Re: [PATCH 1/1] Drivers: hv: Select CONFIG_SYSFB only if EFI is enabled

Roman Kisel
2025-07-07T17:59:55Z

On 6/13/2025 4:00 PM, mhkelley58@gmail.com wrote:
> From: Michael Kelley <mhklinux@outlook.com>
>
> Commit 96959283a58d ("Drivers: hv: Always select CONFIG_SYSFB
> for Hyper-V guests") selects CONFIG_SYSFB for Hyper-V guests
> so that screen_info is available to the VMBus driver to get
> the location of the framebuffer in Generation 2 VMs. However,
> if CONFIG_HYPERV is enabled but CONFIG_EFI is not, a kernel
> link error results in ARM64 builds because screen_info is
> provided by the EFI firmware interface. While configuring
> an ARM64 Hyper-V guest without EFI isn't useful since EFI is
> required to boot, the configuration is still possible and
> the link error should be prevented.
>
> Fix this by making the selection of CONFIG_SYSFB conditional
> on CONFIG_EFI being defined. For Generation 1 VMs on x86/x64,
> which don't use EFI, the additional condition is OK because
> such VMs get the framebuffer information via a mechanism
> that doesn't use screen_info.
>

[...]

LGTM.
Reviewed-by: Roman Kisel <romank@linux.microsoft.com>

--
Thank you,
Roman