aboutsummaryrefslogtreecommitdiff
path: root/gnu/build/vm.scm
blob: 2d41c5756b0fe0e971dca6c42cf0e26fbf87b5b7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013, 2014, 2015, 2016, 2017 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2016 Christopher Allan Webber <cwebber@dustycloud.org>
;;; Copyright © 2016 Leo Famulari <leo@famulari.name>
;;; Copyright © 2017 Mathieu Othacehe <m.othacehe@gmail.com>
;;; Copyright © 2017 Marius Bakke <mbakke@fastmail.com>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.

(define-module (gnu build vm)
  #:use-module (guix build utils)
  #:use-module (guix build store-copy)
  #:use-module (guix build syscalls)
  #:use-module (gnu build linux-boot)
  #:use-module (gnu build install)
  #:use-module (gnu build file-systems)
  #:use-module (guix records)
  #:use-module ((guix combinators) #:select (fold2))
  #:use-module (ice-9 format)
  #:use-module (ice-9 match)
  #:use-module (ice-9 regex)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-9)
  #:use-module (srfi srfi-26)
  #:export (qemu-command
            load-in-linux-vm
            format-partition

            partition
            partition?
            partition-device
            partition-size
            partition-file-system
            partition-label
            partition-flags
            partition-initializer

            estimated-partition-size
            root-partition-initializer
            initialize-partition-table
            initialize-hard-disk
            make-iso9660-image))

;;; Commentary:
;;;
;;; This module provides supporting code to run virtual machines and build
;;; virtual machine images using QEMU.
;;;
;;; Code:

(define* (qemu-command #:optional (system %host-type))
  "Return the default name of the QEMU command for SYSTEM."
  (let ((cpu (substring system 0
                        (string-index system #\-))))
    (string-append "qemu-system-"
                   (if (string-match "^i[3456]86$" cpu)
                       "i386"
                       cpu))))

(define* (load-in-linux-vm builder
                           #:key
                           output
                           (qemu (qemu-command)) (memory-size 512)
                           linux initrd
                           make-disk-image?
                           (disk-image-size (* 100 (expt 2 20)))
                           (disk-image-format "qcow2")
                           (references-graphs '()))
  "Run BUILDER, a Scheme file, into a VM running LINUX with INITRD, and copy
the result to OUTPUT.

When MAKE-DISK-IMAGE? is true, OUTPUT will contain a VM image of
DISK-IMAGE-SIZE bytes resulting from the execution of BUILDER, which may
access it via /dev/hda.

REFERENCES-GRAPHS can specify a list of reference-graph files as produced by
the #:references-graphs parameter of 'derivation'."
  (when make-disk-image?
    (format #t "creating ~a image of ~,2f MiB...~%"
            disk-image-format (/ disk-image-size (expt 2 20)))
    (force-output)
    (unless (zero? (system* "qemu-img" "create" "-f" disk-image-format
                            output
                            (number->string disk-image-size)))
      (error "qemu-img failed")))

  (mkdir "xchg")

  (match references-graphs
    ((graph-files ...)
     ;; Copy the reference-graph files under xchg/ so EXP can access it.
     (map (lambda (file)
            (copy-file file (string-append "xchg/" file)))
          graph-files))
    (_ #f))

  (unless (zero?
           (apply system* qemu "-nographic" "-no-reboot"
                  "-m" (number->string memory-size)
                  "-net" "nic,model=virtio"
                  "-virtfs"
                  (string-append "local,id=store_dev,path="
                                 (%store-directory)
                                 ",security_model=none,mount_tag=store")
                  "-virtfs"
                  (string-append "local,id=xchg_dev,path=xchg"
                                 ",security_model=none,mount_tag=xchg")
                  "-kernel" linux
                  "-initrd" initrd
                  "-append" (string-append "console=ttyS0 --load="
                                           builder)
                  (append
                   (if make-disk-image?
                       `("-drive" ,(string-append "file=" output
                                                  ",if=virtio"))
                       '())
                   ;; Only enable kvm if we see /dev/kvm exists.
                   ;; This allows users without hardware virtualization to still
                   ;; use these commands.
                   (if (file-exists? "/dev/kvm")
                       '("-enable-kvm")
                       '()))))
    (error "qemu failed" qemu))

  ;; When MAKE-DISK-IMAGE? is true, the image is in OUTPUT already.
  (unless make-disk-image?
    (mkdir output)
    (copy-recursively "xchg" output)))


;;;
;;; Partitions.
;;;

(define-record-type* <partition> partition make-partition
  partition?
  (device      partition-device (default #f))
  (size        partition-size)
  (file-system partition-file-system (default "ext4"))
  (label       partition-label (default #f))
  (flags       partition-flags (default '()))
  (initializer partition-initializer (default (const #t))))

(define (estimated-partition-size graphs)
  "Return the estimated size of a partition that can store the store items
given by GRAPHS, a list of file names produced by #:references-graphs."
  ;; Simply add a 20% overhead.
  (round (* 1.2 (closure-size graphs))))

(define* (initialize-partition-table device partitions
                                     #:key
                                     (label-type "msdos")
                                     (offset (expt 2 20)))
  "Create on DEVICE a partition table of type LABEL-TYPE, containing the given
PARTITIONS (a list of <partition> objects), starting at OFFSET bytes.  On
success, return PARTITIONS with their 'device' field changed to reflect their
actual /dev name based on DEVICE."
  (define (partition-options part offset index)
    (cons* "mkpart" "primary" "ext2"
           (format #f "~aB" offset)
           (format #f "~aB" (+ offset (partition-size part)))
           (append-map (lambda (flag)
                         (list "set" (number->string index)
                               (symbol->string flag) "on"))
                       (partition-flags part))))

  (define (options partitions offset)
    (let loop ((partitions partitions)
               (offset     offset)
               (index      1)
               (result     '()))
      (match partitions
        (()
         (concatenate (reverse result)))
        ((head tail ...)
         (loop tail
               ;; Leave one sector (512B) between partitions to placate
               ;; Parted.
               (+ offset 512 (partition-size head))
               (+ 1 index)
               (cons (partition-options head offset index)
                     result))))))

  (format #t "creating partition table with ~a partitions (~a)...\n"
          (length partitions)
          (string-join (map (compose (cut string-append <> " MiB")
                                     number->string
                                     (lambda (size)
                                       (round (/ size (expt 2. 20))))
                                     partition-size)
                            partitions)
                       ", "))
  (unless (zero? (apply system* "parted" "--script"
                        device "mklabel" label-type
                        (options partitions offset)))
    (error "failed to create partition table"))

  ;; Set the 'device' field of each partition.
  (reverse
   (fold2 (lambda (part result index)
            (values (cons  (partition
                            (inherit part)
                            (device (string-append device
                                                   (number->string index))))
                           result)
                    (+ 1 index)))
          '()
          1
          partitions)))

(define MS_BIND 4096)                             ; <sys/mounts.h> again!

(define* (create-ext-file-system partition type
                                 #:key label)
  "Create an ext-family filesystem of TYPE on PARTITION.  If LABEL is true,
use that as the volume name."
  (format #t "creating ~a partition...\n" type)
  (unless (zero? (apply system* (string-append "mkfs." type)
                        "-F" partition
                        (if label
                            `("-L" ,label)
                            '())))
    (error "failed to create partition")))

(define* (create-fat-file-system partition
                                 #:key label)
  "Create a FAT filesystem on PARTITION.  The number of File Allocation Tables
will be determined based on filesystem size.  If LABEL is true, use that as the
volume name."
  (format #t "creating FAT partition...\n")
  (unless (zero? (apply system* "mkfs.fat" partition
                        (if label
                            `("-n" ,label)
                            '())))
    (error "failed to create FAT partition")))

(define* (format-partition partition type
                           #:key label)
  "Create a file system TYPE on PARTITION.  If LABEL is true, use that as the
volume name."
  (cond ((string-prefix? "ext" type)
         (create-ext-file-system partition type #:label label))
        ((or (string-prefix? "fat" type) (string= "vfat" type))
         (create-fat-file-system partition #:label label))
        (else (error "Unsupported file system."))))

(define (initialize-partition partition)
  "Format PARTITION, a <partition> object with a non-#f 'device' field, mount
it, run its initializer, and unmount it."
  (let ((target "/fs"))
   (format-partition (partition-device partition)
                     (partition-file-system partition)
                     #:label (partition-label partition))
   (mkdir-p target)
   (mount (partition-device partition) target
          (partition-file-system partition))

   ((partition-initializer partition) target)

   (umount target)
   partition))

(define* (root-partition-initializer #:key (closures '())
                                     copy-closures?
                                     (register-closures? #t)
                                     system-directory)
  "Return a procedure to initialize a root partition.

If REGISTER-CLOSURES? is true, register all of CLOSURES is the partition's
store.  If COPY-CLOSURES? is true, copy all of CLOSURES to the partition.
SYSTEM-DIRECTORY is the name of the directory of the 'system' derivation."
  (lambda (target)
    (define target-store
      (string-append target (%store-directory)))

    (when copy-closures?
      ;; Populate the store.
      (populate-store (map (cut string-append "/xchg/" <>) closures)
                      target))

    ;; Populate /dev.
    (make-essential-device-nodes #:root target)

    ;; Optionally, register the inputs in the image's store.
    (when register-closures?
      (unless copy-closures?
        ;; XXX: 'guix-register' wants to palpate the things it registers, so
        ;; bind-mount the store on the target.
        (mkdir-p target-store)
        (mount (%store-directory) target-store "" MS_BIND))

      (display "registering closures...\n")
      (for-each (lambda (closure)
                  (register-closure target
                                    (string-append "/xchg/" closure)))
                closures)
      (unless copy-closures?
        (umount target-store)))

    ;; Add the non-store directories and files.
    (display "populating...\n")
    (populate-root-file-system system-directory target)

    ;; 'guix-register' resets timestamps and everything, so no need to do it
    ;; once more in that case.
    (unless register-closures?
      (reset-timestamps target))))

(define (register-bootcfg-root target bootcfg)
  "On file system TARGET, register BOOTCFG as a GC root."
  (let ((directory (string-append target "/var/guix/gcroots")))
    (mkdir-p directory)
    (symlink bootcfg (string-append directory "/bootcfg"))))

(define (install-efi grub esp config-file)
  "Write a self-contained GRUB EFI loader to the mounted ESP using CONFIG-FILE."
  (let* ((system %host-type)
         ;; Hard code the output location to a well-known path recognized by
         ;; compliant firmware. See "3.5.1.1 Removable Media Boot Behaviour":
         ;; http://www.uefi.org/sites/default/files/resources/UEFI%20Spec%202_6.pdf
         (grub-mkstandalone (string-append grub "/bin/grub-mkstandalone"))
         (efi-directory (string-append esp "/EFI/BOOT"))
         ;; Map grub target names to boot file names.
         (efi-targets (cond ((string-prefix? "x86_64" system)
                             '("x86_64-efi" . "BOOTX64.EFI"))
                            ((string-prefix? "i686" system)
                             '("i386-efi" . "BOOTIA32.EFI"))
                            ((string-prefix? "armhf" system)
                             '("arm-efi" . "BOOTARM.EFI"))
                            ((string-prefix? "aarch64" system)
                             '("arm64-efi" . "BOOTAA64.EFI")))))
    ;; grub-mkstandalone requires a TMPDIR to prepare the firmware image.
    (setenv "TMPDIR" esp)

    (mkdir-p efi-directory)
    (unless (zero? (system* grub-mkstandalone "-O" (car efi-targets)
                            "-o" (string-append efi-directory "/"
                                                (cdr efi-targets))
                            ;; Graft the configuration file onto the image.
                            (string-append "boot/grub/grub.cfg=" config-file)))
      (error "failed to create GRUB EFI image"))))

(define* (make-iso9660-image grub config-file os-drv target
                             #:key (volume-id "GuixSD") (volume-uuid #f))
  "Given a GRUB package, creates an iso image as TARGET, using CONFIG-FILE as
Grub configuration and OS-DRV as the stuff in it."
  (let ((grub-mkrescue (string-append grub "/bin/grub-mkrescue")))
    (mkdir-p "/tmp/root/var/run")
    (mkdir-p "/tmp/root/run")
    (unless (zero? (apply system*
                          `(,grub-mkrescue "-o" ,target
                            ,(string-append "boot/grub/grub.cfg=" config-file)
                            ,(string-append "gnu/store=" os-drv "/..")
                            "var=/tmp/root/var"
                            "run=/tmp/root/run"
                            "--"
                            "-volid" ,(string-upcase volume-id)
                            ,@(if volume-uuid
                                  `("-volume_date" "uuid"
                                    ,(string-filter (lambda (value)
                                                      (not (char=? #\- value)))
                                                    (iso9660-uuid->string
                                                     volume-uuid)))
                                  `()))))
      (error "failed to create ISO9660 image"))))

(define* (initialize-hard-disk device
                               #:key
                               bootloader-package
                               bootcfg
                               bootcfg-location
                               bootloader-installer
                               (grub-efi #f)
                               (partitions '()))
  "Initialize DEVICE as a disk containing all the <partition> objects listed
in PARTITIONS, and using BOOTCFG as its bootloader configuration file.

Each partition is initialized by calling its 'initializer' procedure,
passing it a directory name where it is mounted."

  (define (partition-bootable? partition)
    "Return the first partition found with the boot flag set."
    (member 'boot (partition-flags partition)))

  (define (partition-esp? partition)
    "Return the first EFI System Partition."
    (member 'esp (partition-flags partition)))

  (let* ((partitions (initialize-partition-table device partitions))
         (root       (find partition-bootable? partitions))
         (esp        (find partition-esp? partitions))
         (target     "/fs"))
    (unless root
      (error "no bootable partition specified" partitions))

    (for-each initialize-partition partitions)

    (display "mounting root partition...\n")
    (mkdir-p target)
    (mount (partition-device root) target (partition-file-system root))
    (install-boot-config bootcfg bootcfg-location target)
    (when bootloader-installer
      (display "installing bootloader...\n")
      (bootloader-installer bootloader-package device target))

    (when esp
      ;; Mount the ESP somewhere and install GRUB UEFI image.
      (let ((mount-point (string-append target "/boot/efi"))
            (grub-config (string-append target "/tmp/grub-standalone.cfg")))
        (display "mounting EFI system partition...\n")
        (mkdir-p mount-point)
        (mount (partition-device esp) mount-point
               (partition-file-system esp))

        ;; Create a tiny configuration file telling the embedded grub
        ;; where to load the real thing.
        (call-with-output-file grub-config
          (lambda (port)
            (format port
                    "insmod part_msdos~@
                    search --set=root --label GuixSD~@
                    configfile /boot/grub/grub.cfg~%")))

        (display "creating EFI firmware image...")
        (install-efi grub-efi mount-point grub-config)
        (display "done.\n")

        (delete-file grub-config)
        (umount mount-point)))

    ;; Register BOOTCFG as a GC root.
    (register-bootcfg-root target bootcfg)

    (umount target)))

;;; vm.scm ends here