usr.sbin/bhyve/inout.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/linker_set.h>
  34 #include <sys/_iovec.h>
  35 #include <sys/mman.h>
  36
  37 #include <x86/psl.h>
  38 #include <x86/segments.h>
  39
  40 #include <machine/vmm.h>
  41 #include <machine/vmm_instruction_emul.h>
  42 #include <vmmapi.h>
  43
  44 #include <stdio.h>
  45 #include <string.h>
  46 #include <assert.h>
  47
  48 #include "bhyverun.h"
  49 #include "inout.h"
  50
  51 SET_DECLARE(inout_port_set, struct inout_port);
  52
  53 #define MAX_IOPORTS     (1 << 16)
  54
  55 #define VERIFY_IOPORT(port, size) \
  56         assert((port) >= 0 && (size) > 0 && ((port) + (size)) <= MAX_IOPORTS)
  57
  58 static struct {
  59         const char      *name;
  60         int             flags;
  61         inout_func_t    handler;
  62         void            *arg;
  63 } inout_handlers[MAX_IOPORTS];
  64
  65 static int
  66 default_inout(struct vmctx *ctx, int vcpu, int in, int port, int bytes,
  67               uint32_t *eax, void *arg)
  68 {
  69         if (in) {
  70                 switch (bytes) {
  71                 case 4:
  72                         *eax = 0xffffffff;
  73                         break;
  74                 case 2:
  75                         *eax = 0xffff;
  76                         break;
  77                 case 1:
  78                         *eax = 0xff;
  79                         break;
  80                 }
  81         }
  82
  83         return (0);
  84 }
  85
  86 static void
  87 register_default_iohandler(int start, int size)
  88 {
  89         struct inout_port iop;
  90
  91         VERIFY_IOPORT(start, size);
  92
  93         bzero(&iop, sizeof(iop));
  94         iop.name = "default";
  95         iop.port = start;
  96         iop.size = size;
  97         iop.flags = IOPORT_F_INOUT | IOPORT_F_DEFAULT;
  98         iop.handler = default_inout;
  99
 100         register_inout(&iop);
 101 }
 102
 103 int
 104 emulate_inout(struct vmctx *ctx, int vcpu, struct vm_exit *vmexit, int strict)
 105 {
 106         int addrsize, bytes, flags, in, port, prot, rep;
 107         uint32_t eax, val;
 108         inout_func_t handler;
 109         void *arg;
 110         int error, fault, retval;
 111         enum vm_reg_name idxreg;
 112         uint64_t gla, index, iterations, count;
 113         struct vm_inout_str *vis;
 114         struct iovec iov[2];
 115
 116         bytes = vmexit->u.inout.bytes;
 117         in = vmexit->u.inout.in;
 118         port = vmexit->u.inout.port;
 119
 120         assert(port < MAX_IOPORTS);
 121         assert(bytes == 1 || bytes == 2 || bytes == 4);
 122
 123         handler = inout_handlers[port].handler;
 124
 125         if (strict && handler == default_inout)
 126                 return (-1);
 127
 128         flags = inout_handlers[port].flags;
 129         arg = inout_handlers[port].arg;
 130
 131         if (in) {
 132                 if (!(flags & IOPORT_F_IN))
 133                         return (-1);
 134         } else {
 135                 if (!(flags & IOPORT_F_OUT))
 136                         return (-1);
 137         }
 138
 139         retval = 0;
 140         if (vmexit->u.inout.string) {
 141                 vis = &vmexit->u.inout_str;
 142                 rep = vis->inout.rep;
 143                 addrsize = vis->addrsize;
 144                 prot = in ? PROT_WRITE : PROT_READ;
 145                 assert(addrsize == 2 || addrsize == 4 || addrsize == 8);
 146
 147                 /* Index register */
 148                 idxreg = in ? VM_REG_GUEST_RDI : VM_REG_GUEST_RSI;
 149                 index = vis->index & vie_size2mask(addrsize);
 150
 151                 /* Count register */
 152                 count = vis->count & vie_size2mask(addrsize);
 153
 154                 /* Limit number of back-to-back in/out emulations to 16 */
 155                 iterations = MIN(count, 16);
 156                 while (iterations > 0) {
 157                         assert(retval == 0);
 158                         if (vie_calculate_gla(vis->paging.cpu_mode,
 159                             vis->seg_name, &vis->seg_desc, index, bytes,
 160                             addrsize, prot, &gla)) {
 161                                 vm_inject_gp(ctx, vcpu);
 162                                 break;
 163                         }
 164
 165                         error = vm_copy_setup(ctx, vcpu, &vis->paging, gla,
 166                             bytes, prot, iov, nitems(iov), &fault);
 167                         if (error) {
 168                                 retval = -1;  /* Unrecoverable error */
 169                                 break;
 170                         } else if (fault) {
 171                                 retval = 0;  /* Resume guest to handle fault */
 172                                 break;
 173                         }
 174
 175                         if (vie_alignment_check(vis->paging.cpl, bytes,
 176                             vis->cr0, vis->rflags, gla)) {
 177                                 vm_inject_ac(ctx, vcpu, 0);
 178                                 break;
 179                         }
 180
 181                         val = 0;
 182                         if (!in)
 183                                 vm_copyin(ctx, vcpu, iov, &val, bytes);
 184
 185                         retval = handler(ctx, vcpu, in, port, bytes, &val, arg);
 186                         if (retval != 0)
 187                                 break;
 188
 189                         if (in)
 190                                 vm_copyout(ctx, vcpu, &val, iov, bytes);
 191
 192                         /* Update index */
 193                         if (vis->rflags & PSL_D)
 194                                 index -= bytes;
 195                         else
 196                                 index += bytes;
 197
 198                         count--;
 199                         iterations--;
 200                 }
 201
 202                 /* Update index register */
 203                 error = vie_update_register(ctx, vcpu, idxreg, index, addrsize);
 204                 assert(error == 0);
 205
 206                 /*
 207                  * Update count register only if the instruction had a repeat
 208                  * prefix.
 209                  */
 210                 if (rep) {
 211                         error = vie_update_register(ctx, vcpu, VM_REG_GUEST_RCX,
 212                             count, addrsize);
 213                         assert(error == 0);
 214                 }
 215
 216                 /* Restart the instruction if more iterations remain */
 217                 if (retval == 0 && count != 0) {
 218                         error = vm_restart_instruction(ctx, vcpu);
 219                         assert(error == 0);
 220                 }
 221         } else {
 222                 eax = vmexit->u.inout.eax;
 223                 val = eax & vie_size2mask(bytes);
 224                 retval = handler(ctx, vcpu, in, port, bytes, &val, arg);
 225                 if (retval == 0 && in) {
 226                         eax &= ~vie_size2mask(bytes);
 227                         eax |= val & vie_size2mask(bytes);
 228                         error = vm_set_register(ctx, vcpu, VM_REG_GUEST_RAX,
 229                             eax);
 230                         assert(error == 0);
 231                 }
 232         }
 233         return (retval);
 234 }
 235
 236 void
 237 init_inout(void)
 238 {
 239         struct inout_port **iopp, *iop;
 240
 241         /*
 242          * Set up the default handler for all ports
 243          */
 244         register_default_iohandler(0, MAX_IOPORTS);
 245
 246         /*
 247          * Overwrite with specified handlers
 248          */
 249         SET_FOREACH(iopp, inout_port_set) {
 250                 iop = *iopp;
 251                 assert(iop->port < MAX_IOPORTS);
 252                 inout_handlers[iop->port].name = iop->name;
 253                 inout_handlers[iop->port].flags = iop->flags;
 254                 inout_handlers[iop->port].handler = iop->handler;
 255                 inout_handlers[iop->port].arg = NULL;
 256         }
 257 }
 258
 259 int
 260 register_inout(struct inout_port *iop)
 261 {
 262         int i;
 263
 264         VERIFY_IOPORT(iop->port, iop->size);
 265
 266         /*
 267          * Verify that the new registration is not overwriting an already
 268          * allocated i/o range.
 269          */
 270         if ((iop->flags & IOPORT_F_DEFAULT) == 0) {
 271                 for (i = iop->port; i < iop->port + iop->size; i++) {
 272                         if ((inout_handlers[i].flags & IOPORT_F_DEFAULT) == 0)
 273                                 return (-1);
 274                 }
 275         }
 276
 277         for (i = iop->port; i < iop->port + iop->size; i++) {
 278                 inout_handlers[i].name = iop->name;
 279                 inout_handlers[i].flags = iop->flags;
 280                 inout_handlers[i].handler = iop->handler;
 281                 inout_handlers[i].arg = iop->arg;
 282         }
 283
 284         return (0);
 285 }
 286
 287 int
 288 unregister_inout(struct inout_port *iop)
 289 {
 290
 291         VERIFY_IOPORT(iop->port, iop->size);
 292         assert(inout_handlers[iop->port].name == iop->name);
 293
 294         register_default_iohandler(iop->port, iop->size);
 295
 296         return (0);
 297 }