dom0+vm: Update VM kernel mechanism (#242)

Get kernel from global kernels dir (/var/lib/qubes/vm-kernels), not per-VM. Can
be configured by qvm-prefs (kernel parameter).
New tool: qvm-set-default-kernel

For backward compatibility kernel=None means kernel in VM dir (kernels subdir).
(possibly empty) modules.img should be created in it.

common/fstab

@@ -9,6 +9,7 @@
 /dev/mapper/dmroot /                       ext4 defaults,noatime        1 1
 /dev/xvdb		/rw			ext4	noauto,defaults	0 0
 /dev/xvdc1      swap                    swap    defaults        0 0
+/dev/xvdd       /lib/modules        ext3    defaults,ro 0 0
 tmpfs                   /dev/shm                tmpfs   defaults        0 0
 devpts                  /dev/pts                devpts  gid=5,mode=620  0 0
 sysfs                   /sys                    sysfs   defaults        0 0

dom0/misc/vm-template.conf

@@ -15,6 +15,7 @@ name = "{name}"
 disk = [ {rootdev}
          {privatedev}
          {volatiledev}
+         {otherdevs}
        ]
 
 vif = [ {netdev} ]

dom0/qvm-core/qubes.py

@@ -56,6 +56,7 @@ qubes_appvms_dir = qubes_base_dir + "/appvms"
 qubes_templates_dir = qubes_base_dir + "/vm-templates"
 qubes_servicevms_dir = qubes_base_dir + "/servicevms"
 qubes_store_filename = qubes_base_dir + "/qubes.xml"
+qubes_kernels_base_dir = qubes_base_dir + "/vm-kernels"
 
 qubes_max_xid = 1024
 qubes_max_qid = 254
@@ -194,7 +195,9 @@ class QubesVm(object):
                  volatile_img = None,
                  pcidevs = None,
                  internal = False,
-                 vcpus = None):
+                 vcpus = None,
+                 kernel = None,
+                 uses_default_kernel = True):
 
 
         assert qid < qubes_max_qid, "VM id out of bounds!"
@@ -277,11 +280,18 @@ class QubesVm(object):
         else:
             assert self.root_img is not None, "Missing root_img for standalone VM!"
 
+        self.kernel = kernel
+
         if template_vm is not None:
             self.kernels_dir = template_vm.kernels_dir
+        elif self.kernel is not None:
+            self.kernels_dir = qubes_kernels_base_dir + "/" + self.kernel
         else:
+            # for backward compatibility (or another rare case): kernel=None -> kernel in VM dir
             self.kernels_dir = self.dir_path + "/" + default_kernels_subdir
 
+        self.uses_default_kernel = uses_default_kernel
+
         if updateable:
             self.appmenus_templates_dir = self.dir_path + "/" + default_appmenus_templates_subdir
 
@@ -644,6 +654,7 @@ class QubesVm(object):
         args['rootdev'] = self.get_rootdev(source_template=source_template)
         args['privatedev'] = "'script:file:{dir}/private.img,xvdb,w',".format(dir=self.dir_path)
         args['volatiledev'] = "'script:file:{dir}/volatile.img,xvdc,w',".format(dir=self.dir_path)
+        args['otherdevs'] = "'script:file:{dir}/modules.img,xvdd,r',".format(dir=self.kernels_dir)
         args['kernelopts'] = ''
 
         return args
@@ -708,13 +719,6 @@ class QubesVm(object):
                 raise IOError ("Error while copying {0} to {1}".\
                                format(template_root, self.root_img))
 
-            kernels_dir = self.dir_path + '/' + default_kernels_subdir
-            if verbose:
-                print "--> Copying the template's kernel dir: {0}".\
-                        format(source_template.kernels_dir)
-            shutil.copytree (source_template.kernels_dir, kernels_dir)
-
-
         # Create volatile.img
         self.reset_volatile_storage(source_template = source_template)
 
@@ -749,6 +753,21 @@ class QubesVm(object):
             raise QubesException (
                 "VM private image file doesn't exist: {0}".\
                 format(self.private_img))
+
+        if not os.path.exists (self.kernels_dir + '/vmlinuz'):
+            raise QubesException (
+                "VM kernel does not exists: {0}".\
+                format(self.kernels_dir + '/vmlinuz'))
+
+        if not os.path.exists (self.kernels_dir + '/initramfs'):
+            raise QubesException (
+                "VM initramfs does not exists: {0}".\
+                format(self.kernels_dir + '/initramfs'))
+
+        if not os.path.exists (self.kernels_dir + '/modules.img'):
+            raise QubesException (
+                "VM kernel modules image does not exists: {0}".\
+                format(self.kernels_dir + '/modules.img'))
         return True
 
     def reset_volatile_storage(self, source_template = None):
@@ -986,6 +1005,8 @@ class QubesVm(object):
         attrs["pcidevs"] = str(self.pcidevs)
         attrs["vcpus"] = str(self.vcpus)
         attrs["internal"] = str(self.internal)
+        attrs["uses_default_kernel"] = str(self.uses_default_kernel)
+        attrs["kernel"] = str(self.kernel)
         return attrs
 
     def create_xml_element(self):
@@ -1020,7 +1041,7 @@ class QubesTemplateVm(QubesVm):
 
         # Clean image for root-cow and swap (AppVM side)
         self.clean_volatile_img = self.dir_path + "/" + default_clean_volatile_img
-        
+
         # Image for template changes
         self.rootcow_img = self.dir_path + "/" + default_rootcow_img
 
@@ -1097,11 +1118,6 @@ class QubesTemplateVm(QubesVm):
         if retcode != 0:
             raise IOError ("Error while copying {0} to {1}".\
                            format(self.clean_volatile_img, self.volatile_img))
-        if verbose:
-            print "--> Copying the template's kernel dir:\n{0} ==>\n{1}".\
-                    format(src_template_vm.kernels_dir, self.kernels_dir)
-        shutil.copytree (src_template_vm.kernels_dir, self.kernels_dir)
-
         if verbose:
             print "--> Copying the template's appmenus templates dir:\n{0} ==>\n{1}".\
                     format(src_template_vm.appmenus_templates_dir, self.appmenus_templates_dir)
@@ -1766,6 +1782,13 @@ class QubesVmCollection(dict):
         else:
             return self[self.default_netvm_qid]
 
+    def set_default_kernel(self, kernel):
+        assert os.path.exists(qubes_kernels_base_dir + '/' + kernel), "Kerel {0} not installed!".format(kernel)
+        self.default_kernel = kernel
+
+    def get_default_kernel(self):
+        return self.default_kernel
+
     def set_default_fw_netvm_vm(self, vm):
         assert vm.is_netvm(), "VM {0} does not provide network!".format(vm.name)
         self.default_fw_netvm_qid = vm.qid
@@ -1891,7 +1914,10 @@ class QubesVmCollection(dict):
             if self.default_fw_netvm_qid is not None else "None",
 
             updatevm=str(self.updatevm_qid) \
-            if self.updatevm_qid is not None else "None"
+            if self.updatevm_qid is not None else "None",
+
+            default_kernel=str(self.default_kernel) \
+            if self.default_kernel is not None else "None",
         )
 
         for vm in self.values():
@@ -1919,7 +1945,7 @@ class QubesVmCollection(dict):
                 "private_img", "root_img", "template_qid",
                 "installed_by_rpm", "updateable", "internal",
                 "uses_default_netvm", "label", "memory", "vcpus", "pcidevs",
-                "maxmem" )
+                "maxmem", "kernel", "uses_default_kernel" )
 
         for attribute in common_attr_list:
             kwargs[attribute] = element.get(attribute)
@@ -1953,6 +1979,20 @@ class QubesVmCollection(dict):
             else:
                 kwargs["label"] = QubesVmLabels[kwargs["label"]]
 
+        if "kernel" in kwargs and kwargs["kernel"] == "None":
+            kwargs["kernel"] = None
+        if "uses_default_kernel" in kwargs:
+            kwargs["uses_default_kernel"] = True if kwargs["uses_default_kernel"] == "True" else False
+        else:
+            # For backward compatibility
+            kwargs["uses_default_kernel"] = False
+        if kwargs["uses_default_kernel"]:
+            kwargs["kernel"] = self.get_default_kernel()
+        else:
+            if "kernel" in kwargs and kwargs["kernel"]=="None":
+                kwargs["kernel"]=None
+            # for other cases - generic assigment is ok
+
         return kwargs
 
     def set_netvm_dependency(self, element):
@@ -2027,6 +2067,7 @@ class QubesVmCollection(dict):
                     if updatevm != "None" else None
             #assert self.default_netvm_qid is not None
 
+        self.default_kernel = element.get("default_kernel")
 
         # Then, read in the TemplateVMs, because a reference to template VM
         # is needed to create each AppVM

dom0/qvm-tools/qvm-prefs

@@ -22,8 +22,10 @@
 
 from qubes.qubes import QubesVmCollection
 from qubes.qubes import QubesVmLabels
+from qubes.qubes import qubes_kernels_base_dir
 from optparse import OptionParser
 import subprocess
+import os
 
 def do_list(vm):
     label_width = 18
@@ -52,6 +54,10 @@ def do_list(vm):
     print fmt.format ("private img", vm.private_img)
     print fmt.format ("memory", vm.memory)
     print fmt.format ("maxmem", vm.maxmem)
+    if vm.uses_default_kernel:
+        print fmt.format ("kernel", "%s (default)" % vm.kernel)
+    else:
+        print fmt.format ("kernel", vm.kernel)
 
 
 def set_label(vms, vm, args):
@@ -168,6 +174,33 @@ def set_nonupdateable(vms, vm, args):
     vm.set_nonupdateable()
     return True
 
+def set_kernel(vms, vm, args):
+    if len (args) != 1:
+        print "Missing kernel version argument!"
+        print "Possible values:"
+        print "1) default"
+        print "2) none (kernels subdir in VM)"
+        print "3) <kernel version>, one of:"
+        for k in os.listdir(qubes_kernels_base_dir):
+            print "  -", k
+        return
+
+    kernel = args[0]
+    if kernel == "default":
+        kernel = vms.get_default_kernel()
+        vm.uses_default_kernel = True
+    elif kernel == "none":
+        kernel = None
+        vm.uses_default_kernel = False
+    else:
+        if not os.path.exists(qubes_kernels_base_dir + '/' + kernel):
+            print "Kernel version {0} not installed.".format(kernel)
+            exit(1)
+        vm.uses_default_kernel = False
+
+    vm.kernel = kernel
+
+
 properties = {
     "updateable": set_updateable,
     "nonupdateable": set_nonupdateable,
@@ -176,6 +209,7 @@ properties = {
     "netvm" : set_netvm,
     "maxmem" : set_maxmem,
     "memory" : set_memory,
+    "kernel" : set_kernel,
 }
 
 

dom0/qvm-tools/qvm-set-default-kernel

@@ -0,0 +1,48 @@
+#!/usr/bin/python2.6
+#
+# The Qubes OS Project, http://www.qubes-os.org
+#
+# Copyright (C) 2011  Marek Marczykowski <marmarek@mimuw.edu.pl>
+#
+# This program 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 2
+# of the License, or (at your option) any later version.
+#
+# This program 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 this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+#
+
+from qubes.qubes import QubesVmCollection, qubes_kernels_base_dir
+from optparse import OptionParser;
+import os
+
+def main():
+    usage = "usage: %prog <kernel>"
+    parser = OptionParser (usage)
+    (options, args) = parser.parse_args ()
+    if (len (args) != 1):
+        parser.error ("Missing argument!")
+    kernel = args[0]
+    
+    if not os.path.exists(qubes_kernels_base_dir + "/" + kernel):
+        print "Kernel {0} not installed".format(kernel)
+        exit(1)   
+
+    qvm_collection = QubesVmCollection()
+    qvm_collection.lock_db_for_writing()
+    qvm_collection.load()
+    
+    qvm_collection.set_default_kernel(kernel)
+
+    qvm_collection.save()
+    qvm_collection.unlock_db()
+
+main()

rpm_spec/core-commonvm.spec

@@ -86,6 +86,9 @@ mkdir -p $RPM_BUILD_ROOT/usr/lib/qubes
 cp qubes_trigger_sync_appmenus.sh $RPM_BUILD_ROOT/usr/lib/qubes/
 mkdir -p $RPM_BUILD_ROOT/var/lib/qubes/dom0-updates
 
+mkdir -p $RPM_BUILD_ROOT/lib/firmware
+ln -s /lib/modules/firmware $RPM_BUILD_ROOT/lib/firmware/updates
+
 %triggerin -- initscripts
 cp /var/lib/qubes/serial.conf /etc/init/serial.conf
 
@@ -236,3 +239,4 @@ rm -rf $RPM_BUILD_ROOT
 /etc/yum/post-actions/qubes_trigger_sync_appmenus.action
 /usr/lib/qubes/qubes_trigger_sync_appmenus.sh
 /usr/lib/qubes/qubes_download_dom0_updates.sh
+/lib/firmware/updates

rpm_spec/core-dom0.spec

@@ -115,6 +115,7 @@ mkdir -p $RPM_BUILD_ROOT/var/lib/qubes
 mkdir -p $RPM_BUILD_ROOT/var/lib/qubes/vm-templates
 mkdir -p $RPM_BUILD_ROOT/var/lib/qubes/appvms
 mkdir -p $RPM_BUILD_ROOT/var/lib/qubes/servicevms
+mkdir -p $RPM_BUILD_ROOT/var/lib/qubes/vm-kernels
 
 mkdir -p $RPM_BUILD_ROOT/var/lib/qubes/backup
 mkdir -p $RPM_BUILD_ROOT/var/lib/qubes/dvmdata
@@ -295,6 +296,7 @@ fi
 %attr(770,root,qubes) %dir /var/lib/qubes/backup
 %attr(770,root,qubes) %dir /var/lib/qubes/dvmdata
 %attr(770,root,qubes) %dir /var/lib/qubes/updates
+%attr(770,root,qubes) %dir /var/lib/qubes/vm-kernels
 %dir /usr/share/qubes/icons/*.png
 /usr/share/qubes/qubes-vm.directory.template
 /usr/share/qubes/qubes-templatevm.directory.template