[mst-vhost:vhost 5/37] drivers/virtio/virtio_balloon.c:372:37: warning: arithmetic between different enumeration types ('enum vm_event_item' and 'enum zone_type')

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

CC: kvm@vger.kernel.org
CC: virtualization@lists.linux-foundation.org
CC: netdev@vger.kernel.org
TO: zhenwei pi <pizhenwei@bytedance.com>
CC: "Michael S. Tsirkin" <mst@redhat.com>

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git vhost
head:   025b6cabd88a35947637ffb7613e90c871c3381b
commit: c5b70a26aac39f09a23fd72f44cfbb3d4d5a14d5 [5/37] virtio_balloon: introduce memory allocation stall counter
config: hexagon-allmodconfig (https://download.01.org/0day-ci/archive/20240911/202409111508.O5YtdBhp-lkp@intel.com/config)
compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project bf684034844c660b778f0eba103582f582b710c9)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240911/202409111508.O5YtdBhp-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/202409111508.O5YtdBhp-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from drivers/virtio/virtio_balloon.c:9:
   In file included from include/linux/virtio.h:7:
   In file included from include/linux/scatterlist.h:8:
   In file included from include/linux/mm.h:2228:
   include/linux/vmstat.h:517:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
     517 |         return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
         |                               ~~~~~~~~~~~ ^ ~~~
   In file included from drivers/virtio/virtio_balloon.c:9:
   In file included from include/linux/virtio.h:7:
   In file included from include/linux/scatterlist.h:9:
   In file included from arch/hexagon/include/asm/io.h:328:
   include/asm-generic/io.h:548:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     548 |         val = __raw_readb(PCI_IOBASE + addr);
         |                           ~~~~~~~~~~ ^
   include/asm-generic/io.h:561:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     561 |         val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
         |                                                         ~~~~~~~~~~ ^
   include/uapi/linux/byteorder/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu'
      37 | #define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
         |                                                   ^
   In file included from drivers/virtio/virtio_balloon.c:9:
   In file included from include/linux/virtio.h:7:
   In file included from include/linux/scatterlist.h:9:
   In file included from arch/hexagon/include/asm/io.h:328:
   include/asm-generic/io.h:574:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     574 |         val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
         |                                                         ~~~~~~~~~~ ^
   include/uapi/linux/byteorder/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu'
      35 | #define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
         |                                                   ^
   In file included from drivers/virtio/virtio_balloon.c:9:
   In file included from include/linux/virtio.h:7:
   In file included from include/linux/scatterlist.h:9:
   In file included from arch/hexagon/include/asm/io.h:328:
   include/asm-generic/io.h:585:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     585 |         __raw_writeb(value, PCI_IOBASE + addr);
         |                             ~~~~~~~~~~ ^
   include/asm-generic/io.h:595:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     595 |         __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
         |                                                       ~~~~~~~~~~ ^
   include/asm-generic/io.h:605:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     605 |         __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
         |                                                       ~~~~~~~~~~ ^
>> drivers/virtio/virtio_balloon.c:372:37: warning: arithmetic between different enumeration types ('enum vm_event_item' and 'enum zone_type') [-Wenum-enum-conversion]
     372 |                 stall += events[ALLOCSTALL_NORMAL - ZONE_NORMAL + zid];
         |                                 ~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~
   8 warnings generated.


vim +372 drivers/virtio/virtio_balloon.c

   351	
   352	#ifdef CONFIG_VM_EVENT_COUNTERS
   353	/* Return the number of entries filled by vm events */
   354	static inline unsigned int update_balloon_vm_stats(struct virtio_balloon *vb)
   355	{
   356		unsigned long events[NR_VM_EVENT_ITEMS];
   357		unsigned int idx = 0;
   358		unsigned int zid;
   359		unsigned long stall = 0;
   360	
   361		all_vm_events(events);
   362		update_stat(vb, idx++, VIRTIO_BALLOON_S_SWAP_IN,
   363			    pages_to_bytes(events[PSWPIN]));
   364		update_stat(vb, idx++, VIRTIO_BALLOON_S_SWAP_OUT,
   365			    pages_to_bytes(events[PSWPOUT]));
   366		update_stat(vb, idx++, VIRTIO_BALLOON_S_MAJFLT, events[PGMAJFAULT]);
   367		update_stat(vb, idx++, VIRTIO_BALLOON_S_MINFLT, events[PGFAULT]);
   368		update_stat(vb, idx++, VIRTIO_BALLOON_S_OOM_KILL, events[OOM_KILL]);
   369	
   370		/* sum all the stall events */
   371		for (zid = 0; zid < MAX_NR_ZONES; zid++)
 > 372			stall += events[ALLOCSTALL_NORMAL - ZONE_NORMAL + zid];
   373	
   374		update_stat(vb, idx++, VIRTIO_BALLOON_S_ALLOC_STALL, stall);
   375	

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