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| author | Christian Krinitsin <mail@krinitsin.com> | 2025-05-21 21:21:26 +0200 |
|---|---|---|
| committer | Christian Krinitsin <mail@krinitsin.com> | 2025-05-21 21:21:26 +0200 |
| commit | 4b927bc37359dec23f67d3427fc982945f24f404 (patch) | |
| tree | 245449ef9146942dc7fffd0235b48b7e70a00bf2 /gitlab/issues/target_missing/host_missing/accel_missing/1107.toml | |
| parent | aa8bd79cec7bf6790ddb01d156c2ef2201abbaab (diff) | |
| download | emulator-bug-study-4b927bc37359dec23f67d3427fc982945f24f404.tar.gz emulator-bug-study-4b927bc37359dec23f67d3427fc982945f24f404.zip | |
add gitlab issues in toml format
Diffstat (limited to 'gitlab/issues/target_missing/host_missing/accel_missing/1107.toml')
| -rw-r--r-- | gitlab/issues/target_missing/host_missing/accel_missing/1107.toml | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/gitlab/issues/target_missing/host_missing/accel_missing/1107.toml b/gitlab/issues/target_missing/host_missing/accel_missing/1107.toml new file mode 100644 index 00000000..b89a67b9 --- /dev/null +++ b/gitlab/issues/target_missing/host_missing/accel_missing/1107.toml @@ -0,0 +1,34 @@ +id = 1107 +title = "Virtual monitor heads are not \"connected\" until viewed in a front end" +state = "opened" +created_at = "2022-07-14T08:21:50.853Z" +closed_at = "n/a" +labels = ["device:graphics", "device:virtio"] +url = "https://gitlab.com/qemu-project/qemu/-/issues/1107" +host-os = "Debian 11" +host-arch = "AMD64" +qemu-version = "QEMU emulator version 7.0.50 (v7.0.0-2471-g8e3d85d36b)" +guest-os = "Linux" +guest-arch = "Arm Aarch64" +description = """When you attach a virtual GPU to a guest, qemu appears to only "attach" a virtual monitor to an output port when that virtual display is +viewed using the GUI. For example, when you boot using the above command line, there will be four displays in ```/sys/class/drm/``` on the guest, +```card0-Virtual-1``` through to ```card0-Virtual-4```. In each of these directories, there is an "enabled" file, which contains either +"enabled" or "disabled". These contain "disabled" until you switch tab/view to look at it using the GUI, at which point they change to "enabled". + +This causes a problem for us because Weston will not initialise displays that do not have a monitor attached, meaning the system we are trying +to boot fails because not all the Weston display surfaces are available. + +There does not appear to be a command line option to force virtual monitors to be attached to virtual displays immediately. Looking through the +Gtk user interface code (and the other front ends) there does not appear to be a call into the qemu core that requests the connection of a virtual +monitor to the virtual displays - my guess is that qemu only connects a monitor when a render request first happens (or similar), but I have not followed the code paths deeper than the source files in ```QEMU/ui/```. + +I also tried using the ```screengrab``` command to screenshot each head, but this does not need sufficient to cause the display to be marked +enabled in the guest. + +While we could possibly automate the GUI using some external tool, we ultimately need to run this in a CI environment using +```egl-headless``` or similar.""" +reproduce = """1. Launch qemu with virtio-gpu-gl setting max_outputs > 1 +2. On guest, ```cat /sys/drm/class/card0-Virtual-2``` - it reads "disabled" +3. On host, switch the view to look at the second display ("virtio-gpu-gl-pci.1") +4. On guest, ```cat /sys/drm/class/card0-Virtual-2``` - it now reads "enabled"""" +additional = "n/a" |