1 /*- 2 * Copyright (c) 2011 NetApp, Inc. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/pcpu.h> 34 #include <sys/systm.h> 35 #include <sys/cpuset.h> 36 #include <sys/sysctl.h> 37 38 #include <machine/clock.h> 39 #include <machine/cpufunc.h> 40 #include <machine/md_var.h> 41 #include <machine/segments.h> 42 #include <machine/specialreg.h> 43 44 #include <machine/vmm.h> 45 46 #include "vmm_host.h" 47 #include "vmm_ktr.h" 48 #include "vmm_util.h" 49 #include "x86.h" 50 51 SYSCTL_DECL(_hw_vmm); 52 static SYSCTL_NODE(_hw_vmm, OID_AUTO, topology, CTLFLAG_RD, 0, NULL); 53 54 #define CPUID_VM_HIGH 0x40000000 55 56 static const char bhyve_id[12] = "bhyve bhyve "; 57 58 static uint64_t bhyve_xcpuids; 59 SYSCTL_ULONG(_hw_vmm, OID_AUTO, bhyve_xcpuids, CTLFLAG_RW, &bhyve_xcpuids, 0, 60 "Number of times an unknown cpuid leaf was accessed"); 61 62 /* 63 * The default CPU topology is a single thread per package. 64 */ 65 static u_int threads_per_core = 1; 66 SYSCTL_UINT(_hw_vmm_topology, OID_AUTO, threads_per_core, CTLFLAG_RDTUN, 67 &threads_per_core, 0, NULL); 68 69 static u_int cores_per_package = 1; 70 SYSCTL_UINT(_hw_vmm_topology, OID_AUTO, cores_per_package, CTLFLAG_RDTUN, 71 &cores_per_package, 0, NULL); 72 73 static int cpuid_leaf_b = 1; 74 SYSCTL_INT(_hw_vmm_topology, OID_AUTO, cpuid_leaf_b, CTLFLAG_RDTUN, 75 &cpuid_leaf_b, 0, NULL); 76 77 /* 78 * Round up to the next power of two, if necessary, and then take log2. 79 * Returns -1 if argument is zero. 80 */ 81 static __inline int 82 log2(u_int x) 83 { 84 85 return (fls(x << (1 - powerof2(x))) - 1); 86 } 87 88 int 89 x86_emulate_cpuid(struct vm *vm, int vcpu_id, 90 uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx) 91 { 92 const struct xsave_limits *limits; 93 uint64_t cr4; 94 int error, enable_invpcid, level, width, x2apic_id; 95 unsigned int func, regs[4], logical_cpus; 96 enum x2apic_state x2apic_state; 97 98 VCPU_CTR2(vm, vcpu_id, "cpuid %#x,%#x", *eax, *ecx); 99 100 /* 101 * Requests for invalid CPUID levels should map to the highest 102 * available level instead. 103 */ 104 if (cpu_exthigh != 0 && *eax >= 0x80000000) { 105 if (*eax > cpu_exthigh) 106 *eax = cpu_exthigh; 107 } else if (*eax >= 0x40000000) { 108 if (*eax > CPUID_VM_HIGH) 109 *eax = CPUID_VM_HIGH; 110 } else if (*eax > cpu_high) { 111 *eax = cpu_high; 112 } 113 114 func = *eax; 115 116 /* 117 * In general the approach used for CPU topology is to 118 * advertise a flat topology where all CPUs are packages with 119 * no multi-core or SMT. 120 */ 121 switch (func) { 122 /* 123 * Pass these through to the guest 124 */ 125 case CPUID_0000_0000: 126 case CPUID_0000_0002: 127 case CPUID_0000_0003: 128 case CPUID_8000_0000: 129 case CPUID_8000_0002: 130 case CPUID_8000_0003: 131 case CPUID_8000_0004: 132 case CPUID_8000_0006: 133 cpuid_count(*eax, *ecx, regs); 134 break; 135 case CPUID_8000_0008: 136 cpuid_count(*eax, *ecx, regs); 137 if (vmm_is_amd()) { 138 /* 139 * XXX this might appear silly because AMD 140 * cpus don't have threads. 141 * 142 * However this matches the logical cpus as 143 * advertised by leaf 0x1 and will work even 144 * if the 'threads_per_core' tunable is set 145 * incorrectly on an AMD host. 146 */ 147 logical_cpus = threads_per_core * 148 cores_per_package; 149 regs[2] = logical_cpus - 1; 150 } 151 break; 152 153 case CPUID_8000_0001: 154 cpuid_count(*eax, *ecx, regs); 155 156 /* 157 * Hide SVM and Topology Extension features from guest. 158 */ 159 regs[2] &= ~(AMDID2_SVM | AMDID2_TOPOLOGY); 160 161 /* 162 * Don't advertise extended performance counter MSRs 163 * to the guest. 164 */ 165 regs[2] &= ~AMDID2_PCXC; 166 regs[2] &= ~AMDID2_PNXC; 167 regs[2] &= ~AMDID2_PTSCEL2I; 168 169 /* 170 * Don't advertise Instruction Based Sampling feature. 171 */ 172 regs[2] &= ~AMDID2_IBS; 173 174 /* NodeID MSR not available */ 175 regs[2] &= ~AMDID2_NODE_ID; 176 177 /* Don't advertise the OS visible workaround feature */ 178 regs[2] &= ~AMDID2_OSVW; 179 180 /* 181 * Hide rdtscp/ia32_tsc_aux until we know how 182 * to deal with them. 183 */ 184 regs[3] &= ~AMDID_RDTSCP; 185 break; 186 187 case CPUID_8000_0007: 188 /* 189 * AMD uses this leaf to advertise the processor's 190 * power monitoring and RAS capabilities. These 191 * features are hardware-specific and exposing 192 * them to a guest doesn't make a lot of sense. 193 * 194 * Intel uses this leaf only to advertise the 195 * "Invariant TSC" feature with all other bits 196 * being reserved (set to zero). 197 */ 198 regs[0] = 0; 199 regs[1] = 0; 200 regs[2] = 0; 201 regs[3] = 0; 202 203 /* 204 * "Invariant TSC" can be advertised to the guest if: 205 * - host TSC frequency is invariant 206 * - host TSCs are synchronized across physical cpus 207 * 208 * XXX This still falls short because the vcpu 209 * can observe the TSC moving backwards as it 210 * migrates across physical cpus. But at least 211 * it should discourage the guest from using the 212 * TSC to keep track of time. 213 */ 214 if (tsc_is_invariant && smp_tsc) 215 regs[3] |= AMDPM_TSC_INVARIANT; 216 break; 217 218 case CPUID_0000_0001: 219 do_cpuid(1, regs); 220 221 error = vm_get_x2apic_state(vm, vcpu_id, &x2apic_state); 222 if (error) { 223 panic("x86_emulate_cpuid: error %d " 224 "fetching x2apic state", error); 225 } 226 227 /* 228 * Override the APIC ID only in ebx 229 */ 230 regs[1] &= ~(CPUID_LOCAL_APIC_ID); 231 regs[1] |= (vcpu_id << CPUID_0000_0001_APICID_SHIFT); 232 233 /* 234 * Don't expose VMX, SpeedStep or TME capability. 235 * Advertise x2APIC capability and Hypervisor guest. 236 */ 237 regs[2] &= ~(CPUID2_VMX | CPUID2_EST | CPUID2_TM2); 238 239 regs[2] |= CPUID2_HV; 240 241 if (x2apic_state != X2APIC_DISABLED) 242 regs[2] |= CPUID2_X2APIC; 243 else 244 regs[2] &= ~CPUID2_X2APIC; 245 246 /* 247 * Only advertise CPUID2_XSAVE in the guest if 248 * the host is using XSAVE. 249 */ 250 if (!(regs[2] & CPUID2_OSXSAVE)) 251 regs[2] &= ~CPUID2_XSAVE; 252 253 /* 254 * If CPUID2_XSAVE is being advertised and the 255 * guest has set CR4_XSAVE, set 256 * CPUID2_OSXSAVE. 257 */ 258 regs[2] &= ~CPUID2_OSXSAVE; 259 if (regs[2] & CPUID2_XSAVE) { 260 error = vm_get_register(vm, vcpu_id, 261 VM_REG_GUEST_CR4, &cr4); 262 if (error) 263 panic("x86_emulate_cpuid: error %d " 264 "fetching %%cr4", error); 265 if (cr4 & CR4_XSAVE) 266 regs[2] |= CPUID2_OSXSAVE; 267 } 268 269 /* 270 * Hide monitor/mwait until we know how to deal with 271 * these instructions. 272 */ 273 regs[2] &= ~CPUID2_MON; 274 275 /* 276 * Hide the performance and debug features. 277 */ 278 regs[2] &= ~CPUID2_PDCM; 279 280 /* 281 * No TSC deadline support in the APIC yet 282 */ 283 regs[2] &= ~CPUID2_TSCDLT; 284 285 /* 286 * Hide thermal monitoring 287 */ 288 regs[3] &= ~(CPUID_ACPI | CPUID_TM); 289 290 /* 291 * Machine check handling is done in the host. 292 * Hide MTRR capability. 293 */ 294 regs[3] &= ~(CPUID_MCA | CPUID_MCE | CPUID_MTRR); 295 296 /* 297 * Hide the debug store capability. 298 */ 299 regs[3] &= ~CPUID_DS; 300 301 logical_cpus = threads_per_core * cores_per_package; 302 regs[1] &= ~CPUID_HTT_CORES; 303 regs[1] |= (logical_cpus & 0xff) << 16; 304 regs[3] |= CPUID_HTT; 305 break; 306 307 case CPUID_0000_0004: 308 cpuid_count(*eax, *ecx, regs); 309 310 if (regs[0] || regs[1] || regs[2] || regs[3]) { 311 regs[0] &= 0x3ff; 312 regs[0] |= (cores_per_package - 1) << 26; 313 /* 314 * Cache topology: 315 * - L1 and L2 are shared only by the logical 316 * processors in a single core. 317 * - L3 and above are shared by all logical 318 * processors in the package. 319 */ 320 logical_cpus = threads_per_core; 321 level = (regs[0] >> 5) & 0x7; 322 if (level >= 3) 323 logical_cpus *= cores_per_package; 324 regs[0] |= (logical_cpus - 1) << 14; 325 } 326 break; 327 328 case CPUID_0000_0007: 329 regs[0] = 0; 330 regs[1] = 0; 331 regs[2] = 0; 332 regs[3] = 0; 333 334 /* leaf 0 */ 335 if (*ecx == 0) { 336 cpuid_count(*eax, *ecx, regs); 337 338 /* Only leaf 0 is supported */ 339 regs[0] = 0; 340 341 /* 342 * Expose known-safe features. 343 */ 344 regs[1] &= (CPUID_STDEXT_FSGSBASE | 345 CPUID_STDEXT_BMI1 | CPUID_STDEXT_HLE | 346 CPUID_STDEXT_AVX2 | CPUID_STDEXT_BMI2 | 347 CPUID_STDEXT_ERMS | CPUID_STDEXT_RTM | 348 CPUID_STDEXT_AVX512F | 349 CPUID_STDEXT_AVX512PF | 350 CPUID_STDEXT_AVX512ER | 351 CPUID_STDEXT_AVX512CD); 352 regs[2] = 0; 353 regs[3] = 0; 354 355 /* Advertise INVPCID if it is enabled. */ 356 error = vm_get_capability(vm, vcpu_id, 357 VM_CAP_ENABLE_INVPCID, &enable_invpcid); 358 if (error == 0 && enable_invpcid) 359 regs[1] |= CPUID_STDEXT_INVPCID; 360 } 361 break; 362 363 case CPUID_0000_0006: 364 case CPUID_0000_000A: 365 /* 366 * Handle the access, but report 0 for 367 * all options 368 */ 369 regs[0] = 0; 370 regs[1] = 0; 371 regs[2] = 0; 372 regs[3] = 0; 373 break; 374 375 case CPUID_0000_000B: 376 /* 377 * Processor topology enumeration 378 */ 379 if (*ecx == 0) { 380 logical_cpus = threads_per_core; 381 width = log2(logical_cpus); 382 level = CPUID_TYPE_SMT; 383 x2apic_id = vcpu_id; 384 } 385 386 if (*ecx == 1) { 387 logical_cpus = threads_per_core * 388 cores_per_package; 389 width = log2(logical_cpus); 390 level = CPUID_TYPE_CORE; 391 x2apic_id = vcpu_id; 392 } 393 394 if (!cpuid_leaf_b || *ecx >= 2) { 395 width = 0; 396 logical_cpus = 0; 397 level = 0; 398 x2apic_id = 0; 399 } 400 401 regs[0] = width & 0x1f; 402 regs[1] = logical_cpus & 0xffff; 403 regs[2] = (level << 8) | (*ecx & 0xff); 404 regs[3] = x2apic_id; 405 break; 406 407 case CPUID_0000_000D: 408 limits = vmm_get_xsave_limits(); 409 if (!limits->xsave_enabled) { 410 regs[0] = 0; 411 regs[1] = 0; 412 regs[2] = 0; 413 regs[3] = 0; 414 break; 415 } 416 417 cpuid_count(*eax, *ecx, regs); 418 switch (*ecx) { 419 case 0: 420 /* 421 * Only permit the guest to use bits 422 * that are active in the host in 423 * %xcr0. Also, claim that the 424 * maximum save area size is 425 * equivalent to the host's current 426 * save area size. Since this runs 427 * "inside" of vmrun(), it runs with 428 * the guest's xcr0, so the current 429 * save area size is correct as-is. 430 */ 431 regs[0] &= limits->xcr0_allowed; 432 regs[2] = limits->xsave_max_size; 433 regs[3] &= (limits->xcr0_allowed >> 32); 434 break; 435 case 1: 436 /* Only permit XSAVEOPT. */ 437 regs[0] &= CPUID_EXTSTATE_XSAVEOPT; 438 regs[1] = 0; 439 regs[2] = 0; 440 regs[3] = 0; 441 break; 442 default: 443 /* 444 * If the leaf is for a permitted feature, 445 * pass through as-is, otherwise return 446 * all zeroes. 447 */ 448 if (!(limits->xcr0_allowed & (1ul << *ecx))) { 449 regs[0] = 0; 450 regs[1] = 0; 451 regs[2] = 0; 452 regs[3] = 0; 453 } 454 break; 455 } 456 break; 457 458 case 0x40000000: 459 regs[0] = CPUID_VM_HIGH; 460 bcopy(bhyve_id, ®s[1], 4); 461 bcopy(bhyve_id + 4, ®s[2], 4); 462 bcopy(bhyve_id + 8, ®s[3], 4); 463 break; 464 465 default: 466 /* 467 * The leaf value has already been clamped so 468 * simply pass this through, keeping count of 469 * how many unhandled leaf values have been seen. 470 */ 471 atomic_add_long(&bhyve_xcpuids, 1); 472 cpuid_count(*eax, *ecx, regs); 473 break; 474 } 475 476 *eax = regs[0]; 477 *ebx = regs[1]; 478 *ecx = regs[2]; 479 *edx = regs[3]; 480 481 return (1); 482 } 483