<
aboutsummaryrefslogtreecommitdiff
blob: 60ee18ebe076f1ec2fc60edf62d0bcc2278666dc (about) (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
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013, 2014, 2015, 2016 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2016 Christopher Allan Webber <cwebber@dustycloud.org>
;;; Copyright © 2016 Leo Famulari <leo@famulari.name>
;;;
;;; 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 (gnu build linux-boot)
  #:use-module (gnu build install)
  #:use-module (guix records)
  #: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-bootable?
            partition-initializer

            root-partition-initializer
            initialize-partition-table
            initialize-hard-disk))

;;; 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)
                           (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 MiB 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?
    (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))
  (bootable?   partition-bootable? (default #f))
  (initializer partition-initializer (default (const #t))))

(define (fold2 proc seed1 seed2 lst)              ;TODO: factorize
  "Like `fold', but with a single list and two seeds."
  (let loop ((result1 seed1)
             (result2 seed2)
             (lst     lst))
    (if (null? lst)
        (values result1 result2)
        (call-with-values
            (lambda () (proc (car lst) result1 result2))
          (lambda (result1 result2)
            (loop result1 result2 (cdr lst)))))))

(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)))
           (if (partition-bootable? part)
               `("set" ,(number->string index) "boot" "on")
               '())))

  (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...\n"
          (length 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* (format-partition partition type
                           #:key label)
  "Create a file system 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 (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-grub.cfg-root target grub.cfg)
  "On file system TARGET, register GRUB.CFG as a GC root."
  (let ((directory (string-append target "/var/guix/gcroots")))
    (mkdir-p directory)
    (symlink grub.cfg (string-append directory "/grub.cfg"))))

(define* (initialize-hard-disk device
                               #:key
                               grub.cfg
                               (partitions '()))
  "Initialize DEVICE as a disk containing all the <partition> objects listed
in PARTITIONS, and using GRUB.CFG as its bootloader configuration file.

Each partition is initialized by calling its 'initializer' procedure,
passing it a directory name where it is mounted."
  (let* ((partitions (initialize-partition-table device partitions))
         (root       (find partition-bootable? 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-grub grub.cfg device target)

    ;; Register GRUB.CFG as a GC root.
    (register-grub.cfg-root target grub.cfg)

    (umount target)))

;;; vm.scm ends here