Re: [PATCH 1/3] virtio: cache indirect desc for split

Hi Xuan,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on horms-ipvs/master]
[also build test WARNING on linus/master v5.15-rc7 next-20211027]
[cannot apply to mst-vhost/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]

url:    https://github.com/0day-ci/linux/commits/Xuan-Zhuo/virtio-support-cache-indirect-desc/20211027-142025
base:   https://git.kernel.org/pub/scm/linux/kernel/git/horms/ipvs.git master
config: i386-randconfig-s002-20211027 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.4-dirty
        # https://github.com/0day-ci/linux/commit/8935e116c155fb7d484bad35a42b2ca98f75e384
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Xuan-Zhuo/virtio-support-cache-indirect-desc/20211027-142025
        git checkout 8935e116c155fb7d484bad35a42b2ca98f75e384
        # save the attached .config to linux build tree
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=i386 SHELL=/bin/bash drivers/virtio/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <redacted>


sparse warnings: (new ones prefixed by >>)

quoted

drivers/virtio/virtio_ring.c:438:26: sparse: sparse: cast from restricted __virtio64
drivers/virtio/virtio_ring.c:447:28: sparse: sparse: incorrect type in assignment (different base types) @@     expected restricted __virtio64 [usertype] addr @@     got unsigned long long [usertype] @@

   drivers/virtio/virtio_ring.c:447:28: sparse:     expected restricted __virtio64 [usertype] addr
   drivers/virtio/virtio_ring.c:447:28: sparse:     got unsigned long long [usertype]
   drivers/virtio/virtio_ring.c:464:49: sparse: sparse: cast from restricted __virtio64

vim +438 drivers/virtio/virtio_ring.c

   431	
   432	static void desc_cache_chain_free_split(void *chain)
   433	{
   434		struct vring_desc *desc;
   435	
   436		while (chain) {
   437			desc = chain;
 > 438			chain = (void *)desc->addr;
   439			kfree(desc);
   440		}
   441	}
   442	
   443	static void desc_cache_put_split(struct vring_virtqueue *vq,
   444					 struct vring_desc *desc, int n)
   445	{
   446		if (vq->use_desc_cache && n <= VIRT_QUEUE_CACHE_DESC_NUM) {
 > 447			desc->addr = (u64)vq->desc_cache_chain;
   448			vq->desc_cache_chain = desc;
   449		} else {
   450			kfree(desc);
   451		}
   452	}
   453	

---
0-DAY CI Kernel Test Service, Intel Corporation
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