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_SMEP | 445 CPUID_STDEXT_BMI2 | 446 CPUID_STDEXT_ERMS | CPUID_STDEXT_RTM | 447 CPUID_STDEXT_AVX512F | 448 CPUID_STDEXT_RDSEED | 449 CPUID_STDEXT_SMAP | 450 CPUID_STDEXT_AVX512PF | 451 CPUID_STDEXT_AVX512ER | 452 CPUID_STDEXT_AVX512CD | CPUID_STDEXT_SHA); 453 regs[2] = 0; 454 regs[3] &= CPUID_STDEXT3_MD_CLEAR; 455 456 /* Advertise RDPID if it is enabled. */ 457 error = vm_get_capability(vm, vcpu_id, 458 VM_CAP_RDPID, &enable_rdpid); 459 if (error == 0 && enable_rdpid) 460 regs[2] |= CPUID_STDEXT2_RDPID; 461 462 /* Advertise INVPCID if it is enabled. */ 463 error = vm_get_capability(vm, vcpu_id, 464 VM_CAP_ENABLE_INVPCID, &enable_invpcid); 465 if (error == 0 && enable_invpcid) 466 regs[1] |= CPUID_STDEXT_INVPCID; 467 } 468 break; 469 470 case CPUID_0000_0006: 471 regs[0] = CPUTPM1_ARAT; 472 regs[1] = 0; 473 regs[2] = 0; 474 regs[3] = 0; 475 break; 476 477 case CPUID_0000_000A: 478 /* 479 * Handle the access, but report 0 for 480 * all options 481 */ 482 regs[0] = 0; 483 regs[1] = 0; 484 regs[2] = 0; 485 regs[3] = 0; 486 break; 487 488 case CPUID_0000_000B: 489 /* 490 * Intel processor topology enumeration 491 */ 492 if (vmm_is_intel()) { 493 vm_get_topology(vm, &sockets, &cores, &threads, 494 &maxcpus); 495 if (param == 0) { 496 logical_cpus = threads; 497 width = log2(logical_cpus); 498 level = CPUID_TYPE_SMT; 499 x2apic_id = vcpu_id; 500 } 501 502 if (param == 1) { 503 logical_cpus = threads * cores; 504 width = log2(logical_cpus); 505 level = CPUID_TYPE_CORE; 506 x2apic_id = vcpu_id; 507 } 508 509 if (!cpuid_leaf_b || param >= 2) { 510 width = 0; 511 logical_cpus = 0; 512 level = 0; 513 x2apic_id = 0; 514 } 515 516 regs[0] = width & 0x1f; 517 regs[1] = logical_cpus & 0xffff; 518 regs[2] = (level << 8) | (param & 0xff); 519 regs[3] = x2apic_id; 520 } else { 521 regs[0] = 0; 522 regs[1] = 0; 523 regs[2] = 0; 524 regs[3] = 0; 525 } 526 break; 527 528 case CPUID_0000_000D: 529 limits = vmm_get_xsave_limits(); 530 if (!limits->xsave_enabled) { 531 regs[0] = 0; 532 regs[1] = 0; 533 regs[2] = 0; 534 regs[3] = 0; 535 break; 536 } 537 538 cpuid_count(func, param, regs); 539 switch (param) { 540 case 0: 541 /* 542 * Only permit the guest to use bits 543 * that are active in the host in 544 * %xcr0. Also, claim that the 545 * maximum save area size is 546 * equivalent to the host's current 547 * save area size. Since this runs 548 * "inside" of vmrun(), it runs with 549 * the guest's xcr0, so the current 550 * save area size is correct as-is. 551 */ 552 regs[0] &= limits->xcr0_allowed; 553 regs[2] = limits->xsave_max_size; 554 regs[3] &= (limits->xcr0_allowed >> 32); 555 break; 556 case 1: 557 /* Only permit XSAVEOPT. */ 558 regs[0] &= CPUID_EXTSTATE_XSAVEOPT; 559 regs[1] = 0; 560 regs[2] = 0; 561 regs[3] = 0; 562 break; 563 default: 564 /* 565 * If the leaf is for a permitted feature, 566 * pass through as-is, otherwise return 567 * all zeroes. 568 */ 569 if (!(limits->xcr0_allowed & (1ul << param))) { 570 regs[0] = 0; 571 regs[1] = 0; 572 regs[2] = 0; 573 regs[3] = 0; 574 } 575 break; 576 } 577 break; 578 579 case CPUID_0000_0015: 580 /* 581 * Don't report CPU TSC/Crystal ratio and clock 582 * values since guests may use these to derive the 583 * local APIC frequency.. 584 */ 585 regs[0] = 0; 586 regs[1] = 0; 587 regs[2] = 0; 588 regs[3] = 0; 589 break; 590 591 case 0x40000000: 592 regs[0] = CPUID_VM_HIGH; 593 bcopy(bhyve_id, ®s[1], 4); 594 bcopy(bhyve_id + 4, ®s[2], 4); 595 bcopy(bhyve_id + 8, ®s[3], 4); 596 break; 597 598 default: 599 default_leaf: 600 /* 601 * The leaf value has already been clamped so 602 * simply pass this through, keeping count of 603 * how many unhandled leaf values have been seen. 604 */ 605 atomic_add_long(&bhyve_xcpuids, 1); 606 cpuid_count(func, param, regs); 607 break; 608 } 609 610 /* 611 * CPUID clears the upper 32-bits of the long-mode registers. 612 */ 613 *rax = regs[0]; 614 *rbx = regs[1]; 615 *rcx = regs[2]; 616 *rdx = regs[3]; 617 618 return (1); 619 } 620 621 bool 622 vm_cpuid_capability(struct vm *vm, int vcpuid, enum vm_cpuid_capability cap) 623 { 624 bool rv; 625 626 KASSERT(cap > 0 && cap < VCC_LAST, ("%s: invalid vm_cpu_capability %d", 627 __func__, cap)); 628 629 /* 630 * Simply passthrough the capabilities of the host cpu for now. 631 */ 632 rv = false; 633 switch (cap) { 634 case VCC_NO_EXECUTE: 635 if (amd_feature & AMDID_NX) 636 rv = true; 637 break; 638 case VCC_FFXSR: 639 if (amd_feature & AMDID_FFXSR) 640 rv = true; 641 break; 642 case VCC_TCE: 643 if (amd_feature2 & AMDID2_TCE) 644 rv = true; 645 break; 646 default: 647 panic("%s: unknown vm_cpu_capability %d", __func__, cap); 648 } 649 return (rv); 650 } 651