Commit Graph

5 Commits

Author SHA1 Message Date
Jiri Denemark
3b6be3c0c5 cpu: Rework cpuUpdate
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>
2016-09-22 15:40:09 +02:00
Jiri Denemark
3a7cd180a5 cpu_x86: Use array of features in CPU map
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>
2016-05-20 09:18:56 +02:00
Jiri Denemark
f7dd3a4e62 Add support for cpu mode attribute
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>
2012-01-17 11:39:23 +01:00
Jiri Denemark
a6f88cbd2d cpu: Optionally forbid fallback CPU models
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.
2012-01-17 11:39:19 +01:00
Jiri Denemark
598b9fe4af tests: Add unit tests for internal CPU APIs 2010-12-01 14:12:54 +01:00