Using a preferred CPU model which is not in the list of CPU models
supported by a hypervisor does not make sense.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Guest CPUs with match='minimum' should always be updated to match host
CPU model. Trying to get different results by supplying preferred models
does not make sense.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
The reworked API is now called virCPUUpdate and it should change the
provided CPU definition into a one which can be consumed by the QEMU
command line builder:
- host-passthrough remains unchanged
- host-model is turned into custom CPU with a model and features
copied from host
- custom CPU with minimum match is converted similarly to host-model
- optional features are updated according to host's CPU
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Some Intel processor families (e.g. the Intel Xeon processor E5 v3
family) introduced some PQos (Platform Qos) features, including CMT
(Cache Monitoring technology) and MBM (Memory Bandwidth Monitoring),
to monitor or control shared resource. This patch add them into x86
part of cpu_map.xml to be used for applications based on libvirt to
get cpu capabilities. For example, Nova in OpenStack schedules guests
based on the CPU features that the host has.
Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com>
Our current detection code uses just the number of CPU features which
need to be added/removed from the CPU model to fully describe the CPUID
data. The smallest number wins. But this may sometimes generate wrong
results as one can see from the fixed test cases. This patch modifies
the algorithm to prefer the CPU model with matching signature even if
this model results in a longer list of additional features.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
The CPU model was implemented in QEMU by commit f6f949e929.
The change to i7-5600U is wrong since it's a 5th generation CPU, i.e.,
Broadwell rather than Skylake, but that's just the result of our CPU
detection code (which is fixed by the following commit).
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
The actual CPU model in the data files is Penryn which makes the file
name look rather strange. Well, one of them contains Nehalem, but that's
a bug which will be fixed soon.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
As a side effect this changes the order of CPU features in XMLs
generated by libvirt, but that's not a big deal since the order there is
insignificant.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
So far we only test CPUID -> CPU def conversion on artificial CPUID data
computed from another CPU def. This patch adds the infrastructure to
test this conversion on real data gathered from a host CPU and two
helper scripts for adding new test data:
- cpu-gather.sh runs cpuid tool and qemu-system-x86_64 to get CPUID data
from the host CPU; this is what users can be asked to run if they run
into an issue with host CPU detection in libvirt
- cpu-parse.sh takes the data generated by cpu-gather.sh and creates
data files for CPU detection tests
The CPUID data queried from QEMU will eventually switch to the format
used by query-host-cpu QMP command once QEMU implements it. Until then
we just spawn QEMU with -cpu host and query the guest CPU in QOM. They
should both provide the same CPUID results, but query-host-cpu does not
require any guest CPU to be created by QEMU.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
When computing CPU data for a given guest CPU we should set CPUID vendor
bits appropriately so that we don't lose the vendor when transforming
CPU data back to XML description.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
There's no reason for keeping the features in a linked list. Especially
when we know upfront the total number of features we are loading.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Limitations of the POWER architecture mean that you can't run
eg. a POWER7 guest on a POWER8 host when using KVM. This applies
to all guests, not just those using VIR_CPU_MATCH_STRICT in the
CPU definition; in fact, exact and strict CPU matching are
basically the same on ppc64.
This means, of course, that hosts using different CPUs have to be
considered incompatible as well.
Change ppc64Compute(), called by cpuGuestData(), to reflect this
fact and update test cases accordingly.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1250977
QEMU 2.3 adds these new models to cover Haswell and Broadwell CPUs with
updated microcode. Luckily, they also reverted former the machine type
specific changes to existing models. And since these changes were never
released, we don't need to hack around them in libvirt.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Commit fba6bc4 introduced support for the 'invtsc' feature,
which blocks migration. We should not include it in the
host-model CPU by default, because it's intended to be used
with migration.
https://bugzilla.redhat.com/show_bug.cgi?id=1138221
https://bugzilla.redhat.com/show_bug.cgi?id=1049391
When all source CPU XMLs contain just a single CPU model (with a
possibly varying set of additional feature elements),
virConnectBaselineCPU will try to use this CPU model in the computed
guest CPU. Thus, when used on just a single CPU (useful with
VIR_CONNECT_BASELINE_CPU_EXPAND_FEATURES), the result will not use a
different CPU model.
If the computed CPU uses the source model, set fallback mode to 'forbid'
to make sure the guest CPU will always be as close as possible to the
source CPUs.
Currently the virConnectBaselineCPU API does not expose the CPU features
that are part of the CPU's model. This patch adds a new flag,
VIR_CONNECT_BASELINE_CPU_EXPAND_FEATURES, that causes the API to explicitly
list all features that are part of that model.
Signed-off-by: Don Dugger <donald.d.dugger@intel.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Until now CPU features inherited from a specified CPU model could only
be overridden with 'disable' policy. With this patch, any explicitly
specified feature always overrides the same feature inherited from a CPU
model regardless on the specified policy.
The CPU in x86-exact-force-Haswell.xml would previously be incompatible
with x86-host-SandyBridge.xml CPU even though x86-host-SandyBridge.xml
provides all features required by x86-exact-force-Haswell.xml.
We found few more AMD-specific features in cpu64-rhel* models that
made it impossible to start qemu guest on Intel host (with this
setting) even though qemu itself starts correctly with them.
This impacts one test, thus the fix in tests/cputestdata/.
Recently (or not so recently) QEMU added the kvm32 and kvm64
architectures, representing a least common denominator of all
hosts that can run KVM. Add them to the machine map.
Also, some features that TCG supports were added to qemu64.
Add them to the cpu_map.xml whenever KVM is guaranteed to support
those. We still have to leave some out, because they would not
be available to guests running on older hosts.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
VIR_DOMAIN_XML_UPDATE_CPU flag for virDomainGetXMLDesc may be used to
get updated custom mode guest CPU definition in case it depends on host
CPU. This patch implements the same behavior for host-model and
host-passthrough CPU modes.
The mode can be either of "custom" (default), "host-model",
"host-passthrough". The semantics of each mode is described in the
following examples:
- guest CPU is a default model with specified topology:
<cpu>
<topology sockets='1' cores='2' threads='1'/>
</cpu>
- guest CPU matches selected model:
<cpu mode='custom' match='exact'>
<model>core2duo</model>
</cpu>
- guest CPU should be a copy of host CPU as advertised by capabilities
XML (this is a short cut for manually copying host CPU specification
from capabilities to domain XML):
<cpu mode='host-model'/>
In case a hypervisor does not support the exact host model, libvirt
automatically falls back to a closest supported CPU model and
removes/adds features to match host. This behavior can be disabled by
<cpu mode='host-model'>
<model fallback='forbid'/>
</cpu>
- the same as previous returned by virDomainGetXMLDesc with
VIR_DOMAIN_XML_UPDATE_CPU flag:
<cpu mode='host-model' match='exact'>
<model fallback='allow'>Penryn</model> --+
<vendor>Intel</vendor> |
<topology sockets='2' cores='4' threads='1'/> + copied from
<feature policy='require' name='dca'/> | capabilities XML
<feature policy='require' name='xtpr'/> |
... --+
</cpu>
- guest CPU should be exactly the same as host CPU even in the aspects
libvirt doesn't model (such domain cannot be migrated unless both
hosts contain exactly the same CPUs):
<cpu mode='host-passthrough'/>
- the same as previous returned by virDomainGetXMLDesc with
VIR_DOMAIN_XML_UPDATE_CPU flag:
<cpu mode='host-passthrough' match='minimal'>
<model>Penryn</model> --+ copied from caps
<vendor>Intel</vendor> | XML but doesn't
<topology sockets='2' cores='4' threads='1'/> | describe all
<feature policy='require' name='dca'/> | aspects of the
<feature policy='require' name='xtpr'/> | actual guest CPU
... --+
</cpu>
In case a hypervisor doesn't support the exact CPU model requested by a
domain XML, we automatically fallback to a closest CPU model the
hypervisor supports (and make sure we add/remove any additional features
if needed). This patch adds 'fallback' attribute to model element, which
can be used to disable this automatic fallback.
