On Thu, May 12, 2022 at 2:28 AM Jonathon Jongsma <jjongsma@xxxxxxxxxx> wrote:
On 5/11/22 9:56 AM, Han Han wrote:
>
>
> On Wed, May 11, 2022 at 12:26 AM Jonathon Jongsma <jjongsma@xxxxxxxxxx
> <mailto:jjongsma@xxxxxxxxxx>> wrote:
>
> Add the ability to enable blob resources for the virtio video device.
> This will accelerate the display path due to less or no copying of pixel
> data.
>
> Blob resource support can be enabled with e.g.:
>
> <video>
> <model type='virtio' blob='on'/>
> </video>
>
> Some additional background information about blob resources:
> https://lists.freedesktop.org/archives/dri-devel/2020-August/275972.html
> <https://lists.freedesktop.org/archives/dri-devel/2020-August/275972.html>
> https://www.kraxel.org/blog/2021/05/virtio-gpu-qemu-graphics-update/
> <https://www.kraxel.org/blog/2021/05/virtio-gpu-qemu-graphics-update/>
>
> Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2032406
> <https://bugzilla.redhat.com/show_bug.cgi?id=2032406>
>
> Signed-off-by: Jonathon Jongsma <jjongsma@xxxxxxxxxx
> <mailto:jjongsma@xxxxxxxxxx>>
> ---
> docs/formatdomain.rst | 6 ++++++
> src/conf/domain_conf.c | 6 ++++++
> src/conf/domain_conf.h | 1 +
> src/conf/domain_validate.c | 13 ++++++++++---
> src/conf/schemas/domaincommon.rng | 5 +++++
> 5 files changed, 28 insertions(+), 3 deletions(-)
>
> diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst
> index 993c65e50b..2161cc7e30 100644
> --- a/docs/formatdomain.rst
> +++ b/docs/formatdomain.rst
> @@ -6198,6 +6198,12 @@ A video device.
> :since:`since 1.3.3` ) extends secondary bar and makes it
> addressable as
> 64bit memory.
>
> + :since:`Since 8.2.0`, devices with type "virtio" have an
> optional ``blob``
>
> Since 8.4.0 for libvirt.
Oops. Didn't catch that in the rebase.
> And please mention the QEMU version 6.1.0
There are a lot of libvirt features that require minimum versions of
qemu, but it doesn't look like we generally specify these qemu version
requirements in the libvirt documentation. Not sure if I should add it
here...
Generally, the minimal required QEMU version is 3.1.0(https://libvirt.org/drvqemu.html):
"The libvirt KVM/QEMU driver can manage any QEMU emulator from version 3.1.0 or
later"
That's to say, a user can use 3.1.0<=QEMU<6.2.0 with current libvirt.
So it's better to mention the required QEMU version for 'blob' to help users resolved the unsupported error.
>
> + attribute that can be set to "on" or "off". Setting ``blob`` to
> "on" will
> + enable the use of blob resources in the device. This can
> accelerate the
> + display path by reducing or eliminating copying of pixel data
> between the
> + guest and host.
> +
> :since:`Since 5.9.0` , the ``model`` element may also have an
> optional
> ``resolution`` sub-element. The ``resolution`` element has
> attributes ``x``
> and ``y`` to set the minimum resolution for the video device. This
> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
> index 60c27ddd34..ae86f455bd 100644
> --- a/src/conf/domain_conf.c
> +++ b/src/conf/domain_conf.c
> @@ -14154,6 +14154,9 @@
> virDomainVideoModelDefParseXML(virDomainVideoDef *def,
> else if (rc == 0)
> def->heads = 1;
>
> + if (virXMLPropTristateSwitch(node, "blob", VIR_XML_PROP_NONE,
> &def->blob) < 0)
> + return -1;
> +
> return 0;
> }
>
> @@ -26075,6 +26078,9 @@ virDomainVideoDefFormat(virBuffer *buf,
> virBufferAsprintf(buf, " heads='%u'", def->heads);
> if (def->primary)
> virBufferAddLit(buf, " primary='yes'");
> + if (def->blob != VIR_TRISTATE_SWITCH_ABSENT)
> + virBufferAsprintf(buf, " blob='%s'",
> + virTristateSwitchTypeToString(def->blob));
> if (def->accel || def->res) {
> virBufferAddLit(buf, ">\n");
> virBufferAdjustIndent(buf, 2);
> diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
> index acd0588e9b..afa6db2403 100644
> --- a/src/conf/domain_conf.h
> +++ b/src/conf/domain_conf.h
> @@ -1763,6 +1763,7 @@ struct _virDomainVideoDef {
> bool primary;
> virDomainVideoAccelDef *accel;
> virDomainVideoResolutionDef *res;
> + virTristateSwitch blob;
> virDomainVideoDriverDef *driver;
> virDomainDeviceInfo info;
> virDomainVirtioOptions *virtio;
> diff --git a/src/conf/domain_validate.c b/src/conf/domain_validate.c
> index 18eb8d697d..da0ff06570 100644
> --- a/src/conf/domain_validate.c
> +++ b/src/conf/domain_validate.c
> @@ -226,9 +226,16 @@ virDomainVideoDefValidate(const
> virDomainVideoDef *video,
> }
> }
>
> - if (video->type != VIR_DOMAIN_VIDEO_TYPE_VIRTIO &&
> - (virDomainCheckVirtioOptionsAreAbsent(video->virtio) < 0))
> - return -1;
> + if (video->type != VIR_DOMAIN_VIDEO_TYPE_VIRTIO) {
> + if (virDomainCheckVirtioOptionsAreAbsent(video->virtio) < 0)
> + return -1;
> + if (video->blob != VIR_TRISTATE_SWITCH_ABSENT) {
> + virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
> + _("video type '%s' does not support blob
> resources"),
> + virDomainVideoTypeToString(video->type));
> + return -1;
> + }
> + }
>
> return 0;
> }
> diff --git a/src/conf/schemas/domaincommon.rng
> b/src/conf/schemas/domaincommon.rng
> index 2544864eb4..16b3fd9c53 100644
> --- a/src/conf/schemas/domaincommon.rng
> +++ b/src/conf/schemas/domaincommon.rng
> @@ -4251,6 +4251,11 @@
> <ref name="virYesNo"/>
> </attribute>
> </optional>
> + <optional>
> + <attribute name="blob">
> + <ref name="virOnOff"/>
> + </attribute>
> + </optional>
> <optional>
> <element name="acceleration">
> <optional>
> --
> 2.35.1
>
