RE: [PATCH 1/1] Drivers: hv: Select CONFIG_SYSFB only if EFI is enabled
From: Michael Kelley <hidden>
Date: 2025-06-30 20:46:53
Also in:
linux-hyperv, lkml
From: mhkelley58@gmail.com <redacted> Sent: Friday, June 13, 2025 4:01 PM
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.
Fixes: 96959283a58d ("Drivers: hv: Always select CONFIG_SYSFB for Hyper-V guests")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Closes: https://lore.kernel.org/linux-hyperv/20250610091810.2638058-1-arnd@kernel.org/ (local)Arnd -- Can you give a "Reviewed-by:" or "Acked-by:" for this fix? It needs to get into linux-next and then into Linus' tree before we get too late in the 6.16 release cycle. Michael
quoted hunk ↗ jump to hunk
Reported-by: kernel test robot <redacted> Closes: https://lore.kernel.org/oe-kbuild-all/202506080820.1wmkQufc-lkp@intel.com/ (local) Signed-off-by: Michael Kelley <redacted> --- drivers/hv/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig index 1cd188b73b74..57623ca7f350 100644 --- a/drivers/hv/Kconfig +++ b/drivers/hv/Kconfig@@ -9,7 +9,7 @@ config HYPERV select PARAVIRT select X86_HV_CALLBACK_VECTOR if X86 select OF_EARLY_FLATTREE if OF - select SYSFB if !HYPERV_VTL_MODE + select SYSFB if EFI && !HYPERV_VTL_MODE help Select this option to run Linux as a Hyper-V client operating system. --2.25.1