[libvirt] [PATCHv2 5/6] conf: add caching attribute to iommu device

[John Ferlan]

On 04/20/2017 08:19 AM, Ján Tomko wrote:
> Add a new attribute to control the caching mode.
> 
> https://bugzilla.redhat.com/show_bug.cgi?id=1427005
> ---
>  docs/formatdomain.html.in                          |  9 +++++++
>  docs/schemas/domaincommon.rng                      |  5 ++++
>  src/conf/domain_conf.c                             | 24 ++++++++++++++++---
>  src/conf/domain_conf.h                             |  1 +
>  .../qemuxml2argv-intel-iommu-caching.xml           | 28 ++++++++++++++++++++++
>  .../qemuxml2xmlout-intel-iommu-caching.xml         |  1 +
>  tests/qemuxml2xmltest.c                            |  1 +
>  7 files changed, 66 insertions(+), 3 deletions(-)
>  create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-intel-iommu-caching.xml
>  create mode 120000 tests/qemuxml2xmloutdata/qemuxml2xmlout-intel-iommu-caching.xml
> 
> diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
> index f5a8e76..dbca316 100644
> --- a/docs/formatdomain.html.in
> +++ b/docs/formatdomain.html.in
> @@ -7364,6 +7364,15 @@ qemu-kvm -net nic,model=? /dev/null
>                (QEMU only)
>              </p>
>            </dd>
> +          <dt><code>caching</code></dt>
> +          <dd>
> +            <p>
> +              The <code>caching</code> attribute with possible values
> +              <code>on</code> and <code>off</code> can be used to
> +              turn on the caching mode. <span class="since">Since 3.3.0</span>
> +              (QEMU only)

Useful for what?  Required for what?  A bit more description about the
relationship with intremap might be nice as well.

Is there a relationship with the irqmode settings?  If so, then I would
think there should be checks in domain post processing that ensure that
if this is on, then the irqmode setting is adjusted appropriately.


> +            </p>
> +          </dd>
>          </dl>
>        </dd>
>      </dl>



> diff --git a/tests/qemuxml2argvdata/qemuxml2argv-intel-iommu-caching.xml b/tests/qemuxml2argvdata/qemuxml2argv-intel-iommu-caching.xml
> new file mode 100644
> index 0000000..bab4fcb
> --- /dev/null
> +++ b/tests/qemuxml2argvdata/qemuxml2argv-intel-iommu-caching.xml
> @@ -0,0 +1,28 @@
> +<domain type='qemu'>
> +  <name>QEMUGuest1</name>
> +  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
> +  <memory unit='KiB'>219100</memory>
> +  <currentMemory unit='KiB'>219100</currentMemory>
> +  <vcpu placement='static'>1</vcpu>
> +  <os>
> +    <type arch='x86_64' machine='q35'>hvm</type>
> +    <boot dev='hd'/>
> +  </os>
> +  <clock offset='utc'/>
> +  <on_poweroff>destroy</on_poweroff>
> +  <on_reboot>restart</on_reboot>
> +  <on_crash>destroy</on_crash>
> +  <devices>
> +    <emulator>/usr/bin/qemu-system-x86_64</emulator>
> +    <controller type='pci' index='0' model='pcie-root'/>
> +    <controller type='sata' index='0'>
> +      <address type='pci' domain='0x0000' bus='0x00' slot='0x1f' function='0x2'/>
> +    </controller>
> +    <input type='mouse' bus='ps2'/>
> +    <input type='keyboard' bus='ps2'/>
> +    <memballoon model='none'/>
> +    <iommu model='intel'>
> +      <driver intremap='on' caching='on'/>
> +    </iommu>
> +  </devices>
> +</domain>

Maybe this is the XML that gets more devices added that prove the
ordering is correct.  IDC which one, but we should "ensure" the ordering
is right..

John