01/01: vm: Only pass "-enable-kvm" to qemu if /dev/kvm is present.

[Christopher Allan Webber]

cwebber pushed a commit to branch master
in repository guix.

commit 944d2b17b50b6e1890817d4724ed101bc2c4b0ef
Author: Christopher Allan Webber <address@hidden>
Date:   Mon Feb 22 11:23:14 2016 -0800

    vm: Only pass "-enable-kvm" to qemu if /dev/kvm is present.
    
    Fixes <http://bugs.gnu.org/22633>.
    
    * gnu/build/vm.scm (load-in-linux-vm): Only pass "-enable-kvm" flag to qemu
      if "/dev/kvm" is present.
    * gnu/system/vm.scm (common-kvm-options): Same as above.
---
 gnu/build/vm.scm  |   19 ++++++++++++++-----
 gnu/system/vm.scm |   10 +++++++++-
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/gnu/build/vm.scm b/gnu/build/vm.scm
index a095f9d..48e701a 100644
--- a/gnu/build/vm.scm
+++ b/gnu/build/vm.scm
@@ -1,5 +1,7 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2013, 2014, 2015 Ludovic Courtès <address@hidden>
+;;; Copyright © 2016 Christopher Allan Webber <address@hidden>
+;;; Copyright © 2016 Leo Famulari <address@hidden>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -97,7 +99,7 @@ the #:references-graphs parameter of 'derivation'."
     (_ #f))
 
   (unless (zero?
-           (apply system* qemu "-enable-kvm" "-nographic" "-no-reboot"
+           (apply system* qemu "-nographic" "-no-reboot"
                   "-m" (number->string memory-size)
                   "-net" "nic,model=virtio"
                   "-virtfs"
@@ -111,10 +113,17 @@ the #:references-graphs parameter of 'derivation'."
                   "-initrd" initrd
                   "-append" (string-append "console=ttyS0 --load="
                                            builder)
-                  (if make-disk-image?
-                      `("-drive" ,(string-append "file=" image-file
-                                                 ",if=virtio"))
-                      '())))
+                  (append
+                   (if make-disk-image?
+                       `("-drive" ,(string-append "file=" image-file
+                                                  ",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))
 
   (if make-disk-image?
diff --git a/gnu/system/vm.scm b/gnu/system/vm.scm
index a7c03bd..58a476a 100644
--- a/gnu/system/vm.scm
+++ b/gnu/system/vm.scm
@@ -1,5 +1,7 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2013, 2014, 2015, 2016 Ludovic Courtès <address@hidden>
+;;; Copyright © 2016 Christopher Allan Webber <address@hidden>
+;;; Copyright © 2016 Leo Famulari <address@hidden>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -457,7 +459,13 @@ with '-virtfs' options for the host file systems listed in 
SHARED-FS."
                      "\" "))
 
   #~(string-append
-     " -enable-kvm -no-reboot -net nic,model=virtio \
+     ;; Only enable kvm if we see /dev/kvm exists.
+     ;; This allows users without hardware virtualization to still use these
+     ;; commands.
+     #$(if (file-exists? "/dev/kvm")
+           " -enable-kvm "
+           "")
+     " -no-reboot -net nic,model=virtio \
   " #$@(map virtfs-option shared-fs) " \
   -net user \
   -serial stdio -vga std \