Issues with both Generation 1 and Generation 2 Hyper-V Guests

[lunzima]

Bug description

Xorg refuses to start on Generation 1 and Generation 2 Hyper-V guests and 6.10.x kernels. On Generation 2 guests, blacklisting hyperv_fb resolves the issue. On Generation 1 guests, blacklisting hyperv_drm resolves the issue. Downgrading the Linux kernel is required if the hyperv_fb kernel module is not included in the kernel. In some cases, framebuffer corruption of the virtual machine can be observed using the combination of Generation 1 guests + hyperv_drm.

Steps to reproduce

Install AOSC OS with Hyper-V then wait for OS starting up for the first time after installation is complete. My Windows Host is running Windows 11 version 23H2. @KexyBiscuit

Update channel(s)

stable

Package and version

linux-kernel-6.10.x

[KexyBiscuit]

For generation 2 virtual machines in Hyper-V, the problem has been existed not later than linux-kernel-5.11.1.

Another workaround for generation 2 virtual machines in Hyper-V is to disable the splash screen of Plymouth.

[KexyBiscuit]

The problem of generation 2 virtual machines in Hyper-V is actually caused by #6126. After reverting #6126, the splash screen still doesn't appear, but the login screen works well.

[KexyBiscuit]

Part of the problem of generation 1 virtual machines in Hyper-V is also caused by https://github.com/AOSC-Dev/aosc-os-abbs/pull/6126. After reverting https://github.com/AOSC-Dev/aosc-os-abbs/pull/6126, the splash screen still doesn't appear, but the login screen works well.

[KexyBiscuit]

Confirmed that Red Hat Bugzilla – Bug 2000921 contains the fix for hyperv_drm driver plus xorg-server on generation 1 virtual machines in Hyper-V.

I prefer to remove hyperv_fb driver to mitigate the Plymouth splash screen issue, since that's also what Microsoft recommends.

Ref: https://access.redhat.com/downloads/content/xorg-x11-server-Xorg/1.20.11-10.el9/x86_64/fd431d51/package

[lunzima]

With the RHEL patch for Xorg, hyperv_drm now works for Gen1 guests. Plymouth works too with enabled downgrade topic.

Please retire hyperv_fb for kernel config so hyperv_drm will work out-of-box.

[lunzima]

With topic xorg-server-21.1.13-hyperv-drm-fix the issue mentioned above is fixed too.

[MingcongBai]

Very well.