sys/amd64/vmm/x86.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2011 NetApp, Inc.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  *
  28  * $FreeBSD$
  29  */
  30
  31 #include <sys/cdefs.h>
  32 __FBSDID("$FreeBSD$");
  33
  34 #include <sys/param.h>
  35 #include <sys/pcpu.h>
  36 #include <sys/systm.h>
  37 #include <sys/sysctl.h>
  38
  39 #include <machine/clock.h>
  40 #include <machine/cpufunc.h>
  41 #include <machine/md_var.h>
  42 #include <machine/segments.h>
  43 #include <machine/specialreg.h>
  44
  45 #include <machine/vmm.h>
  46
  47 #include "vmm_host.h"
  48 #include "vmm_ktr.h"
  49 #include "vmm_util.h"
  50 #include "x86.h"
  51
  52 SYSCTL_DECL(_hw_vmm);
  53 static SYSCTL_NODE(_hw_vmm, OID_AUTO, topology, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
  54     NULL);
  55
  56 #define CPUID_VM_HIGH           0x40000000
  57
  58 static const char bhyve_id[12] = "bhyve bhyve ";
  59
  60 static uint64_t bhyve_xcpuids;
  61 SYSCTL_ULONG(_hw_vmm, OID_AUTO, bhyve_xcpuids, CTLFLAG_RW, &bhyve_xcpuids, 0,
  62     "Number of times an unknown cpuid leaf was accessed");
  63
  64 #if __FreeBSD_version < 1200060 /* Remove after 11 EOL helps MFCing */
  65 extern u_int threads_per_core;
  66 SYSCTL_UINT(_hw_vmm_topology, OID_AUTO, threads_per_core, CTLFLAG_RDTUN,
  67     &threads_per_core, 0, NULL);
  68
  69 extern u_int cores_per_package;
  70 SYSCTL_UINT(_hw_vmm_topology, OID_AUTO, cores_per_package, CTLFLAG_RDTUN,
  71     &cores_per_package, 0, NULL);
  72 #endif
  73
  74 static int cpuid_leaf_b = 1;
  75 SYSCTL_INT(_hw_vmm_topology, OID_AUTO, cpuid_leaf_b, CTLFLAG_RDTUN,
  76     &cpuid_leaf_b, 0, NULL);
  77
  78 /*
  79  * Round up to the next power of two, if necessary, and then take log2.
  80  * Returns -1 if argument is zero.
  81  */
  82 static __inline int
  83 log2(u_int x)
  84 {
  85
  86         return (fls(x << (1 - powerof2(x))) - 1);
  87 }
  88
  89 int
  90 x86_emulate_cpuid(struct vm *vm, int vcpu_id, uint64_t *rax, uint64_t *rbx,
  91     uint64_t *rcx, uint64_t *rdx)
  92 {
  93         const struct xsave_limits *limits;
  94         uint64_t cr4;
  95         int error, enable_invpcid, enable_rdpid, enable_rdtscp, level,
  96             width, x2apic_id;
  97         unsigned int func, regs[4], logical_cpus, param;
  98         enum x2apic_state x2apic_state;
  99         uint16_t cores, maxcpus, sockets, threads;
 100
 101         /*
 102          * The function of CPUID is controlled through the provided value of
 103          * %eax (and secondarily %ecx, for certain leaf data).
 104          */
 105         func = (uint32_t)*rax;
 106         param = (uint32_t)*rcx;
 107
 108         VCPU_CTR2(vm, vcpu_id, "cpuid %#x,%#x", func, param);
 109
 110         /*
 111          * Requests for invalid CPUID levels should map to the highest
 112          * available level instead.
 113          */
 114         if (cpu_exthigh != 0 && func >= 0x80000000) {
 115                 if (func > cpu_exthigh)
 116                         func = cpu_exthigh;
 117         } else if (func >= 0x40000000) {
 118                 if (func > CPUID_VM_HIGH)
 119                         func = CPUID_VM_HIGH;
 120         } else if (func > cpu_high) {
 121                 func = cpu_high;
 122         }
 123
 124         /*
 125          * In general the approach used for CPU topology is to
 126          * advertise a flat topology where all CPUs are packages with
 127          * no multi-core or SMT.
 128          */
 129         switch (func) {
 130                 /*
 131                  * Pass these through to the guest
 132                  */
 133                 case CPUID_0000_0000:
 134                 case CPUID_0000_0002:
 135                 case CPUID_0000_0003:
 136                 case CPUID_8000_0000:
 137                 case CPUID_8000_0002:
 138                 case CPUID_8000_0003:
 139                 case CPUID_8000_0004:
 140                 case CPUID_8000_0006:
 141                         cpuid_count(func, param, regs);
 142                         break;
 143                 case CPUID_8000_0008:
 144                         cpuid_count(func, param, regs);
 145                         if (vmm_is_svm()) {
 146                                 /*
 147                                  * As on Intel (0000_0007:0, EDX), mask out
 148                                  * unsupported or unsafe AMD extended features
 149                                  * (8000_0008 EBX).
 150                                  */
 151                                 regs[1] &= (AMDFEID_CLZERO | AMDFEID_IRPERF |
 152                                     AMDFEID_XSAVEERPTR);
 153
 154                                 vm_get_topology(vm, &sockets, &cores, &threads,
 155                                     &maxcpus);
 156                                 /*
 157                                  * Here, width is ApicIdCoreIdSize, present on
 158                                  * at least Family 15h and newer.  It
 159                                  * represents the "number of bits in the
 160                                  * initial apicid that indicate thread id
 161                                  * within a package."
 162                                  *
 163                                  * Our topo_probe_amd() uses it for
 164                                  * pkg_id_shift and other OSes may rely on it.
 165                                  */
 166                                 width = MIN(0xF, log2(threads * cores));
 167                                 if (width < 0x4)
 168                                         width = 0;
 169                                 logical_cpus = MIN(0xFF, threads * cores - 1);
 170                                 regs[2] = (width << AMDID_COREID_SIZE_SHIFT) | logical_cpus;
 171                         }
 172                         break;
 173
 174                 case CPUID_8000_0001:
 175                         cpuid_count(func, param, regs);
 176
 177                         /*
 178                          * Hide SVM from guest.
 179                          */
 180                         regs[2] &= ~AMDID2_SVM;
 181
 182                         /*
 183                          * Don't advertise extended performance counter MSRs
 184                          * to the guest.
 185                          */
 186                         regs[2] &= ~AMDID2_PCXC;
 187                         regs[2] &= ~AMDID2_PNXC;
 188                         regs[2] &= ~AMDID2_PTSCEL2I;
 189
 190                         /*
 191                          * Don't advertise Instruction Based Sampling feature.
 192                          */
 193                         regs[2] &= ~AMDID2_IBS;
 194
 195                         /* NodeID MSR not available */
 196                         regs[2] &= ~AMDID2_NODE_ID;
 197
 198                         /* Don't advertise the OS visible workaround feature */
 199                         regs[2] &= ~AMDID2_OSVW;
 200
 201                         /* Hide mwaitx/monitorx capability from the guest */
 202                         regs[2] &= ~AMDID2_MWAITX;
 203
 204                         /* Advertise RDTSCP if it is enabled. */
 205                         error = vm_get_capability(vm, vcpu_id,
 206                             VM_CAP_RDTSCP, &enable_rdtscp);
 207                         if (error == 0 && enable_rdtscp)
 208                                 regs[3] |= AMDID_RDTSCP;
 209                         else
 210                                 regs[3] &= ~AMDID_RDTSCP;
 211                         break;
 212
 213                 case CPUID_8000_0007:
 214                         /*
 215                          * AMD uses this leaf to advertise the processor's
 216                          * power monitoring and RAS capabilities. These
 217                          * features are hardware-specific and exposing
 218                          * them to a guest doesn't make a lot of sense.
 219                          *
 220                          * Intel uses this leaf only to advertise the
 221                          * "Invariant TSC" feature with all other bits
 222                          * being reserved (set to zero).
 223                          */
 224                         regs[0] = 0;
 225                         regs[1] = 0;
 226                         regs[2] = 0;
 227                         regs[3] = 0;
 228
 229                         /*
 230                          * "Invariant TSC" can be advertised to the guest if:
 231                          * - host TSC frequency is invariant
 232                          * - host TSCs are synchronized across physical cpus
 233                          *
 234                          * XXX This still falls short because the vcpu
 235                          * can observe the TSC moving backwards as it
 236                          * migrates across physical cpus. But at least
 237                          * it should discourage the guest from using the
 238                          * TSC to keep track of time.
 239                          */
 240                         if (tsc_is_invariant && smp_tsc)
 241                                 regs[3] |= AMDPM_TSC_INVARIANT;
 242                         break;
 243
 244                 case CPUID_8000_001D:
 245                         /* AMD Cache topology, like 0000_0004 for Intel. */
 246                         if (!vmm_is_svm())
 247                                 goto default_leaf;
 248
 249                         /*
 250                          * Similar to Intel, generate a ficticious cache
 251                          * topology for the guest with L3 shared by the
 252                          * package, and L1 and L2 local to a core.
 253                          */
 254                         vm_get_topology(vm, &sockets, &cores, &threads,
 255                             &maxcpus);
 256                         switch (param) {
 257                         case 0:
 258                                 logical_cpus = threads;
 259                                 level = 1;
 260                                 func = 1;       /* data cache */
 261                                 break;
 262                         case 1:
 263                                 logical_cpus = threads;
 264                                 level = 2;
 265                                 func = 3;       /* unified cache */
 266                                 break;
 267                         case 2:
 268                                 logical_cpus = threads * cores;
 269                                 level = 3;
 270                                 func = 3;       /* unified cache */
 271                                 break;
 272                         default:
 273                                 logical_cpus = 0;
 274                                 level = 0;
 275                                 func = 0;
 276                                 break;
 277                         }
 278
 279                         logical_cpus = MIN(0xfff, logical_cpus - 1);
 280                         regs[0] = (logical_cpus << 14) | (1 << 8) |
 281                             (level << 5) | func;
 282                         regs[1] = (func > 0) ? (CACHE_LINE_SIZE - 1) : 0;
 283                         regs[2] = 0;
 284                         regs[3] = 0;
 285                         break;
 286
 287                 case CPUID_8000_001E:
 288                         /*
 289                          * AMD Family 16h+ and Hygon Family 18h additional
 290                          * identifiers.
 291                          */
 292                         if (!vmm_is_svm() || CPUID_TO_FAMILY(cpu_id) < 0x16)
 293                                 goto default_leaf;
 294
 295                         vm_get_topology(vm, &sockets, &cores, &threads,
 296                             &maxcpus);
 297                         regs[0] = vcpu_id;
 298                         threads = MIN(0xFF, threads - 1);
 299                         regs[1] = (threads << 8) |
 300                             (vcpu_id >> log2(threads + 1));
 301                         /*
 302                          * XXX Bhyve topology cannot yet represent >1 node per
 303                          * processor.
 304                          */
 305                         regs[2] = 0;
 306                         regs[3] = 0;
 307                         break;
 308
 309                 case CPUID_0000_0001:
 310                         do_cpuid(1, regs);
 311
 312                         error = vm_get_x2apic_state(vm, vcpu_id, &x2apic_state);
 313                         if (error) {
 314                                 panic("x86_emulate_cpuid: error %d "
 315                                       "fetching x2apic state", error);
 316                         }
 317
 318                         /*
 319                          * Override the APIC ID only in ebx
 320                          */
 321                         regs[1] &= ~(CPUID_LOCAL_APIC_ID);
 322                         regs[1] |= (vcpu_id << CPUID_0000_0001_APICID_SHIFT);
 323
 324                         /*
 325                          * Don't expose VMX, SpeedStep, TME or SMX capability.
 326                          * Advertise x2APIC capability and Hypervisor guest.
 327                          */
 328                         regs[2] &= ~(CPUID2_VMX | CPUID2_EST | CPUID2_TM2);
 329                         regs[2] &= ~(CPUID2_SMX);
 330
 331                         regs[2] |= CPUID2_HV;
 332
 333                         if (x2apic_state != X2APIC_DISABLED)
 334                                 regs[2] |= CPUID2_X2APIC;
 335                         else
 336                                 regs[2] &= ~CPUID2_X2APIC;
 337
 338                         /*
 339                          * Only advertise CPUID2_XSAVE in the guest if
 340                          * the host is using XSAVE.
 341                          */
 342                         if (!(regs[2] & CPUID2_OSXSAVE))
 343                                 regs[2] &= ~CPUID2_XSAVE;
 344
 345                         /*
 346                          * If CPUID2_XSAVE is being advertised and the
 347                          * guest has set CR4_XSAVE, set
 348                          * CPUID2_OSXSAVE.
 349                          */
 350                         regs[2] &= ~CPUID2_OSXSAVE;
 351                         if (regs[2] & CPUID2_XSAVE) {
 352                                 error = vm_get_register(vm, vcpu_id,
 353                                     VM_REG_GUEST_CR4, &cr4);
 354                                 if (error)
 355                                         panic("x86_emulate_cpuid: error %d "
 356                                               "fetching %%cr4", error);
 357                                 if (cr4 & CR4_XSAVE)
 358                                         regs[2] |= CPUID2_OSXSAVE;
 359                         }
 360
 361                         /*
 362                          * Hide monitor/mwait until we know how to deal with
 363                          * these instructions.
 364                          */
 365                         regs[2] &= ~CPUID2_MON;
 366
 367                         /*
 368                          * Hide the performance and debug features.
 369                          */
 370                         regs[2] &= ~CPUID2_PDCM;
 371
 372                         /*
 373                          * No TSC deadline support in the APIC yet
 374                          */
 375                         regs[2] &= ~CPUID2_TSCDLT;
 376
 377                         /*
 378                          * Hide thermal monitoring
 379                          */
 380                         regs[3] &= ~(CPUID_ACPI | CPUID_TM);
 381
 382                         /*
 383                          * Hide the debug store capability.
 384                          */
 385                         regs[3] &= ~CPUID_DS;
 386
 387                         /*
 388                          * Advertise the Machine Check and MTRR capability.
 389                          *
 390                          * Some guest OSes (e.g. Windows) will not boot if
 391                          * these features are absent.
 392                          */
 393                         regs[3] |= (CPUID_MCA | CPUID_MCE | CPUID_MTRR);
 394
 395                         vm_get_topology(vm, &sockets, &cores, &threads,
 396                             &maxcpus);
 397                         logical_cpus = threads * cores;
 398                         regs[1] &= ~CPUID_HTT_CORES;
 399                         regs[1] |= (logical_cpus & 0xff) << 16;
 400                         regs[3] |= CPUID_HTT;
 401                         break;
 402
 403                 case CPUID_0000_0004:
 404                         cpuid_count(func, param, regs);
 405
 406                         if (regs[0] || regs[1] || regs[2] || regs[3]) {
 407                                 vm_get_topology(vm, &sockets, &cores, &threads,
 408                                     &maxcpus);
 409                                 regs[0] &= 0x3ff;
 410                                 regs[0] |= (cores - 1) << 26;
 411                                 /*
 412                                  * Cache topology:
 413                                  * - L1 and L2 are shared only by the logical
 414                                  *   processors in a single core.
 415                                  * - L3 and above are shared by all logical
 416                                  *   processors in the package.
 417                                  */
 418                                 logical_cpus = threads;
 419                                 level = (regs[0] >> 5) & 0x7;
 420                                 if (level >= 3)
 421                                         logical_cpus *= cores;
 422                                 regs[0] |= (logical_cpus - 1) << 14;
 423                         }
 424                         break;
 425
 426                 case CPUID_0000_0007:
 427                         regs[0] = 0;
 428                         regs[1] = 0;
 429                         regs[2] = 0;
 430                         regs[3] = 0;
 431
 432                         /* leaf 0 */
 433                         if (param == 0) {
 434                                 cpuid_count(func, param, regs);
 435
 436                                 /* Only leaf 0 is supported */
 437                                 regs[0] = 0;
 438
 439                                 /*
 440                                  * Expose known-safe features.
 441                                  */
 442                                 regs[1] &= (CPUID_STDEXT_FSGSBASE |
 443                                     CPUID_STDEXT_BMI1 | CPUID_STDEXT_HLE |
 444                                     CPUID_STDEXT_AVX2 | CPUID_STDEXT_BMI2 |
 445                                     CPUID_STDEXT_ERMS | CPUID_STDEXT_RTM |
 446                                     CPUID_STDEXT_AVX512F |
 447                                     CPUID_STDEXT_RDSEED |
 448                                     CPUID_STDEXT_AVX512PF |
 449                                     CPUID_STDEXT_AVX512ER |
 450                                     CPUID_STDEXT_AVX512CD | CPUID_STDEXT_SHA);
 451                                 regs[2] = 0;
 452                                 regs[3] &= CPUID_STDEXT3_MD_CLEAR;
 453
 454                                 /* Advertise RDPID if it is enabled. */
 455                                 error = vm_get_capability(vm, vcpu_id,
 456                                     VM_CAP_RDPID, &enable_rdpid);
 457                                 if (error == 0 && enable_rdpid)
 458                                         regs[2] |= CPUID_STDEXT2_RDPID;
 459
 460                                 /* Advertise INVPCID if it is enabled. */
 461                                 error = vm_get_capability(vm, vcpu_id,
 462                                     VM_CAP_ENABLE_INVPCID, &enable_invpcid);
 463                                 if (error == 0 && enable_invpcid)
 464                                         regs[1] |= CPUID_STDEXT_INVPCID;
 465                         }
 466                         break;
 467
 468                 case CPUID_0000_0006:
 469                         regs[0] = CPUTPM1_ARAT;
 470                         regs[1] = 0;
 471                         regs[2] = 0;
 472                         regs[3] = 0;
 473                         break;
 474
 475                 case CPUID_0000_000A:
 476                         /*
 477                          * Handle the access, but report 0 for
 478                          * all options
 479                          */
 480                         regs[0] = 0;
 481                         regs[1] = 0;
 482                         regs[2] = 0;
 483                         regs[3] = 0;
 484                         break;
 485
 486                 case CPUID_0000_000B:
 487                         /*
 488                          * Intel processor topology enumeration
 489                          */
 490                         if (vmm_is_intel()) {
 491                                 vm_get_topology(vm, &sockets, &cores, &threads,
 492                                     &maxcpus);
 493                                 if (param == 0) {
 494                                         logical_cpus = threads;
 495                                         width = log2(logical_cpus);
 496                                         level = CPUID_TYPE_SMT;
 497                                         x2apic_id = vcpu_id;
 498                                 }
 499
 500                                 if (param == 1) {
 501                                         logical_cpus = threads * cores;
 502                                         width = log2(logical_cpus);
 503                                         level = CPUID_TYPE_CORE;
 504                                         x2apic_id = vcpu_id;
 505                                 }
 506
 507                                 if (!cpuid_leaf_b || param >= 2) {
 508                                         width = 0;
 509                                         logical_cpus = 0;
 510                                         level = 0;
 511                                         x2apic_id = 0;
 512                                 }
 513
 514                                 regs[0] = width & 0x1f;
 515                                 regs[1] = logical_cpus & 0xffff;
 516                                 regs[2] = (level << 8) | (param & 0xff);
 517                                 regs[3] = x2apic_id;
 518                         } else {
 519                                 regs[0] = 0;
 520                                 regs[1] = 0;
 521                                 regs[2] = 0;
 522                                 regs[3] = 0;
 523                         }
 524                         break;
 525
 526                 case CPUID_0000_000D:
 527                         limits = vmm_get_xsave_limits();
 528                         if (!limits->xsave_enabled) {
 529                                 regs[0] = 0;
 530                                 regs[1] = 0;
 531                                 regs[2] = 0;
 532                                 regs[3] = 0;
 533                                 break;
 534                         }
 535
 536                         cpuid_count(func, param, regs);
 537                         switch (param) {
 538                         case 0:
 539                                 /*
 540                                  * Only permit the guest to use bits
 541                                  * that are active in the host in
 542                                  * %xcr0.  Also, claim that the
 543                                  * maximum save area size is
 544                                  * equivalent to the host's current
 545                                  * save area size.  Since this runs
 546                                  * "inside" of vmrun(), it runs with
 547                                  * the guest's xcr0, so the current
 548                                  * save area size is correct as-is.
 549                                  */
 550                                 regs[0] &= limits->xcr0_allowed;
 551                                 regs[2] = limits->xsave_max_size;
 552                                 regs[3] &= (limits->xcr0_allowed >> 32);
 553                                 break;
 554                         case 1:
 555                                 /* Only permit XSAVEOPT. */
 556                                 regs[0] &= CPUID_EXTSTATE_XSAVEOPT;
 557                                 regs[1] = 0;
 558                                 regs[2] = 0;
 559                                 regs[3] = 0;
 560                                 break;
 561                         default:
 562                                 /*
 563                                  * If the leaf is for a permitted feature,
 564                                  * pass through as-is, otherwise return
 565                                  * all zeroes.
 566                                  */
 567                                 if (!(limits->xcr0_allowed & (1ul << param))) {
 568                                         regs[0] = 0;
 569                                         regs[1] = 0;
 570                                         regs[2] = 0;
 571                                         regs[3] = 0;
 572                                 }
 573                                 break;
 574                         }
 575                         break;
 576
 577                 case CPUID_0000_0015:
 578                         /*
 579                          * Don't report CPU TSC/Crystal ratio and clock
 580                          * values since guests may use these to derive the
 581                          * local APIC frequency..
 582                          */
 583                         regs[0] = 0;
 584                         regs[1] = 0;
 585                         regs[2] = 0;
 586                         regs[3] = 0;
 587                         break;
 588
 589                 case 0x40000000:
 590                         regs[0] = CPUID_VM_HIGH;
 591                         bcopy(bhyve_id, &regs[1], 4);
 592                         bcopy(bhyve_id + 4, &regs[2], 4);
 593                         bcopy(bhyve_id + 8, &regs[3], 4);
 594                         break;
 595
 596                 default:
 597 default_leaf:
 598                         /*
 599                          * The leaf value has already been clamped so
 600                          * simply pass this through, keeping count of
 601                          * how many unhandled leaf values have been seen.
 602                          */
 603                         atomic_add_long(&bhyve_xcpuids, 1);
 604                         cpuid_count(func, param, regs);
 605                         break;
 606         }
 607
 608         /*
 609          * CPUID clears the upper 32-bits of the long-mode registers.
 610          */
 611         *rax = regs[0];
 612         *rbx = regs[1];
 613         *rcx = regs[2];
 614         *rdx = regs[3];
 615
 616         return (1);
 617 }
 618
 619 bool
 620 vm_cpuid_capability(struct vm *vm, int vcpuid, enum vm_cpuid_capability cap)
 621 {
 622         bool rv;
 623
 624         KASSERT(cap > 0 && cap < VCC_LAST, ("%s: invalid vm_cpu_capability %d",
 625             __func__, cap));
 626
 627         /*
 628          * Simply passthrough the capabilities of the host cpu for now.
 629          */
 630         rv = false;
 631         switch (cap) {
 632         case VCC_NO_EXECUTE:
 633                 if (amd_feature & AMDID_NX)
 634                         rv = true;
 635                 break;
 636         case VCC_FFXSR:
 637                 if (amd_feature & AMDID_FFXSR)
 638                         rv = true;
 639                 break;
 640         case VCC_TCE:
 641                 if (amd_feature2 & AMDID2_TCE)
 642                         rv = true;
 643                 break;
 644         default:
 645                 panic("%s: unknown vm_cpu_capability %d", __func__, cap);
 646         }
 647         return (rv);
 648 }