guix-devel/gnu/build/vm.scm

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;;; 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