[libvirt] [PATCH 03/23 v2] Add support for <hostdev mode="capabilities">

[Eric Blake]

> The <hostdev> device type has long had a redundant "mode"
> attribute, which has always been "subsys". This finally
> introduces a new mode "capabilities", which will be used
> by the LXC driver for device assignment. Since container
> based virtualization uses a single kernel, the idea of
> assigning physical PCI devices doesn't make sense. It is
> still reasonable to assign USB devices, but for assigning
> arbitrary nodes in /dev, the new 'capabilities' mode is
> to be used.
> 
> 
> Changes since v1:
> 
>  - Add missing docs
>  - Add missing schema change

Yep, that was what I complained about in v1.

> 
> Signed-off-by: Daniel P. Berrange <berrange at redhat.com>
> ---
>  docs/formatdomain.html.in            |  55 ++++++++++-
>  docs/schemas/domaincommon.rng        | 139
>  +++++++++++++++++++---------
>  src/conf/domain_audit.c              |  92 ++++++++++++++-----
>  src/conf/domain_conf.c               | 173
>  ++++++++++++++++++++++++++++++++++-
>  src/conf/domain_conf.h               |  31 +++++--
>  src/libvirt_private.syms             |   1 +
>  tests/lxcxml2xmldata/lxc-hostdev.xml |  34 +++++++
>  tests/lxcxml2xmltest.c               |   1 +
>  8 files changed, 448 insertions(+), 78 deletions(-)
>  create mode 100644 tests/lxcxml2xmldata/lxc-hostdev.xml
> 
> diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
> index 292e032..d8fe35d 100644
> --- a/docs/formatdomain.html.in
> +++ b/docs/formatdomain.html.in
> @@ -2123,13 +2123,15 @@
>        </dd>
>      </dl>
>  
> -    <h4><a name="elementsUSB">USB and PCI devices</a></h4>

You are deleting an anchor name; this will invalidate any URLs that were
previously pointing to that name.  Not necessarily the end of the world;
such URLs will still be to the right page, just wrong area of the page.

> +    <h4><a name="elementsHostDev">Host device assignment</a></h4>
> +
> +    <h5><a href="elementsHostDevSubsys">USB / PCI devices</a></h5>

> @@ -2247,6 +2249,51 @@
>        more details on the address element.
>      </dl>
>  
> +
> +    <h5><a href="elementsHostDevSubsys">Block / character
> devices</a></h5>

Oops, you used the anchor name #elementsHostDevSubsys twice.  How did
that validate?  I think you want this anchor to be
#elementsHostDevCapabilities

> +
> +    <p>
> +      Block / character devices from the host can be passed through
> +      to the guest using the <code>hostdev</code> element. This is
> +      only possible with container based virtualization.
> +      <span class="since">since after 1.0.1 for LXC</span>:
> +    </p>
> +
> +    <pre>
> +...
> +<hostdev mode='capabilities' type='storage'>
> +  <source>
> +    <block>/dev/sdf1</block>
> +  </source>
> +</hostdev>
> +...
> +    </pre>
> +
> +    <pre>
> +...
> +<hostdev mode='capabilities' type='misc'>
> +  <source>
> +    <char>/dev/input/event3</char>
> +  </source>
> +</hostdev>
> +...
> +    </pre>
> +
> +    <dl>
> +      <dt><code>hostdev</code></dt>
> +      <dd>The <code>hostdev</code> element is the main container for
> describing
> +        host devices. For block/characgter device passthrough

s/characgter/character/

> <code>mode</code> is
> +        always "capabilities" and <code>type</code> is "block" for a
> block
> +        device and "char" for a character device.
> +      </dd>
> +      <dt><code>source</code></dt>
> +      <dd>The source element describes the device as seen from the
> host.
> +        For block devices, the path to the block device in the host
> +        OS is provided in the nested "block" element, while for
> character
> +        devices the "char" element is used
> +      </dd>
> +    </dl>
> +
>      <h4><a name="elementsRedir">Redirected devices</a></h4>
>  
>      <p>
> diff --git a/docs/schemas/domaincommon.rng
> b/docs/schemas/domaincommon.rng
> index cdc5115..5e4f59b 100644
> --- a/docs/schemas/domaincommon.rng
> +++ b/docs/schemas/domaincommon.rng
> @@ -2834,63 +2834,120 @@
>        </zeroOrMore>
>      </element>
>    </define>
> +
>    <define name="hostdev">
>      <element name="hostdev">
> +      <choice>
> +        <group>
> +          <ref name="hostdevsubsys"/>
> +        </group>
> +        <group>
> +          <ref name="hostdevcaps"/>
> +        </group>
> +      </choice>
>        <optional>

> +  <define name="hostdevcaps">
> +    <attribute name="mode">
> +      <value>capabilities</value>
> +    </attribute>
> +    <choice>
> +      <group>
> +        <ref name="hostdevcapsstorage"/>
> +      </group>
> +    </choice>

No choice for hostdevcapsmisc yet...

> +
> +  <define name="hostdevcapsmisc">
> +    <attribute name="type">
> +      <value>misc</value>
> +    </attribute>
> +    <element name="source">
> +      <element name="char">
> +        <ref name="absFilePath"/>
> +      </element>
> +    </element>
> +  </define>

...which makes this <define> unused.  I don't know if that was
intentional, or just an accidental omission, but trust that
you'll get it sorted out before the end of the series.

> +++ b/tests/lxcxml2xmldata/lxc-hostdev.xml
> @@ -0,0 +1,34 @@

> +    <hostdev mode='capabilities' type='storage'>
> +      <source>
> +        <block>/dev/sdf1</block>
> +      </source>
> +    </hostdev>
> +    <hostdev mode='capabilities' type='char'>

How did this validate?  Shouldn't it be type='misc'?

ACK with those issues fixed.

-- 
Eric Blake   eblake at redhat.com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org