From 540fe3f55286782bdc756cbe4b627bfe29bfccb2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?=
 <marmarek@invisiblethingslab.com>
Date: Tue, 10 Nov 2015 17:07:57 +0100
Subject: [PATCH] core: set vm.uses_default_kernel=False when setting vm.kernel

Forgetting this leads to misterious errors (VM started with different
kernel than it was just set), so simplify the API.

Fixes QubesOS/qubes-issues#1400
---
 core-modules/000QubesVm.py |  1 +
 qvm-tools/qvm-prefs        | 10 ++++------
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/core-modules/000QubesVm.py b/core-modules/000QubesVm.py
index f5513520..90413bb2 100644
--- a/core-modules/000QubesVm.py
+++ b/core-modules/000QubesVm.py
@@ -526,6 +526,7 @@ class QubesVm(object):
                         "Kernel '%s' not properly installed: missing %s "
                         "file" % (new_value, f))
         self._kernel = new_value
+        self.uses_default_kernel = False
 
     @property
     def updateable(self):
diff --git a/qvm-tools/qvm-prefs b/qvm-tools/qvm-prefs
index 96cb164d..dea3aa4f 100755
--- a/qvm-tools/qvm-prefs
+++ b/qvm-tools/qvm-prefs
@@ -285,7 +285,7 @@ def set_dispvm_netvm(vms, vm, args):
     return True
 
 def set_kernel(vms, vm, args):
-    if len (args) != 1:
+    if len(args) != 1:
         print >> sys.stderr, "Missing kernel version argument!"
         print >> sys.stderr, "Possible values:"
         print >> sys.stderr, "1) default"
@@ -297,18 +297,16 @@ def set_kernel(vms, vm, args):
 
     kernel = args[0]
     if kernel == "default":
-        kernel = vms.get_default_kernel()
+        vm.kernel = vms.get_default_kernel()
         vm.uses_default_kernel = True
     elif kernel == "none":
-        kernel = None
-        vm.uses_default_kernel = False
+        vm.kernel = None
     else:
         if not os.path.exists(os.path.join(system_path["qubes_kernels_base_dir"], kernel)):
             print >> sys.stderr, "Kernel version {0} not installed.".format(kernel)
             return False
-        vm.uses_default_kernel = False
+        vm.kernel = kernel
 
-    vm.kernel = kernel
     return True
 
 def set_template(vms, vm, args):