Re: [PATCH] KVM: optionally post write on ioeventfd write

[kernel test robot <lkp@intel.com>]

Hi Thanos,

kernel test robot noticed the following build errors:

[auto build test ERROR on kvm/queue]
[also build test ERROR on kvm/next linus/master v7.0-rc2 next-20260304]
[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/Thanos-Makatos/KVM-optionally-post-write-on-ioeventfd-write/20260302-204031
base:   https://git.kernel.org/pub/scm/virt/kvm/kvm.git queue
patch link:    https://lore.kernel.org/r/20260302122826.2572-1-thanos.makatos%40nutanix.com
patch subject: [PATCH] KVM: optionally post write on ioeventfd write
config: i386-randconfig-141-20260305 (https://download.01.org/0day-ci/archive/20260305/202603051704.nmQyEAnO-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
smatch: v0.5.0-9004-gb810ac53
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260305/202603051704.nmQyEAnO-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/202603051704.nmQyEAnO-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from arch/x86/events/intel/core.c:17:
   In file included from include/linux/kvm_host.h:40:
>> include/uapi/linux/kvm.h:669:16: error: static assertion failed due to requirement 'sizeof(struct kvm_ioeventfd) == 1 << 6': bad size
     669 | _Static_assert(sizeof(struct kvm_ioeventfd) == 1 << 6, "bad size");
         |                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/uapi/linux/kvm.h:669:45: note: expression evaluates to '56 == 64'
     669 | _Static_assert(sizeof(struct kvm_ioeventfd) == 1 << 6, "bad size");
         |                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~
   1 error generated.


vim +669 include/uapi/linux/kvm.h

   659	
   660	struct kvm_ioeventfd {
   661		__u64 datamatch;
   662		__u64 addr;        /* legal pio/mmio address */
   663		__u32 len;         /* 1, 2, 4, or 8 bytes; or 0 to ignore length */
   664		__s32 fd;
   665		__u32 flags;
   666		void __user *post_addr; /* address to write to if POST_WRITE is set */
   667		__u8  pad[24];
   668	};
 > 669	_Static_assert(sizeof(struct kvm_ioeventfd) == 1 << 6, "bad size");
   670	

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