psa-systems/vervain-agent
Watch
9
0
Fork
You've already forked vervain-agent
 0
Code Issues Pull requests Projects Releases 7 Packages Wiki Activity Actions

feat(kvm): DRM/KMS scanout enumeration + capture probe (VA-104) #107

Merged
David merged 1 commit from fix/VA-104-drm-kms-capture into main 2026-07-04 01:01:46 +02:00
Conversation 0 Commits 1 Files changed 6 +425
David commented 2026-07-04 00:57:36 +02:00
Owner
Copy link

Foundation for consent-free Wayland capture: read the active CRTC's scanout framebuffer off /dev/dri as root, the compositor-agnostic path that works on KWin/GNOME where wlr-screencopy (grim) and the consent-gated portal do not. Enumerates cards/CRTCs, resolves the primary framebuffer (directly or via its plane), exports the plane's DMA-BUF, and reads a LINEAR buffer via mmap into packed RGB. Adds a drm_probe example plus just drm-probe / just deploy-local recipes for the on-host dev loop.

Confirmed on an AMD KWin host: the scanout is 3840x2160 ABGR2101010, reported linear but resident in VRAM, so a CPU mmap is denied (EPERM). The GPU readback path (EGL/gbm DMA-BUF import) that handles VRAM and tiled buffers is the next increment; this lands the enumeration, format/modifier probe, and the linear read that covers software / UMA-linear scanout.

Not yet wired into wayland::capture_rgb; the module and probe stand alone until the GPU readback lands.

#VA-104

Co-Authored-By: Claude Opus 4.8 (1M context) noreply@anthropic.com

Foundation for consent-free Wayland capture: read the active CRTC's scanout framebuffer off /dev/dri as root, the compositor-agnostic path that works on KWin/GNOME where wlr-screencopy (grim) and the consent-gated portal do not. Enumerates cards/CRTCs, resolves the primary framebuffer (directly or via its plane), exports the plane's DMA-BUF, and reads a LINEAR buffer via mmap into packed RGB. Adds a drm_probe example plus `just drm-probe` / `just deploy-local` recipes for the on-host dev loop. Confirmed on an AMD KWin host: the scanout is 3840x2160 ABGR2101010, reported linear but resident in VRAM, so a CPU mmap is denied (EPERM). The GPU readback path (EGL/gbm DMA-BUF import) that handles VRAM and tiled buffers is the next increment; this lands the enumeration, format/modifier probe, and the linear read that covers software / UMA-linear scanout. Not yet wired into wayland::capture_rgb; the module and probe stand alone until the GPU readback lands. #VA-104 Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
feat(kvm): DRM/KMS scanout enumeration + capture probe (VA-104)
All checks were successful
Check / fmt + clippy + tests (pull_request) Successful in 4m7s
Details
Create release / Create release from merged PR (pull_request) Has been skipped
Details
2db3417739 
Foundation for consent-free Wayland capture: read the active CRTC's scanout framebuffer off /dev/dri as root, the compositor-agnostic path that works on KWin/GNOME where wlr-screencopy (grim) and the consent-gated portal do not. Enumerates cards/CRTCs, resolves the primary framebuffer (directly or via its plane), exports the plane's DMA-BUF, and reads a LINEAR buffer via mmap into packed RGB. Adds a drm_probe example plus `just drm-probe` / `just deploy-local` recipes for the on-host dev loop.

Confirmed on an AMD KWin host: the scanout is 3840x2160 ABGR2101010, reported linear but resident in VRAM, so a CPU mmap is denied (EPERM). The GPU readback path (EGL/gbm DMA-BUF import) that handles VRAM and tiled buffers is the next increment; this lands the enumeration, format/modifier probe, and the linear read that covers software / UMA-linear scanout.

Not yet wired into wayland::capture_rgb; the module and probe stand alone until the GPU readback lands.

#VA-104

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
David scheduled this pull request to auto merge when all checks succeed 2026-07-04 00:57:38 +02:00
David merged commit 2cc0d6b63b into main 2026-07-04 01:01:46 +02:00
David deleted branch fix/VA-104-drm-kms-capture 2026-07-04 01:01:47 +02:00
Sign in to join this conversation.
Reviewers
No reviewers
Labels
Clear labels
No items
No labels
Milestone
Clear milestone
No items
No milestone
Projects
Clear projects
No items
No project
Assignees
Clear assignees
No assignees
1 participant
Notifications
Due date
The due date is invalid or out of range. Please use the format "yyyy-mm-dd".

No due date set.

Dependencies

No dependencies set

Reference
psa-systems/vervain-agent!107
No description provided.