arch/x86/kvm/svm/sev.c

   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
  10 #include <linux/kvm_types.h>
  11 #include <linux/kvm_host.h>
  12 #include <linux/kernel.h>
  13 #include <linux/highmem.h>
  14 #include <linux/psp-sev.h>
  15 #include <linux/pagemap.h>
  16 #include <linux/swap.h>
  17
  18 #include "x86.h"
  19 #include "svm.h"
  20
  21 static int sev_flush_asids(void);
  22 static DECLARE_RWSEM(sev_deactivate_lock);
  23 static DEFINE_MUTEX(sev_bitmap_lock);
  24 unsigned int max_sev_asid;
  25 static unsigned int min_sev_asid;
  26 static unsigned long *sev_asid_bitmap;
  27 static unsigned long *sev_reclaim_asid_bitmap;
  28 #define __sme_page_pa(x) __sme_set(page_to_pfn(x) << PAGE_SHIFT)
  29
  30 struct enc_region {
  31         struct list_head list;
  32         unsigned long npages;
  33         struct page **pages;
  34         unsigned long uaddr;
  35         unsigned long size;
  36 };
  37
  38 static int sev_flush_asids(void)
  39 {
  40         int ret, error = 0;
  41
  42         /*
  43          * DEACTIVATE will clear the WBINVD indicator causing DF_FLUSH to fail,
  44          * so it must be guarded.
  45          */
  46         down_write(&sev_deactivate_lock);
  47
  48         wbinvd_on_all_cpus();
  49         ret = sev_guest_df_flush(&error);
  50
  51         up_write(&sev_deactivate_lock);
  52
  53         if (ret)
  54                 pr_err("SEV: DF_FLUSH failed, ret=%d, error=%#x\n", ret, error);
  55
  56         return ret;
  57 }
  58
  59 /* Must be called with the sev_bitmap_lock held */
  60 static bool __sev_recycle_asids(void)
  61 {
  62         int pos;
  63
  64         /* Check if there are any ASIDs to reclaim before performing a flush */
  65         pos = find_next_bit(sev_reclaim_asid_bitmap,
  66                             max_sev_asid, min_sev_asid - 1);
  67         if (pos >= max_sev_asid)
  68                 return false;
  69
  70         if (sev_flush_asids())
  71                 return false;
  72
  73         bitmap_xor(sev_asid_bitmap, sev_asid_bitmap, sev_reclaim_asid_bitmap,
  74                    max_sev_asid);
  75         bitmap_zero(sev_reclaim_asid_bitmap, max_sev_asid);
  76
  77         return true;
  78 }
  79
  80 static int sev_asid_new(void)
  81 {
  82         bool retry = true;
  83         int pos;
  84
  85         mutex_lock(&sev_bitmap_lock);
  86
  87         /*
  88          * SEV-enabled guest must use asid from min_sev_asid to max_sev_asid.
  89          */
  90 again:
  91         pos = find_next_zero_bit(sev_asid_bitmap, max_sev_asid, min_sev_asid - 1);
  92         if (pos >= max_sev_asid) {
  93                 if (retry && __sev_recycle_asids()) {
  94                         retry = false;
  95                         goto again;
  96                 }
  97                 mutex_unlock(&sev_bitmap_lock);
  98                 return -EBUSY;
  99         }
 100
 101         __set_bit(pos, sev_asid_bitmap);
 102
 103         mutex_unlock(&sev_bitmap_lock);
 104
 105         return pos + 1;
 106 }
 107
 108 static int sev_get_asid(struct kvm *kvm)
 109 {
 110         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
 111
 112         return sev->asid;
 113 }
 114
 115 static void sev_asid_free(int asid)
 116 {
 117         struct svm_cpu_data *sd;
 118         int cpu, pos;
 119
 120         mutex_lock(&sev_bitmap_lock);
 121
 122         pos = asid - 1;
 123         __set_bit(pos, sev_reclaim_asid_bitmap);
 124
 125         for_each_possible_cpu(cpu) {
 126                 sd = per_cpu(svm_data, cpu);
 127                 sd->sev_vmcbs[pos] = NULL;
 128         }
 129
 130         mutex_unlock(&sev_bitmap_lock);
 131 }
 132
 133 static void sev_unbind_asid(struct kvm *kvm, unsigned int handle)
 134 {
 135         struct sev_data_decommission *decommission;
 136         struct sev_data_deactivate *data;
 137
 138         if (!handle)
 139                 return;
 140
 141         data = kzalloc(sizeof(*data), GFP_KERNEL);
 142         if (!data)
 143                 return;
 144
 145         /* deactivate handle */
 146         data->handle = handle;
 147
 148         /* Guard DEACTIVATE against WBINVD/DF_FLUSH used in ASID recycling */
 149         down_read(&sev_deactivate_lock);
 150         sev_guest_deactivate(data, NULL);
 151         up_read(&sev_deactivate_lock);
 152
 153         kfree(data);
 154
 155         decommission = kzalloc(sizeof(*decommission), GFP_KERNEL);
 156         if (!decommission)
 157                 return;
 158
 159         /* decommission handle */
 160         decommission->handle = handle;
 161         sev_guest_decommission(decommission, NULL);
 162
 163         kfree(decommission);
 164 }
 165
 166 static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
 167 {
 168         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
 169         int asid, ret;
 170
 171         ret = -EBUSY;
 172         if (unlikely(sev->active))
 173                 return ret;
 174
 175         asid = sev_asid_new();
 176         if (asid < 0)
 177                 return ret;
 178
 179         ret = sev_platform_init(&argp->error);
 180         if (ret)
 181                 goto e_free;
 182
 183         sev->active = true;
 184         sev->asid = asid;
 185         INIT_LIST_HEAD(&sev->regions_list);
 186
 187         return 0;
 188
 189 e_free:
 190         sev_asid_free(asid);
 191         return ret;
 192 }
 193
 194 static int sev_bind_asid(struct kvm *kvm, unsigned int handle, int *error)
 195 {
 196         struct sev_data_activate *data;
 197         int asid = sev_get_asid(kvm);
 198         int ret;
 199
 200         data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT);
 201         if (!data)
 202                 return -ENOMEM;
 203
 204         /* activate ASID on the given handle */
 205         data->handle = handle;
 206         data->asid   = asid;
 207         ret = sev_guest_activate(data, error);
 208         kfree(data);
 209
 210         return ret;
 211 }
 212
 213 static int __sev_issue_cmd(int fd, int id, void *data, int *error)
 214 {
 215         struct fd f;
 216         int ret;
 217
 218         f = fdget(fd);
 219         if (!f.file)
 220                 return -EBADF;
 221
 222         ret = sev_issue_cmd_external_user(f.file, id, data, error);
 223
 224         fdput(f);
 225         return ret;
 226 }
 227
 228 static int sev_issue_cmd(struct kvm *kvm, int id, void *data, int *error)
 229 {
 230         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
 231
 232         return __sev_issue_cmd(sev->fd, id, data, error);
 233 }
 234
 235 static int sev_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
 236 {
 237         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
 238         struct sev_data_launch_start *start;
 239         struct kvm_sev_launch_start params;
 240         void *dh_blob, *session_blob;
 241         int *error = &argp->error;
 242         int ret;
 243
 244         if (!sev_guest(kvm))
 245                 return -ENOTTY;
 246
 247         if (copy_from_user(&params, (void __user *)(uintptr_t)argp->data, sizeof(params)))
 248                 return -EFAULT;
 249
 250         start = kzalloc(sizeof(*start), GFP_KERNEL_ACCOUNT);
 251         if (!start)
 252                 return -ENOMEM;
 253
 254         dh_blob = NULL;
 255         if (params.dh_uaddr) {
 256                 dh_blob = psp_copy_user_blob(params.dh_uaddr, params.dh_len);
 257                 if (IS_ERR(dh_blob)) {
 258                         ret = PTR_ERR(dh_blob);
 259                         goto e_free;
 260                 }
 261
 262                 start->dh_cert_address = __sme_set(__pa(dh_blob));
 263                 start->dh_cert_len = params.dh_len;
 264         }
 265
 266         session_blob = NULL;
 267         if (params.session_uaddr) {
 268                 session_blob = psp_copy_user_blob(params.session_uaddr, params.session_len);
 269                 if (IS_ERR(session_blob)) {
 270                         ret = PTR_ERR(session_blob);
 271                         goto e_free_dh;
 272                 }
 273
 274                 start->session_address = __sme_set(__pa(session_blob));
 275                 start->session_len = params.session_len;
 276         }
 277
 278         start->handle = params.handle;
 279         start->policy = params.policy;
 280
 281         /* create memory encryption context */
 282         ret = __sev_issue_cmd(argp->sev_fd, SEV_CMD_LAUNCH_START, start, error);
 283         if (ret)
 284                 goto e_free_session;
 285
 286         /* Bind ASID to this guest */
 287         ret = sev_bind_asid(kvm, start->handle, error);
 288         if (ret)
 289                 goto e_free_session;
 290
 291         /* return handle to userspace */
 292         params.handle = start->handle;
 293         if (copy_to_user((void __user *)(uintptr_t)argp->data, &params, sizeof(params))) {
 294                 sev_unbind_asid(kvm, start->handle);
 295                 ret = -EFAULT;
 296                 goto e_free_session;
 297         }
 298
 299         sev->handle = start->handle;
 300         sev->fd = argp->sev_fd;
 301
 302 e_free_session:
 303         kfree(session_blob);
 304 e_free_dh:
 305         kfree(dh_blob);
 306 e_free:
 307         kfree(start);
 308         return ret;
 309 }
 310
 311 static struct page **sev_pin_memory(struct kvm *kvm, unsigned long uaddr,
 312                                     unsigned long ulen, unsigned long *n,
 313                                     int write)
 314 {
 315         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
 316         unsigned long npages, npinned, size;
 317         unsigned long locked, lock_limit;
 318         struct page **pages;
 319         unsigned long first, last;
 320
 321         if (ulen == 0 || uaddr + ulen < uaddr)
 322                 return NULL;
 323
 324         /* Calculate number of pages. */
 325         first = (uaddr & PAGE_MASK) >> PAGE_SHIFT;
 326         last = ((uaddr + ulen - 1) & PAGE_MASK) >> PAGE_SHIFT;
 327         npages = (last - first + 1);
 328
 329         locked = sev->pages_locked + npages;
 330         lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
 331         if (locked > lock_limit && !capable(CAP_IPC_LOCK)) {
 332                 pr_err("SEV: %lu locked pages exceed the lock limit of %lu.\n", locked, lock_limit);
 333                 return NULL;
 334         }
 335
 336         /* Avoid using vmalloc for smaller buffers. */
 337         size = npages * sizeof(struct page *);
 338         if (size > PAGE_SIZE)
 339                 pages = __vmalloc(size, GFP_KERNEL_ACCOUNT | __GFP_ZERO,
 340                                   PAGE_KERNEL);
 341         else
 342                 pages = kmalloc(size, GFP_KERNEL_ACCOUNT);
 343
 344         if (!pages)
 345                 return NULL;
 346
 347         /* Pin the user virtual address. */
 348         npinned = get_user_pages_fast(uaddr, npages, write ? FOLL_WRITE : 0, pages);
 349         if (npinned != npages) {
 350                 pr_err("SEV: Failure locking %lu pages.\n", npages);
 351                 goto err;
 352         }
 353
 354         *n = npages;
 355         sev->pages_locked = locked;
 356
 357         return pages;
 358
 359 err:
 360         if (npinned > 0)
 361                 release_pages(pages, npinned);
 362
 363         kvfree(pages);
 364         return NULL;
 365 }
 366
 367 static void sev_unpin_memory(struct kvm *kvm, struct page **pages,
 368                              unsigned long npages)
 369 {
 370         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
 371
 372         release_pages(pages, npages);
 373         kvfree(pages);
 374         sev->pages_locked -= npages;
 375 }
 376
 377 static void sev_clflush_pages(struct page *pages[], unsigned long npages)
 378 {
 379         uint8_t *page_virtual;
 380         unsigned long i;
 381
 382         if (npages == 0 || pages == NULL)
 383                 return;
 384
 385         for (i = 0; i < npages; i++) {
 386                 page_virtual = kmap_atomic(pages[i]);
 387                 clflush_cache_range(page_virtual, PAGE_SIZE);
 388                 kunmap_atomic(page_virtual);
 389         }
 390 }
 391
 392 static unsigned long get_num_contig_pages(unsigned long idx,
 393                                 struct page **inpages, unsigned long npages)
 394 {
 395         unsigned long paddr, next_paddr;
 396         unsigned long i = idx + 1, pages = 1;
 397
 398         /* find the number of contiguous pages starting from idx */
 399         paddr = __sme_page_pa(inpages[idx]);
 400         while (i < npages) {
 401                 next_paddr = __sme_page_pa(inpages[i++]);
 402                 if ((paddr + PAGE_SIZE) == next_paddr) {
 403                         pages++;
 404                         paddr = next_paddr;
 405                         continue;
 406                 }
 407                 break;
 408         }
 409
 410         return pages;
 411 }
 412
 413 static int sev_launch_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
 414 {
 415         unsigned long vaddr, vaddr_end, next_vaddr, npages, pages, size, i;
 416         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
 417         struct kvm_sev_launch_update_data params;
 418         struct sev_data_launch_update_data *data;
 419         struct page **inpages;
 420         int ret;
 421
 422         if (!sev_guest(kvm))
 423                 return -ENOTTY;
 424
 425         if (copy_from_user(&params, (void __user *)(uintptr_t)argp->data, sizeof(params)))
 426                 return -EFAULT;
 427
 428         data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT);
 429         if (!data)
 430                 return -ENOMEM;
 431
 432         vaddr = params.uaddr;
 433         size = params.len;
 434         vaddr_end = vaddr + size;
 435
 436         /* Lock the user memory. */
 437         inpages = sev_pin_memory(kvm, vaddr, size, &npages, 1);
 438         if (!inpages) {
 439                 ret = -ENOMEM;
 440                 goto e_free;
 441         }
 442
 443         /*
 444          * The LAUNCH_UPDATE command will perform in-place encryption of the
 445          * memory content (i.e it will write the same memory region with C=1).
 446          * It's possible that the cache may contain the data with C=0, i.e.,
 447          * unencrypted so invalidate it first.
 448          */
 449         sev_clflush_pages(inpages, npages);
 450
 451         for (i = 0; vaddr < vaddr_end; vaddr = next_vaddr, i += pages) {
 452                 int offset, len;
 453
 454                 /*
 455                  * If the user buffer is not page-aligned, calculate the offset
 456                  * within the page.
 457                  */
 458                 offset = vaddr & (PAGE_SIZE - 1);
 459
 460                 /* Calculate the number of pages that can be encrypted in one go. */
 461                 pages = get_num_contig_pages(i, inpages, npages);
 462
 463                 len = min_t(size_t, ((pages * PAGE_SIZE) - offset), size);
 464
 465                 data->handle = sev->handle;
 466                 data->len = len;
 467                 data->address = __sme_page_pa(inpages[i]) + offset;
 468                 ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_UPDATE_DATA, data, &argp->error);
 469                 if (ret)
 470                         goto e_unpin;
 471
 472                 size -= len;
 473                 next_vaddr = vaddr + len;
 474         }
 475
 476 e_unpin:
 477         /* content of memory is updated, mark pages dirty */
 478         for (i = 0; i < npages; i++) {
 479                 set_page_dirty_lock(inpages[i]);
 480                 mark_page_accessed(inpages[i]);
 481         }
 482         /* unlock the user pages */
 483         sev_unpin_memory(kvm, inpages, npages);
 484 e_free:
 485         kfree(data);
 486         return ret;
 487 }
 488
 489 static int sev_launch_measure(struct kvm *kvm, struct kvm_sev_cmd *argp)
 490 {
 491         void __user *measure = (void __user *)(uintptr_t)argp->data;
 492         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
 493         struct sev_data_launch_measure *data;
 494         struct kvm_sev_launch_measure params;
 495         void __user *p = NULL;
 496         void *blob = NULL;
 497         int ret;
 498
 499         if (!sev_guest(kvm))
 500                 return -ENOTTY;
 501
 502         if (copy_from_user(&params, measure, sizeof(params)))
 503                 return -EFAULT;
 504
 505         data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT);
 506         if (!data)
 507                 return -ENOMEM;
 508
 509         /* User wants to query the blob length */
 510         if (!params.len)
 511                 goto cmd;
 512
 513         p = (void __user *)(uintptr_t)params.uaddr;
 514         if (p) {
 515                 if (params.len > SEV_FW_BLOB_MAX_SIZE) {
 516                         ret = -EINVAL;
 517                         goto e_free;
 518                 }
 519
 520                 ret = -ENOMEM;
 521                 blob = kmalloc(params.len, GFP_KERNEL);
 522                 if (!blob)
 523                         goto e_free;
 524
 525                 data->address = __psp_pa(blob);
 526                 data->len = params.len;
 527         }
 528
 529 cmd:
 530         data->handle = sev->handle;
 531         ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_MEASURE, data, &argp->error);
 532
 533         /*
 534          * If we query the session length, FW responded with expected data.
 535          */
 536         if (!params.len)
 537                 goto done;
 538
 539         if (ret)
 540                 goto e_free_blob;
 541
 542         if (blob) {
 543                 if (copy_to_user(p, blob, params.len))
 544                         ret = -EFAULT;
 545         }
 546
 547 done:
 548         params.len = data->len;
 549         if (copy_to_user(measure, &params, sizeof(params)))
 550                 ret = -EFAULT;
 551 e_free_blob:
 552         kfree(blob);
 553 e_free:
 554         kfree(data);
 555         return ret;
 556 }
 557
 558 static int sev_launch_finish(struct kvm *kvm, struct kvm_sev_cmd *argp)
 559 {
 560         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
 561         struct sev_data_launch_finish *data;
 562         int ret;
 563
 564         if (!sev_guest(kvm))
 565                 return -ENOTTY;
 566
 567         data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT);
 568         if (!data)
 569                 return -ENOMEM;
 570
 571         data->handle = sev->handle;
 572         ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_FINISH, data, &argp->error);
 573
 574         kfree(data);
 575         return ret;
 576 }
 577
 578 static int sev_guest_status(struct kvm *kvm, struct kvm_sev_cmd *argp)
 579 {
 580         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
 581         struct kvm_sev_guest_status params;
 582         struct sev_data_guest_status *data;
 583         int ret;
 584
 585         if (!sev_guest(kvm))
 586                 return -ENOTTY;
 587
 588         data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT);
 589         if (!data)
 590                 return -ENOMEM;
 591
 592         data->handle = sev->handle;
 593         ret = sev_issue_cmd(kvm, SEV_CMD_GUEST_STATUS, data, &argp->error);
 594         if (ret)
 595                 goto e_free;
 596
 597         params.policy = data->policy;
 598         params.state = data->state;
 599         params.handle = data->handle;
 600
 601         if (copy_to_user((void __user *)(uintptr_t)argp->data, &params, sizeof(params)))
 602                 ret = -EFAULT;
 603 e_free:
 604         kfree(data);
 605         return ret;
 606 }
 607
 608 static int __sev_issue_dbg_cmd(struct kvm *kvm, unsigned long src,
 609                                unsigned long dst, int size,
 610                                int *error, bool enc)
 611 {
 612         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
 613         struct sev_data_dbg *data;
 614         int ret;
 615
 616         data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT);
 617         if (!data)
 618                 return -ENOMEM;
 619
 620         data->handle = sev->handle;
 621         data->dst_addr = dst;
 622         data->src_addr = src;
 623         data->len = size;
 624
 625         ret = sev_issue_cmd(kvm,
 626                             enc ? SEV_CMD_DBG_ENCRYPT : SEV_CMD_DBG_DECRYPT,
 627                             data, error);
 628         kfree(data);
 629         return ret;
 630 }
 631
 632 static int __sev_dbg_decrypt(struct kvm *kvm, unsigned long src_paddr,
 633                              unsigned long dst_paddr, int sz, int *err)
 634 {
 635         int offset;
 636
 637         /*
 638          * Its safe to read more than we are asked, caller should ensure that
 639          * destination has enough space.
 640          */
 641         src_paddr = round_down(src_paddr, 16);
 642         offset = src_paddr & 15;
 643         sz = round_up(sz + offset, 16);
 644
 645         return __sev_issue_dbg_cmd(kvm, src_paddr, dst_paddr, sz, err, false);
 646 }
 647
 648 static int __sev_dbg_decrypt_user(struct kvm *kvm, unsigned long paddr,
 649                                   unsigned long __user dst_uaddr,
 650                                   unsigned long dst_paddr,
 651                                   int size, int *err)
 652 {
 653         struct page *tpage = NULL;
 654         int ret, offset;
 655
 656         /* if inputs are not 16-byte then use intermediate buffer */
 657         if (!IS_ALIGNED(dst_paddr, 16) ||
 658             !IS_ALIGNED(paddr,     16) ||
 659             !IS_ALIGNED(size,      16)) {
 660                 tpage = (void *)alloc_page(GFP_KERNEL);
 661                 if (!tpage)
 662                         return -ENOMEM;
 663
 664                 dst_paddr = __sme_page_pa(tpage);
 665         }
 666
 667         ret = __sev_dbg_decrypt(kvm, paddr, dst_paddr, size, err);
 668         if (ret)
 669                 goto e_free;
 670
 671         if (tpage) {
 672                 offset = paddr & 15;
 673                 if (copy_to_user((void __user *)(uintptr_t)dst_uaddr,
 674                                  page_address(tpage) + offset, size))
 675                         ret = -EFAULT;
 676         }
 677
 678 e_free:
 679         if (tpage)
 680                 __free_page(tpage);
 681
 682         return ret;
 683 }
 684
 685 static int __sev_dbg_encrypt_user(struct kvm *kvm, unsigned long paddr,
 686                                   unsigned long __user vaddr,
 687                                   unsigned long dst_paddr,
 688                                   unsigned long __user dst_vaddr,
 689                                   int size, int *error)
 690 {
 691         struct page *src_tpage = NULL;
 692         struct page *dst_tpage = NULL;
 693         int ret, len = size;
 694
 695         /* If source buffer is not aligned then use an intermediate buffer */
 696         if (!IS_ALIGNED(vaddr, 16)) {
 697                 src_tpage = alloc_page(GFP_KERNEL);
 698                 if (!src_tpage)
 699                         return -ENOMEM;
 700
 701                 if (copy_from_user(page_address(src_tpage),
 702                                 (void __user *)(uintptr_t)vaddr, size)) {
 703                         __free_page(src_tpage);
 704                         return -EFAULT;
 705                 }
 706
 707                 paddr = __sme_page_pa(src_tpage);
 708         }
 709
 710         /*
 711          *  If destination buffer or length is not aligned then do read-modify-write:
 712          *   - decrypt destination in an intermediate buffer
 713          *   - copy the source buffer in an intermediate buffer
 714          *   - use the intermediate buffer as source buffer
 715          */
 716         if (!IS_ALIGNED(dst_vaddr, 16) || !IS_ALIGNED(size, 16)) {
 717                 int dst_offset;
 718
 719                 dst_tpage = alloc_page(GFP_KERNEL);
 720                 if (!dst_tpage) {
 721                         ret = -ENOMEM;
 722                         goto e_free;
 723                 }
 724
 725                 ret = __sev_dbg_decrypt(kvm, dst_paddr,
 726                                         __sme_page_pa(dst_tpage), size, error);
 727                 if (ret)
 728                         goto e_free;
 729
 730                 /*
 731                  *  If source is kernel buffer then use memcpy() otherwise
 732                  *  copy_from_user().
 733                  */
 734                 dst_offset = dst_paddr & 15;
 735
 736                 if (src_tpage)
 737                         memcpy(page_address(dst_tpage) + dst_offset,
 738                                page_address(src_tpage), size);
 739                 else {
 740                         if (copy_from_user(page_address(dst_tpage) + dst_offset,
 741                                            (void __user *)(uintptr_t)vaddr, size)) {
 742                                 ret = -EFAULT;
 743                                 goto e_free;
 744                         }
 745                 }
 746
 747                 paddr = __sme_page_pa(dst_tpage);
 748                 dst_paddr = round_down(dst_paddr, 16);
 749                 len = round_up(size, 16);
 750         }
 751
 752         ret = __sev_issue_dbg_cmd(kvm, paddr, dst_paddr, len, error, true);
 753
 754 e_free:
 755         if (src_tpage)
 756                 __free_page(src_tpage);
 757         if (dst_tpage)
 758                 __free_page(dst_tpage);
 759         return ret;
 760 }
 761
 762 static int sev_dbg_crypt(struct kvm *kvm, struct kvm_sev_cmd *argp, bool dec)
 763 {
 764         unsigned long vaddr, vaddr_end, next_vaddr;
 765         unsigned long dst_vaddr;
 766         struct page **src_p, **dst_p;
 767         struct kvm_sev_dbg debug;
 768         unsigned long n;
 769         unsigned int size;
 770         int ret;
 771
 772         if (!sev_guest(kvm))
 773                 return -ENOTTY;
 774
 775         if (copy_from_user(&debug, (void __user *)(uintptr_t)argp->data, sizeof(debug)))
 776                 return -EFAULT;
 777
 778         if (!debug.len || debug.src_uaddr + debug.len < debug.src_uaddr)
 779                 return -EINVAL;
 780         if (!debug.dst_uaddr)
 781                 return -EINVAL;
 782
 783         vaddr = debug.src_uaddr;
 784         size = debug.len;
 785         vaddr_end = vaddr + size;
 786         dst_vaddr = debug.dst_uaddr;
 787
 788         for (; vaddr < vaddr_end; vaddr = next_vaddr) {
 789                 int len, s_off, d_off;
 790
 791                 /* lock userspace source and destination page */
 792                 src_p = sev_pin_memory(kvm, vaddr & PAGE_MASK, PAGE_SIZE, &n, 0);
 793                 if (!src_p)
 794                         return -EFAULT;
 795
 796                 dst_p = sev_pin_memory(kvm, dst_vaddr & PAGE_MASK, PAGE_SIZE, &n, 1);
 797                 if (!dst_p) {
 798                         sev_unpin_memory(kvm, src_p, n);
 799                         return -EFAULT;
 800                 }
 801
 802                 /*
 803                  * The DBG_{DE,EN}CRYPT commands will perform {dec,en}cryption of the
 804                  * memory content (i.e it will write the same memory region with C=1).
 805                  * It's possible that the cache may contain the data with C=0, i.e.,
 806                  * unencrypted so invalidate it first.
 807                  */
 808                 sev_clflush_pages(src_p, 1);
 809                 sev_clflush_pages(dst_p, 1);
 810
 811                 /*
 812                  * Since user buffer may not be page aligned, calculate the
 813                  * offset within the page.
 814                  */
 815                 s_off = vaddr & ~PAGE_MASK;
 816                 d_off = dst_vaddr & ~PAGE_MASK;
 817                 len = min_t(size_t, (PAGE_SIZE - s_off), size);
 818
 819                 if (dec)
 820                         ret = __sev_dbg_decrypt_user(kvm,
 821                                                      __sme_page_pa(src_p[0]) + s_off,
 822                                                      dst_vaddr,
 823                                                      __sme_page_pa(dst_p[0]) + d_off,
 824                                                      len, &argp->error);
 825                 else
 826                         ret = __sev_dbg_encrypt_user(kvm,
 827                                                      __sme_page_pa(src_p[0]) + s_off,
 828                                                      vaddr,
 829                                                      __sme_page_pa(dst_p[0]) + d_off,
 830                                                      dst_vaddr,
 831                                                      len, &argp->error);
 832
 833                 sev_unpin_memory(kvm, src_p, n);
 834                 sev_unpin_memory(kvm, dst_p, n);
 835
 836                 if (ret)
 837                         goto err;
 838
 839                 next_vaddr = vaddr + len;
 840                 dst_vaddr = dst_vaddr + len;
 841                 size -= len;
 842         }
 843 err:
 844         return ret;
 845 }
 846
 847 static int sev_launch_secret(struct kvm *kvm, struct kvm_sev_cmd *argp)
 848 {
 849         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
 850         struct sev_data_launch_secret *data;
 851         struct kvm_sev_launch_secret params;
 852         struct page **pages;
 853         void *blob, *hdr;
 854         unsigned long n;
 855         int ret, offset;
 856
 857         if (!sev_guest(kvm))
 858                 return -ENOTTY;
 859
 860         if (copy_from_user(&params, (void __user *)(uintptr_t)argp->data, sizeof(params)))
 861                 return -EFAULT;
 862
 863         pages = sev_pin_memory(kvm, params.guest_uaddr, params.guest_len, &n, 1);
 864         if (!pages)
 865                 return -ENOMEM;
 866
 867         /*
 868          * The secret must be copied into contiguous memory region, lets verify
 869          * that userspace memory pages are contiguous before we issue command.
 870          */
 871         if (get_num_contig_pages(0, pages, n) != n) {
 872                 ret = -EINVAL;
 873                 goto e_unpin_memory;
 874         }
 875
 876         ret = -ENOMEM;
 877         data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT);
 878         if (!data)
 879                 goto e_unpin_memory;
 880
 881         offset = params.guest_uaddr & (PAGE_SIZE - 1);
 882         data->guest_address = __sme_page_pa(pages[0]) + offset;
 883         data->guest_len = params.guest_len;
 884
 885         blob = psp_copy_user_blob(params.trans_uaddr, params.trans_len);
 886         if (IS_ERR(blob)) {
 887                 ret = PTR_ERR(blob);
 888                 goto e_free;
 889         }
 890
 891         data->trans_address = __psp_pa(blob);
 892         data->trans_len = params.trans_len;
 893
 894         hdr = psp_copy_user_blob(params.hdr_uaddr, params.hdr_len);
 895         if (IS_ERR(hdr)) {
 896                 ret = PTR_ERR(hdr);
 897                 goto e_free_blob;
 898         }
 899         data->hdr_address = __psp_pa(hdr);
 900         data->hdr_len = params.hdr_len;
 901
 902         data->handle = sev->handle;
 903         ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_UPDATE_SECRET, data, &argp->error);
 904
 905         kfree(hdr);
 906
 907 e_free_blob:
 908         kfree(blob);
 909 e_free:
 910         kfree(data);
 911 e_unpin_memory:
 912         sev_unpin_memory(kvm, pages, n);
 913         return ret;
 914 }
 915
 916 int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
 917 {
 918         struct kvm_sev_cmd sev_cmd;
 919         int r;
 920
 921         if (!svm_sev_enabled())
 922                 return -ENOTTY;
 923
 924         if (!argp)
 925                 return 0;
 926
 927         if (copy_from_user(&sev_cmd, argp, sizeof(struct kvm_sev_cmd)))
 928                 return -EFAULT;
 929
 930         mutex_lock(&kvm->lock);
 931
 932         switch (sev_cmd.id) {
 933         case KVM_SEV_INIT:
 934                 r = sev_guest_init(kvm, &sev_cmd);
 935                 break;
 936         case KVM_SEV_LAUNCH_START:
 937                 r = sev_launch_start(kvm, &sev_cmd);
 938                 break;
 939         case KVM_SEV_LAUNCH_UPDATE_DATA:
 940                 r = sev_launch_update_data(kvm, &sev_cmd);
 941                 break;
 942         case KVM_SEV_LAUNCH_MEASURE:
 943                 r = sev_launch_measure(kvm, &sev_cmd);
 944                 break;
 945         case KVM_SEV_LAUNCH_FINISH:
 946                 r = sev_launch_finish(kvm, &sev_cmd);
 947                 break;
 948         case KVM_SEV_GUEST_STATUS:
 949                 r = sev_guest_status(kvm, &sev_cmd);
 950                 break;
 951         case KVM_SEV_DBG_DECRYPT:
 952                 r = sev_dbg_crypt(kvm, &sev_cmd, true);
 953                 break;
 954         case KVM_SEV_DBG_ENCRYPT:
 955                 r = sev_dbg_crypt(kvm, &sev_cmd, false);
 956                 break;
 957         case KVM_SEV_LAUNCH_SECRET:
 958                 r = sev_launch_secret(kvm, &sev_cmd);
 959                 break;
 960         default:
 961                 r = -EINVAL;
 962                 goto out;
 963         }
 964
 965         if (copy_to_user(argp, &sev_cmd, sizeof(struct kvm_sev_cmd)))
 966                 r = -EFAULT;
 967
 968 out:
 969         mutex_unlock(&kvm->lock);
 970         return r;
 971 }
 972
 973 int svm_register_enc_region(struct kvm *kvm,
 974                             struct kvm_enc_region *range)
 975 {
 976         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
 977         struct enc_region *region;
 978         int ret = 0;
 979
 980         if (!sev_guest(kvm))
 981                 return -ENOTTY;
 982
 983         if (range->addr > ULONG_MAX || range->size > ULONG_MAX)
 984                 return -EINVAL;
 985
 986         region = kzalloc(sizeof(*region), GFP_KERNEL_ACCOUNT);
 987         if (!region)
 988                 return -ENOMEM;
 989
 990         region->pages = sev_pin_memory(kvm, range->addr, range->size, &region->npages, 1);
 991         if (!region->pages) {
 992                 ret = -ENOMEM;
 993                 goto e_free;
 994         }
 995
 996         /*
 997          * The guest may change the memory encryption attribute from C=0 -> C=1
 998          * or vice versa for this memory range. Lets make sure caches are
 999          * flushed to ensure that guest data gets written into memory with
1000          * correct C-bit.
1001          */
1002         sev_clflush_pages(region->pages, region->npages);
1003
1004         region->uaddr = range->addr;
1005         region->size = range->size;
1006
1007         mutex_lock(&kvm->lock);
1008         list_add_tail(&region->list, &sev->regions_list);
1009         mutex_unlock(&kvm->lock);
1010
1011         return ret;
1012
1013 e_free:
1014         kfree(region);
1015         return ret;
1016 }
1017
1018 static struct enc_region *
1019 find_enc_region(struct kvm *kvm, struct kvm_enc_region *range)
1020 {
1021         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1022         struct list_head *head = &sev->regions_list;
1023         struct enc_region *i;
1024
1025         list_for_each_entry(i, head, list) {
1026                 if (i->uaddr == range->addr &&
1027                     i->size == range->size)
1028                         return i;
1029         }
1030
1031         return NULL;
1032 }
1033
1034 static void __unregister_enc_region_locked(struct kvm *kvm,
1035                                            struct enc_region *region)
1036 {
1037         sev_unpin_memory(kvm, region->pages, region->npages);
1038         list_del(&region->list);
1039         kfree(region);
1040 }
1041
1042 int svm_unregister_enc_region(struct kvm *kvm,
1043                               struct kvm_enc_region *range)
1044 {
1045         struct enc_region *region;
1046         int ret;
1047
1048         mutex_lock(&kvm->lock);
1049
1050         if (!sev_guest(kvm)) {
1051                 ret = -ENOTTY;
1052                 goto failed;
1053         }
1054
1055         region = find_enc_region(kvm, range);
1056         if (!region) {
1057                 ret = -EINVAL;
1058                 goto failed;
1059         }
1060
1061         /*
1062          * Ensure that all guest tagged cache entries are flushed before
1063          * releasing the pages back to the system for use. CLFLUSH will
1064          * not do this, so issue a WBINVD.
1065          */
1066         wbinvd_on_all_cpus();
1067
1068         __unregister_enc_region_locked(kvm, region);
1069
1070         mutex_unlock(&kvm->lock);
1071         return 0;
1072
1073 failed:
1074         mutex_unlock(&kvm->lock);
1075         return ret;
1076 }
1077
1078 void sev_vm_destroy(struct kvm *kvm)
1079 {
1080         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1081         struct list_head *head = &sev->regions_list;
1082         struct list_head *pos, *q;
1083
1084         if (!sev_guest(kvm))
1085                 return;
1086
1087         mutex_lock(&kvm->lock);
1088
1089         /*
1090          * Ensure that all guest tagged cache entries are flushed before
1091          * releasing the pages back to the system for use. CLFLUSH will
1092          * not do this, so issue a WBINVD.
1093          */
1094         wbinvd_on_all_cpus();
1095
1096         /*
1097          * if userspace was terminated before unregistering the memory regions
1098          * then lets unpin all the registered memory.
1099          */
1100         if (!list_empty(head)) {
1101                 list_for_each_safe(pos, q, head) {
1102                         __unregister_enc_region_locked(kvm,
1103                                 list_entry(pos, struct enc_region, list));
1104                 }
1105         }
1106
1107         mutex_unlock(&kvm->lock);
1108
1109         sev_unbind_asid(kvm, sev->handle);
1110         sev_asid_free(sev->asid);
1111 }
1112
1113 int __init sev_hardware_setup(void)
1114 {
1115         struct sev_user_data_status *status;
1116         int rc;
1117
1118         /* Maximum number of encrypted guests supported simultaneously */
1119         max_sev_asid = cpuid_ecx(0x8000001F);
1120
1121         if (!svm_sev_enabled())
1122                 return 1;
1123
1124         /* Minimum ASID value that should be used for SEV guest */
1125         min_sev_asid = cpuid_edx(0x8000001F);
1126
1127         /* Initialize SEV ASID bitmaps */
1128         sev_asid_bitmap = bitmap_zalloc(max_sev_asid, GFP_KERNEL);
1129         if (!sev_asid_bitmap)
1130                 return 1;
1131
1132         sev_reclaim_asid_bitmap = bitmap_zalloc(max_sev_asid, GFP_KERNEL);
1133         if (!sev_reclaim_asid_bitmap)
1134                 return 1;
1135
1136         status = kmalloc(sizeof(*status), GFP_KERNEL);
1137         if (!status)
1138                 return 1;
1139
1140         /*
1141          * Check SEV platform status.
1142          *
1143          * PLATFORM_STATUS can be called in any state, if we failed to query
1144          * the PLATFORM status then either PSP firmware does not support SEV
1145          * feature or SEV firmware is dead.
1146          */
1147         rc = sev_platform_status(status, NULL);
1148         if (rc)
1149                 goto err;
1150
1151         pr_info("SEV supported\n");
1152
1153 err:
1154         kfree(status);
1155         return rc;
1156 }
1157
1158 void sev_hardware_teardown(void)
1159 {
1160         if (!svm_sev_enabled())
1161                 return;
1162
1163         bitmap_free(sev_asid_bitmap);
1164         bitmap_free(sev_reclaim_asid_bitmap);
1165
1166         sev_flush_asids();
1167 }
1168
1169 void pre_sev_run(struct vcpu_svm *svm, int cpu)
1170 {
1171         struct svm_cpu_data *sd = per_cpu(svm_data, cpu);
1172         int asid = sev_get_asid(svm->vcpu.kvm);
1173
1174         /* Assign the asid allocated with this SEV guest */
1175         svm->vmcb->control.asid = asid;
1176
1177         /*
1178          * Flush guest TLB:
1179          *
1180          * 1) when different VMCB for the same ASID is to be run on the same host CPU.
1181          * 2) or this VMCB was executed on different host CPU in previous VMRUNs.
1182          */
1183         if (sd->sev_vmcbs[asid] == svm->vmcb &&
1184             svm->last_cpu == cpu)
1185                 return;
1186
1187         svm->last_cpu = cpu;
1188         sd->sev_vmcbs[asid] = svm->vmcb;
1189         svm->vmcb->control.tlb_ctl = TLB_CONTROL_FLUSH_ASID;
1190         mark_dirty(svm->vmcb, VMCB_ASID);
1191 }