f5c3f8e59e
This is a followup to 05a9d1f378, which
removed its sole user.
* gnu/system/vm.scm (%linux-vm-file-systems): Remove.
(mapping->file-system): Add comment about “cache=loose”.
377 lines
16 KiB
Scheme
377 lines
16 KiB
Scheme
;;; GNU Guix --- Functional package management for GNU
|
||
;;; Copyright © 2013-2022 Ludovic Courtès <ludo@gnu.org>
|
||
;;; Copyright © 2016 Christine Lemmer-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 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 utils)
|
||
#:use-module (gcrypt hash)
|
||
#:use-module (guix base32)
|
||
#:use-module ((guix self) #:select (make-config.scm))
|
||
|
||
#:use-module ((gnu build marionette)
|
||
#: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) (guile-gcrypt)
|
||
#:use-module (gnu packages gawk)
|
||
#:use-module (gnu packages bash)
|
||
#:use-module (gnu packages virtualization)
|
||
#:use-module (gnu packages disk)
|
||
#:use-module (gnu packages linux)
|
||
|
||
#:use-module (gnu bootloader)
|
||
#:use-module (gnu bootloader grub)
|
||
#:use-module (gnu image)
|
||
#:use-module (gnu system image)
|
||
#:use-module (gnu system linux-container)
|
||
#: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 services base)
|
||
#:use-module (gnu system uuid)
|
||
|
||
#:use-module ((srfi srfi-1) #:hide (partition))
|
||
#:use-module (srfi srfi-26)
|
||
#:use-module (rnrs bytevectors)
|
||
#:use-module (ice-9 match)
|
||
|
||
#:export (virtualized-operating-system
|
||
system-qemu-image/shared-store-script
|
||
|
||
virtual-machine
|
||
virtual-machine?))
|
||
|
||
|
||
;;; Commentary:
|
||
;;;
|
||
;;; Tools to evaluate build expressions within virtual machines.
|
||
;;;
|
||
;;; Code:
|
||
|
||
;; By default, the msize value is 8 KiB, which according to QEMU is
|
||
;; insufficient and would degrade performance. The msize value should roughly
|
||
;; match the bandwidth of the system's IO (see:
|
||
;; https://wiki.qemu.org/Documentation/9psetup#msize). Use 100 MiB as a
|
||
;; conservative default.
|
||
(define %default-msize-value (* 100 (expt 2 20))) ;100 MiB
|
||
|
||
;;;
|
||
;;; 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)))
|
||
|
||
;; The 9p documentation says that cache=loose is "intended for
|
||
;; exclusive, read-only mounts", without additional details. It's
|
||
;; faster than the default cache=none, especially when copying and
|
||
;; registering store items. Thus, use cache=loose, except for writable
|
||
;; mounts, to ensure consistency.
|
||
(options (string-append "trans=virtio"
|
||
(if writable? "" ",cache=loose")
|
||
",msize=" (number->string %default-msize-value)))
|
||
(check? #f)
|
||
(create-mount-point? #t)))))
|
||
|
||
(define* (virtualized-operating-system os mappings
|
||
#:key (full-boot? #f) volatile?)
|
||
"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 (string? source)
|
||
(string-prefix? "/dev/" source))
|
||
|
||
;; Labels and UUIDs are necessarily invalid in the VM.
|
||
(and (file-system-mount? fs)
|
||
(or (file-system-label? source)
|
||
(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
|
||
(inherit (operating-system-bootloader os))
|
||
(bootloader grub-bootloader)
|
||
(targets '("/dev/vda"))))
|
||
|
||
(initrd (lambda (file-systems . rest)
|
||
(apply (operating-system-initrd os)
|
||
file-systems
|
||
#:volatile-root? volatile?
|
||
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* (common-qemu-options image shared-fs
|
||
#:key rw-image?)
|
||
"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.
|
||
#$@(if (file-exists? "/dev/kvm")
|
||
'("-enable-kvm")
|
||
'())
|
||
|
||
"-no-reboot"
|
||
"-object" "rng-random,filename=/dev/urandom,id=guix-vm-rng"
|
||
"-device" "virtio-rng-pci,rng=guix-vm-rng"
|
||
|
||
#$@(map virtfs-option shared-fs)
|
||
#$@(if rw-image?
|
||
#~((format #f "-drive file=~a,format=qcow2,if=virtio" #$image))
|
||
#~((format #f "-drive file=~a,format=raw,if=virtio,cache=writeback,werror=report,readonly=on"
|
||
#$image)))))
|
||
|
||
(define* (system-qemu-image/shared-store-script os
|
||
#:key
|
||
(system (%current-system))
|
||
(target (%current-target-system))
|
||
(qemu qemu)
|
||
(graphic? #t)
|
||
(volatile? #t)
|
||
(memory-size 512)
|
||
(mappings '())
|
||
full-boot?
|
||
(disk-image-size
|
||
(* (if full-boot? 500 70)
|
||
(expt 2 20)))
|
||
(options '()))
|
||
"Return a derivation that builds a script to run a virtual machine image of
|
||
OS that shares its store with the host. The virtual machine runs with
|
||
MEMORY-SIZE MiB of memory.
|
||
|
||
MAPPINGS is a list of <file-system-mapping> specifying mapping of host file
|
||
systems into the guest.
|
||
|
||
When FULL-BOOT? is true, the returned script runs everything starting from the
|
||
bootloader; otherwise it directly starts the operating system kernel. When
|
||
VOLATILE? is true, an overlay is created on top of a read-only
|
||
storage. Otherwise the storage is made persistent. The DISK-IMAGE-SIZE
|
||
parameter specifies the size in bytes of the root disk image; it is mostly
|
||
useful when FULL-BOOT? is true."
|
||
(mlet* %store-monad ((os -> (virtualized-operating-system
|
||
os mappings
|
||
#:full-boot? full-boot?
|
||
#:volatile? volatile?))
|
||
(base-image -> (system-image
|
||
(image
|
||
(inherit
|
||
(raw-with-offset-disk-image))
|
||
(operating-system os)
|
||
(size disk-image-size)
|
||
(shared-store?
|
||
(and (not full-boot?) volatile?))
|
||
(volatile-root? volatile?)))))
|
||
(define kernel-arguments
|
||
#~(list #$@(if graphic? #~() #~("console=ttyS0"))
|
||
#+@(operating-system-kernel-arguments os "/dev/vda1")))
|
||
|
||
(define rw-image
|
||
#~(format #f "/tmp/guix-image-~a" (basename #$base-image)))
|
||
|
||
(define qemu-exec
|
||
#~(list #+(file-append qemu "/bin/"
|
||
(qemu-command (or target system)))
|
||
;; Tells qemu to use the terminal it was started in for IO.
|
||
#$@(if graphic? '() #~("-nographic"))
|
||
#$@(if full-boot?
|
||
#~()
|
||
#~("-kernel" #$(operating-system-kernel-file os)
|
||
"-initrd" #$(file-append os "/initrd")
|
||
(format #f "-append ~s"
|
||
(string-join #$kernel-arguments " "))))
|
||
#$@(common-qemu-options (if volatile? base-image rw-image)
|
||
(map file-system-mapping-source
|
||
(cons %store-mapping mappings))
|
||
#:rw-image? (not volatile?))
|
||
"-m " (number->string #$memory-size)
|
||
#$@options))
|
||
|
||
(define copy-image
|
||
;; Script that "copies" BASE-IMAGE to /tmp. Make a copy-on-write image,
|
||
;; which is much cheaper than actually copying it.
|
||
(program-file "copy-image"
|
||
(with-imported-modules '((guix build utils))
|
||
#~(begin
|
||
(use-modules (guix build utils))
|
||
(unless (file-exists? #$rw-image)
|
||
(invoke #+(file-append qemu "/bin/qemu-img")
|
||
"create" "-b" #$base-image
|
||
"-F" "raw" "-f" "qcow2" #$rw-image))))))
|
||
|
||
(define builder
|
||
#~(call-with-output-file #$output
|
||
(lambda (port)
|
||
(format port "#!~a~%"
|
||
#+(file-append bash "/bin/sh"))
|
||
#$@(if volatile?
|
||
#~()
|
||
#~((format port "~a~%" #+copy-image)))
|
||
(format port "exec ~a \"$@\"~%"
|
||
(string-join #$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-minimal))
|
||
(volatile? virtual-machine-volatile? ;Boolean
|
||
(default #t))
|
||
(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)
|
||
(match vm
|
||
(($ <virtual-machine> os qemu volatile? graphic? memory-size
|
||
disk-image-size ())
|
||
(system-qemu-image/shared-store-script os
|
||
#:system system
|
||
#:target target
|
||
#:qemu qemu
|
||
#:graphic? graphic?
|
||
#:volatile? volatile?
|
||
#:memory-size memory-size
|
||
#:disk-image-size
|
||
disk-image-size))
|
||
(($ <virtual-machine> os qemu volatile? graphic? memory-size
|
||
disk-image-size forwardings)
|
||
(let ((options
|
||
`("-nic" ,(string-append
|
||
"user,model=virtio-net-pci,"
|
||
(port-forwardings->qemu-options forwardings)))))
|
||
(system-qemu-image/shared-store-script os
|
||
#:system system
|
||
#:target target
|
||
#:qemu qemu
|
||
#:graphic? graphic?
|
||
#:volatile? volatile?
|
||
#:memory-size memory-size
|
||
#:disk-image-size
|
||
disk-image-size
|
||
#:options options)))))
|
||
|
||
;;; vm.scm ends here
|