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.
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.or... Reported-by: kernel test robot lkp@intel.com Closes: https://lore.kernel.org/oe-kbuild-all/202506080820.1wmkQufc-lkp@intel.com/ Signed-off-by: Michael Kelley mhklinux@outlook.com --- 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.
Hi,
Thanks for your patch.
FYI: kernel test robot notices the stable kernel rule is not satisfied.
The check is based on https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html#opti...
Rule: add the tag "Cc: stable@vger.kernel.org" in the sign-off area to have the patch automatically included in the stable tree. Subject: [PATCH 1/1] Drivers: hv: Select CONFIG_SYSFB only if EFI is enabled Link: https://lore.kernel.org/stable/20250613230059.380483-1-mhklinux%40outlook.co...
From: mhkelley58@gmail.com mhkelley58@gmail.com 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.or...
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
Reported-by: kernel test robot lkp@intel.com Closes: https://lore.kernel.org/oe-kbuild-all/202506080820.1wmkQufc-lkp@intel.com/ Signed-off-by: Michael Kelley mhklinux@outlook.com
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
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
On Fri, Jun 13, 2025 at 04:00:59PM -0700, 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.
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.or... Reported-by: kernel test robot lkp@intel.com Closes: https://lore.kernel.org/oe-kbuild-all/202506080820.1wmkQufc-lkp@intel.com/ Signed-off-by: Michael Kelley mhklinux@outlook.com
Applied to hyperv-fixes. Thanks!
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