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| 32 | .\" $DragonFly: src/share/man/man7/vkernel.7,v 1.30 2007/08/18 16:09:57 swildner Exp $ |
| 33 | .\" |
| 34 | .Dd August 18, 2007 |
| 35 | .Dt VKERNEL 7 |
| 36 | .Os |
| 37 | .Sh NAME |
| 38 | .Nm vkernel , |
| 39 | .Nm vcd , |
| 40 | .Nm vkd , |
| 41 | .Nm vke |
| 42 | .Nd virtual kernel architecture |
| 43 | .Sh SYNOPSIS |
| 44 | .Cd "platform vkernel" |
| 45 | .Cd "device vcd" |
| 46 | .Cd "device vkd" |
| 47 | .Cd "device vke" |
| 48 | .Pp |
| 49 | .Pa /usr/obj/usr/src/sys/VKERNEL/kernel.debug |
| 50 | .Op Fl sUv |
| 51 | .Op Fl c Ar file |
| 52 | .Op Fl e Ar name Ns = Ns Li value : Ns Ar name Ns = Ns Li value : Ns ... |
| 53 | .Op Fl i Ar file |
| 54 | .Op Fl I Ar interface Ns Op Ar :address1 Ns Oo Ar :address2 Oc Ns Oo Ar /netmask Oc |
| 55 | .Op Fl l Ar cpulock |
| 56 | .Op Fl m Ar size |
| 57 | .Op Fl n Ar numcpus |
| 58 | .Op Fl p Ar file |
| 59 | .Op Fl r Ar file |
| 60 | .Sh DESCRIPTION |
| 61 | The |
| 62 | .Nm |
| 63 | architecture allows for running |
| 64 | .Dx |
| 65 | kernels in userland. |
| 66 | .Pp |
| 67 | The following options are available: |
| 68 | .Bl -tag -width ".Fl m Ar size" |
| 69 | .It Fl c Ar file |
| 70 | Specify a readonly CD-ROM image |
| 71 | .Ar file |
| 72 | to be used by the kernel, with the first |
| 73 | .Fl c |
| 74 | option defining |
| 75 | .Li vcd0 , |
| 76 | the second one |
| 77 | .Li vcd1 , |
| 78 | and so on. The first |
| 79 | .Fl r |
| 80 | or |
| 81 | .Fl c |
| 82 | option specified on the command line will be the boot disk. |
| 83 | The CD9660 filesystem is assumed when booting from this media. |
| 84 | .It Fl e Ar name Ns = Ns Li value : Ns Ar name Ns = Ns Li value : Ns ... |
| 85 | Specify an environment to be used by the kernel. |
| 86 | .It Fl i Ar file |
| 87 | Specify a memory image |
| 88 | .Ar file |
| 89 | to be used by the virtual kernel. |
| 90 | If no |
| 91 | .Fl i |
| 92 | option is given, the kernel will generate a name of the form |
| 93 | .Pa /var/vkernel/memimg.XXXXXX , |
| 94 | with the trailing |
| 95 | .Ql X Ns s |
| 96 | being replaced by a sequential number, e.g.\& |
| 97 | .Pa memimg.000001 . |
| 98 | .It Fl I Ar interface Ns Op Ar :address1 Ns Oo Ar :address2 Oc Ns Oo Ar /netmask Oc |
| 99 | Create a virtual network device, with the first |
| 100 | .Fl I |
| 101 | option defining |
| 102 | .Li vke0 , |
| 103 | the second one |
| 104 | .Li vke1 , |
| 105 | and so on. |
| 106 | .Pp |
| 107 | The |
| 108 | .Ar interface |
| 109 | argument is the name of a |
| 110 | .Xr tap 4 |
| 111 | device node. |
| 112 | The |
| 113 | .Pa /dev/ |
| 114 | path prefix does not have to be specified and will be automatically prepended. |
| 115 | Specifying |
| 116 | .Cm auto |
| 117 | will pick the first unused |
| 118 | .Xr tap 4 |
| 119 | device. |
| 120 | .Pp |
| 121 | The |
| 122 | .Ar address1 |
| 123 | and |
| 124 | .Ar address2 |
| 125 | arguments are the IP addresses of the |
| 126 | .Xr tap 4 |
| 127 | and |
| 128 | .Nm vke |
| 129 | interfaces. |
| 130 | Optionally, |
| 131 | .Ar address1 |
| 132 | may be of the form |
| 133 | .Li bridge Ns Em X |
| 134 | in which case the |
| 135 | .Xr tap 4 |
| 136 | interface is added to the specified |
| 137 | .Xr bridge 4 |
| 138 | interface. |
| 139 | The |
| 140 | .Nm vke |
| 141 | address is not assigned until the interface is brought up in the guest. |
| 142 | .Pp |
| 143 | The |
| 144 | .Ar netmask |
| 145 | argument applies to all interfaces for which an address is specified. |
| 146 | .It Fl l Ar cpulock |
| 147 | Specify which, if any, real CPUs to lock virtual CPUs to. |
| 148 | .Ar cpulock |
| 149 | is one of |
| 150 | .Cm any , |
| 151 | .Cm map Ns Op Ns , Ns Ar startCPU , |
| 152 | or |
| 153 | .Ar CPU . |
| 154 | .Pp |
| 155 | .Cm any |
| 156 | does not map virtual CPUs to real CPUs. |
| 157 | This is the default. |
| 158 | .Pp |
| 159 | .Cm map Ns Op Ns , Ns Ar startCPU |
| 160 | maps each virtual CPU to a real CPU starting with real CPU 0 or |
| 161 | .Ar startCPU |
| 162 | if specified. |
| 163 | .Pp |
| 164 | .Ar CPU |
| 165 | locks all virtual CPUs to the real CPU specified by |
| 166 | .Ar CPU . |
| 167 | .It Fl m Ar size |
| 168 | Specify the amount of memory to be used by the kernel in bytes, |
| 169 | .Cm K |
| 170 | .Pq kilobytes , |
| 171 | .Cm M |
| 172 | .Pq megabytes |
| 173 | or |
| 174 | .Cm G |
| 175 | .Pq gigabytes . |
| 176 | Lowercase versions of |
| 177 | .Cm K , M , |
| 178 | and |
| 179 | .Cm G |
| 180 | are allowed. |
| 181 | .It Fl n Ar numcpus |
| 182 | Specify the number of CPUs you wish to emulate. |
| 183 | Up to 31 CPUs are supported. |
| 184 | The virtual kernel must be built with |
| 185 | .Cd options SMP |
| 186 | to use this option and will default to 2 CPUs unless otherwise specified. |
| 187 | .It Fl p Ar file |
| 188 | Specify a file in which to store the process ID. |
| 189 | A warning is issued if this file cannot be opened for writing. |
| 190 | .It Fl r Ar file |
| 191 | Specify a R/W disk image |
| 192 | .Ar file |
| 193 | to be used by the kernel, with the first |
| 194 | .Fl r |
| 195 | option defining |
| 196 | .Li vkd0 , |
| 197 | the second one |
| 198 | .Li vkd1 , |
| 199 | and so on. The first |
| 200 | .Fl r |
| 201 | or |
| 202 | .Fl c |
| 203 | option specified on the command line will be the boot disk. |
| 204 | .It Fl s |
| 205 | Boot into single-user mode. |
| 206 | .It Fl U |
| 207 | Enable writing to kernel memory and module loading. |
| 208 | By default, those are disabled for security reasons. |
| 209 | .It Fl v |
| 210 | Turn on verbose booting. |
| 211 | .El |
| 212 | .Sh DEVICES |
| 213 | A number of virtual device drivers exist to supplement the virtual kernel. |
| 214 | .Ss Disk device |
| 215 | The |
| 216 | .Nm vkd |
| 217 | driver allows for up to 16 |
| 218 | .Xr vn 4 |
| 219 | based disk devices. |
| 220 | The root device will be |
| 221 | .Li vkd0 |
| 222 | (see |
| 223 | .Sx EXAMPLES |
| 224 | for further information on how to prepare a root image). |
| 225 | .Ss CD-ROM device |
| 226 | The |
| 227 | .Nm vcd |
| 228 | driver allows for up to 16 virtual CD-ROM devices. |
| 229 | Basically this is a read only |
| 230 | .Nm vkd |
| 231 | device with a block size of 2048. |
| 232 | .Ss Network interface |
| 233 | The |
| 234 | .Nm vke |
| 235 | driver supports up to 16 virtual network interfaces which are associated with |
| 236 | .Xr tap 4 |
| 237 | devices on the host. |
| 238 | For each |
| 239 | .Nm vke |
| 240 | device, the per-interface read only |
| 241 | .Xr sysctl 3 |
| 242 | variable |
| 243 | .Va hw.vke Ns Em X Ns Va .tap_unit |
| 244 | holds the unit number of the associated |
| 245 | .Xr tap 4 |
| 246 | device. |
| 247 | .Sh SIGNALS |
| 248 | The virtual kernel only enables |
| 249 | .Dv SIGQUIT |
| 250 | and |
| 251 | .Dv SIGTERM |
| 252 | while operating in regular console mode. |
| 253 | Sending |
| 254 | .Ql \&^\e |
| 255 | .Pq Dv SIGQUIT |
| 256 | to the virtual kernel causes the virtual kernel to enter its internal |
| 257 | .Xr ddb 4 |
| 258 | debugger and re-enable all other terminal signals. |
| 259 | Sending |
| 260 | .Dv SIGTERM |
| 261 | to the virtual kernel triggers a clean shutdown by passing a |
| 262 | .Dv SIGUSR2 |
| 263 | to the virtual kernel's |
| 264 | .Xr init 8 |
| 265 | process. |
| 266 | .Sh DEBUGGING |
| 267 | It is possible to directly gdb the virtual kernel's process. |
| 268 | It is recommended that you do a |
| 269 | .Ql handle SIGSEGV noprint |
| 270 | to ignore page faults processed by the virtual kernel itself. |
| 271 | .Sh EXAMPLES |
| 272 | A couple of steps are necessary in order to prepare the system to build and |
| 273 | run a virtual kernel. |
| 274 | .Ss Setting up the filesystem |
| 275 | The |
| 276 | .Nm |
| 277 | architecture needs a number of files which reside in |
| 278 | .Pa /var/vkernel . |
| 279 | Since these files tend to get rather big and the |
| 280 | .Pa /var |
| 281 | partition is usually of limited size, we recommend the directory to be |
| 282 | created in the |
| 283 | .Pa /home |
| 284 | partition with a link to it in |
| 285 | .Pa /var : |
| 286 | .Bd -literal |
| 287 | mkdir /home/var.vkernel |
| 288 | ln -s /home/var.vkernel /var/vkernel |
| 289 | .Ed |
| 290 | .Pp |
| 291 | Next, a filesystem image to be used by the virtual kernel has to be |
| 292 | created and populated (assuming world has been built previously): |
| 293 | .Bd -literal |
| 294 | dd if=/dev/zero of=/var/vkernel/rootimg.01 bs=1m count=2048 |
| 295 | vnconfig -c -s labels vn0 /var/vkernel/rootimg.01 |
| 296 | disklabel -r -w vn0s0 auto |
| 297 | disklabel -e vn0s0 # edit the label to create a vn0s0a partition |
| 298 | newfs /dev/vn0s0a |
| 299 | mount /dev/vn0s0a /mnt |
| 300 | cd /usr/src |
| 301 | make installworld DESTDIR=/mnt |
| 302 | cd etc |
| 303 | make distribution DESTDIR=/mnt |
| 304 | echo '/dev/vkd0s0a / ufs rw 1 1' >/mnt/etc/fstab |
| 305 | echo 'proc /proc procfs rw 0 0' >>/mnt/etc/fstab |
| 306 | .Ed |
| 307 | .Pp |
| 308 | Edit |
| 309 | .Pa /mnt/etc/ttys |
| 310 | and replace the |
| 311 | .Li console |
| 312 | entry with the following line and turn off all other gettys. |
| 313 | .Bd -literal |
| 314 | console "/usr/libexec/getty Pc" cons25 on secure |
| 315 | .Ed |
| 316 | .Pp |
| 317 | Then, unmount the disk. |
| 318 | .Bd -literal |
| 319 | umount /mnt |
| 320 | vnconfig -u vn0 |
| 321 | .Ed |
| 322 | .Ss Compiling the virtual kernel |
| 323 | In order to compile a virtual kernel use the |
| 324 | .Li VKERNEL |
| 325 | kernel configuration file residing in |
| 326 | .Pa /usr/src/sys/config |
| 327 | (or a configuration file derived thereof): |
| 328 | .Bd -literal |
| 329 | cd /usr/src |
| 330 | make -DNO_MODULES buildkernel KERNCONF=VKERNEL |
| 331 | .Ed |
| 332 | .Ss Enabling virtual kernel operation |
| 333 | A special |
| 334 | .Xr sysctl 8 , |
| 335 | .Va vm.vkernel_enable , |
| 336 | must be set to enable |
| 337 | .Nm |
| 338 | operation: |
| 339 | .Bd -literal |
| 340 | sysctl vm.vkernel_enable=1 |
| 341 | .Ed |
| 342 | .Ss Configuring the network on the host system |
| 343 | In order to access a network interface of the host system from the |
| 344 | .Nm , |
| 345 | you must add the interface to a |
| 346 | .Xr bridge 4 |
| 347 | device which will then be passed to the |
| 348 | .Fl I |
| 349 | option: |
| 350 | .Bd -literal |
| 351 | kldload if_bridge.ko |
| 352 | kldload if_tap.ko |
| 353 | ifconfig bridge0 create |
| 354 | ifconfig bridge0 addm re0 # assuming re0 is the host's interface |
| 355 | ifconfig bridge0 up |
| 356 | .Ed |
| 357 | .Ss Running the kernel |
| 358 | Finally, the virtual kernel can be run: |
| 359 | .Bd -literal |
| 360 | cd /usr/obj/usr/src/sys/VKERNEL |
| 361 | \&./kernel.debug -m 64m -r /var/vkernel/rootimg.01 -I auto:bridge0 |
| 362 | .Ed |
| 363 | .Pp |
| 364 | The |
| 365 | .Xr reboot 8 |
| 366 | command can be used to stop a virtual kernel. |
| 367 | .Sh BUILDING THE WORLD UNDER A VKERNEL |
| 368 | The virtual kernel platform does not have all the header files expected |
| 369 | by a world build, so the easiest thing to do right now is to specify a |
| 370 | pc32 target when building the world under a virtual kernel, like this: |
| 371 | .Bd -literal |
| 372 | vkernel# make MACHINE_PLATFORM=pc32 buildworld |
| 373 | vkernel# make MACHINE_PLATFORM=pc32 installworld |
| 374 | .Ed |
| 375 | .Sh SEE ALSO |
| 376 | .Xr bridge 4 , |
| 377 | .Xr tap 4 , |
| 378 | .Xr vn 4 , |
| 379 | .Xr build 7 , |
| 380 | .Xr disklabel 8 , |
| 381 | .Xr ifconfig 8 , |
| 382 | .Xr vnconfig 8 |
| 383 | .Sh HISTORY |
| 384 | Virtual kernels were introduced in |
| 385 | .Dx 1.7 . |
| 386 | .Sh AUTHORS |
| 387 | .An -nosplit |
| 388 | .An Matt Dillon |
| 389 | thought up and implemented the |
| 390 | .Nm |
| 391 | architecture and wrote the |
| 392 | .Nm vkd |
| 393 | device driver. |
| 394 | .An Sepherosa Ziehau |
| 395 | wrote the |
| 396 | .Nm vke |
| 397 | device driver. |
| 398 | This manual page was written by |
| 399 | .An Sascha Wildner . |