#1002450 debian-installer: garbled display when using kvm's display=default (bochsdrm)

Package:
debian-installer
Source:
debian-installer
Description:
Debian Installer documentation
Submitter:
Jan De Luyck
Date:
2021-12-22 09:57:03 UTC
Severity:
normal
#1002450#5
Date:
2021-12-22 09:54:35 UTC
From:
To:
Dear Maintainer,

Trying to install debian 11.2 into a KVM VM on Proxmox, the display becomes unreadable
immediately after Grub loads the kernel.

The vm specs are:
* display: default
* machine type: q35
* ovmf uefi boot

None of the usual parameters (drm/kms related) worked, but I stumbled across this bug report
on ubuntu:

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1872863

which suggests it's a problem with bochsdrm not being loaded correctly, or more specifically the
fb not being handed over to bochs fb driver from efifb.

I tested with virtio-gpu driver, which gives me a working display.
Debian 10 ISO images also work fine.

Kind regards.
---
Debian Release: bookworm/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.15.0-2-amd64 (SMP w/4 CPU threads)
Kernel taint flags: TAINT_PROPRIETARY_MODULE, TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
Locale: LANG=en_BE.UTF-8, LC_CTYPE=en_BE.UTF-8 (charmap=UTF-8), LANGUAGE=en_BE:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled