 misc_cg_uncharge(type, sev->misc_cg, 1);
143 }
144
sev_asid_new(struct kvm_sev_info * sev)145 static int sev_asid_new(struct kvm_sev_info *sev)
146 {
147 /*
148 * SEV-enabled guests must use asid from min_sev_asid to max_sev_asid.
149 * SEV-ES-enabled guest can use from 1 to min_sev_asid - 1.
150 * Note: min ASID can end up larger than the max if basic SEV support is
151 * effectively disabled by disallowing use of ASIDs for SEV guests.
152 */
153 unsigned int min_asid = sev->es_active ? 1 : min_sev_asid;
154 unsigned int max_asid = sev->es_active ? min_sev_asid - 1 : max_sev_asid;
155 unsigned int asid;
156 bool retry = true;
157 int ret;
158
159 if (min_asid > max_asid)
160 return -ENOTTY;
161
162 WARN_ON(sev->misc_cg);
163 sev->misc_cg = get_current_misc_cg();
164 ret = sev_misc_cg_try_charge(sev);
165 if (ret) {
166 put_misc_cg(sev->misc_cg);
167 sev->misc_cg = NULL;
168 return ret;
169 }
170
171 mutex_lock(&sev_bitmap_lock);
172
173 again:
174 asid = find_next_zero_bit(sev_asid_bitmap, max_asid + 1, min_asid);
175 if (asid > max_asid) {
176 if (retry && __sev_recycle_asids(min_asid, max_asid)) {
177 retry = false;
178 goto again;
179 }
180 mutex_unlock(&sev_bitmap_lock);
181 ret = -EBUSY;
182 goto e_uncharge;
183 }
184
185 __set_bit(asid, sev_asid_bitmap);
186
187 mutex_unlock(&sev_bitmap_lock);
188
189 return asid;
190 e_uncharge:
191 sev_misc_cg_uncharge(sev);
192 put_misc_cg(sev->misc_cg);
193 sev->misc_cg = NULL;
194 return ret;
195 }
196
sev_get_asid(struct kvm * kvm)197 static unsigned int sev_get_asid(struct kvm *kvm)
198 {
199 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
200
201 return sev->asid;
202 }
203
sev_asid_free(struct kvm_sev_info * sev)204 static void sev_asid_free(struct kvm_sev_info *sev)
205 {
206 struct svm_cpu_data *sd;
207 int cpu;
208
209 mutex_lock(&sev_bitmap_lock);
210
211 __set_bit(sev->asid, sev_reclaim_asid_bitmap);
212
213 for_each_possible_cpu(cpu) {
214 sd = per_cpu_ptr(&svm_data, cpu);
215 sd->sev_vmcbs[sev->asid] = NULL;
216 }
217
218 mutex_unlock(&sev_bitmap_lock);
219
220 sev_misc_cg_uncharge(sev);
221 put_misc_cg(sev->misc_cg);
222 sev->misc_cg = NULL;
223 }
224
sev_decommission(unsigned int handle)225 static void sev_decommission(unsigned int handle)
226 {
227 struct sev_data_decommission decommission;
228
229 if (!handle)
230 return;
231
232 decommission.handle = handle;
233 sev_guest_decommission(&decommission, NULL);
234 }
235
sev_unbind_asid(struct kvm * kvm,unsigned int handle)236 static void sev_unbind_asid(struct kvm *kvm, unsigned int handle)
237 {
238 struct sev_data_deactivate deactivate;
239
240 if (!handle)
241 return;
242
243 deactivate.handle = handle;
244
245 /* Guard DEACTIVATE against WBINVD/DF_FLUSH used in ASID recycling */
246 down_read(&sev_deactivate_lock);
247 sev_guest_deactivate(&deactivate, NULL);
248 up_read(&sev_deactivate_lock);
249
250 sev_decommission(handle);
251 }
252
sev_guest_init(struct kvm * kvm,struct kvm_sev_cmd * argp)253 static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
254 {
255 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
256 int asid, ret;
257
258 if (kvm->created_vcpus)
259 return -EINVAL;
260
261 ret = -EBUSY;
262 if (unlikely(sev->active))
263 return ret;
264
265 sev->active = true;
266 sev->es_active = argp->id == KVM_SEV_ES_INIT;
267 asid = sev_asid_new(sev);
268 if (asid < 0)
269 goto e_no_asid;
270 sev->asid = asid;
271
272 ret = sev_platform_init(&argp->error);
273 if (ret)
274 goto e_free;
275
276 INIT_LIST_HEAD(&sev->regions_list);
277 INIT_LIST_HEAD(&sev->mirror_vms);
278
279 kvm_set_apicv_inhibit(kvm, APICV_INHIBIT_REASON_SEV);
280
281 return 0;
282
283 e_free:
284 sev_asid_free(sev);
285 sev->asid = 0;
286 e_no_asid:
287 sev->es_active = false;
288 sev->active = false;
289 return ret;
290 }
291
sev_bind_asid(struct kvm * kvm,unsigned int handle,int * error)292 static int sev_bind_asid(struct kvm *kvm, unsigned int handle, int *error)
293 {
294 unsigned int asid = sev_get_asid(kvm);
295 struct sev_data_activate activate;
296 int ret;
297
298 /* activate ASID on the given handle */
299 activate.handle = handle;
300 activate.asid = asid;
301 ret = sev_guest_activate(&activate, error);
302
303 return ret;
304 }
305
__sev_issue_cmd(int fd,int id,void * data,int * error)306 static int __sev_issue_cmd(int fd, int id, void *data, int *error)
307 {
308 struct fd f;
309 int ret;
310
311 f = fdget(fd);
312 if (!f.file)
313 return -EBADF;
314
315 ret = sev_issue_cmd_external_user(f.file, id, data, error);
316
317 fdput(f);
318 return ret;
319 }
320
sev_issue_cmd(struct kvm * kvm,int id,void * data,int * error)321 static int sev_issue_cmd(struct kvm *kvm, int id, void *data, int *error)
322 {
323 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
324
325 return __sev_issue_cmd(sev->fd, id, data, error);
326 }
327
sev_launch_start(struct kvm * kvm,struct kvm_sev_cmd * argp)328 static int sev_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
329 {
330 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
331 struct sev_data_launch_start start;
332 struct kvm_sev_launch_start params;
333 void *dh_blob, *session_blob;
334 int *error = &argp->error;
335 int ret;
336
337 if (!sev_guest(kvm))
338 return -ENOTTY;
339
340 if (copy_from_user(¶ms, (void __user *)(uintptr_t)argp->data, sizeof(params)))
341 return -EFAULT;
342
343 memset(&start, 0, sizeof(start));
344
345 dh_blob = NULL;
346 if (params.dh_uaddr) {
347 dh_blob = psp_copy_user_blob(params.dh_uaddr, params.dh_len);
348 if (IS_ERR(dh_blob))
349 return PTR_ERR(dh_blob);
350
351 start.dh_cert_address = __sme_set(__pa(dh_blob));
352 start.dh_cert_len = params.dh_len;
353 }
354
355 session_blob = NULL;
356 if (params.session_uaddr) {
357 session_blob = psp_copy_user_blob(params.session_uaddr, params.session_len);
358 if (IS_ERR(session_blob)) {
359 ret = PTR_ERR(session_blob);
360 goto e_free_dh;
361 }
362
363 start.session_address = __sme_set(__pa(session_blob));
364 start.session_len = params.session_len;
365 }
366
367 start.handle = params.handle;
368 start.policy = params.policy;
369
370 /* create memory encryption context */
371 ret = __sev_issue_cmd(argp->sev_fd, SEV_CMD_LAUNCH_START, &start, error);
372 if (ret)
373 goto e_free_session;
374
375 /* Bind ASID to this guest */
376 ret = sev_bind_asid(kvm, start.handle, error);
377 if (ret) {
378 sev_decommission(start.handle);
379 goto e_free_session;
380 }
381
382 /* return handle to userspace */
383 params.handle = start.handle;
384 if (copy_to_user((void __user *)(uintptr_t)argp->data, ¶ms, sizeof(params))) {
385 sev_unbind_asid(kvm, start.handle);
386 ret = -EFAULT;
387 goto e_free_session;
388 }
389
390 sev->handle = start.handle;
391 sev->fd = argp->sev_fd;
392
393 e_free_session:
394 kfree(session_blob);
395 e_free_dh:
396 kfree(dh_blob);
397 return ret;
398 }
399
sev_pin_memory(struct kvm * kvm,unsigned long uaddr,unsigned long ulen,unsigned long * n,int write)400 static struct page **sev_pin_memory(struct kvm *kvm, unsigned long uaddr,
401 unsigned long ulen, unsigned long *n,
402 int write)
403 {
404 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
405 unsigned long npages, size;
406 int npinned;
407 unsigned long locked, lock_limit;
408 struct page **pages;
409 unsigned long first, last;
410 int ret;
411
412 lockdep_assert_held(&kvm->lock);
413
414 if (ulen == 0 || uaddr + ulen < uaddr)
415 return ERR_PTR(-EINVAL);
416
417 /* Calculate number of pages. */
418 first = (uaddr & PAGE_MASK) >> PAGE_SHIFT;
419 last = ((uaddr + ulen - 1) & PAGE_MASK) >> PAGE_SHIFT;
420 npages = (last - first + 1);
421
422 locked = sev->pages_locked + npages;
423 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
424 if (locked > lock_limit && !capable(CAP_IPC_LOCK)) {
425 pr_err("SEV: %lu locked pages exceed the lock limit of %lu.\n", locked, lock_limit);
426 return ERR_PTR(-ENOMEM);
427 }
428
429 if (WARN_ON_ONCE(npages > INT_MAX))
430 return ERR_PTR(-EINVAL);
431
432 /* Avoid using vmalloc for smaller buffers. */
433 size = npages * sizeof(struct page *);
434 if (size > PAGE_SIZE)
435 pages = __vmalloc(size, GFP_KERNEL_ACCOUNT | __GFP_ZERO);
436 else
437 pages = kmalloc(size, GFP_KERNEL_ACCOUNT);
438
439 if (!pages)
440 return ERR_PTR(-ENOMEM);
441
442 /* Pin the user virtual address. */
443 npinned = pin_user_pages_fast(uaddr, npages, write ? FOLL_WRITE : 0, pages);
444 if (npinned != npages) {
445 pr_err("SEV: Failure locking %lu pages.\n", npages);
446 ret = -ENOMEM;
447 goto err;
448 }
449
450 *n = npages;
451 sev->pages_locked = locked;
452
453 return pages;
454
455 err:
456 if (npinned > 0)
457 unpin_user_pages(pages, npinned);
458
459 kvfree(pages);
460 return ERR_PTR(ret);
461 }
462
sev_unpin_memory(struct kvm * kvm,struct page ** pages,unsigned long npages)463 static void sev_unpin_memory(struct kvm *kvm, struct page **pages,
464 unsigned long npages)
465 {
466 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
467
468 unpin_user_pages(pages, npages);
469 kvfree(pages);
470 sev->pages_locked -= npages;
471 }
472
sev_clflush_pages(struct page * pages[],unsigned long npages)473 static void sev_clflush_pages(struct page *pages[], unsigned long npages)
474 {
475 uint8_t *page_virtual;
476 unsigned long i;
477
478 if (this_cpu_has(X86_FEATURE_SME_COHERENT) || npages == 0 ||
479 pages == NULL)
480 return;
481
482 for (i = 0; i < npages; i++) {
483 page_virtual = kmap_local_page(pages[i]);
484 clflush_cache_range(page_virtual, PAGE_SIZE);
485 kunmap_local(page_virtual);
486 cond_resched();
487 }
488 }
489
get_num_contig_pages(unsigned long idx,struct page ** inpages,unsigned long npages)490 static unsigned long get_num_contig_pages(unsigned long idx,
491 struct page **inpages, unsigned long npages)
492 {
493 unsigned long paddr, next_paddr;
494 unsigned long i = idx + 1, pages = 1;
495
496 /* find the number of contiguous pages starting from idx */
497 paddr = __sme_page_pa(inpages[idx]);
498 while (i < npages) {
499 next_paddr = __sme_page_pa(inpages[i++]);
500 if ((paddr + PAGE_SIZE) == next_paddr) {
501 pages++;
502 paddr = next_paddr;
503 continue;
504 }
505 break;
506 }
507
508 return pages;
509 }
510
sev_launch_update_data(struct kvm * kvm,struct kvm_sev_cmd * argp)511 static int sev_launch_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
512 {
513 unsigned long vaddr, vaddr_end, next_vaddr, npages, pages, size, i;
514 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
515 struct kvm_sev_launch_update_data params;
516 struct sev_data_launch_update_data data;
517 struct page **inpages;
518 int ret;
519
520 if (!sev_guest(kvm))
521 return -ENOTTY;
522
523 if (copy_from_user(¶ms, (void __user *)(uintptr_t)argp->data, sizeof(params)))
524 return -EFAULT;
525
526 vaddr = params.uaddr;
527 size = params.len;
528 vaddr_end = vaddr + size;
529
530 /* Lock the user memory. */
531 inpages = sev_pin_memory(kvm, vaddr, size, &npages, 1);
532 if (IS_ERR(inpages))
533 return PTR_ERR(inpages);
534
535 /*
536 * Flush (on non-coherent CPUs) before LAUNCH_UPDATE encrypts pages in
537 * place; the cache may contain the data that was written unencrypted.
538 */
539 sev_clflush_pages(inpages, npages);
540
541 data.reserved = 0;
542 data.handle = sev->handle;
543
544 for (i = 0; vaddr < vaddr_end; vaddr = next_vaddr, i += pages) {
545 int offset, len;
546
547 /*
548 * If the user buffer is not page-aligned, calculate the offset
549 * within the page.
550 */
551 offset = vaddr & (PAGE_SIZE - 1);
552
553 /* Calculate the number of pages that can be encrypted in one go. */
554 pages = get_num_contig_pages(i, inpages, npages);
555
556 len = min_t(size_t, ((pages * PAGE_SIZE) - offset), size);
557
558 data.len = len;
559 data.address = __sme_page_pa(inpages[i]) + offset;
560 ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_UPDATE_DATA, &data, &argp->error);
561 if (ret)
562 goto e_unpin;
563
564 size -= len;
565 next_vaddr = vaddr + len;
566 }
567
568 e_unpin:
569 /* content of memory is updated, mark pages dirty */
570 for (i = 0; i < npages; i++) {
571 set_page_dirty_lock(inpages[i]);
572 mark_page_accessed(inpages[i]);
573 }
574 /* unlock the user pages */
575 sev_unpin_memory(kvm, inpages, npages);
576 return ret;
577 }
578
sev_es_sync_vmsa(struct vcpu_svm * svm)579 static int sev_es_sync_vmsa(struct vcpu_svm *svm)
580 {
581 struct sev_es_save_area *save = svm->sev_es.vmsa;
582
583 /* Check some debug related fields before encrypting the VMSA */
584 if (svm->vcpu.guest_debug || (svm->vmcb->save.dr7 & ~DR7_FIXED_1))
585 return -EINVAL;
586
587 /*
588 * SEV-ES will use a VMSA that is pointed to by the VMCB, not
589 * the traditional VMSA that is part of the VMCB. Copy the
590 * traditional VMSA as it has been built so far (in prep
591 * for LAUNCH_UPDATE_VMSA) to be the initial SEV-ES state.
592 */
593 memcpy(save, &svm->vmcb->save, sizeof(svm->vmcb->save));
594
595 /* Sync registgers */
596 save->rax = svm->vcpu.arch.regs[VCPU_REGS_RAX];
597 save->rbx = svm->vcpu.arch.regs[VCPU_REGS_RBX];
598 save->rcx = svm->vcpu.arch.regs[VCPU_REGS_RCX];
599 save->rdx = svm->vcpu.arch.regs[VCPU_REGS_RDX];
600 save->rsp = svm->vcpu.arch.regs[VCPU_REGS_RSP];
601 save->rbp = svm->vcpu.arch.regs[VCPU_REGS_RBP];
602 save->rsi = svm->vcpu.arch.regs[VCPU_REGS_RSI];
603 save->rdi = svm->vcpu.arch.regs[VCPU_REGS_RDI];
604 #ifdef CONFIG_X86_64
605 save->r8 = svm->vcpu.arch.regs[VCPU_REGS_R8];
606 save->r9 = svm->vcpu.arch.regs[VCPU_REGS_R9];
607 save->r10 = svm->vcpu.arch.regs[VCPU_REGS_R10];
608 save->r11 = svm->vcpu.arch.regs[VCPU_REGS_R11];
609 save->r12 = svm->vcpu.arch.regs[VCPU_REGS_R12];
610 save->r13 = svm->vcpu.arch.regs[VCPU_REGS_R13];
611 save->r14 = svm->vcpu.arch.regs[VCPU_REGS_R14];
612 save->r15 = svm->vcpu.arch.regs[VCPU_REGS_R15];
613 #endif
614 save->rip = svm->vcpu.arch.regs[VCPU_REGS_RIP];
615
616 /* Sync some non-GPR registers before encrypting */
617 save->xcr0 = svm->vcpu.arch.xcr0;
618 save->pkru = svm->vcpu.arch.pkru;
619 save->xss = svm->vcpu.arch.ia32_xss;
620 save->dr6 = svm->vcpu.arch.dr6;
621
622 if (sev_es_debug_swap_enabled) {
623 save->sev_features |= SVM_SEV_FEAT_DEBUG_SWAP;
624 pr_warn_once("Enabling DebugSwap with KVM_SEV_ES_INIT. "
625 "This will not work starting with Linux 6.10\n");
626 }
627
628 pr_debug("Virtual Machine Save Area (VMSA):\n");
629 print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, save, sizeof(*save), false);
630
631 return 0;
632 }
633
__sev_launch_update_vmsa(struct kvm * kvm,struct kvm_vcpu * vcpu,int * error)634 static int __sev_launch_update_vmsa(struct kvm *kvm, struct kvm_vcpu *vcpu,
635 int *error)
636 {
637 struct sev_data_launch_update_vmsa vmsa;
638 struct vcpu_svm *svm = to_svm(vcpu);
639 int ret;
640
641 if (vcpu->guest_debug) {
642 pr_warn_once("KVM_SET_GUEST_DEBUG for SEV-ES guest is not supported");
643 return -EINVAL;
644 }
645
646 /* Perform some pre-encryption checks against the VMSA */
647 ret = sev_es_sync_vmsa(svm);
648 if (ret)
649 return ret;
650
651 /*
652 * The LAUNCH_UPDATE_VMSA command will perform in-place encryption of
653 * the VMSA memory content (i.e it will write the same memory region
654 * with the guest's key), so invalidate it first.
655 */
656 clflush_cache_range(svm->sev_es.vmsa, PAGE_SIZE);
657
658 vmsa.reserved = 0;
659 vmsa.handle = to_kvm_svm(kvm)->sev_info.handle;
660 vmsa.address = __sme_pa(svm->sev_es.vmsa);
661 vmsa.len = PAGE_SIZE;
662 ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_UPDATE_VMSA, &vmsa, error);
663 if (ret)
664 return ret;
665
666 vcpu->arch.guest_state_protected = true;
667
668 /*
669 * SEV-ES guest mandates LBR Virtualization to be _always_ ON. Enable it
670 * only after setting guest_state_protected because KVM_SET_MSRS allows
671 * dynamic toggling of LBRV (for performance reason) on write access to
672 * MSR_IA32_DEBUGCTLMSR when guest_state_protected is not set.
673 */
674 svm_enable_lbrv(vcpu);
675 return 0;
676 }
677
sev_launch_update_vmsa(struct kvm * kvm,struct kvm_sev_cmd * argp)678 static int sev_launch_update_vmsa(struct kvm *kvm, struct kvm_sev_cmd *argp)
679 {
680 struct kvm_vcpu *vcpu;
681 unsigned long i;
682 int ret;
683
684 if (!sev_es_guest(kvm))
685 return -ENOTTY;
686
687 kvm_for_each_vcpu(i, vcpu, kvm) {
688 ret = mutex_lock_killable(&vcpu->mutex);
689 if (ret)
690 return ret;
691
692 ret = __sev_launch_update_vmsa(kvm, vcpu, &argp->error);
693
694 mutex_unlock(&vcpu->mutex);
695 if (ret)
696 return ret;
697 }
698
699 return 0;
700 }
701
sev_launch_measure(struct kvm * kvm,struct kvm_sev_cmd * argp)702 static int sev_launch_measure(struct kvm *kvm, struct kvm_sev_cmd *argp)
703 {
704 void __user *measure = (void __user *)(uintptr_t)argp->data;
705 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
706 struct sev_data_launch_measure data;
707 struct kvm_sev_launch_measure params;
708 void __user *p = NULL;
709 void *blob = NULL;
710 int ret;
711
712 if (!sev_guest(kvm))
713 return -ENOTTY;
714
715 if (copy_from_user(¶ms, measure, sizeof(params)))
716 return -EFAULT;
717
718 memset(&data, 0, sizeof(data));
719
720 /* User wants to query the blob length */
721 if (!params.len)
722 goto cmd;
723
724 p = (void __user *)(uintptr_t)params.uaddr;
725 if (p) {
726 if (params.len > SEV_FW_BLOB_MAX_SIZE)
727 return -EINVAL;
728
729 blob = kzalloc(params.len, GFP_KERNEL_ACCOUNT);
730 if (!blob)
731 return -ENOMEM;
732
733 data.address = __psp_pa(blob);
734 data.len = params.len;
735 }
736
737 cmd:
738 data.handle = sev->handle;
739 ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_MEASURE, &data, &argp->error);
740
741 /*
742 * If we query the session length, FW responded with expected data.
743 */
744 if (!params.len)
745 goto done;
746
747 if (ret)
748 goto e_free_blob;
749
750 if (blob) {
751 if (copy_to_user(p, blob, params.len))
752 ret = -EFAULT;
753 }
754
755 done:
756 params.len = data.len;
757 if (copy_to_user(measure, ¶ms, sizeof(params)))
758 ret = -EFAULT;
759 e_free_blob:
760 kfree(blob);
761 return ret;
762 }
763
sev_launch_finish(struct kvm * kvm,struct kvm_sev_cmd * argp)764 static int sev_launch_finish(struct kvm *kvm, struct kvm_sev_cmd *argp)
765 {
766 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
767 struct sev_data_launch_finish data;
768
769 if (!sev_guest(kvm))
770 return -ENOTTY;
771
772 data.handle = sev->handle;
773 return sev_issue_cmd(kvm, SEV_CMD_LAUNCH_FINISH, &data, &argp->error);
774 }
775
sev_guest_status(struct kvm * kvm,struct kvm_sev_cmd * argp)776 static int sev_guest_status(struct kvm *kvm, struct kvm_sev_cmd *argp)
777 {
778 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
779 struct kvm_sev_guest_status params;
780 struct sev_data_guest_status data;
781 int ret;
782
783 if (!sev_guest(kvm))
784 return -ENOTTY;
785
786 memset(&data, 0, sizeof(data));
787
788 data.handle = sev->handle;
789 ret = sev_issue_cmd(kvm, SEV_CMD_GUEST_STATUS, &data, &argp->error);
790 if (ret)
791 return ret;
792
793 params.policy = data.policy;
794 params.state = data.state;
795 params.handle = data.handle;
796
797 if (copy_to_user((void __user *)(uintptr_t)argp->data, ¶ms, sizeof(params)))
798 ret = -EFAULT;
799
800 return ret;
801 }
802
__sev_issue_dbg_cmd(struct kvm * kvm,unsigned long src,unsigned long dst,int size,int * error,bool enc)803 static int __sev_issue_dbg_cmd(struct kvm *kvm, unsigned long src,
804 unsigned long dst, int size,
805 int *error, bool enc)
806 {
807 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
808 struct sev_data_dbg data;
809
810 data.reserved = 0;
811 data.handle = sev->handle;
812 data.dst_addr = dst;
813 data.src_addr = src;
814 data.len = size;
815
816 return sev_issue_cmd(kvm,
817 enc ? SEV_CMD_DBG_ENCRYPT : SEV_CMD_DBG_DECRYPT,
818 &data, error);
819 }
820
__sev_dbg_decrypt(struct kvm * kvm,unsigned long src_paddr,unsigned long dst_paddr,int sz,int * err)821 static int __sev_dbg_decrypt(struct kvm *kvm, unsigned long src_paddr,
822 unsigned long dst_paddr, int sz, int *err)
823 {
824 int offset;
825
826 /*
827 * Its safe to read more than we are asked, caller should ensure that
828 * destination has enough space.
829 */
830 offset = src_paddr & 15;
831 src_paddr = round_down(src_paddr, 16);
832 sz = round_up(sz + offset, 16);
833
834 return __sev_issue_dbg_cmd(kvm, src_paddr, dst_paddr, sz, err, false);
835 }
836
__sev_dbg_decrypt_user(struct kvm * kvm,unsigned long paddr,void __user * dst_uaddr,unsigned long dst_paddr,int size,int * err)837 static int __sev_dbg_decrypt_user(struct kvm *kvm, unsigned long paddr,
838 void __user *dst_uaddr,
839 unsigned long dst_paddr,
840 int size, int *err)
841 {
842 struct page *tpage = NULL;
843 int ret, offset;
844
845 /* if inputs are not 16-byte then use intermediate buffer */
846 if (!IS_ALIGNED(dst_paddr, 16) ||
847 !IS_ALIGNED(paddr, 16) ||
848 !IS_ALIGNED(size, 16)) {
849 tpage = (void *)alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
850 if (!tpage)
851 return -ENOMEM;
852
853 dst_paddr = __sme_page_pa(tpage);
854 }
855
856 ret = __sev_dbg_decrypt(kvm, paddr, dst_paddr, size, err);
857 if (ret)
858 goto e_free;
859
860 if (tpage) {
861 offset = paddr & 15;
862 if (copy_to_user(dst_uaddr, page_address(tpage) + offset, size))
863 ret = -EFAULT;
864 }
865
866 e_free:
867 if (tpage)
868 __free_page(tpage);
869
870 return ret;
871 }
872
__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)873 static int __sev_dbg_encrypt_user(struct kvm *kvm, unsigned long paddr,
874 void __user *vaddr,
875 unsigned long dst_paddr,
876 void __user *dst_vaddr,
877 int size, int *error)
878 {
879 struct page *src_tpage = NULL;
880 struct page *dst_tpage = NULL;
881 int ret, len = size;
882
883 /* If source buffer is not aligned then use an intermediate buffer */
884 if (!IS_ALIGNED((unsigned long)vaddr, 16)) {
885 src_tpage = alloc_page(GFP_KERNEL_ACCOUNT);
886 if (!src_tpage)
887 return -ENOMEM;
888
889 if (copy_from_user(page_address(src_tpage), vaddr, size)) {
890 __free_page(src_tpage);
891 return -EFAULT;
892 }
893
894 paddr = __sme_page_pa(src_tpage);
895 }
896
897 /*
898 * If destination buffer or length is not aligned then do read-modify-write:
899 * - decrypt destination in an intermediate buffer
900 * - copy the source buffer in an intermediate buffer
901 * - use the intermediate buffer as source buffer
902 */
903 if (!IS_ALIGNED((unsigned long)dst_vaddr, 16) || !IS_ALIGNED(size, 16)) {
904 int dst_offset;
905
906 dst_tpage = alloc_page(GFP_KERNEL_ACCOUNT);
907 if (!dst_tpage) {
908 ret = -ENOMEM;
909 goto e_free;
910 }
911
912 ret = __sev_dbg_decrypt(kvm, dst_paddr,
913 __sme_page_pa(dst_tpage), size, error);
914 if (ret)
915 goto e_free;
916
917 /*
918 * If source is kernel buffer then use memcpy() otherwise
919 * copy_from_user().
920 */
921 dst_offset = dst_paddr & 15;
922
923 if (src_tpage)
924 memcpy(page_address(dst_tpage) + dst_offset,
925 page_address(src_tpage), size);
926 else {
927 if (copy_from_user(page_address(dst_tpage) + dst_offset,
928 vaddr, size)) {
929 ret = -EFAULT;
930 goto e_free;
931 }
932 }
933
934 paddr = __sme_page_pa(dst_tpage);
935 dst_paddr = round_down(dst_paddr, 16);
936 len = round_up(size, 16);
937 }
938
939 ret = __sev_issue_dbg_cmd(kvm, paddr, dst_paddr, len, error, true);
940
941 e_free:
942 if (src_tpage)
943 __free_page(src_tpage);
944 if (dst_tpage)
945 __free_page(dst_tpage);
946 return ret;
947 }
948
sev_dbg_crypt(struct kvm * kvm,struct kvm_sev_cmd * argp,bool dec)949 static int sev_dbg_crypt(struct kvm *kvm, struct kvm_sev_cmd *argp, bool dec)
950 {
951 unsigned long vaddr, vaddr_end, next_vaddr;
952 unsigned long dst_vaddr;
953 struct page **src_p, **dst_p;
954 struct kvm_sev_dbg debug;
955 unsigned long n;
956 unsigned int size;
957 int ret;
958
959 if (!sev_guest(kvm))
960 return -ENOTTY;
961
962 if (copy_from_user(&debug, (void __user *)(uintptr_t)argp->data, sizeof(debug)))
963 return -EFAULT;
964
965 if (!debug.len || debug.src_uaddr + debug.len < debug.src_uaddr)
966 return -EINVAL;
967 if (!debug.dst_uaddr)
968 return -EINVAL;
969
970 vaddr = debug.src_uaddr;
971 size = debug.len;
972 vaddr_end = vaddr + size;
973 dst_vaddr = debug.dst_uaddr;
974
975 for (; vaddr < vaddr_end; vaddr = next_vaddr) {
976 int len, s_off, d_off;
977
978 /* lock userspace source and destination page */
979 src_p = sev_pin_memory(kvm, vaddr & PAGE_MASK, PAGE_SIZE, &n, 0);
980 if (IS_ERR(src_p))
981 return PTR_ERR(src_p);
982
983 dst_p = sev_pin_memory(kvm, dst_vaddr & PAGE_MASK, PAGE_SIZE, &n, 1);
984 if (IS_ERR(dst_p)) {
985 sev_unpin_memory(kvm, src_p, n);
986 return PTR_ERR(dst_p);
987 }
988
989 /*
990 * Flush (on non-coherent CPUs) before DBG_{DE,EN}CRYPT read or modify
991 * the pages; flush the destination too so that future accesses do not
992 * see stale data.
993 */
994 sev_clflush_pages(src_p, 1);
995 sev_clflush_pages(dst_p, 1);
996
997 /*
998 * Since user buffer may not be page aligned, calculate the
999 * offset within the page.
1000 */
1001 s_off = vaddr & ~PAGE_MASK;
1002 d_off = dst_vaddr & ~PAGE_MASK;
1003 len = min_t(size_t, (PAGE_SIZE - s_off), size);
1004
1005 if (dec)
1006 ret = __sev_dbg_decrypt_user(kvm,
1007 __sme_page_pa(src_p[0]) + s_off,
1008 (void __user *)dst_vaddr,
1009 __sme_page_pa(dst_p[0]) + d_off,
1010 len, &argp->error);
1011 else
1012 ret = __sev_dbg_encrypt_user(kvm,
1013 __sme_page_pa(src_p[0]) + s_off,
1014 (void __user *)vaddr,
1015 __sme_page_pa(dst_p[0]) + d_off,
1016 (void __user *)dst_vaddr,
1017 len, &argp->error);
1018
1019 sev_unpin_memory(kvm, src_p, n);
1020 sev_unpin_memory(kvm, dst_p, n);
1021
1022 if (ret)
1023 goto err;
1024
1025 next_vaddr = vaddr + len;
1026 dst_vaddr = dst_vaddr + len;
1027 size -= len;
1028 }
1029 err:
1030 return ret;
1031 }
1032
sev_launch_secret(struct kvm * kvm,struct kvm_sev_cmd * argp)1033 static int sev_launch_secret(struct kvm *kvm, struct kvm_sev_cmd *argp)
1034 {
1035 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1036 struct sev_data_launch_secret data;
1037 struct kvm_sev_launch_secret params;
1038 struct page **pages;
1039 void *blob, *hdr;
1040 unsigned long n, i;
1041 int ret, offset;
1042
1043 if (!sev_guest(kvm))
1044 return -ENOTTY;
1045
1046 if (copy_from_user(¶ms, (void __user *)(uintptr_t)argp->data, sizeof(params)))
1047 return -EFAULT;
1048
1049 pages = sev_pin_memory(kvm, params.guest_uaddr, params.guest_len, &n, 1);
1050 if (IS_ERR(pages))
1051 return PTR_ERR(pages);
1052
1053 /*
1054 * Flush (on non-coherent CPUs) before LAUNCH_SECRET encrypts pages in
1055 * place; the cache may contain the data that was written unencrypted.
1056 */
1057 sev_clflush_pages(pages, n);
1058
1059 /*
1060 * The secret must be copied into contiguous memory region, lets verify
1061 * that userspace memory pages are contiguous before we issue command.
1062 */
1063 if (get_num_contig_pages(0, pages, n) != n) {
1064 ret = -EINVAL;
1065 goto e_unpin_memory;
1066 }
1067
1068 memset(&data, 0, sizeof(data));
1069
1070 offset = params.guest_uaddr & (PAGE_SIZE - 1);
1071 data.guest_address = __sme_page_pa(pages[0]) + offset;
1072 data.guest_len = params.guest_len;
1073
1074 blob = psp_copy_user_blob(params.trans_uaddr, params.trans_len);
1075 if (IS_ERR(blob)) {
1076 ret = PTR_ERR(blob);
1077 goto e_unpin_memory;
1078 }
1079
1080 data.trans_address = __psp_pa(blob);
1081 data.trans_len = params.trans_len;
1082
1083 hdr = psp_copy_user_blob(params.hdr_uaddr, params.hdr_len);
1084 if (IS_ERR(hdr)) {
1085 ret = PTR_ERR(hdr);
1086 goto e_free_blob;
1087 }
1088 data.hdr_address = __psp_pa(hdr);
1089 data.hdr_len = params.hdr_len;
1090
1091 data.handle = sev->handle;
1092 ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_UPDATE_SECRET, &data, &argp->error);
1093
1094 kfree(hdr);
1095
1096 e_free_blob:
1097 kfree(blob);
1098 e_unpin_memory:
1099 /* content of memory is updated, mark pages dirty */
1100 for (i = 0; i < n; i++) {
1101 set_page_dirty_lock(pages[i]);
1102 mark_page_accessed(pages[i]);
1103 }
1104 sev_unpin_memory(kvm, pages, n);
1105 return ret;
1106 }
1107
sev_get_attestation_report(struct kvm * kvm,struct kvm_sev_cmd * argp)1108 static int sev_get_attestation_report(struct kvm *kvm, struct kvm_sev_cmd *argp)
1109 {
1110 void __user *report = (void __user *)(uintptr_t)argp->data;
1111 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1112 struct sev_data_attestation_report data;
1113 struct kvm_sev_attestation_report params;
1114 void __user *p;
1115 void *blob = NULL;
1116 int ret;
1117
1118 if (!sev_guest(kvm))
1119 return -ENOTTY;
1120
1121 if (copy_from_user(¶ms, (void __user *)(uintptr_t)argp->data, sizeof(params)))
1122 return -EFAULT;
1123
1124 memset(&data, 0, sizeof(data));
1125
1126 /* User wants to query the blob length */
1127 if (!params.len)
1128 goto cmd;
1129
1130 p = (void __user *)(uintptr_t)params.uaddr;
1131 if (p) {
1132 if (params.len > SEV_FW_BLOB_MAX_SIZE)
1133 return -EINVAL;
1134
1135 blob = kzalloc(params.len, GFP_KERNEL_ACCOUNT);
1136 if (!blob)
1137 return -ENOMEM;
1138
1139 data.address = __psp_pa(blob);
1140 data.len = params.len;
1141 memcpy(data.mnonce, params.mnonce, sizeof(params.mnonce));
1142 }
1143 cmd:
1144 data.handle = sev->handle;
1145 ret = sev_issue_cmd(kvm, SEV_CMD_ATTESTATION_REPORT, &data, &argp->error);
1146 /*
1147 * If we query the session length, FW responded with expected data.
1148 */
1149 if (!params.len)
1150 goto done;
1151
1152 if (ret)
1153 goto e_free_blob;
1154
1155 if (blob) {
1156 if (copy_to_user(p, blob, params.len))
1157 ret = -EFAULT;
1158 }
1159
1160 done:
1161 params.len = data.len;
1162 if (copy_to_user(report, ¶ms, sizeof(params)))
1163 ret = -EFAULT;
1164 e_free_blob:
1165 kfree(blob);
1166 return ret;
1167 }
1168
1169 /* Userspace wants to query session length. */
1170 static int
__sev_send_start_query_session_length(struct kvm * kvm,struct kvm_sev_cmd * argp,struct kvm_sev_send_start * params)1171 __sev_send_start_query_session_length(struct kvm *kvm, struct kvm_sev_cmd *argp,
1172 struct kvm_sev_send_start *params)
1173 {
1174 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1175 struct sev_data_send_start data;
1176 int ret;
1177
1178 memset(&data, 0, sizeof(data));
1179 data.handle = sev->handle;
1180 ret = sev_issue_cmd(kvm, SEV_CMD_SEND_START, &data, &argp->error);
1181
1182 params->session_len = data.session_len;
1183 if (copy_to_user((void __user *)(uintptr_t)argp->data, params,
1184 sizeof(struct kvm_sev_send_start)))
1185 ret = -EFAULT;
1186
1187 return ret;
1188 }
1189
sev_send_start(struct kvm * kvm,struct kvm_sev_cmd * argp)1190 static int sev_send_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
1191 {
1192 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1193 struct sev_data_send_start data;
1194 struct kvm_sev_send_start params;
1195 void *amd_certs, *session_data;
1196 void *pdh_cert, *plat_certs;
1197 int ret;
1198
1199 if (!sev_guest(kvm))
1200 return -ENOTTY;
1201
1202 if (copy_from_user(¶ms, (void __user *)(uintptr_t)argp->data,
1203 sizeof(struct kvm_sev_send_start)))
1204 return -EFAULT;
1205
1206 /* if session_len is zero, userspace wants to query the session length */
1207 if (!params.session_len)
1208 return __sev_send_start_query_session_length(kvm, argp,
1209 ¶ms);
1210
1211 /* some sanity checks */
1212 if (!params.pdh_cert_uaddr || !params.pdh_cert_len ||
1213 !params.session_uaddr || params.session_len > SEV_FW_BLOB_MAX_SIZE)
1214 return -EINVAL;
1215
1216 /* allocate the memory to hold the session data blob */
1217 session_data = kzalloc(params.session_len, GFP_KERNEL_ACCOUNT);
1218 if (!session_data)
1219 return -ENOMEM;
1220
1221 /* copy the certificate blobs from userspace */
1222 pdh_cert = psp_copy_user_blob(params.pdh_cert_uaddr,
1223 params.pdh_cert_len);
1224 if (IS_ERR(pdh_cert)) {
1225 ret = PTR_ERR(pdh_cert);
1226 goto e_free_session;
1227 }
1228
1229 plat_certs = psp_copy_user_blob(params.plat_certs_uaddr,
1230 params.plat_certs_len);
1231 if (IS_ERR(plat_certs)) {
1232 ret = PTR_ERR(plat_certs);
1233 goto e_free_pdh;
1234 }
1235
1236 amd_certs = psp_copy_user_blob(params.amd_certs_uaddr,
1237 params.amd_certs_len);
1238 if (IS_ERR(amd_certs)) {
1239 ret = PTR_ERR(amd_certs);
1240 goto e_free_plat_cert;
1241 }
1242
1243 /* populate the FW SEND_START field with system physical address */
1244 memset(&data, 0, sizeof(data));
1245 data.pdh_cert_address = __psp_pa(pdh_cert);
1246 data.pdh_cert_len = params.pdh_cert_len;
1247 data.plat_certs_address = __psp_pa(plat_certs);
1248 data.plat_certs_len = params.plat_certs_len;
1249 data.amd_certs_address = __psp_pa(amd_certs);
1250 data.amd_certs_len = params.amd_certs_len;
1251 data.session_address = __psp_pa(session_data);
1252 data.session_len = params.session_len;
1253 data.handle = sev->handle;
1254
1255 ret = sev_issue_cmd(kvm, SEV_CMD_SEND_START, &data, &argp->error);
1256
1257 if (!ret && copy_to_user((void __user *)(uintptr_t)params.session_uaddr,
1258 session_data, params.session_len)) {
1259 ret = -EFAULT;
1260 goto e_free_amd_cert;
1261 }
1262
1263 params.policy = data.policy;
1264 params.session_len = data.session_len;
1265 if (copy_to_user((void __user *)(uintptr_t)argp->data, ¶ms,
1266 sizeof(struct kvm_sev_send_start)))
1267 ret = -EFAULT;
1268
1269 e_free_amd_cert:
1270 kfree(amd_certs);
1271 e_free_plat_cert:
1272 kfree(plat_certs);
1273 e_free_pdh:
1274 kfree(pdh_cert);
1275 e_free_session:
1276 kfree(session_data);
1277 return ret;
1278 }
1279
1280 /* Userspace wants to query either header or trans length. */
1281 static int
__sev_send_update_data_query_lengths(struct kvm * kvm,struct kvm_sev_cmd * argp,struct kvm_sev_send_update_data * params)1282 __sev_send_update_data_query_lengths(struct kvm *kvm, struct kvm_sev_cmd *argp,
1283 struct kvm_sev_send_update_data *params)
1284 {
1285 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1286 struct sev_data_send_update_data data;
1287 int ret;
1288
1289 memset(&data, 0, sizeof(data));
1290 data.handle = sev->handle;
1291 ret = sev_issue_cmd(kvm, SEV_CMD_SEND_UPDATE_DATA, &data, &argp->error);
1292
1293 params->hdr_len = data.hdr_len;
1294 params->trans_len = data.trans_len;
1295
1296 if (copy_to_user((void __user *)(uintptr_t)argp->data, params,
1297 sizeof(struct kvm_sev_send_update_data)))
1298 ret = -EFAULT;
1299
1300 return ret;
1301 }
1302
sev_send_update_data(struct kvm * kvm,struct kvm_sev_cmd * argp)1303 static int sev_send_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
1304 {
1305 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1306 struct sev_data_send_update_data data;
1307 struct kvm_sev_send_update_data params;
1308 void *hdr, *trans_data;
1309 struct page **guest_page;
1310 unsigned long n;
1311 int ret, offset;
1312
1313 if (!sev_guest(kvm))
1314 return -ENOTTY;
1315
1316 if (copy_from_user(¶ms, (void __user *)(uintptr_t)argp->data,
1317 sizeof(struct kvm_sev_send_update_data)))
1318 return -EFAULT;
1319
1320 /* userspace wants to query either header or trans length */
1321 if (!params.trans_len || !params.hdr_len)
1322 return __sev_send_update_data_query_lengths(kvm, argp, ¶ms);
1323
1324 if (!params.trans_uaddr || !params.guest_uaddr ||
1325 !params.guest_len || !params.hdr_uaddr)
1326 return -EINVAL;
1327
1328 /* Check if we are crossing the page boundary */
1329 offset = params.guest_uaddr & (PAGE_SIZE - 1);
1330 if (params.guest_len > PAGE_SIZE || (params.guest_len + offset) > PAGE_SIZE)
1331 return -EINVAL;
1332
1333 /* Pin guest memory */
1334 guest_page = sev_pin_memory(kvm, params.guest_uaddr & PAGE_MASK,
1335 PAGE_SIZE, &n, 0);
1336 if (IS_ERR(guest_page))
1337 return PTR_ERR(guest_page);
1338
1339 /* allocate memory for header and transport buffer */
1340 ret = -ENOMEM;
1341 hdr = kzalloc(params.hdr_len, GFP_KERNEL_ACCOUNT);
1342 if (!hdr)
1343 goto e_unpin;
1344
1345 trans_data = kzalloc(params.trans_len, GFP_KERNEL_ACCOUNT);
1346 if (!trans_data)
1347 goto e_free_hdr;
1348
1349 memset(&data, 0, sizeof(data));
1350 data.hdr_address = __psp_pa(hdr);
1351 data.hdr_len = params.hdr_len;
1352 data.trans_address = __psp_pa(trans_data);
1353 data.trans_len = params.trans_len;
1354
1355 /* The SEND_UPDATE_DATA command requires C-bit to be always set. */
1356 data.guest_address = (page_to_pfn(guest_page[0]) << PAGE_SHIFT) + offset;
1357 data.guest_address |= sev_me_mask;
1358 data.guest_len = params.guest_len;
1359 data.handle = sev->handle;
1360
1361 ret = sev_issue_cmd(kvm, SEV_CMD_SEND_UPDATE_DATA, &data, &argp->error);
1362
1363 if (ret)
1364 goto e_free_trans_data;
1365
1366 /* copy transport buffer to user space */
1367 if (copy_to_user((void __user *)(uintptr_t)params.trans_uaddr,
1368 trans_data, params.trans_len)) {
1369 ret = -EFAULT;
1370 goto e_free_trans_data;
1371 }
1372
1373 /* Copy packet header to userspace. */
1374 if (copy_to_user((void __user *)(uintptr_t)params.hdr_uaddr, hdr,
1375 params.hdr_len))
1376 ret = -EFAULT;
1377
1378 e_free_trans_data:
1379 kfree(trans_data);
1380 e_free_hdr:
1381 kfree(hdr);
1382 e_unpin:
1383 sev_unpin_memory(kvm, guest_page, n);
1384
1385 return ret;
1386 }
1387
sev_send_finish(struct kvm * kvm,struct kvm_sev_cmd * argp)1388 static int sev_send_finish(struct kvm *kvm, struct kvm_sev_cmd *argp)
1389 {
1390 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1391 struct sev_data_send_finish data;
1392
1393 if (!sev_guest(kvm))
1394 return -ENOTTY;
1395
1396 data.handle = sev->handle;
1397 return sev_issue_cmd(kvm, SEV_CMD_SEND_FINISH, &data, &argp->error);
1398 }
1399
sev_send_cancel(struct kvm * kvm,struct kvm_sev_cmd * argp)1400 static int sev_send_cancel(struct kvm *kvm, struct kvm_sev_cmd *argp)
1401 {
1402 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1403 struct sev_data_send_cancel data;
1404
1405 if (!sev_guest(kvm))
1406 return -ENOTTY;
1407
1408 data.handle = sev->handle;
1409 return sev_issue_cmd(kvm, SEV_CMD_SEND_CANCEL, &data, &argp->error);
1410 }
1411
sev_receive_start(struct kvm * kvm,struct kvm_sev_cmd * argp)1412 static int sev_receive_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
1413 {
1414 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1415 struct sev_data_receive_start start;
1416 struct kvm_sev_receive_start params;
1417 int *error = &argp->error;
1418 void *session_data;
1419 void *pdh_data;
1420 int ret;
1421
1422 if (!sev_guest(kvm))
1423 return -ENOTTY;
1424
1425 /* Get parameter from the userspace */
1426 if (copy_from_user(¶ms, (void __user *)(uintptr_t)argp->data,
1427 sizeof(struct kvm_sev_receive_start)))
1428 return -EFAULT;
1429
1430 /* some sanity checks */
1431 if (!params.pdh_uaddr || !params.pdh_len ||
1432 !params.session_uaddr || !params.session_len)
1433 return -EINVAL;
1434
1435 pdh_data = psp_copy_user_blob(params.pdh_uaddr, params.pdh_len);
1436 if (IS_ERR(pdh_data))
1437 return PTR_ERR(pdh_data);
1438
1439 session_data = psp_copy_user_blob(params.session_uaddr,
1440 params.session_len);
1441 if (IS_ERR(session_data)) {
1442 ret = PTR_ERR(session_data);
1443 goto e_free_pdh;
1444 }
1445
1446 memset(&start, 0, sizeof(start));
1447 start.handle = params.handle;
1448 start.policy = params.policy;
1449 start.pdh_cert_address = __psp_pa(pdh_data);
1450 start.pdh_cert_len = params.pdh_len;
1451 start.session_address = __psp_pa(session_data);
1452 start.session_len = params.session_len;
1453
1454 /* create memory encryption context */
1455 ret = __sev_issue_cmd(argp->sev_fd, SEV_CMD_RECEIVE_START, &start,
1456 error);
1457 if (ret)
1458 goto e_free_session;
1459
1460 /* Bind ASID to this guest */
1461 ret = sev_bind_asid(kvm, start.handle, error);
1462 if (ret) {
1463 sev_decommission(start.handle);
1464 goto e_free_session;
1465 }
1466
1467 params.handle = start.handle;
1468 if (copy_to_user((void __user *)(uintptr_t)argp->data,
1469 ¶ms, sizeof(struct kvm_sev_receive_start))) {
1470 ret = -EFAULT;
1471 sev_unbind_asid(kvm, start.handle);
1472 goto e_free_session;
1473 }
1474
1475 sev->handle = start.handle;
1476 sev->fd = argp->sev_fd;
1477
1478 e_free_session:
1479 kfree(session_data);
1480 e_free_pdh:
1481 kfree(pdh_data);
1482
1483 return ret;
1484 }
1485
sev_receive_update_data(struct kvm * kvm,struct kvm_sev_cmd * argp)1486 static int sev_receive_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
1487 {
1488 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1489 struct kvm_sev_receive_update_data params;
1490 struct sev_data_receive_update_data data;
1491 void *hdr = NULL, *trans = NULL;
1492 struct page **guest_page;
1493 unsigned long n;
1494 int ret, offset;
1495
1496 if (!sev_guest(kvm))
1497 return -EINVAL;
1498
1499 if (copy_from_user(¶ms, (void __user *)(uintptr_t)argp->data,
1500 sizeof(struct kvm_sev_receive_update_data)))
1501 return -EFAULT;
1502
1503 if (!params.hdr_uaddr || !params.hdr_len ||
1504 !params.guest_uaddr || !params.guest_len ||
1505 !params.trans_uaddr || !params.trans_len)
1506 return -EINVAL;
1507
1508 /* Check if we are crossing the page boundary */
1509 offset = params.guest_uaddr & (PAGE_SIZE - 1);
1510 if (params.guest_len > PAGE_SIZE || (params.guest_len + offset) > PAGE_SIZE)
1511 return -EINVAL;
1512
1513 hdr = psp_copy_user_blob(params.hdr_uaddr, params.hdr_len);
1514 if (IS_ERR(hdr))
1515 return PTR_ERR(hdr);
1516
1517 trans = psp_copy_user_blob(params.trans_uaddr, params.trans_len);
1518 if (IS_ERR(trans)) {
1519 ret = PTR_ERR(trans);
1520 goto e_free_hdr;
1521 }
1522
1523 memset(&data, 0, sizeof(data));
1524 data.hdr_address = __psp_pa(hdr);
1525 data.hdr_len = params.hdr_len;
1526 data.trans_address = __psp_pa(trans);
1527 data.trans_len = params.trans_len;
1528
1529 /* Pin guest memory */
1530 guest_page = sev_pin_memory(kvm, params.guest_uaddr & PAGE_MASK,
1531 PAGE_SIZE, &n, 1);
1532 if (IS_ERR(guest_page)) {
1533 ret = PTR_ERR(guest_page);
1534 goto e_free_trans;
1535 }
1536
1537 /*
1538 * Flush (on non-coherent CPUs) before RECEIVE_UPDATE_DATA, the PSP
1539 * encrypts the written data with the guest's key, and the cache may
1540 * contain dirty, unencrypted data.
1541 */
1542 sev_clflush_pages(guest_page, n);
1543
1544 /* The RECEIVE_UPDATE_DATA command requires C-bit to be always set. */
1545 data.guest_address = (page_to_pfn(guest_page[0]) << PAGE_SHIFT) + offset;
1546 data.guest_address |= sev_me_mask;
1547 data.guest_len = params.guest_len;
1548 data.handle = sev->handle;
1549
1550 ret = sev_issue_cmd(kvm, SEV_CMD_RECEIVE_UPDATE_DATA, &data,
1551 &argp->error);
1552
1553 sev_unpin_memory(kvm, guest_page, n);
1554
1555 e_free_trans:
1556 kfree(trans);
1557 e_free_hdr:
1558 kfree(hdr);
1559
1560 return ret;
1561 }
1562
sev_receive_finish(struct kvm * kvm,struct kvm_sev_cmd * argp)1563 static int sev_receive_finish(struct kvm *kvm, struct kvm_sev_cmd *argp)
1564 {
1565 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1566 struct sev_data_receive_finish data;
1567
1568 if (!sev_guest(kvm))
1569 return -ENOTTY;
1570
1571 data.handle = sev->handle;
1572 return sev_issue_cmd(kvm, SEV_CMD_RECEIVE_FINISH, &data, &argp->error);
1573 }
1574
is_cmd_allowed_from_mirror(u32 cmd_id)1575 static bool is_cmd_allowed_from_mirror(u32 cmd_id)
1576 {
1577 /*
1578 * Allow mirrors VM to call KVM_SEV_LAUNCH_UPDATE_VMSA to enable SEV-ES
1579 * active mirror VMs. Also allow the debugging and status commands.
1580 */
1581 if (cmd_id == KVM_SEV_LAUNCH_UPDATE_VMSA ||
1582 cmd_id == KVM_SEV_GUEST_STATUS || cmd_id == KVM_SEV_DBG_DECRYPT ||
1583 cmd_id == KVM_SEV_DBG_ENCRYPT)
1584 return true;
1585
1586 return false;
1587 }
1588
sev_lock_two_vms(struct kvm * dst_kvm,struct kvm * src_kvm)1589 static int sev_lock_two_vms(struct kvm *dst_kvm, struct kvm *src_kvm)
1590 {
1591 struct kvm_sev_info *dst_sev = &to_kvm_svm(dst_kvm)->sev_info;
1592 struct kvm_sev_info *src_sev = &to_kvm_svm(src_kvm)->sev_info;
1593 int r = -EBUSY;
1594
1595 if (dst_kvm == src_kvm)
1596 return -EINVAL;
1597
1598 /*
1599 * Bail if these VMs are already involved in a migration to avoid
1600 * deadlock between two VMs trying to migrate to/from each other.
1601 */
1602 if (atomic_cmpxchg_acquire(&dst_sev->migration_in_progress, 0, 1))
1603 return -EBUSY;
1604
1605 if (atomic_cmpxchg_acquire(&src_sev->migration_in_progress, 0, 1))
1606 goto release_dst;
1607
1608 r = -EINTR;
1609 if (mutex_lock_killable(&dst_kvm->lock))
1610 goto release_src;
1611 if (mutex_lock_killable_nested(&src_kvm->lock, SINGLE_DEPTH_NESTING))
1612 goto unlock_dst;
1613 return 0;
1614
1615 unlock_dst:
1616 mutex_unlock(&dst_kvm->lock);
1617 release_src:
1618 atomic_set_release(&src_sev->migration_in_progress, 0);
1619 release_dst:
1620 atomic_set_release(&dst_sev->migration_in_progress, 0);
1621 return r;
1622 }
1623
sev_unlock_two_vms(struct kvm * dst_kvm,struct kvm * src_kvm)1624 static void sev_unlock_two_vms(struct kvm *dst_kvm, struct kvm *src_kvm)
1625 {
1626 struct kvm_sev_info *dst_sev = &to_kvm_svm(dst_kvm)->sev_info;
1627 struct kvm_sev_info *src_sev = &to_kvm_svm(src_kvm)->sev_info;
1628
1629 mutex_unlock(&dst_kvm->lock);
1630 mutex_unlock(&src_kvm->lock);
1631 atomic_set_release(&dst_sev->migration_in_progress, 0);
1632 atomic_set_release(&src_sev->migration_in_progress, 0);
1633 }
1634
1635 /* vCPU mutex subclasses. */
1636 enum sev_migration_role {
1637 SEV_MIGRATION_SOURCE = 0,
1638 SEV_MIGRATION_TARGET,
1639 SEV_NR_MIGRATION_ROLES,
1640 };
1641
sev_lock_vcpus_for_migration(struct kvm * kvm,enum sev_migration_role role)1642 static int sev_lock_vcpus_for_migration(struct kvm *kvm,
1643 enum sev_migration_role role)
1644 {
1645 struct kvm_vcpu *vcpu;
1646 unsigned long i, j;
1647
1648 kvm_for_each_vcpu(i, vcpu, kvm) {
1649 if (mutex_lock_killable_nested(&vcpu->mutex, role))
1650 goto out_unlock;
1651
1652 #ifdef CONFIG_PROVE_LOCKING
1653 if (!i)
1654 /*
1655 * Reset the role to one that avoids colliding with
1656 * the role used for the first vcpu mutex.
1657 */
1658 role = SEV_NR_MIGRATION_ROLES;
1659 else
1660 mutex_release(&vcpu->mutex.dep_map, _THIS_IP_);
1661 #endif
1662 }
1663
1664 return 0;
1665
1666 out_unlock:
1667
1668 kvm_for_each_vcpu(j, vcpu, kvm) {
1669 if (i == j)
1670 break;
1671
1672 #ifdef CONFIG_PROVE_LOCKING
1673 if (j)
1674 mutex_acquire(&vcpu->mutex.dep_map, role, 0, _THIS_IP_);
1675 #endif
1676
1677 mutex_unlock(&vcpu->mutex);
1678 }
1679 return -EINTR;
1680 }
1681
sev_unlock_vcpus_for_migration(struct kvm * kvm)1682 static void sev_unlock_vcpus_for_migration(struct kvm *kvm)
1683 {
1684 struct kvm_vcpu *vcpu;
1685 unsigned long i;
1686 bool first = true;
1687
1688 kvm_for_each_vcpu(i, vcpu, kvm) {
1689 if (first)
1690 first = false;
1691 else
1692 mutex_acquire(&vcpu->mutex.dep_map,
1693 SEV_NR_MIGRATION_ROLES, 0, _THIS_IP_);
1694
1695 mutex_unlock(&vcpu->mutex);
1696 }
1697 }
1698
sev_migrate_from(struct kvm * dst_kvm,struct kvm * src_kvm)1699 static void sev_migrate_from(struct kvm *dst_kvm, struct kvm *src_kvm)
1700 {
1701 struct kvm_sev_info *dst = &to_kvm_svm(dst_kvm)->sev_info;
1702 struct kvm_sev_info *src = &to_kvm_svm(src_kvm)->sev_info;
1703 struct kvm_vcpu *dst_vcpu, *src_vcpu;
1704 struct vcpu_svm *dst_svm, *src_svm;
1705 struct kvm_sev_info *mirror;
1706 unsigned long i;
1707
1708 dst->active = true;
1709 dst->asid = src->asid;
1710 dst->handle = src->handle;
1711 dst->pages_locked = src->pages_locked;
1712 dst->enc_context_owner = src->enc_context_owner;
1713 dst->es_active = src->es_active;
1714
1715 src->asid = 0;
1716 src->active = false;
1717 src->handle = 0;
1718 src->pages_locked = 0;
1719 src->enc_context_owner = NULL;
1720 src->es_active = false;
1721
1722 list_cut_before(&dst->regions_list, &src->regions_list, &src->regions_list);
1723
1724 /*
1725 * If this VM has mirrors, "transfer" each mirror's refcount of the
1726 * source to the destination (this KVM). The caller holds a reference
1727 * to the source, so there's no danger of use-after-free.
1728 */
1729 list_cut_before(&dst->mirror_vms, &src->mirror_vms, &src->mirror_vms);
1730 list_for_each_entry(mirror, &dst->mirror_vms, mirror_entry) {
1731 kvm_get_kvm(dst_kvm);
1732 kvm_put_kvm(src_kvm);
1733 mirror->enc_context_owner = dst_kvm;
1734 }
1735
1736 /*
1737 * If this VM is a mirror, remove the old mirror from the owners list
1738 * and add the new mirror to the list.
1739 */
1740 if (is_mirroring_enc_context(dst_kvm)) {
1741 struct kvm_sev_info *owner_sev_info =
1742 &to_kvm_svm(dst->enc_context_owner)->sev_info;
1743
1744 list_del(&src->mirror_entry);
1745 list_add_tail(&dst->mirror_entry, &owner_sev_info->mirror_vms);
1746 }
1747
1748 kvm_for_each_vcpu(i, dst_vcpu, dst_kvm) {
1749 dst_svm = to_svm(dst_vcpu);
1750
1751 sev_init_vmcb(dst_svm);
1752
1753 if (!dst->es_active)
1754 continue;
1755
1756 /*
1757 * Note, the source is not required to have the same number of
1758 * vCPUs as the destination when migrating a vanilla SEV VM.
1759 */
1760 src_vcpu = kvm_get_vcpu(src_kvm, i);
1761 src_svm = to_svm(src_vcpu);
1762
1763 /*
1764 * Transfer VMSA and GHCB state to the destination. Nullify and
1765 * clear source fields as appropriate, the state now belongs to
1766 * the destination.
1767 */
1768 memcpy(&dst_svm->sev_es, &src_svm->sev_es, sizeof(src_svm->sev_es));
1769 dst_svm->vmcb->control.ghcb_gpa = src_svm->vmcb->control.ghcb_gpa;
1770 dst_svm->vmcb->control.vmsa_pa = src_svm->vmcb->control.vmsa_pa;
1771 dst_vcpu->arch.guest_state_protected = true;
1772
1773 memset(&src_svm->sev_es, 0, sizeof(src_svm->sev_es));
1774 src_svm->vmcb->control.ghcb_gpa = INVALID_PAGE;
1775 src_svm->vmcb->control.vmsa_pa = INVALID_PAGE;
1776 src_vcpu->arch.guest_state_protected = false;
1777 }
1778 }
1779
sev_check_source_vcpus(struct kvm * dst,struct kvm * src)1780 static int sev_check_source_vcpus(struct kvm *dst, struct kvm *src)
1781 {
1782 struct kvm_vcpu *src_vcpu;
1783 unsigned long i;
1784
1785 if (!sev_es_guest(src))
1786 return 0;
1787
1788 if (atomic_read(&src->online_vcpus) != atomic_read(&dst->online_vcpus))
1789 return -EINVAL;
1790
1791 kvm_for_each_vcpu(i, src_vcpu, src) {
1792 if (!src_vcpu->arch.guest_state_protected)
1793 return -EINVAL;
1794 }
1795
1796 return 0;
1797 }
1798
sev_vm_move_enc_context_from(struct kvm * kvm,unsigned int source_fd)1799 int sev_vm_move_enc_context_from(struct kvm *kvm, unsigned int source_fd)
1800 {
1801 struct kvm_sev_info *dst_sev = &to_kvm_svm(kvm)->sev_info;
1802 struct kvm_sev_info *src_sev, *cg_cleanup_sev;
1803 struct fd f = fdget(source_fd);
1804 struct kvm *source_kvm;
1805 bool charged = false;
1806 int ret;
1807
1808 if (!f.file)
1809 return -EBADF;
1810
1811 if (!file_is_kvm(f.file)) {
1812 ret = -EBADF;
1813 goto out_fput;
1814 }
1815
1816 source_kvm = f.file->private_data;
1817 ret = sev_lock_two_vms(kvm, source_kvm);
1818 if (ret)
1819 goto out_fput;
1820
1821 if (sev_guest(kvm) || !sev_guest(source_kvm)) {
1822 ret = -EINVAL;
1823 goto out_unlock;
1824 }
1825
1826 src_sev = &to_kvm_svm(source_kvm)->sev_info;
1827
1828 dst_sev->misc_cg = get_current_misc_cg();
1829 cg_cleanup_sev = dst_sev;
1830 if (dst_sev->misc_cg != src_sev->misc_cg) {
1831 ret = sev_misc_cg_try_charge(dst_sev);
1832 if (ret)
1833 goto out_dst_cgroup;
1834 charged = true;
1835 }
1836
1837 ret = sev_lock_vcpus_for_migration(kvm, SEV_MIGRATION_SOURCE);
1838 if (ret)
1839 goto out_dst_cgroup;
1840 ret = sev_lock_vcpus_for_migration(source_kvm, SEV_MIGRATION_TARGET);
1841 if (ret)
1842 goto out_dst_vcpu;
1843
1844 ret = sev_check_source_vcpus(kvm, source_kvm);
1845 if (ret)
1846 goto out_source_vcpu;
1847
1848 sev_migrate_from(kvm, source_kvm);
1849 kvm_vm_dead(source_kvm);
1850 cg_cleanup_sev = src_sev;
1851 ret = 0;
1852
1853 out_source_vcpu:
1854 sev_unlock_vcpus_for_migration(source_kvm);
1855 out_dst_vcpu:
1856 sev_unlock_vcpus_for_migration(kvm);
1857 out_dst_cgroup:
1858 /* Operates on the source on success, on the destination on failure. */
1859 if (charged)
1860 sev_misc_cg_uncharge(cg_cleanup_sev);
1861 put_misc_cg(cg_cleanup_sev->misc_cg);
1862 cg_cleanup_sev->misc_cg = NULL;
1863 out_unlock:
1864 sev_unlock_two_vms(kvm, source_kvm);
1865 out_fput:
1866 fdput(f);
1867 return ret;
1868 }
1869
sev_mem_enc_ioctl(struct kvm * kvm,void __user * argp)1870 int sev_mem_enc_ioctl(struct kvm *kvm, void __user *argp)
1871 {
1872 struct kvm_sev_cmd sev_cmd;
1873 int r;
1874
1875 if (!sev_enabled)
1876 return -ENOTTY;
1877
1878 if (!argp)
1879 return 0;
1880
1881 if (copy_from_user(&sev_cmd, argp, sizeof(struct kvm_sev_cmd)))
1882 return -EFAULT;
1883
1884 mutex_lock(&kvm->lock);
1885
1886 /* Only the enc_context_owner handles some memory enc operations. */
1887 if (is_mirroring_enc_context(kvm) &&
1888 !is_cmd_allowed_from_mirror(sev_cmd.id)) {
1889 r = -EINVAL;
1890 goto out;
1891 }
1892
1893 switch (sev_cmd.id) {
1894 case KVM_SEV_ES_INIT:
1895 if (!sev_es_enabled) {
1896 r = -ENOTTY;
1897 goto out;
1898 }
1899 fallthrough;
1900 case KVM_SEV_INIT:
1901 r = sev_guest_init(kvm, &sev_cmd);
1902 break;
1903 case KVM_SEV_LAUNCH_START:
1904 r = sev_launch_start(kvm, &sev_cmd);
1905 break;
1906 case KVM_SEV_LAUNCH_UPDATE_DATA:
1907 r = sev_launch_update_data(kvm, &sev_cmd);
1908 break;
1909 case KVM_SEV_LAUNCH_UPDATE_VMSA:
1910 r = sev_launch_update_vmsa(kvm, &sev_cmd);
1911 break;
1912 case KVM_SEV_LAUNCH_MEASURE:
1913 r = sev_launch_measure(kvm, &sev_cmd);
1914 break;
1915 case KVM_SEV_LAUNCH_FINISH:
1916 r = sev_launch_finish(kvm, &sev_cmd);
1917 break;
1918 case KVM_SEV_GUEST_STATUS:
1919 r = sev_guest_status(kvm, &sev_cmd);
1920 break;
1921 case KVM_SEV_DBG_DECRYPT:
1922 r = sev_dbg_crypt(kvm, &sev_cmd, true);
1923 break;
1924 case KVM_SEV_DBG_ENCRYPT:
1925 r = sev_dbg_crypt(kvm, &sev_cmd, false);
1926 break;
1927 case KVM_SEV_LAUNCH_SECRET:
1928 r = sev_launch_secret(kvm, &sev_cmd);
1929 break;
1930 case KVM_SEV_GET_ATTESTATION_REPORT:
1931 r = sev_get_attestation_report(kvm, &sev_cmd);
1932 break;
1933 case KVM_SEV_SEND_START:
1934 r = sev_send_start(kvm, &sev_cmd);
1935 break;
1936 case KVM_SEV_SEND_UPDATE_DATA:
1937 r = sev_send_update_data(kvm, &sev_cmd);
1938 break;
1939 case KVM_SEV_SEND_FINISH:
1940 r = sev_send_finish(kvm, &sev_cmd);
1941 break;
1942 case KVM_SEV_SEND_CANCEL:
1943 r = sev_send_cancel(kvm, &sev_cmd);
1944 break;
1945 case KVM_SEV_RECEIVE_START:
1946 r = sev_receive_start(kvm, &sev_cmd);
1947 break;
1948 case KVM_SEV_RECEIVE_UPDATE_DATA:
1949 r = sev_receive_update_data(kvm, &sev_cmd);
1950 break;
1951 case KVM_SEV_RECEIVE_FINISH:
1952 r = sev_receive_finish(kvm, &sev_cmd);
1953 break;
1954 default:
1955 r = -EINVAL;
1956 goto out;
1957 }
1958
1959 if (copy_to_user(argp, &sev_cmd, sizeof(struct kvm_sev_cmd)))
1960 r = -EFAULT;
1961
1962 out:
1963 mutex_unlock(&kvm->lock);
1964 return r;
1965 }
1966
sev_mem_enc_register_region(struct kvm * kvm,struct kvm_enc_region * range)1967 int sev_mem_enc_register_region(struct kvm *kvm,
1968 struct kvm_enc_region *range)
1969 {
1970 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1971 struct enc_region *region;
1972 int ret = 0;
1973
1974 if (!sev_guest(kvm))
1975 return -ENOTTY;
1976
1977 /* If kvm is mirroring encryption context it isn't responsible for it */
1978 if (is_mirroring_enc_context(kvm))
1979 return -EINVAL;
1980
1981 if (range->addr > ULONG_MAX || range->size > ULONG_MAX)
1982 return -EINVAL;
1983
1984 region = kzalloc(sizeof(*region), GFP_KERNEL_ACCOUNT);
1985 if (!region)
1986 return -ENOMEM;
1987
1988 mutex_lock(&kvm->lock);
1989 region->pages = sev_pin_memory(kvm, range->addr, range->size, ®ion->npages, 1);
1990 if (IS_ERR(region->pages)) {
1991 ret = PTR_ERR(region->pages);
1992 mutex_unlock(&kvm->lock);
1993 goto e_free;
1994 }
1995
1996 /*
1997 * The guest may change the memory encryption attribute from C=0 -> C=1
1998 * or vice versa for this memory range. Lets make sure caches are
1999 * flushed to ensure that guest data gets written into memory with
2000 * correct C-bit. Note, this must be done before dropping kvm->lock,
2001 * as region and its array of pages can be freed by a different task
2002 * once kvm->lock is released.
2003 */
2004 sev_clflush_pages(region->pages, region->npages);
2005
2006 region->uaddr = range->addr;
2007 region->size = range->size;
2008
2009 list_add_tail(®ion->list, &sev->regions_list);
2010 mutex_unlock(&kvm->lock);
2011
2012 return ret;
2013
2014 e_free:
2015 kfree(region);
2016 return ret;
2017 }
2018
2019 static struct enc_region *
find_enc_region(struct kvm * kvm,struct kvm_enc_region * range)2020 find_enc_region(struct kvm *kvm, struct kvm_enc_region *range)
2021 {
2022 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
2023 struct list_head *head = &sev->regions_list;
2024 struct enc_region *i;
2025
2026 list_for_each_entry(i, head, list) {
2027 if (i->uaddr == range->addr &&
2028 i->size == range->size)
2029 return i;
2030 }
2031
2032 return NULL;
2033 }
2034
__unregister_enc_region_locked(struct kvm * kvm,struct enc_region * region)2035 static void __unregister_enc_region_locked(struct kvm *kvm,
2036 struct enc_region *region)
2037 {
2038 sev_unpin_memory(kvm, region->pages, region->npages);
2039 list_del(®ion->list);
2040 kfree(region);
2041 }
2042
sev_mem_enc_unregister_region(struct kvm * kvm,struct kvm_enc_region * range)2043 int sev_mem_enc_unregister_region(struct kvm *kvm,
2044 struct kvm_enc_region *range)
2045 {
2046 struct enc_region *region;
2047 int ret;
2048
2049 /* If kvm is mirroring encryption context it isn't responsible for it */
2050 if (is_mirroring_enc_context(kvm))
2051 return -EINVAL;
2052
2053 mutex_lock(&kvm->lock);
2054
2055 if (!sev_guest(kvm)) {
2056 ret = -ENOTTY;
2057 goto failed;
2058 }
2059
2060 region = find_enc_region(kvm, range);
2061 if (!region) {
2062 ret = -EINVAL;
2063 goto failed;
2064 }
2065
2066 /*
2067 * Ensure that all guest tagged cache entries are flushed before
2068 * releasing the pages back to the system for use. CLFLUSH will
2069 * not do this, so issue a WBINVD.
2070 */
2071 wbinvd_on_all_cpus();
2072
2073 __unregister_enc_region_locked(kvm, region);
2074
2075 mutex_unlock(&kvm->lock);
2076 return 0;
2077
2078 failed:
2079 mutex_unlock(&kvm->lock);
2080 return ret;
2081 }
2082
sev_vm_copy_enc_context_from(struct kvm * kvm,unsigned int source_fd)2083 int sev_vm_copy_enc_context_from(struct kvm *kvm, unsigned int source_fd)
2084 {
2085 struct fd f = fdget(source_fd);
2086 struct kvm *source_kvm;
2087 struct kvm_sev_info *source_sev, *mirror_sev;
2088 int ret;
2089
2090 if (!f.file)
2091 return -EBADF;
2092
2093 if (!file_is_kvm(f.file)) {
2094 ret = -EBADF;
2095 goto e_source_fput;
2096 }
2097
2098 source_kvm = f.file->private_data;
2099 ret = sev_lock_two_vms(kvm, source_kvm);
2100 if (ret)
2101 goto e_source_fput;
2102
2103 /*
2104 * Mirrors of mirrors should work, but let's not get silly. Also
2105 * disallow out-of-band SEV/SEV-ES init if the target is already an
2106 * SEV guest, or if vCPUs have been created. KVM relies on vCPUs being
2107 * created after SEV/SEV-ES initialization, e.g. to init intercepts.
2108 */
2109 if (sev_guest(kvm) || !sev_guest(source_kvm) ||
2110 is_mirroring_enc_context(source_kvm) || kvm->created_vcpus) {
2111 ret = -EINVAL;
2112 goto e_unlock;
2113 }
2114
2115 /*
2116 * The mirror kvm holds an enc_context_owner ref so its asid can't
2117 * disappear until we're done with it
2118 */
2119 source_sev = &to_kvm_svm(source_kvm)->sev_info;
2120 kvm_get_kvm(source_kvm);
2121 mirror_sev = &to_kvm_svm(kvm)->sev_info;
2122 list_add_tail(&mirror_sev->mirror_entry, &source_sev->mirror_vms);
2123
2124 /* Set enc_context_owner and copy its encryption context over */
2125 mirror_sev->enc_context_owner = source_kvm;
2126 mirror_sev->active = true;
2127 mirror_sev->asid = source_sev->asid;
2128 mirror_sev->fd = source_sev->fd;
2129 mirror_sev->es_active = source_sev->es_active;
2130 mirror_sev->handle = source_sev->handle;
2131 INIT_LIST_HEAD(&mirror_sev->regions_list);
2132 INIT_LIST_HEAD(&mirror_sev->mirror_vms);
2133 ret = 0;
2134
2135 /*
2136 * Do not copy ap_jump_table. Since the mirror does not share the same
2137 * KVM contexts as the original, and they may have different
2138 * memory-views.
2139 */
2140
2141 e_unlock:
2142 sev_unlock_two_vms(kvm, source_kvm);
2143 e_source_fput:
2144 fdput(f);
2145 return ret;
2146 }
2147
sev_vm_destroy(struct kvm * kvm)2148 void sev_vm_destroy(struct kvm *kvm)
2149 {
2150 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
2151 struct list_head *head = &sev->regions_list;
2152 struct list_head *pos, *q;
2153
2154 if (!sev_guest(kvm))
2155 return;
2156
2157 WARN_ON(!list_empty(&sev->mirror_vms));
2158
2159 /* If this is a mirror_kvm release the enc_context_owner and skip sev cleanup */
2160 if (is_mirroring_enc_context(kvm)) {
2161 struct kvm *owner_kvm = sev->enc_context_owner;
2162
2163 mutex_lock(&owner_kvm->lock);
2164 list_del(&sev->mirror_entry);
2165 mutex_unlock(&owner_kvm->lock);
2166 kvm_put_kvm(owner_kvm);
2167 return;
2168 }
2169
2170 /*
2171 * Ensure that all guest tagged cache entries are flushed before
2172 * releasing the pages back to the system for use. CLFLUSH will
2173 * not do this, so issue a WBINVD.
2174 */
2175 wbinvd_on_all_cpus();
2176
2177 /*
2178 * if userspace was terminated before unregistering the memory regions
2179 * then lets unpin all the registered memory.
2180 */
2181 if (!list_empty(head)) {
2182 list_for_each_safe(pos, q, head) {
2183 __unregister_enc_region_locked(kvm,
2184 list_entry(pos, struct enc_region, list));
2185 cond_resched();
2186 }
2187 }
2188
2189 sev_unbind_asid(kvm, sev->handle);
2190 sev_asid_free(sev);
2191 }
2192
sev_set_cpu_caps(void)2193 void __init sev_set_cpu_caps(void)
2194 {
2195 if (!sev_enabled)
2196 kvm_cpu_cap_clear(X86_FEATURE_SEV);
2197 if (!sev_es_enabled)
2198 kvm_cpu_cap_clear(X86_FEATURE_SEV_ES);
2199 }
2200
sev_hardware_setup(void)2201 void __init sev_hardware_setup(void)
2202 {
2203 #ifdef CONFIG_KVM_AMD_SEV
2204 unsigned int eax, ebx, ecx, edx, sev_asid_count, sev_es_asid_count;
2205 bool sev_es_supported = false;
2206 bool sev_supported = false;
2207
2208 if (!sev_enabled || !npt_enabled || !nrips)
2209 goto out;
2210
2211 /*
2212 * SEV must obviously be supported in hardware. Sanity check that the
2213 * CPU supports decode assists, which is mandatory for SEV guests to
2214 * support instruction emulation.
2215 */
2216 if (!boot_cpu_has(X86_FEATURE_SEV) ||
2217 WARN_ON_ONCE(!boot_cpu_has(X86_FEATURE_DECODEASSISTS)))
2218 goto out;
2219
2220 /* Retrieve SEV CPUID information */
2221 cpuid(0x8000001f, &eax, &ebx, &ecx, &edx);
2222
2223 /* Set encryption bit location for SEV-ES guests */
2224 sev_enc_bit = ebx & 0x3f;
2225
2226 /* Maximum number of encrypted guests supported simultaneously */
2227 max_sev_asid = ecx;
2228 if (!max_sev_asid)
2229 goto out;
2230
2231 /* Minimum ASID value that should be used for SEV guest */
2232 min_sev_asid = edx;
2233 sev_me_mask = 1UL << (ebx & 0x3f);
2234
2235 /*
2236 * Initialize SEV ASID bitmaps. Allocate space for ASID 0 in the bitmap,
2237 * even though it's never used, so that the bitmap is indexed by the
2238 * actual ASID.
2239 */
2240 nr_asids = max_sev_asid + 1;
2241 sev_asid_bitmap = bitmap_zalloc(nr_asids, GFP_KERNEL);
2242 if (!sev_asid_bitmap)
2243 goto out;
2244
2245 sev_reclaim_asid_bitmap = bitmap_zalloc(nr_asids, GFP_KERNEL);
2246 if (!sev_reclaim_asid_bitmap) {
2247 bitmap_free(sev_asid_bitmap);
2248 sev_asid_bitmap = NULL;
2249 goto out;
2250 }
2251
2252 if (min_sev_asid <= max_sev_asid) {
2253 sev_asid_count = max_sev_asid - min_sev_asid + 1;
2254 WARN_ON_ONCE(misc_cg_set_capacity(MISC_CG_RES_SEV, sev_asid_count));
2255 }
2256 sev_supported = true;
2257
2258 /* SEV-ES support requested? */
2259 if (!sev_es_enabled)
2260 goto out;
2261
2262 /*
2263 * SEV-ES requires MMIO caching as KVM doesn't have access to the guest
2264 * instruction stream, i.e. can't emulate in response to a #NPF and
2265 * instead relies on #NPF(RSVD) being reflected into the guest as #VC
2266 * (the guest can then do a #VMGEXIT to request MMIO emulation).
2267 */
2268 if (!enable_mmio_caching)
2269 goto out;
2270
2271 /* Does the CPU support SEV-ES? */
2272 if (!boot_cpu_has(X86_FEATURE_SEV_ES))
2273 goto out;
2274
2275 if (!lbrv) {
2276 WARN_ONCE(!boot_cpu_has(X86_FEATURE_LBRV),
2277 "LBRV must be present for SEV-ES support");
2278 goto out;
2279 }
2280
2281 /* Has the system been allocated ASIDs for SEV-ES? */
2282 if (min_sev_asid == 1)
2283 goto out;
2284
2285 sev_es_asid_count = min_sev_asid - 1;
2286 WARN_ON_ONCE(misc_cg_set_capacity(MISC_CG_RES_SEV_ES, sev_es_asid_count));
2287 sev_es_supported = true;
2288
2289 out:
2290 if (boot_cpu_has(X86_FEATURE_SEV))
2291 pr_info("SEV %s (ASIDs %u - %u)\n",
2292 sev_supported ? min_sev_asid <= max_sev_asid ? "enabled" :
2293 "unusable" :
2294 "disabled",
2295 min_sev_asid, max_sev_asid);
2296 if (boot_cpu_has(X86_FEATURE_SEV_ES))
2297 pr_info("SEV-ES %s (ASIDs %u - %u)\n",
2298 sev_es_supported ? "enabled" : "disabled",
2299 min_sev_asid > 1 ? 1 : 0, min_sev_asid - 1);
2300
2301 sev_enabled = sev_supported;
2302 sev_es_enabled = sev_es_supported;
2303 if (!sev_es_enabled || !cpu_feature_enabled(X86_FEATURE_DEBUG_SWAP) ||
2304 !cpu_feature_enabled(X86_FEATURE_NO_NESTED_DATA_BP))
2305 sev_es_debug_swap_enabled = false;
2306 #endif
2307 }
2308
sev_hardware_unsetup(void)2309 void sev_hardware_unsetup(void)
2310 {
2311 if (!sev_enabled)
2312 return;
2313
2314 /* No need to take sev_bitmap_lock, all VMs have been destroyed. */
2315 sev_flush_asids(1, max_sev_asid);
2316
2317 bitmap_free(sev_asid_bitmap);
2318 bitmap_free(sev_reclaim_asid_bitmap);
2319
2320 misc_cg_set_capacity(MISC_CG_RES_SEV, 0);
2321 misc_cg_set_capacity(MISC_CG_RES_SEV_ES, 0);
2322 }
2323
sev_cpu_init(struct svm_cpu_data * sd)2324 int sev_cpu_init(struct svm_cpu_data *sd)
2325 {
2326 if (!sev_enabled)
2327 return 0;
2328
2329 sd->sev_vmcbs = kcalloc(nr_asids, sizeof(void *), GFP_KERNEL);
2330 if (!sd->sev_vmcbs)
2331 return -ENOMEM;
2332
2333 return 0;
2334 }
2335
2336 /*
2337 * Pages used by hardware to hold guest encrypted state must be flushed before
2338 * returning them to the system.
2339 */
sev_flush_encrypted_page(struct kvm_vcpu * vcpu,void * va)2340 static void sev_flush_encrypted_page(struct kvm_vcpu *vcpu, void *va)
2341 {
2342 unsigned int asid = sev_get_asid(vcpu->kvm);
2343
2344 /*
2345 * Note! The address must be a kernel address, as regular page walk
2346 * checks are performed by VM_PAGE_FLUSH, i.e. operating on a user
2347 * address is non-deterministic and unsafe. This function deliberately
2348 * takes a pointer to deter passing in a user address.
2349 */
2350 unsigned long addr = (unsigned long)va;
2351
2352 /*
2353 * If CPU enforced cache coherency for encrypted mappings of the
2354 * same physical page is supported, use CLFLUSHOPT instead. NOTE: cache
2355 * flush is still needed in order to work properly with DMA devices.
2356 */
2357 if (boot_cpu_has(X86_FEATURE_SME_COHERENT)) {
2358 clflush_cache_range(va, PAGE_SIZE);
2359 return;
2360 }
2361
2362 /*
2363 * VM Page Flush takes a host virtual address and a guest ASID. Fall
2364 * back to WBINVD if this faults so as not to make any problems worse
2365 * by leaving stale encrypted data in the cache.
2366 */
2367 if (WARN_ON_ONCE(wrmsrl_safe(MSR_AMD64_VM_PAGE_FLUSH, addr | asid)))
2368 goto do_wbinvd;
2369
2370 return;
2371
2372 do_wbinvd:
2373 wbinvd_on_all_cpus();
2374 }
2375
sev_guest_memory_reclaimed(struct kvm * kvm)2376 void sev_guest_memory_reclaimed(struct kvm *kvm)
2377 {
2378 if (!sev_guest(kvm))
2379 return;
2380
2381 wbinvd_on_all_cpus();
2382 }
2383
sev_free_vcpu(struct kvm_vcpu * vcpu)2384 void sev_free_vcpu(struct kvm_vcpu *vcpu)
2385 {
2386 struct vcpu_svm *svm;
2387
2388 if (!sev_es_guest(vcpu->kvm))
2389 return;
2390
2391 svm = to_svm(vcpu);
2392
2393 if (vcpu->arch.guest_state_protected)
2394 sev_flush_encrypted_page(vcpu, svm->sev_es.vmsa);
2395
2396 __free_page(virt_to_page(svm->sev_es.vmsa));
2397
2398 if (svm->sev_es.ghcb_sa_free)
2399 kvfree(svm->sev_es.ghcb_sa);
2400 }
2401
dump_ghcb(struct vcpu_svm * svm)2402 static void dump_ghcb(struct vcpu_svm *svm)
2403 {
2404 struct ghcb *ghcb = svm->sev_es.ghcb;
2405 unsigned int nbits;
2406
2407 /* Re-use the dump_invalid_vmcb module parameter */
2408 if (!dump_invalid_vmcb) {
2409 pr_warn_ratelimited("set kvm_amd.dump_invalid_vmcb=1 to dump internal KVM state.\n");
2410 return;
2411 }
2412
2413 nbits = sizeof(ghcb->save.valid_bitmap) * 8;
2414
2415 pr_err("GHCB (GPA=%016llx):\n", svm->vmcb->control.ghcb_gpa);
2416 pr_err("%-20s%016llx is_valid: %u\n", "sw_exit_code",
2417 ghcb->save.sw_exit_code, ghcb_sw_exit_code_is_valid(ghcb));
2418 pr_err("%-20s%016llx is_valid: %u\n", "sw_exit_info_1",
2419 ghcb->save.sw_exit_info_1, ghcb_sw_exit_info_1_is_valid(ghcb));
2420 pr_err("%-20s%016llx is_valid: %u\n", "sw_exit_info_2",
2421 ghcb->save.sw_exit_info_2, ghcb_sw_exit_info_2_is_valid(ghcb));
2422 pr_err("%-20s%016llx is_valid: %u\n", "sw_scratch",
2423 ghcb->save.sw_scratch, ghcb_sw_scratch_is_valid(ghcb));
2424 pr_err("%-20s%*pb\n", "valid_bitmap", nbits, ghcb->save.valid_bitmap);
2425 }
2426
sev_es_sync_to_ghcb(struct vcpu_svm * svm)2427 static void sev_es_sync_to_ghcb(struct vcpu_svm *svm)
2428 {
2429 struct kvm_vcpu *vcpu = &svm->vcpu;
2430 struct ghcb *ghcb = svm->sev_es.ghcb;
2431
2432 /*
2433 * The GHCB protocol so far allows for the following data
2434 * to be returned:
2435 * GPRs RAX, RBX, RCX, RDX
2436 *
2437 * Copy their values, even if they may not have been written during the
2438 * VM-Exit. It's the guest's responsibility to not consume random data.
2439 */
2440 ghcb_set_rax(ghcb, vcpu->arch.regs[VCPU_REGS_RAX]);
2441 ghcb_set_rbx(ghcb, vcpu->arch.regs[VCPU_REGS_RBX]);
2442 ghcb_set_rcx(ghcb, vcpu->arch.regs[VCPU_REGS_RCX]);
2443 ghcb_set_rdx(ghcb, vcpu->arch.regs[VCPU_REGS_RDX]);
2444 }
2445
sev_es_sync_from_ghcb(struct vcpu_svm * svm)2446 static void sev_es_sync_from_ghcb(struct vcpu_svm *svm)
2447 {
2448 struct vmcb_control_area *control = &svm->vmcb->control;
2449 struct kvm_vcpu *vcpu = &svm->vcpu;
2450 struct ghcb *ghcb = svm->sev_es.ghcb;
2451 u64 exit_code;
2452
2453 /*
2454 * The GHCB protocol so far allows for the following data
2455 * to be supplied:
2456 * GPRs RAX, RBX, RCX, RDX
2457 * XCR0
2458 * CPL
2459 *
2460 * VMMCALL allows the guest to provide extra registers. KVM also
2461 * expects RSI for hypercalls, so include that, too.
2462 *
2463 * Copy their values to the appropriate location if supplied.
2464 */
2465 memset(vcpu->arch.regs, 0, sizeof(vcpu->arch.regs));
2466
2467 BUILD_BUG_ON(sizeof(svm->sev_es.valid_bitmap) != sizeof(ghcb->save.valid_bitmap));
2468 memcpy(&svm->sev_es.valid_bitmap, &ghcb->save.valid_bitmap, sizeof(ghcb->save.valid_bitmap));
2469
2470 vcpu->arch.regs[VCPU_REGS_RAX] = kvm_ghcb_get_rax_if_valid(svm, ghcb);
2471 vcpu->arch.regs[VCPU_REGS_RBX] = kvm_ghcb_get_rbx_if_valid(svm, ghcb);
2472 vcpu->arch.regs[VCPU_REGS_RCX] = kvm_ghcb_get_rcx_if_valid(svm, ghcb);
2473 vcpu->arch.regs[VCPU_REGS_RDX] = kvm_ghcb_get_rdx_if_valid(svm, ghcb);
2474 vcpu->arch.regs[VCPU_REGS_RSI] = kvm_ghcb_get_rsi_if_valid(svm, ghcb);
2475
2476 svm->vmcb->save.cpl = kvm_ghcb_get_cpl_if_valid(svm, ghcb);
2477
2478 if (kvm_ghcb_xcr0_is_valid(svm)) {
2479 vcpu->arch.xcr0 = ghcb_get_xcr0(ghcb);
2480 kvm_update_cpuid_runtime(vcpu);
2481 }
2482
2483 /* Copy the GHCB exit information into the VMCB fields */
2484 exit_code = ghcb_get_sw_exit_code(ghcb);
2485 control->exit_code = lower_32_bits(exit_code);
2486 control->exit_code_hi = upper_32_bits(exit_code);
2487 control->exit_info_1 = ghcb_get_sw_exit_info_1(ghcb);
2488 control->exit_info_2 = ghcb_get_sw_exit_info_2(ghcb);
2489 svm->sev_es.sw_scratch = kvm_ghcb_get_sw_scratch_if_valid(svm, ghcb);
2490
2491 /* Clear the valid entries fields */
2492 memset(ghcb->save.valid_bitmap, 0, sizeof(ghcb->save.valid_bitmap));
2493 }
2494
kvm_ghcb_get_sw_exit_code(struct vmcb_control_area * control)2495 static u64 kvm_ghcb_get_sw_exit_code(struct vmcb_control_area *control)
2496 {
2497 return (((u64)control->exit_code_hi) << 32) | control->exit_code;
2498 }
2499
sev_es_validate_vmgexit(struct vcpu_svm * svm)2500 static int sev_es_validate_vmgexit(struct vcpu_svm *svm)
2501 {
2502 struct vmcb_control_area *control = &svm->vmcb->control;
2503 struct kvm_vcpu *vcpu = &svm->vcpu;
2504 u64 exit_code;
2505 u64 reason;
2506
2507 /*
2508 * Retrieve the exit code now even though it may not be marked valid
2509 * as it could help with debugging.
2510 */
2511 exit_code = kvm_ghcb_get_sw_exit_code(control);
2512
2513 /* Only GHCB Usage code 0 is supported */
2514 if (svm->sev_es.ghcb->ghcb_usage) {
2515 reason = GHCB_ERR_INVALID_USAGE;
2516 goto vmgexit_err;
2517 }
2518
2519 reason = GHCB_ERR_MISSING_INPUT;
2520
2521 if (!kvm_ghcb_sw_exit_code_is_valid(svm) ||
2522 !kvm_ghcb_sw_exit_info_1_is_valid(svm) ||
2523 !kvm_ghcb_sw_exit_info_2_is_valid(svm))
2524 goto vmgexit_err;
2525
2526 switch (exit_code) {
2527 case SVM_EXIT_READ_DR7:
2528 break;
2529 case SVM_EXIT_WRITE_DR7:
2530 if (!kvm_ghcb_rax_is_valid(svm))
2531 goto vmgexit_err;
2532 break;
2533 case SVM_EXIT_RDTSC:
2534 break;
2535 case SVM_EXIT_RDPMC:
2536 if (!kvm_ghcb_rcx_is_valid(svm))
2537 goto vmgexit_err;
2538 break;
2539 case SVM_EXIT_CPUID:
2540 if (!kvm_ghcb_rax_is_valid(svm) ||
2541 !kvm_ghcb_rcx_is_valid(svm))
2542 goto vmgexit_err;
2543 if (vcpu->arch.regs[VCPU_REGS_RAX] == 0xd)
2544 if (!kvm_ghcb_xcr0_is_valid(svm))
2545 goto vmgexit_err;
2546 break;
2547 case SVM_EXIT_INVD:
2548 break;
2549 case SVM_EXIT_IOIO:
2550 if (control->exit_info_1 & SVM_IOIO_STR_MASK) {
2551 if (!kvm_ghcb_sw_scratch_is_valid(svm))
2552 goto vmgexit_err;
2553 } else {
2554 if (!(control->exit_info_1 & SVM_IOIO_TYPE_MASK))
2555 if (!kvm_ghcb_rax_is_valid(svm))
2556 goto vmgexit_err;
2557 }
2558 break;
2559 case SVM_EXIT_MSR:
2560 if (!kvm_ghcb_rcx_is_valid(svm))
2561 goto vmgexit_err;
2562 if (control->exit_info_1) {
2563 if (!kvm_ghcb_rax_is_valid(svm) ||
2564 !kvm_ghcb_rdx_is_valid(svm))
2565 goto vmgexit_err;
2566 }
2567 break;
2568 case SVM_EXIT_VMMCALL:
2569 if (!kvm_ghcb_rax_is_valid(svm) ||
2570 !kvm_ghcb_cpl_is_valid(svm))
2571 goto vmgexit_err;
2572 break;
2573 case SVM_EXIT_RDTSCP:
2574 break;
2575 case SVM_EXIT_WBINVD:
2576 break;
2577 case SVM_EXIT_MONITOR:
2578 if (!kvm_ghcb_rax_is_valid(svm) ||
2579 !kvm_ghcb_rcx_is_valid(svm) ||
2580 !kvm_ghcb_rdx_is_valid(svm))
2581 goto vmgexit_err;
2582 break;
2583 case SVM_EXIT_MWAIT:
2584 if (!kvm_ghcb_rax_is_valid(svm) ||
2585 !kvm_ghcb_rcx_is_valid(svm))
2586 goto vmgexit_err;
2587 break;
2588 case SVM_VMGEXIT_MMIO_READ:
2589 case SVM_VMGEXIT_MMIO_WRITE:
2590 if (!kvm_ghcb_sw_scratch_is_valid(svm))
2591 goto vmgexit_err;
2592 break;
2593 case SVM_VMGEXIT_NMI_COMPLETE:
2594 case SVM_VMGEXIT_AP_HLT_LOOP:
2595 case SVM_VMGEXIT_AP_JUMP_TABLE:
2596 case SVM_VMGEXIT_UNSUPPORTED_EVENT:
2597 break;
2598 default:
2599 reason = GHCB_ERR_INVALID_EVENT;
2600 goto vmgexit_err;
2601 }
2602
2603 return 0;
2604
2605 vmgexit_err:
2606 if (reason == GHCB_ERR_INVALID_USAGE) {
2607 vcpu_unimpl(vcpu, "vmgexit: ghcb usage %#x is not valid\n",
2608 svm->sev_es.ghcb->ghcb_usage);
2609 } else if (reason == GHCB_ERR_INVALID_EVENT) {
2610 vcpu_unimpl(vcpu, "vmgexit: exit code %#llx is not valid\n",
2611 exit_code);
2612 } else {
2613 vcpu_unimpl(vcpu, "vmgexit: exit code %#llx input is not valid\n",
2614 exit_code);
2615 dump_ghcb(svm);
2616 }
2617
2618 ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2);
2619 ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, reason);
2620
2621 /* Resume the guest to "return" the error code. */
2622 return 1;
2623 }
2624
sev_es_unmap_ghcb(struct vcpu_svm * svm)2625 void sev_es_unmap_ghcb(struct vcpu_svm *svm)
2626 {
2627 if (!svm->sev_es.ghcb)
2628 return;
2629
2630 if (svm->sev_es.ghcb_sa_free) {
2631 /*
2632 * The scratch area lives outside the GHCB, so there is a
2633 * buffer that, depending on the operation performed, may
2634 * need to be synced, then freed.
2635 */
2636 if (svm->sev_es.ghcb_sa_sync) {
2637 kvm_write_guest(svm->vcpu.kvm,
2638 svm->sev_es.sw_scratch,
2639 svm->sev_es.ghcb_sa,
2640 svm->sev_es.ghcb_sa_len);
2641 svm->sev_es.ghcb_sa_sync = false;
2642 }
2643
2644 kvfree(svm->sev_es.ghcb_sa);
2645 svm->sev_es.ghcb_sa = NULL;
2646 svm->sev_es.ghcb_sa_free = false;
2647 }
2648
2649 trace_kvm_vmgexit_exit(svm->vcpu.vcpu_id, svm->sev_es.ghcb);
2650
2651 sev_es_sync_to_ghcb(svm);
2652
2653 kvm_vcpu_unmap(&svm->vcpu, &svm->sev_es.ghcb_map, true);
2654 svm->sev_es.ghcb = NULL;
2655 }
2656
pre_sev_run(struct vcpu_svm * svm,int cpu)2657 void pre_sev_run(struct vcpu_svm *svm, int cpu)
2658 {
2659 struct svm_cpu_data *sd = per_cpu_ptr(&svm_data, cpu);
2660 unsigned int asid = sev_get_asid(svm->vcpu.kvm);
2661
2662 /* Assign the asid allocated with this SEV guest */
2663 svm->asid = asid;
2664
2665 /*
2666 * Flush guest TLB:
2667 *
2668 * 1) when different VMCB for the same ASID is to be run on the same host CPU.
2669 * 2) or this VMCB was executed on different host CPU in previous VMRUNs.
2670 */
2671 if (sd->sev_vmcbs[asid] == svm->vmcb &&
2672 svm->vcpu.arch.last_vmentry_cpu == cpu)
2673 return;
2674
2675 sd->sev_vmcbs[asid] = svm->vmcb;
2676 svm->vmcb->control.tlb_ctl = TLB_CONTROL_FLUSH_ASID;
2677 vmcb_mark_dirty(svm->vmcb, VMCB_ASID);
2678 }
2679
2680 #define GHCB_SCRATCH_AREA_LIMIT (16ULL * PAGE_SIZE)
setup_vmgexit_scratch(struct vcpu_svm * svm,bool sync,u64 len)2681 static int setup_vmgexit_scratch(struct vcpu_svm *svm, bool sync, u64 len)
2682 {
2683 struct vmcb_control_area *control = &svm->vmcb->control;
2684 u64 ghcb_scratch_beg, ghcb_scratch_end;
2685 u64 scratch_gpa_beg, scratch_gpa_end;
2686 void *scratch_va;
2687
2688 scratch_gpa_beg = svm->sev_es.sw_scratch;
2689 if (!scratch_gpa_beg) {
2690 pr_err("vmgexit: scratch gpa not provided\n");
2691 goto e_scratch;
2692 }
2693
2694 scratch_gpa_end = scratch_gpa_beg + len;
2695 if (scratch_gpa_end < scratch_gpa_beg) {
2696 pr_err("vmgexit: scratch length (%#llx) not valid for scratch address (%#llx)\n",
2697 len, scratch_gpa_beg);
2698 goto e_scratch;
2699 }
2700
2701 if ((scratch_gpa_beg & PAGE_MASK) == control->ghcb_gpa) {
2702 /* Scratch area begins within GHCB */
2703 ghcb_scratch_beg = control->ghcb_gpa +
2704 offsetof(struct ghcb, shared_buffer);
2705 ghcb_scratch_end = control->ghcb_gpa +
2706 offsetof(struct ghcb, reserved_0xff0);
2707
2708 /*
2709 * If the scratch area begins within the GHCB, it must be
2710 * completely contained in the GHCB shared buffer area.
2711 */
2712 if (scratch_gpa_beg < ghcb_scratch_beg ||
2713 scratch_gpa_end > ghcb_scratch_end) {
2714 pr_err("vmgexit: scratch area is outside of GHCB shared buffer area (%#llx - %#llx)\n",
2715 scratch_gpa_beg, scratch_gpa_end);
2716 goto e_scratch;
2717 }
2718
2719 scratch_va = (void *)svm->sev_es.ghcb;
2720 scratch_va += (scratch_gpa_beg - control->ghcb_gpa);
2721 } else {
2722 /*
2723 * The guest memory must be read into a kernel buffer, so
2724 * limit the size
2725 */
2726 if (len > GHCB_SCRATCH_AREA_LIMIT) {
2727 pr_err("vmgexit: scratch area exceeds KVM limits (%#llx requested, %#llx limit)\n",
2728 len, GHCB_SCRATCH_AREA_LIMIT);
2729 goto e_scratch;
2730 }
2731 scratch_va = kvzalloc(len, GFP_KERNEL_ACCOUNT);
2732 if (!scratch_va)
2733 return -ENOMEM;
2734
2735 if (kvm_read_guest(svm->vcpu.kvm, scratch_gpa_beg, scratch_va, len)) {
2736 /* Unable to copy scratch area from guest */
2737 pr_err("vmgexit: kvm_read_guest for scratch area failed\n");
2738
2739 kvfree(scratch_va);
2740 return -EFAULT;
2741 }
2742
2743 /*
2744 * The scratch area is outside the GHCB. The operation will
2745 * dictate whether the buffer needs to be synced before running
2746 * the vCPU next time (i.e. a read was requested so the data
2747 * must be written back to the guest memory).
2748 */
2749 svm->sev_es.ghcb_sa_sync = sync;
2750 svm->sev_es.ghcb_sa_free = true;
2751 }
2752
2753 svm->sev_es.ghcb_sa = scratch_va;
2754 svm->sev_es.ghcb_sa_len = len;
2755
2756 return 0;
2757
2758 e_scratch:
2759 ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2);
2760 ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_ERR_INVALID_SCRATCH_AREA);
2761
2762 return 1;
2763 }
2764
set_ghcb_msr_bits(struct vcpu_svm * svm,u64 value,u64 mask,unsigned int pos)2765 static void set_ghcb_msr_bits(struct vcpu_svm *svm, u64 value, u64 mask,
2766 unsigned int pos)
2767 {
2768 svm->vmcb->control.ghcb_gpa &= ~(mask << pos);
2769 svm->vmcb->control.ghcb_gpa |= (value & mask) << pos;
2770 }
2771
get_ghcb_msr_bits(struct vcpu_svm * svm,u64 mask,unsigned int pos)2772 static u64 get_ghcb_msr_bits(struct vcpu_svm *svm, u64 mask, unsigned int pos)
2773 {
2774 return (svm->vmcb->control.ghcb_gpa >> pos) & mask;
2775 }
2776
set_ghcb_msr(struct vcpu_svm * svm,u64 value)2777 static void set_ghcb_msr(struct vcpu_svm *svm, u64 value)
2778 {
2779 svm->vmcb->control.ghcb_gpa = value;
2780 }
2781
sev_handle_vmgexit_msr_protocol(struct vcpu_svm * svm)2782 static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm)
2783 {
2784 struct vmcb_control_area *control = &svm->vmcb->control;
2785 struct kvm_vcpu *vcpu = &svm->vcpu;
2786 u64 ghcb_info;
2787 int ret = 1;
2788
2789 ghcb_info = control->ghcb_gpa & GHCB_MSR_INFO_MASK;
2790
2791 trace_kvm_vmgexit_msr_protocol_enter(svm->vcpu.vcpu_id,
2792 control->ghcb_gpa);
2793
2794 switch (ghcb_info) {
2795 case GHCB_MSR_SEV_INFO_REQ:
2796 set_ghcb_msr(svm, GHCB_MSR_SEV_INFO(GHCB_VERSION_MAX,
2797 GHCB_VERSION_MIN,
2798 sev_enc_bit));
2799 break;
2800 case GHCB_MSR_CPUID_REQ: {
2801 u64 cpuid_fn, cpuid_reg, cpuid_value;
2802
2803 cpuid_fn = get_ghcb_msr_bits(svm,
2804 GHCB_MSR_CPUID_FUNC_MASK,
2805 GHCB_MSR_CPUID_FUNC_POS);
2806
2807 /* Initialize the registers needed by the CPUID intercept */
2808 vcpu->arch.regs[VCPU_REGS_RAX] = cpuid_fn;
2809 vcpu->arch.regs[VCPU_REGS_RCX] = 0;
2810
2811 ret = svm_invoke_exit_handler(vcpu, SVM_EXIT_CPUID);
2812 if (!ret) {
2813 /* Error, keep GHCB MSR value as-is */
2814 break;
2815 }
2816
2817 cpuid_reg = get_ghcb_msr_bits(svm,
2818 GHCB_MSR_CPUID_REG_MASK,
2819 GHCB_MSR_CPUID_REG_POS);
2820 if (cpuid_reg == 0)
2821 cpuid_value = vcpu->arch.regs[VCPU_REGS_RAX];
2822 else if (cpuid_reg == 1)
2823 cpuid_value = vcpu->arch.regs[VCPU_REGS_RBX];
2824 else if (cpuid_reg == 2)
2825 cpuid_value = vcpu->arch.regs[VCPU_REGS_RCX];
2826 else
2827 cpuid_value = vcpu->arch.regs[VCPU_REGS_RDX];
2828
2829 set_ghcb_msr_bits(svm, cpuid_value,
2830 GHCB_MSR_CPUID_VALUE_MASK,
2831 GHCB_MSR_CPUID_VALUE_POS);
2832
2833 set_ghcb_msr_bits(svm, GHCB_MSR_CPUID_RESP,
2834 GHCB_MSR_INFO_MASK,
2835 GHCB_MSR_INFO_POS);
2836 break;
2837 }
2838 case GHCB_MSR_TERM_REQ: {
2839 u64 reason_set, reason_code;
2840
2841 reason_set = get_ghcb_msr_bits(svm,
2842 GHCB_MSR_TERM_REASON_SET_MASK,
2843 GHCB_MSR_TERM_REASON_SET_POS);
2844 reason_code = get_ghcb_msr_bits(svm,
2845 GHCB_MSR_TERM_REASON_MASK,
2846 GHCB_MSR_TERM_REASON_POS);
2847 pr_info("SEV-ES guest requested termination: %#llx:%#llx\n",
2848 reason_set, reason_code);
2849
2850 vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
2851 vcpu->run->system_event.type = KVM_SYSTEM_EVENT_SEV_TERM;
2852 vcpu->run->system_event.ndata = 1;
2853 vcpu->run->system_event.data[0] = control->ghcb_gpa;
2854
2855 return 0;
2856 }
2857 default:
2858 /* Error, keep GHCB MSR value as-is */
2859 break;
2860 }
2861
2862 trace_kvm_vmgexit_msr_protocol_exit(svm->vcpu.vcpu_id,
2863 control->ghcb_gpa, ret);
2864
2865 return ret;
2866 }
2867
sev_handle_vmgexit(struct kvm_vcpu * vcpu)2868 int sev_handle_vmgexit(struct kvm_vcpu *vcpu)
2869 {
2870 struct vcpu_svm *svm = to_svm(vcpu);
2871 struct vmcb_control_area *control = &svm->vmcb->control;
2872 u64 ghcb_gpa, exit_code;
2873 int ret;
2874
2875 /* Validate the GHCB */
2876 ghcb_gpa = control->ghcb_gpa;
2877 if (ghcb_gpa & GHCB_MSR_INFO_MASK)
2878 return sev_handle_vmgexit_msr_protocol(svm);
2879
2880 if (!ghcb_gpa) {
2881 vcpu_unimpl(vcpu, "vmgexit: GHCB gpa is not set\n");
2882
2883 /* Without a GHCB, just return right back to the guest */
2884 return 1;
2885 }
2886
2887 if (kvm_vcpu_map(vcpu, ghcb_gpa >> PAGE_SHIFT, &svm->sev_es.ghcb_map)) {
2888 /* Unable to map GHCB from guest */
2889 vcpu_unimpl(vcpu, "vmgexit: error mapping GHCB [%#llx] from guest\n",
2890 ghcb_gpa);
2891
2892 /* Without a GHCB, just return right back to the guest */
2893 return 1;
2894 }
2895
2896 svm->sev_es.ghcb = svm->sev_es.ghcb_map.hva;
2897
2898 trace_kvm_vmgexit_enter(vcpu->vcpu_id, svm->sev_es.ghcb);
2899
2900 sev_es_sync_from_ghcb(svm);
2901 ret = sev_es_validate_vmgexit(svm);
2902 if (ret)
2903 return ret;
2904
2905 ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 0);
2906 ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, 0);
2907
2908 exit_code = kvm_ghcb_get_sw_exit_code(control);
2909 switch (exit_code) {
2910 case SVM_VMGEXIT_MMIO_READ:
2911 ret = setup_vmgexit_scratch(svm, true, control->exit_info_2);
2912 if (ret)
2913 break;
2914
2915 ret = kvm_sev_es_mmio_read(vcpu,
2916 control->exit_info_1,
2917 control->exit_info_2,
2918 svm->sev_es.ghcb_sa);
2919 break;
2920 case SVM_VMGEXIT_MMIO_WRITE:
2921 ret = setup_vmgexit_scratch(svm, false, control->exit_info_2);
2922 if (ret)
2923 break;
2924
2925 ret = kvm_sev_es_mmio_write(vcpu,
2926 control->exit_info_1,
2927 control->exit_info_2,
2928 svm->sev_es.ghcb_sa);
2929 break;
2930 case SVM_VMGEXIT_NMI_COMPLETE:
2931 ++vcpu->stat.nmi_window_exits;
2932 svm->nmi_masked = false;
2933 kvm_make_request(KVM_REQ_EVENT, vcpu);
2934 ret = 1;
2935 break;
2936 case SVM_VMGEXIT_AP_HLT_LOOP:
2937 ret = kvm_emulate_ap_reset_hold(vcpu);
2938 break;
2939 case SVM_VMGEXIT_AP_JUMP_TABLE: {
2940 struct kvm_sev_info *sev = &to_kvm_svm(vcpu->kvm)->sev_info;
2941
2942 switch (control->exit_info_1) {
2943 case 0:
2944 /* Set AP jump table address */
2945 sev->ap_jump_table = control->exit_info_2;
2946 break;
2947 case 1:
2948 /* Get AP jump table address */
2949 ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, sev->ap_jump_table);
2950 break;
2951 default:
2952 pr_err("svm: vmgexit: unsupported AP jump table request - exit_info_1=%#llx\n",
2953 control->exit_info_1);
2954 ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2);
2955 ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_ERR_INVALID_INPUT);
2956 }
2957
2958 ret = 1;
2959 break;
2960 }
2961 case SVM_VMGEXIT_UNSUPPORTED_EVENT:
2962 vcpu_unimpl(vcpu,
2963 "vmgexit: unsupported event - exit_info_1=%#llx, exit_info_2=%#llx\n",
2964 control->exit_info_1, control->exit_info_2);
2965 ret = -EINVAL;
2966 break;
2967 default:
2968 ret = svm_invoke_exit_handler(vcpu, exit_code);
2969 }
2970
2971 return ret;
2972 }
2973
sev_es_string_io(struct vcpu_svm * svm,int size,unsigned int port,int in)2974 int sev_es_string_io(struct vcpu_svm *svm, int size, unsigned int port, int in)
2975 {
2976 int count;
2977 int bytes;
2978 int r;
2979
2980 if (svm->vmcb->control.exit_info_2 > INT_MAX)
2981 return -EINVAL;
2982
2983 count = svm->vmcb->control.exit_info_2;
2984 if (unlikely(check_mul_overflow(count, size, &bytes)))
2985 return -EINVAL;
2986
2987 r = setup_vmgexit_scratch(svm, in, bytes);
2988 if (r)
2989 return r;
2990
2991 return kvm_sev_es_string_io(&svm->vcpu, size, port, svm->sev_es.ghcb_sa,
2992 count, in);
2993 }
2994
sev_es_vcpu_after_set_cpuid(struct vcpu_svm * svm)2995 static void sev_es_vcpu_after_set_cpuid(struct vcpu_svm *svm)
2996 {
2997 struct kvm_vcpu *vcpu = &svm->vcpu;
2998
2999 if (boot_cpu_has(X86_FEATURE_V_TSC_AUX)) {
3000 bool v_tsc_aux = guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP) ||
3001 guest_cpuid_has(vcpu, X86_FEATURE_RDPID);
3002
3003 set_msr_interception(vcpu, svm->msrpm, MSR_TSC_AUX, v_tsc_aux, v_tsc_aux);
3004 }
3005
3006 /*
3007 * For SEV-ES, accesses to MSR_IA32_XSS should not be intercepted if
3008 * the host/guest supports its use.
3009 *
3010 * guest_can_use() checks a number of requirements on the host/guest to
3011 * ensure that MSR_IA32_XSS is available, but it might report true even
3012 * if X86_FEATURE_XSAVES isn't configured in the guest to ensure host
3013 * MSR_IA32_XSS is always properly restored. For SEV-ES, it is better
3014 * to further check that the guest CPUID actually supports
3015 * X86_FEATURE_XSAVES so that accesses to MSR_IA32_XSS by misbehaved
3016 * guests will still get intercepted and caught in the normal
3017 * kvm_emulate_rdmsr()/kvm_emulated_wrmsr() paths.
3018 */
3019 if (guest_can_use(vcpu, X86_FEATURE_XSAVES) &&
3020 guest_cpuid_has(vcpu, X86_FEATURE_XSAVES))
3021 set_msr_interception(vcpu, svm->msrpm, MSR_IA32_XSS, 1, 1);
3022 else
3023 set_msr_interception(vcpu, svm->msrpm, MSR_IA32_XSS, 0, 0);
3024 }
3025
sev_vcpu_after_set_cpuid(struct vcpu_svm * svm)3026 void sev_vcpu_after_set_cpuid(struct vcpu_svm *svm)
3027 {
3028 struct kvm_vcpu *vcpu = &svm->vcpu;
3029 struct kvm_cpuid_entry2 *best;
3030
3031 /* For sev guests, the memory encryption bit is not reserved in CR3. */
3032 best = kvm_find_cpuid_entry(vcpu, 0x8000001F);
3033 if (best)
3034 vcpu->arch.reserved_gpa_bits &= ~(1UL << (best->ebx & 0x3f));
3035
3036 if (sev_es_guest(svm->vcpu.kvm))
3037 sev_es_vcpu_after_set_cpuid(svm);
3038 }
3039
sev_es_init_vmcb(struct vcpu_svm * svm)3040 static void sev_es_init_vmcb(struct vcpu_svm *svm)
3041 {
3042 struct vmcb *vmcb = svm->vmcb01.ptr;
3043 struct kvm_vcpu *vcpu = &svm->vcpu;
3044
3045 svm->vmcb->control.nested_ctl |= SVM_NESTED_CTL_SEV_ES_ENABLE;
3046
3047 /*
3048 * An SEV-ES guest requires a VMSA area that is a separate from the
3049 * VMCB page. Do not include the encryption mask on the VMSA physical
3050 * address since hardware will access it using the guest key. Note,
3051 * the VMSA will be NULL if this vCPU is the destination for intrahost
3052 * migration, and will be copied later.
3053 */
3054 if (svm->sev_es.vmsa)
3055 svm->vmcb->control.vmsa_pa = __pa(svm->sev_es.vmsa);
3056
3057 /* Can't intercept CR register access, HV can't modify CR registers */
3058 svm_clr_intercept(svm, INTERCEPT_CR0_READ);
3059 svm_clr_intercept(svm, INTERCEPT_CR4_READ);
3060 svm_clr_intercept(svm, INTERCEPT_CR8_READ);
3061 svm_clr_intercept(svm, INTERCEPT_CR0_WRITE);
3062 svm_clr_intercept(svm, INTERCEPT_CR4_WRITE);
3063 svm_clr_intercept(svm, INTERCEPT_CR8_WRITE);
3064
3065 svm_clr_intercept(svm, INTERCEPT_SELECTIVE_CR0);
3066
3067 /* Track EFER/CR register changes */
3068 svm_set_intercept(svm, TRAP_EFER_WRITE);
3069 svm_set_intercept(svm, TRAP_CR0_WRITE);
3070 svm_set_intercept(svm, TRAP_CR4_WRITE);
3071 svm_set_intercept(svm, TRAP_CR8_WRITE);
3072
3073 vmcb->control.intercepts[INTERCEPT_DR] = 0;
3074 if (!sev_es_debug_swap_enabled) {
3075 vmcb_set_intercept(&vmcb->control, INTERCEPT_DR7_READ);
3076 vmcb_set_intercept(&vmcb->control, INTERCEPT_DR7_WRITE);
3077 recalc_intercepts(svm);
3078 } else {
3079 /*
3080 * Disable #DB intercept iff DebugSwap is enabled. KVM doesn't
3081 * allow debugging SEV-ES guests, and enables DebugSwap iff
3082 * NO_NESTED_DATA_BP is supported, so there's no reason to
3083 * intercept #DB when DebugSwap is enabled. For simplicity
3084 * with respect to guest debug, intercept #DB for other VMs
3085 * even if NO_NESTED_DATA_BP is supported, i.e. even if the
3086 * guest can't DoS the CPU with infinite #DB vectoring.
3087 */
3088 clr_exception_intercept(svm, DB_VECTOR);
3089 }
3090
3091 /* Can't intercept XSETBV, HV can't modify XCR0 directly */
3092 svm_clr_intercept(svm, INTERCEPT_XSETBV);
3093
3094 /* Clear intercepts on selected MSRs */
3095 set_msr_interception(vcpu, svm->msrpm, MSR_EFER, 1, 1);
3096 set_msr_interception(vcpu, svm->msrpm, MSR_IA32_CR_PAT, 1, 1);
3097 }
3098
sev_init_vmcb(struct vcpu_svm * svm)3099 void sev_init_vmcb(struct vcpu_svm *svm)
3100 {
3101 svm->vmcb->control.nested_ctl |= SVM_NESTED_CTL_SEV_ENABLE;
3102 clr_exception_intercept(svm, UD_VECTOR);
3103
3104 /*
3105 * Don't intercept #GP for SEV guests, e.g. for the VMware backdoor, as
3106 * KVM can't decrypt guest memory to decode the faulting instruction.
3107 */
3108 clr_exception_intercept(svm, GP_VECTOR);
3109
3110 if (sev_es_guest(svm->vcpu.kvm))
3111 sev_es_init_vmcb(svm);
3112 }
3113
sev_es_vcpu_reset(struct vcpu_svm * svm)3114 void sev_es_vcpu_reset(struct vcpu_svm *svm)
3115 {
3116 /*
3117 * Set the GHCB MSR value as per the GHCB specification when emulating
3118 * vCPU RESET for an SEV-ES guest.
3119 */
3120 set_ghcb_msr(svm, GHCB_MSR_SEV_INFO(GHCB_VERSION_MAX,
3121 GHCB_VERSION_MIN,
3122 sev_enc_bit));
3123 }
3124
sev_es_prepare_switch_to_guest(struct sev_es_save_area * hostsa)3125 void sev_es_prepare_switch_to_guest(struct sev_es_save_area *hostsa)
3126 {
3127 /*
3128 * All host state for SEV-ES guests is categorized into three swap types
3129 * based on how it is handled by hardware during a world switch:
3130 *
3131 * A: VMRUN: Host state saved in host save area
3132 * VMEXIT: Host state loaded from host save area
3133 *
3134 * B: VMRUN: Host state _NOT_ saved in host save area
3135 * VMEXIT: Host state loaded from host save area
3136 *
3137 * C: VMRUN: Host state _NOT_ saved in host save area
3138 * VMEXIT: Host state initialized to default(reset) values
3139 *
3140 * Manually save type-B state, i.e. state that is loaded by VMEXIT but
3141 * isn't saved by VMRUN, that isn't already saved by VMSAVE (performed
3142 * by common SVM code).
3143 */
3144 hostsa->xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
3145 hostsa->pkru = read_pkru();
3146 hostsa->xss = host_xss;
3147
3148 /*
3149 * If DebugSwap is enabled, debug registers are loaded but NOT saved by
3150 * the CPU (Type-B). If DebugSwap is disabled/unsupported, the CPU both
3151 * saves and loads debug registers (Type-A).
3152 */
3153 if (sev_es_debug_swap_enabled) {
3154 hostsa->dr0 = native_get_debugreg(0);
3155 hostsa->dr1 = native_get_debugreg(1);
3156 hostsa->dr2 = native_get_debugreg(2);
3157 hostsa->dr3 = native_get_debugreg(3);
3158 hostsa->dr0_addr_mask = amd_get_dr_addr_mask(0);
3159 hostsa->dr1_addr_mask = amd_get_dr_addr_mask(1);
3160 hostsa->dr2_addr_mask = amd_get_dr_addr_mask(2);
3161 hostsa->dr3_addr_mask = amd_get_dr_addr_mask(3);
3162 }
3163 }
3164
sev_vcpu_deliver_sipi_vector(struct kvm_vcpu * vcpu,u8 vector)3165 void sev_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector)
3166 {
3167 struct vcpu_svm *svm = to_svm(vcpu);
3168
3169 /* First SIPI: Use the values as initially set by the VMM */
3170 if (!svm->sev_es.received_first_sipi) {
3171 svm->sev_es.received_first_sipi = true;
3172 return;
3173 }
3174
3175 /*
3176 * Subsequent SIPI: Return from an AP Reset Hold VMGEXIT, where
3177 * the guest will set the CS and RIP. Set SW_EXIT_INFO_2 to a
3178 * non-zero value.
3179 */
3180 if (!svm->sev_es.ghcb)
3181 return;
3182
3183 ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, 1);
3184 }
3185