Public bug reported:
# Summary
Ubuntu’s virglrenderer package is built with the Meson option for video
acceleration disabled (-Dvideo=false). This prevents the VirGL video
path (VA-API encode/decode exposure via virtio-gpu/virgl) from being
usable on Ubuntu hosts, even when the underlying stack supports it.
Please enable the feature in Ubuntu builds for the 26.04 cycle by
switching to -Dvideo=enabled (or equivalent).
# Background / Motivation
VirGL already enables accelerated rendering for virtio-gpu guests.
Upstream virglrenderer also has an optional video acceleration path
intended to expose video encode/decode to the guest via VA-API (virtio-
gpu VA-API driver), which can significantly reduce guest CPU load and
improve responsiveness for multimedia and remote desktop streaming
workloads (e.g. “VDI-like” interactive desktops, remote developer
workstations, training labs).
# Current Ubuntu State (evidence)
1) Ubuntu previously carried an explicit delta to disable video acceleration:
“Disable video acceleration on Ubuntu until libva gets repromoted.”
(See Launchpad bug: #2040435)
2) Ubuntu builds still pass -Dvideo=false. For example, in Ubuntu 25.10
(Questing) virglrenderer 1.1.0-2 build logs show dh_auto_configure
invoking Meson with -Dvideo=false and reporting “video : false”.
3) The original stated blocker (libva component) appears to have
changed: libva is published in “main” in Ubuntu 25.10 (Questing). This
suggests it is worth re-evaluating the continued forced disablement of
virglrenderer video.
# Request
Please modify Ubuntu’s virglrenderer packaging to enable the Meson video
feature:
- Remove the explicit -Dvideo=false override
- Enable the feature (preferably as a Meson “feature” option: -Dvideo=enabled)
If there are remaining blockers beyond the original libva component
rationale (e.g., dependency policy, stability/regression concerns,
security support), please document them in this bug so they can be
addressed during the 26.04 cycle.
# Notes / Scope
- This bug is specifically about enabling the virglrenderer build
feature. Runtime enablement may additionally require QEMU to pass
VIRGL_RENDERER_USE_VIDEO during virgl init. If Ubuntu QEMU does not
currently set this, that would be a separate (but related) issue;
enabling the virglrenderer feature is still a necessary prerequisite and
should be tracked independently.
# Test Plan (for maintainers/testers)
Host (Ubuntu):
1) Build/install virglrenderer with Meson video enabled.
2) Run a VM with virtio-gpu + virgl/virtio-gl enabled (virt-manager “3D
acceleration” / OpenGL).
Guest (Ubuntu):
3) Install libva-utils and run:
LIBVA_DRIVER_NAME=virtio_gpu vainfo
Expected:
- virtio_gpu VA-API driver loads
- Additional codec profiles (decode/encode depending on host capabilities)
appear compared to stock Ubuntu build
# Impact
Enabling this feature can:
- Reduce CPU use in guests for video encode/decode workloads (where supported)
- Improve “desktop-as-video” remote desktop performance when streaming
solutions inside the guest can use VA-API encode
- Improve Ubuntu’s competitiveness for GPU-accelerated VM desktop/VDI-like
scenarios
# References
- LP: #2040435 (Ubuntu delta mentions disabling video acceleration until libva
repromotion)
- Questing virglrenderer build logs show -Dvideo=false (“video : false”)
- libva is published in “main” in Questing (component change vs Noble)
** Affects: virglrenderer (Ubuntu)
Importance: Undecided
Status: New
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https://bugs.launchpad.net/bugs/2141692
Title:
Enable VirGL video acceleration in Ubuntu virglrenderer builds (Meson
-Dvideo=enabled) for 26.04
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