[kvm:kvm-coco-queue 39/125] WARNING: modpost: vmlinux: section mismatch in reference: vt_init+0x2f (section: .init.text) -> vmx_exit (section: .exit.text)

[kvm:kvm-coco-queue 39/125] WARNING: modpost: vmlinux: section mismatch in reference: vt_init+0x2f (section: .init.text) -> vmx_exit (section: .exit.text)

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/virt/kvm/kvm.git kvm-coco-queue
head:   46bf7963a06a56a6c411329d06642836450d19a7
commit: 45c7c4a6fbf00d0ca3f033f30c39e6c12c517381 [39/125] KVM: VMX: Refactor VMX module init/exit functions
config: i386-buildonly-randconfig-002-20250123 (https://download.01.org/0day-ci/archive/20250123/202501231202.viiY8Abl-lkp@intel.com/config)
compiler: clang version 19.1.3 (https://github.com/llvm/llvm-project ab51eccf88f5321e7c60591c5546b254b6afab99)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250123/202501231202.viiY8Abl-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202501231202.viiY8Abl-lkp@intel.com/

All warnings (new ones prefixed by >>, old ones prefixed by <<):

>> WARNING: modpost: vmlinux: section mismatch in reference: vt_init+0x2f (section: .init.text) -> vmx_exit (section: .exit.text)

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

RE: [kvm:kvm-coco-queue 39/125] WARNING: modpost: vmlinux: section mismatch in reference: vt_init+0x2f (section: .init.text) -> vmx_exit (section: .exit.text)

[Huang, Kai]

> tree:   https://git.kernel.org/pub/scm/virt/kvm/kvm.git kvm-coco-queue
> head:   46bf7963a06a56a6c411329d06642836450d19a7
> commit: 45c7c4a6fbf00d0ca3f033f30c39e6c12c517381 [39/125] KVM: VMX:
> Refactor VMX module init/exit functions
> config: i386-buildonly-randconfig-002-20250123
> (https://download.01.org/0day-ci/archive/20250123/202501231202.viiY8Abl-
> lkp@intel.com/config)
> compiler: clang version 19.1.3 (https://github.com/llvm/llvm-project
> ab51eccf88f5321e7c60591c5546b254b6afab99)
> reproduce (this is a W=1 build): (https://download.01.org/0day-
> ci/archive/20250123/202501231202.viiY8Abl-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes:
> | https://lore.kernel.org/oe-kbuild-all/202501231202.viiY8Abl-lkp@intel.
> | com/
> 
> All warnings (new ones prefixed by >>, old ones prefixed by <<):
> 
> >> WARNING: modpost: vmlinux: section mismatch in reference:
> >> vt_init+0x2f (section: .init.text) -> vmx_exit (section: .exit.text)
> 

I checked the code, I think it is because vt_init() calls vmx_exit() in the error path when kvm_init() fails.

vt_init() is annotated with __init and vmx_exit() is annotated with __exit.

Perhaps we need to remove the __exit annotation from vmx_exit().

However I will be on airplane soon so cannot actually work on the code to verify.  Will do it once have time.

Re: [kvm:kvm-coco-queue 39/125] WARNING: modpost: vmlinux: section mismatch in reference: vt_init+0x2f (section: .init.text) -> vmx_exit (section: .exit.text)

[Edgecombe, Rick P]

On Thu, 2025-01-23 at 08:35 +0000, Huang, Kai wrote:
> I checked the code, I think it is because vt_init() calls vmx_exit() in the error path when kvm_init() fails.
> 
> vt_init() is annotated with __init and vmx_exit() is annotated with __exit.

Yea. The __exit was just added recently:
https://lore.kernel.org/kvm/20250102154050.2403-1-costas.argyris@amd.com/

> 
> Perhaps we need to remove the __exit annotation from vmx_exit().
> 

Re: [kvm:kvm-coco-queue 39/125] WARNING: modpost: vmlinux: section mismatch in reference: vt_init+0x2f (section: .init.text) -> vmx_exit (section: .exit.text)

[Huang, Kai]

On 24/01/2025 11:54 am, Edgecombe, Rick P wrote:
> On Thu, 2025-01-23 at 08:35 +0000, Huang, Kai wrote:
>> I checked the code, I think it is because vt_init() calls vmx_exit() in the error path when kvm_init() fails.
>>
>> vt_init() is annotated with __init and vmx_exit() is annotated with __exit.
> 
> Yea. The __exit was just added recently:
> https://lore.kernel.org/kvm/20250102154050.2403-1-costas.argyris@amd.com/

Yeah the __exit was added (back) because vmx_exit() is no longer called 
in the __init path.  Now with vt_init() for TDX, vmx_exit() is called by 
vt_init() again in the error handling path.  I think we should just drop 
the __exit again in this patch.

I tried below code change and the warning disappeared:

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 58915395da8a..9ab3507248c6 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -8586,7 +8586,7 @@ __init int vmx_hardware_setup(void)
         return r;
  }

-static void __exit vmx_cleanup_l1d_flush(void)
+static void vmx_cleanup_l1d_flush(void)
  {
         if (vmx_l1d_flush_pages) {
                 free_pages((unsigned long)vmx_l1d_flush_pages, 
L1D_CACHE_ORDER);
@@ -8596,7 +8596,7 @@ static void __exit vmx_cleanup_l1d_flush(void)
         l1tf_vmx_mitigation = VMENTER_L1D_FLUSH_AUTO;
  }

-void __exit vmx_exit(void)
+void vmx_exit(void)
  {
         allow_smaller_maxphyaddr = false;