sys/amd64/vmm/x86.c

   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/types.h>
  34 #include <sys/systm.h>
  35 #include <sys/cpuset.h>
  36
  37 #include <machine/clock.h>
  38 #include <machine/cpufunc.h>
  39 #include <machine/md_var.h>
  40 #include <machine/specialreg.h>
  41
  42 #include <machine/vmm.h>
  43
  44 #include "x86.h"
  45
  46 #define CPUID_VM_HIGH           0x40000000
  47
  48 static const char bhyve_id[12] = "bhyve bhyve ";
  49
  50 static uint64_t bhyve_xcpuids;
  51
  52 int
  53 x86_emulate_cpuid(struct vm *vm, int vcpu_id,
  54                   uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx)
  55 {
  56         int error;
  57         unsigned int    func, regs[4];
  58         enum x2apic_state x2apic_state;
  59
  60         /*
  61          * Requests for invalid CPUID levels should map to the highest
  62          * available level instead.
  63          */
  64         if (cpu_exthigh != 0 && *eax >= 0x80000000) {
  65                 if (*eax > cpu_exthigh)
  66                         *eax = cpu_exthigh;
  67         } else if (*eax >= 0x40000000) {
  68                 if (*eax > CPUID_VM_HIGH)
  69                         *eax = CPUID_VM_HIGH;
  70         } else if (*eax > cpu_high) {
  71                 *eax = cpu_high;
  72         }
  73
  74         func = *eax;
  75
  76         /*
  77          * In general the approach used for CPU topology is to
  78          * advertise a flat topology where all CPUs are packages with
  79          * no multi-core or SMT.
  80          */
  81         switch (func) {
  82                 /*
  83                  * Pass these through to the guest
  84                  */
  85                 case CPUID_0000_0000:
  86                 case CPUID_0000_0002:
  87                 case CPUID_0000_0003:
  88                 case CPUID_8000_0000:
  89                 case CPUID_8000_0002:
  90                 case CPUID_8000_0003:
  91                 case CPUID_8000_0004:
  92                 case CPUID_8000_0006:
  93                 case CPUID_8000_0008:
  94                         cpuid_count(*eax, *ecx, regs);
  95                         break;
  96
  97                 case CPUID_8000_0001:
  98                         /*
  99                          * Hide rdtscp/ia32_tsc_aux until we know how
 100                          * to deal with them.
 101                          */
 102                         cpuid_count(*eax, *ecx, regs);
 103                         regs[3] &= ~AMDID_RDTSCP;
 104                         break;
 105
 106                 case CPUID_8000_0007:
 107                         cpuid_count(*eax, *ecx, regs);
 108                         /*
 109                          * If the host TSCs are not synchronized across
 110                          * physical cpus then we cannot advertise an
 111                          * invariant tsc to a vcpu.
 112                          *
 113                          * XXX This still falls short because the vcpu
 114                          * can observe the TSC moving backwards as it
 115                          * migrates across physical cpus. But at least
 116                          * it should discourage the guest from using the
 117                          * TSC to keep track of time.
 118                          */
 119                         if (!smp_tsc)
 120                                 regs[3] &= ~AMDPM_TSC_INVARIANT;
 121                         break;
 122
 123                 case CPUID_0000_0001:
 124                         do_cpuid(1, regs);
 125
 126                         error = vm_get_x2apic_state(vm, vcpu_id, &x2apic_state);
 127                         if (error) {
 128                                 panic("x86_emulate_cpuid: error %d "
 129                                       "fetching x2apic state", error);
 130                         }
 131
 132                         /*
 133                          * Override the APIC ID only in ebx
 134                          */
 135                         regs[1] &= ~(CPUID_LOCAL_APIC_ID);
 136                         regs[1] |= (vcpu_id << CPUID_0000_0001_APICID_SHIFT);
 137
 138                         /*
 139                          * Don't expose VMX, SpeedStep or TME capability.
 140                          * Advertise x2APIC capability and Hypervisor guest.
 141                          */
 142                         regs[2] &= ~(CPUID2_VMX | CPUID2_EST | CPUID2_TM2);
 143
 144                         regs[2] |= CPUID2_HV;
 145
 146                         if (x2apic_state != X2APIC_DISABLED)
 147                                 regs[2] |= CPUID2_X2APIC;
 148
 149                         /*
 150                          * Hide xsave/osxsave/avx until the FPU save/restore
 151                          * issues are resolved
 152                          */
 153                         regs[2] &= ~(CPUID2_XSAVE | CPUID2_OSXSAVE |
 154                                      CPUID2_AVX);
 155
 156                         /*
 157                          * Hide monitor/mwait until we know how to deal with
 158                          * these instructions.
 159                          */
 160                         regs[2] &= ~CPUID2_MON;
 161
 162                         /*
 163                          * Hide the performance and debug features.
 164                          */
 165                         regs[2] &= ~CPUID2_PDCM;
 166
 167                         /*
 168                          * Hide thermal monitoring
 169                          */
 170                         regs[3] &= ~(CPUID_ACPI | CPUID_TM);
 171
 172                         /*
 173                          * Machine check handling is done in the host.
 174                          * Hide MTRR capability.
 175                          */
 176                         regs[3] &= ~(CPUID_MCA | CPUID_MCE | CPUID_MTRR);
 177
 178                         /*
 179                         * Hide the debug store capability.
 180                         */
 181                         regs[3] &= ~CPUID_DS;
 182
 183                         /*
 184                          * Disable multi-core.
 185                          */
 186                         regs[1] &= ~CPUID_HTT_CORES;
 187                         regs[3] &= ~CPUID_HTT;
 188                         break;
 189
 190                 case CPUID_0000_0004:
 191                         do_cpuid(4, regs);
 192
 193                         /*
 194                          * Do not expose topology.
 195                          */
 196                         regs[0] &= 0xffff8000;
 197                         regs[0] |= 0x04008000;
 198                         break;
 199
 200                 case CPUID_0000_0006:
 201                 case CPUID_0000_0007:
 202                 case CPUID_0000_000A:
 203                         /*
 204                          * Handle the access, but report 0 for
 205                          * all options
 206                          */
 207                         regs[0] = 0;
 208                         regs[1] = 0;
 209                         regs[2] = 0;
 210                         regs[3] = 0;
 211                         break;
 212
 213                 case CPUID_0000_000B:
 214                         /*
 215                          * Processor topology enumeration
 216                          */
 217                         regs[0] = 0;
 218                         regs[1] = 0;
 219                         regs[2] = *ecx & 0xff;
 220                         regs[3] = vcpu_id;
 221                         break;
 222
 223                 case 0x40000000:
 224                         regs[0] = CPUID_VM_HIGH;
 225                         bcopy(bhyve_id, &regs[1], 4);
 226                         bcopy(bhyve_id + 4, &regs[2], 4);
 227                         bcopy(bhyve_id + 8, &regs[3], 4);
 228                         break;
 229
 230                 default:
 231                         /*
 232                          * The leaf value has already been clamped so
 233                          * simply pass this through, keeping count of
 234                          * how many unhandled leaf values have been seen.
 235                          */
 236                         atomic_add_long(&bhyve_xcpuids, 1);
 237                         cpuid_count(*eax, *ecx, regs);
 238                         break;
 239         }
 240
 241         *eax = regs[0];
 242         *ebx = regs[1];
 243         *ecx = regs[2];
 244         *edx = regs[3];
 245
 246         return (1);
 247 }