The issue is when the host has been updated with microcode for Spectre
but qemu has _not_ been updated. In this scenario (as an example),
'virsh capabilities' shows the host cpu model as IvyBridge-IBRS, which is
correct. However, 'virsh domcapabilities' shows IvyBridge as the host-model
and does not show any of the '-IBRS' flavors available under the custom model,
which is also correct since the qemu does not have Spectre patches.
Be default, virt-manager uses 'custom' for the cpu mode XML. For example,
<cpu mode="custom" match="exact">
<model>IvyBridge-IBRS</model>
</cpu>
Starting an installation in the above scenario will fail because qemu
doesn't understand '-IBRS' until it has been updated to do so.
The patch below validates that the capabilities cpu is present in domcapabilities,
and if they differ, log a message and set the CPU model to None.
Signed-off-by: Charles Arnold <carnold@xxxxxxxx>
diff --git a/virtinst/domain/cpu.py b/virtinst/domain/cpu.py
index 3c1089c0..f3055dc7 100644
--- a/virtinst/domain/cpu.py
+++ b/virtinst/domain/cpu.py
@@ -6,6 +6,8 @@
# See the COPYING file in the top-level directory.
from ..xmlbuilder import XMLBuilder, XMLProperty, XMLChildProperty
+from .domcapabilities import DomainCapabilities
+import logging
class _CPUCellSibling(XMLBuilder):
@@ -79,7 +81,7 @@ class DomainCpu(XMLBuilder):
SPECIAL_MODES = [SPECIAL_MODE_HOST_MODEL_ONLY, SPECIAL_MODE_HV_DEFAULT,
SPECIAL_MODE_HOST_COPY, SPECIAL_MODE_HOST_MODEL,
SPECIAL_MODE_HOST_PASSTHROUGH, SPECIAL_MODE_CLEAR]
- def set_special_mode(self, val):
+ def set_special_mode(self, val, guest=None):
if (val == self.SPECIAL_MODE_HOST_MODEL or
val == self.SPECIAL_MODE_HOST_PASSTHROUGH):
self.model = None
@@ -97,6 +99,15 @@ class DomainCpu(XMLBuilder):
if self.conn.caps.host.cpu.model:
self.clear()
self.model = self.conn.caps.host.cpu.model
+ if guest:
+ domcaps = DomainCapabilities.build_from_guest(guest)
+ domcaps_model = domcaps.cpu.get_mode("host-model").get_models()
+ if (isinstance(domcaps_model, list) and len(domcaps_model) and
+ domcaps_model[0] != self.conn.caps.host.cpu.model):
+ logging.debug("Host capabilities CPU '%s' does not match "
+ "domain capabilities CPU '%s'. Leaving CPU model unset.",
+ self.conn.caps.host.cpu.model, domcaps_model[0])
+ self.model = None
else:
raise RuntimeError("programming error: unknown "
"special cpu mode '%s'" % val)
diff --git a/virtinst/domcapabilities.py b/virtinst/domcapabilities.py
index f98c807b..8387838c 100644
--- a/virtinst/domcapabilities.py
+++ b/virtinst/domcapabilities.py
@@ -29,9 +29,27 @@ class _Enum(_HasValues):
name = XMLProperty("./@name")
+class _Model(XMLBuilder):
+ _XML_ROOT_NAME = "model"
+ model = XMLProperty(".")
+
+
+class _HasModels(XMLBuilder):
+ models = XMLChildProperty(_Model)
+
+ def get_models(self):
+ return [m.model for m in self.models]
+
+
+class _CPUMode(_HasModels):
+ _XML_ROOT_NAME = "mode"
+ name = XMLProperty("./@name")
+
+
class _CapsBlock(_HasValues):
supported = XMLProperty("./@supported", is_yesno=True)
enums = XMLChildProperty(_Enum)
+ modes = XMLChildProperty(_CPUMode)
def enum_names(self):
return [e.name for e in self.enums]
@@ -40,6 +58,12 @@ class _CapsBlock(_HasValues):
d = dict((e.name, e) for e in self.enums)
return d[name]
+ def mode_names(self):
+ return [m.name for m in self.modes]
+
+ def get_mode(self, name):
+ d = dict((m.name, m) for m in self.modes)
+ return d[name]
def _make_capsblock(xml_root_name):
class TmpClass(_CapsBlock):
@@ -53,6 +77,11 @@ class _OS(_CapsBlock):
loader = XMLChildProperty(_make_capsblock("loader"), is_single=True)
+class _CPU(_CapsBlock):
+ _XML_ROOT_NAME = "cpu"
+ mode = XMLChildProperty(_make_capsblock("mode"), is_single=True)
+
+
class _Devices(_CapsBlock):
XML_NAME = "devices"
hostdev = XMLChildProperty(_make_capsblock("hostdev"), is_single=True)
@@ -151,6 +180,7 @@ class DomainCapabilities(XMLBuilder):
XML_NAME = "domainCapabilities"
os = XMLChildProperty(_OS, is_single=True)
+ cpu = XMLChildProperty(_CPU, is_single=True)
devices = XMLChildProperty(_Devices, is_single=True)
arch = XMLProperty("./arch")
diff --git a/virtinst/guest.py b/virtinst/guest.py
index 5e7d8077..35d162c5 100644
--- a/virtinst/guest.py
+++ b/virtinst/guest.py
@@ -868,7 +868,7 @@ class Guest(XMLBuilder):
if self.os.arch != self.conn.caps.host.cpu.arch:
return
- self.cpu.set_special_mode(self.x86_cpu_default)
+ self.cpu.set_special_mode(self.x86_cpu_default, self)
if self._os_object.broken_x2apic():
self.cpu.add_feature("x2apic", policy="disable")
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