Re: [RFC PATCH 2/2] KVM: pfncache: Use vmap() for guest_memfd pages without direct map

Re: [RFC PATCH 2/2] KVM: pfncache: Use vmap() for guest_memfd pages without direct map

[kernel test robot]

Hi Takahiro,

[This is a private test report for your RFC patch.]
kernel test robot noticed the following build errors:

[auto build test ERROR on kvm/queue]
[also build test ERROR on kvm/next mst-vhost/linux-next linus/master v6.18 next-20251205]
[cannot apply to kvm/linux-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Takahiro-Itazuri/KVM-pfncache-Use-kvm_gmem_get_pfn-for-guest_memfd-backed-memslots/20251203-224344
base:   https://git.kernel.org/pub/scm/virt/kvm/kvm.git queue
patch link:    https://lore.kernel.org/r/20251203144159.6131-3-itazur%40amazon.com
patch subject: [RFC PATCH 2/2] KVM: pfncache: Use vmap() for guest_memfd pages without direct map
config: x86_64-rhel-9.4-rust (https://download.01.org/0day-ci/archive/20251205/202512051702.JVgyDZnV-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
rustc: rustc 1.88.0 (6b00bc388 2025-06-23)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251205/202512051702.JVgyDZnV-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/202512051702.JVgyDZnV-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from arch/x86/events/intel/core.c:17:
>> include/linux/kvm_host.h:634:9: error: call to undeclared function 'mapping_no_direct_map'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     634 |                mapping_no_direct_map(slot->gmem.file->f_mapping);
         |                ^
   1 error generated.


vim +/mapping_no_direct_map +634 include/linux/kvm_host.h

   630	
   631	static inline bool kvm_slot_no_direct_map(const struct kvm_memory_slot *slot)
   632	{
   633		return slot && kvm_slot_has_gmem(slot) &&
 > 634		       mapping_no_direct_map(slot->gmem.file->f_mapping);
   635	}
   636	

-- 
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