core: add pci_e820_host property

Enable e820_host option for VMs with PCI devices (to allow VM kernel to
deal with address space conflicts). But add a property to allow
disabling it.

Fixes QubesOS/qubes-issues#2019

core-modules/000QubesVm.py

@@ -136,6 +136,7 @@ class QubesVm(object):
                     eval(value) if value.find("[") >= 0 else
                     eval("[" + value + "]") },
             "pci_strictreset": {"default": True},
+            "pci_e820_host": {"default": True},
             # Internal VM (not shown in qubes-manager, doesn't create appmenus entries
             "internal": { "default": False, 'attr': '_internal' },
             "vcpus": { "default": 2 },
@@ -1191,6 +1192,7 @@ class QubesVm(object):
             # If dynamic memory management disabled, set maxmem=mem
             args['maxmem'] = args['mem']
         args['vcpus'] = str(self.vcpus)
+        args['features'] = ''
         if self.netvm is not None:
             args['ip'] = self.ip
             args['mac'] = self.mac
@@ -1215,6 +1217,8 @@ class QubesVm(object):
             args['network_end'] = '-->'
             args['no_network_begin'] = ''
             args['no_network_end'] = ''
+        if len(self.pcidevs) and self.pci_e820_host:
+            args['features'] = '<xen><e820_host state=\'on\'/></xen>'
         args.update(self.storage.get_config_params())
         if hasattr(self, 'kernelopts'):
             args['kernelopts'] = self.kernelopts

doc/qvm-tools/qvm-prefs.rst

@@ -49,6 +49,14 @@ pci_strictreset
     cases it could make sense - for example when the VM to which it is assigned
     is trusted one, or is running all the time.
 
+pci_e820_host
+    Accepted values: ``True``, ``False``
+
+    Give VM with PCI devices a memory map (e820) of the host. This is
+    required for some devices to properly resolve conflicts in address space.
+    This option is enabled by default for VMs with PCI devices and have no
+    effect for VMs without devices.
+
 label
     Accepted values: ``red``, ``orange``, ``yellow``, ``green``, ``gray``,
     ``blue``, ``purple``, ``black``

qvm-tools/qvm-prefs

@@ -58,6 +58,7 @@ def do_list(vm):
     print fmt.format ("config", vm.conf_file)
     print fmt.format ("pcidevs", vm.pcidevs)
     print fmt.format ("pci_strictreset", vm.pci_strictreset)
+    print fmt.format ("pci_e820_host", vm.pci_e820_host)
     if vm.template is None:
         print fmt.format ("root_img", vm.root_img)
     if hasattr(vm, "rootcow_img") and vm.rootcow_img is not None:
@@ -228,6 +229,14 @@ def set_pci_strictreset(vms, vm, args):
     vm.pci_strictreset = bool(eval(args[0].capitalize()))
     return True
 
+def set_pci_e820_host(vms, vm, args):
+    if len (args) != 1:
+        print >> sys.stderr, "Missing value (True/False)!"
+        return False
+
+    vm.pci_e820_host = bool(eval(args[0].capitalize()))
+    return True
+
 def set_netvm(vms, vm, args):
     if len (args) != 1:
         print >> sys.stderr, "Missing netvm name argument!"
@@ -485,6 +494,7 @@ properties = {
     "include_in_backups": set_include_in_backups,
     "pcidevs": set_pcidevs,
     "pci_strictreset": set_pci_strictreset,
+    "pci_e820_host": set_pci_e820_host,
     "label" : set_label,
     "netvm" : set_netvm,
     "dispvm_netvm" : set_dispvm_netvm,

rpm_spec/core-dom0.spec

@@ -62,7 +62,7 @@ Requires:       libvirt-python
 %if x%{?backend_vmm} == xxen
 Requires:       xen-runtime
 Requires:       xen-hvm
-Requires:       libvirt-daemon-xen >= 1.2.20-4
+Requires:       libvirt-daemon-xen >= 1.2.20-6
 %endif
 Requires:       createrepo
 Requires:       gnome-packagekit

vm-config/xen-vm-template-hvm.xml

@@ -15,6 +15,7 @@
     <acpi/>
     <apic/>
     <viridian/>
+    {features}
   </features>
   <clock offset='variable' adjustment='{timeoffset}' basis='{time_basis}'/>
   <on_poweroff>destroy</on_poweroff>

vm-config/xen-vm-template.xml

@@ -10,6 +10,7 @@
     <initrd>{kerneldir}/initramfs</initrd>
     <cmdline>root=/dev/mapper/dmroot ro nomodeset console=hvc0 rd_NO_PLYMOUTH 3 {kernelopts}</cmdline>
   </os>
+  <features>{features}</features>
   <clock offset='utc' adjustment='reset'>
     <timer name="tsc" mode="native"/>
   </clock>