guix/gnu/system/vm.scm
Ludovic Courtès 56f9d442e0
vm: Use a deterministic file system UUID in shared-store VMs.
* gnu/system/vm.scm (system-qemu-image/shared-store): Pass
 #:file-system-uuid to 'qemu-image'.
2018-05-23 10:21:02 +02:00

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;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013, 2014, 2015, 2016, 2017, 2018 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2016 Christopher Allan Webber <cwebber@dustycloud.org>
;;; Copyright © 2016, 2017 Leo Famulari <leo@famulari.name>
;;; Copyright © 2017 Mathieu Othacehe <m.othacehe@gmail.com>
;;; Copyright © 2017 Marius Bakke <mbakke@fastmail.com>
;;; Copyright © 2018 Chris Marusich <cmmarusich@gmail.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 system vm)
#:use-module (guix config)
#:use-module (guix docker)
#:use-module (guix store)
#:use-module (guix gexp)
#:use-module (guix derivations)
#:use-module (guix packages)
#:use-module (guix monads)
#:use-module (guix records)
#:use-module (guix modules)
#:use-module (guix scripts pack)
#:use-module (guix utils)
#:use-module (guix hash)
#:use-module (guix base32)
#:use-module ((gnu build vm)
#:select (qemu-command))
#:use-module (gnu packages base)
#:use-module (gnu packages bootloaders)
#:use-module (gnu packages cdrom)
#:use-module (gnu packages compression)
#:use-module (gnu packages guile)
#:autoload (gnu packages gnupg) (libgcrypt)
#:use-module (gnu packages gawk)
#:use-module (gnu packages bash)
#:use-module (gnu packages less)
#:use-module (gnu packages virtualization)
#:use-module (gnu packages disk)
#:use-module (gnu packages zile)
#:use-module (gnu packages linux)
#:use-module (gnu packages package-management)
#:use-module ((gnu packages make-bootstrap)
#:select (%guile-static-stripped))
#:use-module (gnu packages admin)
#:use-module (gnu bootloader)
#:use-module (gnu bootloader grub)
#:use-module (gnu system shadow)
#:use-module (gnu system pam)
#:use-module (gnu system linux-initrd)
#:use-module (gnu bootloader)
#:use-module (gnu system file-systems)
#:use-module (gnu system)
#:use-module (gnu services)
#:use-module (gnu system uuid)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-26)
#:use-module (rnrs bytevectors)
#:use-module (ice-9 match)
#:export (expression->derivation-in-linux-vm
qemu-image
virtualized-operating-system
system-qemu-image
system-qemu-image/shared-store
system-qemu-image/shared-store-script
system-disk-image
system-docker-image
virtual-machine
virtual-machine?))
;;; Commentary:
;;;
;;; Tools to evaluate build expressions within virtual machines.
;;;
;;; Code:
(define %linux-vm-file-systems
;; File systems mounted for 'derivation-in-linux-vm'. These are shared with
;; the host over 9p.
(list (file-system
(mount-point (%store-prefix))
(device "store")
(type "9p")
(needed-for-boot? #t)
(options "trans=virtio")
(check? #f))
(file-system
(mount-point "/xchg")
(device "xchg")
(type "9p")
(needed-for-boot? #t)
(options "trans=virtio")
(check? #f))
(file-system
(mount-point "/tmp")
(device "tmp")
(type "9p")
(needed-for-boot? #t)
(options "trans=virtio")
(check? #f))))
(define* (expression->derivation-in-linux-vm name exp
#:key
(system (%current-system))
(linux linux-libre)
initrd
(qemu qemu-minimal)
(env-vars '())
(guile-for-build
(%guile-for-build))
(single-file-output? #f)
(make-disk-image? #f)
(references-graphs #f)
(memory-size 256)
(disk-image-format "qcow2")
(disk-image-size 'guess))
"Evaluate EXP in a QEMU virtual machine running LINUX with INITRD (a
derivation). The virtual machine runs with MEMORY-SIZE MiB of memory. In the
virtual machine, EXP has access to all its inputs from the store; it should
put its output file(s) in the '/xchg' directory.
If SINGLE-FILE-OUTPUT? is true, copy a single file from '/xchg' to OUTPUT.
Otherwise, copy the contents of /xchg to a new directory OUTPUT.
When MAKE-DISK-IMAGE? is true, then create a QEMU disk image of type
DISK-IMAGE-FORMAT (e.g., 'qcow2' or 'raw'), of DISK-IMAGE-SIZE bytes and
return it. When DISK-IMAGE-SIZE is 'guess, estimate the image size based
based on the size of the closure of REFERENCES-GRAPHS.
When REFERENCES-GRAPHS is true, it must be a list of file name/store path
pairs, as for `derivation'. The files containing the reference graphs are
made available under the /xchg CIFS share."
(mlet* %store-monad
((user-builder (gexp->file "builder-in-linux-vm" exp))
(loader (gexp->file "linux-vm-loader"
#~(primitive-load #$user-builder)))
(coreutils -> (canonical-package coreutils))
(initrd (if initrd ; use the default initrd?
(return initrd)
(base-initrd %linux-vm-file-systems
#:on-error 'backtrace
#:linux linux
#:linux-modules %base-initrd-modules
#:qemu-networking? #t))))
(define builder
;; Code that launches the VM that evaluates EXP.
(with-imported-modules (source-module-closure '((guix build utils)
(gnu build vm)))
#~(begin
(use-modules (guix build utils)
(gnu build vm))
(let* ((inputs '#$(list qemu coreutils))
(linux (string-append #$linux "/"
#$(system-linux-image-file-name)))
(initrd (string-append #$initrd "/initrd"))
(loader #$loader)
(graphs '#$(match references-graphs
(((graph-files . _) ...) graph-files)
(_ #f)))
(size #$(if (eq? 'guess disk-image-size)
#~(+ (* 70 (expt 2 20)) ;ESP
(estimated-partition-size graphs))
disk-image-size)))
(set-path-environment-variable "PATH" '("bin") inputs)
(load-in-linux-vm loader
#:output #$output
#:linux linux #:initrd initrd
#:memory-size #$memory-size
#:make-disk-image? #$make-disk-image?
#:single-file-output? #$single-file-output?
;; FIXME: target-arm32? may not operate on
;; the right system/target values. Rewrite
;; using let-system when available.
#:target-arm32? #$(target-arm32?)
#:disk-image-format #$disk-image-format
#:disk-image-size size
#:references-graphs graphs)))))
(gexp->derivation name builder
;; TODO: Require the "kvm" feature.
#:system system
#:env-vars env-vars
#:guile-for-build guile-for-build
#:references-graphs references-graphs)))
(define* (iso9660-image #:key
(name "iso9660-image")
file-system-label
file-system-uuid
(system (%current-system))
(qemu qemu-minimal)
os-drv
bootcfg-drv
bootloader
register-closures?
(inputs '()))
"Return a bootable, stand-alone iso9660 image.
INPUTS is a list of inputs (as for packages)."
(expression->derivation-in-linux-vm
name
(with-imported-modules (source-module-closure '((gnu build vm)
(guix build utils)))
#~(begin
(use-modules (gnu build vm)
(guix build utils))
(let ((inputs
'#$(append (list qemu parted e2fsprogs dosfstools xorriso)
(map canonical-package
(list sed grep coreutils findutils gawk))
(if register-closures? (list guix) '())))
(graphs '#$(match inputs
(((names . _) ...)
names)))
;; This variable is unused but allows us to add INPUTS-TO-COPY
;; as inputs.
(to-register
'#$(map (match-lambda
((name thing) thing)
((name thing output) `(,thing ,output)))
inputs)))
(set-path-environment-variable "PATH" '("bin" "sbin") inputs)
(make-iso9660-image #$(bootloader-package bootloader)
#$bootcfg-drv
#$os-drv
"/xchg/guixsd.iso"
#:register-closures? #$register-closures?
#:closures graphs
#:volume-id #$file-system-label
#:volume-uuid #$(and=> file-system-uuid
uuid-bytevector))
(reboot))))
#:system system
#:make-disk-image? #f
#:single-file-output? #t
#:references-graphs inputs))
(define* (qemu-image #:key
(name "qemu-image")
(system (%current-system))
(qemu qemu-minimal)
(disk-image-size 'guess)
(disk-image-format "qcow2")
(file-system-type "ext4")
file-system-label
file-system-uuid
os-drv
bootcfg-drv
bootloader
(register-closures? #t)
(inputs '())
copy-inputs?)
"Return a bootable, stand-alone QEMU image of type DISK-IMAGE-FORMAT (e.g.,
'qcow2' or 'raw'), with a root partition of type FILE-SYSTEM-TYPE.
Optionally, FILE-SYSTEM-LABEL can be specified as the volume name for the root
partition; likewise FILE-SYSTEM-UUID, if true, specifies the UUID of the root
partition (a UUID object).
The returned image is a full disk image that runs OS-DERIVATION,
with a GRUB installation that uses GRUB-CONFIGURATION as its configuration
file (GRUB-CONFIGURATION must be the name of a file in the VM.)
INPUTS is a list of inputs (as for packages). When COPY-INPUTS? is true, copy
all of INPUTS into the image being built. When REGISTER-CLOSURES? is true,
register INPUTS in the store database of the image so that Guix can be used in
the image."
(expression->derivation-in-linux-vm
name
(with-imported-modules (source-module-closure '((gnu build bootloader)
(gnu build vm)
(guix build utils)))
#~(begin
(use-modules (gnu build bootloader)
(gnu build vm)
(guix build utils)
(srfi srfi-26)
(ice-9 binary-ports))
(let ((inputs
'#$(append (list qemu parted e2fsprogs dosfstools)
(map canonical-package
(list sed grep coreutils findutils gawk))
(if register-closures? (list guix) '())))
;; This variable is unused but allows us to add INPUTS-TO-COPY
;; as inputs.
(to-register
'#$(map (match-lambda
((name thing) thing)
((name thing output) `(,thing ,output)))
inputs)))
(set-path-environment-variable "PATH" '("bin" "sbin") inputs)
(let* ((graphs '#$(match inputs
(((names . _) ...)
names)))
(initialize (root-partition-initializer
#:closures graphs
#:copy-closures? #$copy-inputs?
#:register-closures? #$register-closures?
#:system-directory #$os-drv))
(root-size #$(if (eq? 'guess disk-image-size)
#~(max
;; Minimum 20 MiB root size
(* 20 (expt 2 20))
(estimated-partition-size
(map (cut string-append "/xchg/" <>)
graphs)))
(- disk-image-size
(* 50 (expt 2 20)))))
(partitions
(append
(list (partition
(size root-size)
(label #$file-system-label)
(uuid #$(and=> file-system-uuid
uuid-bytevector))
(file-system #$file-system-type)
(flags '(boot))
(initializer initialize)))
;; Append a small EFI System Partition for use with UEFI
;; bootloaders if we are not targeting ARM because UEFI
;; support in U-Boot is experimental.
;;
;; FIXME: target-arm32? may be not operate on the right
;; system/target values. Rewrite using let-system when
;; available.
(if #$(target-arm32?)
'()
(list (partition
;; The standalone grub image is about 10MiB, but
;; leave some room for custom or multiple images.
(size (* 40 (expt 2 20)))
(label "GNU-ESP") ;cosmetic only
;; Use "vfat" here since this property is used
;; when mounting. The actual FAT-ness is based
;; on file system size (16 in this case).
(file-system "vfat")
(flags '(esp))))))))
(initialize-hard-disk "/dev/vda"
#:partitions partitions
#:grub-efi #$grub-efi
#:bootloader-package
#$(bootloader-package bootloader)
#:bootcfg #$bootcfg-drv
#:bootcfg-location
#$(bootloader-configuration-file bootloader)
#:bootloader-installer
#$(bootloader-installer bootloader))
(reboot)))))
#:system system
#:make-disk-image? #t
#:disk-image-size disk-image-size
#:disk-image-format disk-image-format
#:references-graphs inputs))
(define* (system-docker-image os
#:key
(name "guixsd-docker-image")
register-closures?)
"Build a docker image. OS is the desired <operating-system>. NAME is the
base name to use for the output file. When REGISTER-CLOSURES? is not #f,
register the closure of OS with Guix in the resulting Docker image. This only
makes sense when you want to build a GuixSD Docker image that has Guix
installed inside of it. If you don't need Guix (e.g., your GuixSD Docker
image just contains a web server that is started by the Shepherd), then you
should set REGISTER-CLOSURES? to #f."
(define not-config?
(match-lambda
(('guix 'config) #f)
(('guix rest ...) #t)
(('gnu rest ...) #t)
(rest #f)))
(define config
;; (guix config) module for consumption by (guix gcrypt).
(scheme-file "gcrypt-config.scm"
#~(begin
(define-module (guix config)
#:export (%libgcrypt))
;; XXX: Work around <http://bugs.gnu.org/15602>.
(eval-when (expand load eval)
(define %libgcrypt
#+(file-append libgcrypt "/lib/libgcrypt"))))))
(mlet %store-monad ((os-drv (operating-system-derivation os #:container? #t))
(name -> (string-append name ".tar.gz"))
(graph -> "system-graph"))
(define build
(with-imported-modules `(,@(source-module-closure '((guix docker)
(guix build utils)
(gnu build vm))
#:select? not-config?)
(guix build store-copy)
((guix config) => ,config))
#~(begin
;; Guile-JSON is required by (guix docker).
(add-to-load-path
(string-append #+guile-json "/share/guile/site/"
(effective-version)))
(use-modules (guix docker)
(guix build utils)
(gnu build vm)
(srfi srfi-19)
(guix build store-copy))
(let* ((inputs '#$(append (list tar)
(if register-closures?
(list guix)
'())))
;; This initializer requires elevated privileges that are
;; not normally available in the build environment (e.g.,
;; it needs to create device nodes). In order to obtain
;; such privileges, we run it as root in a VM.
(initialize (root-partition-initializer
#:closures '(#$graph)
#:register-closures? #$register-closures?
#:system-directory #$os-drv
;; De-duplication would fail due to
;; cross-device link errors, so don't do it.
#:deduplicate? #f))
;; Even as root in a VM, the initializer would fail due to
;; lack of privileges if we use a root-directory that is on
;; a file system that is shared with the host (e.g., /tmp).
(root-directory "/guixsd-system-root"))
(set-path-environment-variable "PATH" '("bin" "sbin") inputs)
(mkdir root-directory)
(initialize root-directory)
(build-docker-image
(string-append "/xchg/" #$name) ;; The output file.
(cons* root-directory
(call-with-input-file (string-append "/xchg/" #$graph)
read-reference-graph))
#$os-drv
#:compressor '(#+(file-append gzip "/bin/gzip") "-9n")
#:creation-time (make-time time-utc 0 1)
#:transformations `((,root-directory -> "")))))))
(expression->derivation-in-linux-vm
name
;; The VM's initrd Guile doesn't support dlopen, but our "build" gexp
;; needs to be run by a Guile that can dlopen libgcrypt. The following
;; hack works around that problem by putting the "build" gexp into an
;; executable script (created by program-file) which, when executed, will
;; run using a Guile that supports dlopen. That way, the VM's initrd
;; Guile can just execute it via invoke, without using dlopen. See:
;; https://lists.gnu.org/archive/html/guix-devel/2017-10/msg00233.html
(with-imported-modules `((guix build utils))
#~(begin
(use-modules (guix build utils))
;; If we use execl instead of invoke here, the VM will crash with a
;; kernel panic.
(invoke #$(program-file "build-docker-image" build))))
#:make-disk-image? #f
#:single-file-output? #t
#:references-graphs `((,graph ,os-drv)))))
;;;
;;; VM and disk images.
;;;
(define* (operating-system-uuid os #:optional (type 'dce))
"Compute UUID object with a deterministic \"UUID\" for OS, of the given
TYPE (one of 'iso9660 or 'dce). Return a UUID object."
(if (eq? type 'iso9660)
(let ((pad (compose (cut string-pad <> 2 #\0)
number->string))
(h (hash (operating-system-services os) 3600)))
(bytevector->uuid
(string->iso9660-uuid
(string-append "1970-01-01-"
(pad (hash (operating-system-host-name os) 24)) "-"
(pad (quotient h 60)) "-"
(pad (modulo h 60)) "-"
(pad (hash (operating-system-file-systems os) 100))))
'iso9660))
(bytevector->uuid
(uint-list->bytevector
(list (hash file-system-type
(- (expt 2 32) 1))
(hash (operating-system-host-name os)
(- (expt 2 32) 1))
(hash (operating-system-services os)
(- (expt 2 32) 1))
(hash (operating-system-file-systems os)
(- (expt 2 32) 1)))
(endianness little)
4)
type)))
(define* (system-disk-image os
#:key
(name "disk-image")
(file-system-type "ext4")
(disk-image-size (* 900 (expt 2 20)))
(volatile? #t))
"Return the derivation of a disk image of DISK-IMAGE-SIZE bytes of the
system described by OS. Said image can be copied on a USB stick as is. When
VOLATILE? is true, the root file system is made volatile; this is useful
to USB sticks meant to be read-only."
(define normalize-label
;; ISO labels are all-caps (case-insensitive), but since
;; 'find-partition-by-label' is case-sensitive, make it all-caps here.
(if (string=? "iso9660" file-system-type)
string-upcase
identity))
(define root-label
;; Volume name of the root file system.
(normalize-label "GuixSD_image"))
(define root-uuid
;; UUID of the root file system, computed in a deterministic fashion.
;; This is what we use to locate the root file system so it has to be
;; different from the user's own file system UUIDs.
(operating-system-uuid os
(if (string=? file-system-type "iso9660")
'iso9660
'dce)))
(define file-systems-to-keep
(remove (lambda (fs)
(string=? (file-system-mount-point fs) "/"))
(operating-system-file-systems os)))
(let ((os (operating-system (inherit os)
;; Since this is meant to be used on real hardware, don't
;; install QEMU networking or anything like that. Assume USB
;; mass storage devices (usb-storage.ko) are available.
(initrd (lambda (file-systems . rest)
(apply (operating-system-initrd os)
file-systems
#:volatile-root? #t
rest)))
(bootloader (if (string=? "iso9660" file-system-type)
(bootloader-configuration
(inherit (operating-system-bootloader os))
(bootloader grub-mkrescue-bootloader))
(operating-system-bootloader os)))
;; Force our own root file system.
(file-systems (cons (file-system
(mount-point "/")
(device root-uuid)
(title 'uuid)
(type file-system-type))
file-systems-to-keep)))))
(mlet* %store-monad ((os-drv (operating-system-derivation os))
(bootcfg (operating-system-bootcfg os)))
(if (string=? "iso9660" file-system-type)
(iso9660-image #:name name
#:file-system-label root-label
#:file-system-uuid root-uuid
#:os-drv os-drv
#:register-closures? #t
#:bootcfg-drv bootcfg
#:bootloader (bootloader-configuration-bootloader
(operating-system-bootloader os))
#:inputs `(("system" ,os-drv)
("bootcfg" ,bootcfg)))
(qemu-image #:name name
#:os-drv os-drv
#:bootcfg-drv bootcfg
#:bootloader (bootloader-configuration-bootloader
(operating-system-bootloader os))
#:disk-image-size disk-image-size
#:disk-image-format "raw"
#:file-system-type file-system-type
#:file-system-label root-label
#:file-system-uuid root-uuid
#:copy-inputs? #t
#:register-closures? #t
#:inputs `(("system" ,os-drv)
("bootcfg" ,bootcfg)))))))
(define* (system-qemu-image os
#:key
(file-system-type "ext4")
(disk-image-size (* 900 (expt 2 20))))
"Return the derivation of a freestanding QEMU image of DISK-IMAGE-SIZE bytes
of the GNU system as described by OS."
(define file-systems-to-keep
;; Keep only file systems other than root and not normally bound to real
;; devices.
(remove (lambda (fs)
(let ((target (file-system-mount-point fs))
(source (file-system-device fs)))
(or (string=? target "/")
(string-prefix? "/dev/" source))))
(operating-system-file-systems os)))
(define root-uuid
;; UUID of the root file system.
(operating-system-uuid os
(if (string=? file-system-type "iso9660")
'iso9660
'dce)))
(let ((os (operating-system (inherit os)
;; Assume we have an initrd with the whole QEMU shebang.
;; Force our own root file system. Refer to it by UUID so that
;; it works regardless of how the image is used ("qemu -hda",
;; Xen, etc.).
(file-systems (cons (file-system
(mount-point "/")
(device root-uuid)
(title 'uuid)
(type file-system-type))
file-systems-to-keep)))))
(mlet* %store-monad
((os-drv (operating-system-derivation os))
(bootcfg (operating-system-bootcfg os)))
(qemu-image #:os-drv os-drv
#:bootcfg-drv bootcfg
#:bootloader (bootloader-configuration-bootloader
(operating-system-bootloader os))
#:disk-image-size disk-image-size
#:file-system-type file-system-type
#:file-system-uuid root-uuid
#:inputs `(("system" ,os-drv)
("bootcfg" ,bootcfg))
#:copy-inputs? #t))))
;;;
;;; VMs that share file systems with the host.
;;;
(define (file-system->mount-tag fs)
"Return a 9p mount tag for host file system FS."
;; QEMU mount tags must be ASCII, at most 31-byte long, cannot contain
;; slashes, and cannot start with '_'. Compute an identifier that
;; corresponds to the rules.
(string-append "TAG"
(string-drop (bytevector->base32-string
(sha1 (string->utf8 fs)))
4)))
(define (mapping->file-system mapping)
"Return a 9p file system that realizes MAPPING."
(match mapping
(($ <file-system-mapping> source target writable?)
(file-system
(mount-point target)
(device (file-system->mount-tag source))
(type "9p")
(flags (if writable? '() '(read-only)))
(options "trans=virtio,cache=loose")
(check? #f)
(create-mount-point? #t)))))
(define* (virtualized-operating-system os mappings #:optional (full-boot? #f))
"Return an operating system based on OS suitable for use in a virtualized
environment with the store shared with the host. MAPPINGS is a list of
<file-system-mapping> to realize in the virtualized OS."
(define user-file-systems
;; Remove file systems that conflict with those added below, or that are
;; normally bound to real devices.
(remove (lambda (fs)
(let ((target (file-system-mount-point fs))
(source (file-system-device fs)))
(or (string=? target (%store-prefix))
(string=? target "/")
(and (eq? 'device (file-system-title fs))
(string-prefix? "/dev/" source))
;; Labels and UUIDs are necessarily invalid in the VM.
(and (file-system-mount? fs)
(or (eq? 'label (file-system-title fs))
(eq? 'uuid (file-system-title fs))
(uuid? source))))))
(operating-system-file-systems os)))
(define virtual-file-systems
(cons (file-system
(mount-point "/")
(device "/dev/vda1")
(type "ext4"))
(append (map mapping->file-system mappings)
user-file-systems)))
(operating-system (inherit os)
;; XXX: Until we run QEMU with UEFI support (with the OVMF firmware),
;; force the traditional i386/BIOS method.
;; See <https://bugs.gnu.org/28768>.
(bootloader (bootloader-configuration
(bootloader grub-bootloader)
(target "/dev/vda")))
(initrd (lambda (file-systems . rest)
(apply (operating-system-initrd os)
file-systems
#:volatile-root? #t
rest)))
;; Disable swap.
(swap-devices '())
;; XXX: When FULL-BOOT? is true, do not add a 9p mount for /gnu/store
;; since that would lead the bootloader config to look for the kernel and
;; initrd in it.
(file-systems (if full-boot?
virtual-file-systems
(cons
(file-system
(inherit (mapping->file-system %store-mapping))
(needed-for-boot? #t))
virtual-file-systems)))))
(define* (system-qemu-image/shared-store
os
#:key
full-boot?
(disk-image-size (* (if full-boot? 500 30) (expt 2 20))))
"Return a derivation that builds a QEMU image of OS that shares its store
with the host.
When FULL-BOOT? is true, return an image that does a complete boot sequence,
bootloaded included; thus, make a disk image that contains everything the
bootloader refers to: OS kernel, initrd, bootloader data, etc."
(define root-uuid
;; Use a fixed UUID to improve determinism.
(operating-system-uuid os 'dce))
(mlet* %store-monad ((os-drv (operating-system-derivation os))
(bootcfg (operating-system-bootcfg os)))
;; XXX: When FULL-BOOT? is true, we end up creating an image that contains
;; BOOTCFG and all its dependencies, including the output of OS-DRV.
;; This is more than needed (we only need the kernel, initrd, GRUB for its
;; font, and the background image), but it's hard to filter that.
(qemu-image #:os-drv os-drv
#:bootcfg-drv bootcfg
#:bootloader (bootloader-configuration-bootloader
(operating-system-bootloader os))
#:disk-image-size disk-image-size
#:file-system-uuid root-uuid
#:inputs (if full-boot?
`(("bootcfg" ,bootcfg))
'())
;; XXX: Passing #t here is too slow, so let it off by default.
#:register-closures? #f
#:copy-inputs? full-boot?)))
(define* (common-qemu-options image shared-fs)
"Return the a string-value gexp with the common QEMU options to boot IMAGE,
with '-virtfs' options for the host file systems listed in SHARED-FS."
(define (virtfs-option fs)
#~(format #f "-virtfs local,path=~s,security_model=none,mount_tag=~s"
#$fs #$(file-system->mount-tag fs)))
#~(;; Only enable kvm if we see /dev/kvm exists.
;; This allows users without hardware virtualization to still use these
;; commands.
#$@(if (file-exists? "/dev/kvm")
'("-enable-kvm")
'())
"-no-reboot"
"-net nic,model=virtio"
"-object" "rng-random,filename=/dev/urandom,id=guixsd-vm-rng"
"-device" "virtio-rng-pci,rng=guixsd-vm-rng"
#$@(map virtfs-option shared-fs)
"-vga std"
(format #f "-drive file=~a,if=virtio,cache=writeback,werror=report,readonly"
#$image)))
(define* (system-qemu-image/shared-store-script os
#:key
(qemu qemu)
(graphic? #t)
(memory-size 256)
(mappings '())
full-boot?
(disk-image-size
(* (if full-boot? 500 70)
(expt 2 20)))
(options '()))
"Return a derivation that builds a script to run a virtual machine image of
OS that shares its store with the host. The virtual machine runs with
MEMORY-SIZE MiB of memory.
MAPPINGS is a list of <file-system-mapping> specifying mapping of host file
systems into the guest.
When FULL-BOOT? is true, the returned script runs everything starting from the
bootloader; otherwise it directly starts the operating system kernel. The
DISK-IMAGE-SIZE parameter specifies the size in bytes of the root disk image;
it is mostly useful when FULL-BOOT? is true."
(mlet* %store-monad ((os -> (virtualized-operating-system os mappings full-boot?))
(os-drv (operating-system-derivation os))
(image (system-qemu-image/shared-store
os
#:full-boot? full-boot?
#:disk-image-size disk-image-size)))
(define kernel-arguments
#~(list #$@(if graphic? #~() #~("console=ttyS0"))
#+@(operating-system-kernel-arguments os os-drv "/dev/vda1")))
(define qemu-exec
#~(list (string-append #$qemu "/bin/" #$(qemu-command (%current-system)))
#$@(if full-boot?
#~()
#~("-kernel" #$(operating-system-kernel-file os)
"-initrd" #$(file-append os-drv "/initrd")
(format #f "-append ~s"
(string-join #$kernel-arguments " "))))
#$@(common-qemu-options image
(map file-system-mapping-source
(cons %store-mapping mappings)))
"-m " (number->string #$memory-size)
#$@options))
(define builder
#~(call-with-output-file #$output
(lambda (port)
(format port "#!~a~% exec ~a \"$@\"~%"
#$(file-append bash "/bin/sh")
(string-join #$qemu-exec " "))
(chmod port #o555))))
(gexp->derivation "run-vm.sh" builder)))
;;;
;;; High-level abstraction.
;;;
(define-record-type* <virtual-machine> %virtual-machine
make-virtual-machine
virtual-machine?
(operating-system virtual-machine-operating-system) ;<operating-system>
(qemu virtual-machine-qemu ;<package>
(default qemu))
(graphic? virtual-machine-graphic? ;Boolean
(default #f))
(memory-size virtual-machine-memory-size ;integer (MiB)
(default 256))
(disk-image-size virtual-machine-disk-image-size ;integer (bytes)
(default 'guess))
(port-forwardings virtual-machine-port-forwardings ;list of integer pairs
(default '())))
(define-syntax virtual-machine
(syntax-rules ()
"Declare a virtual machine running the specified OS, with the given
options."
((_ os) ;shortcut
(%virtual-machine (operating-system os)))
((_ fields ...)
(%virtual-machine fields ...))))
(define (port-forwardings->qemu-options forwardings)
"Return the QEMU option for the given port FORWARDINGS as a string, where
FORWARDINGS is a list of host-port/guest-port pairs."
(string-join
(map (match-lambda
((host-port . guest-port)
(string-append "hostfwd=tcp::"
(number->string host-port)
"-:" (number->string guest-port))))
forwardings)
","))
(define-gexp-compiler (virtual-machine-compiler (vm <virtual-machine>)
system target)
;; XXX: SYSTEM and TARGET are ignored.
(match vm
(($ <virtual-machine> os qemu graphic? memory-size disk-image-size ())
(system-qemu-image/shared-store-script os
#:qemu qemu
#:graphic? graphic?
#:memory-size memory-size
#:disk-image-size
disk-image-size))
(($ <virtual-machine> os qemu graphic? memory-size disk-image-size
forwardings)
(let ((options
`("-net" ,(string-append
"user,"
(port-forwardings->qemu-options forwardings)))))
(system-qemu-image/shared-store-script os
#:qemu qemu
#:graphic? graphic?
#:memory-size memory-size
#:disk-image-size
disk-image-size
#:options options)))))
;;; vm.scm ends here