Hi Kirti,

I love your patch! Perhaps something to improve:

[auto build test WARNING on vfio/next]
[also build test WARNING on v5.7-rc7 next-20200526]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Kirti-Wankhede/Add-UAPIs-to-support-migration-for-VFIO-devices/20200521-060843
base:   https://github.com/awilliam/linux-vfio.git next
config: x86_64-randconfig-s021-20200527 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-13) 9.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.1-240-gf0fe1cd9-dirty
        # save the attached .config to linux build tree
        make W=1 C=1 ARCH=x86_64 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__'

If you fix the issue, kindly add following tag as appropriate
Reported-by: kbuild test robot <lkp@intel.com>


sparse warnings: (new ones prefixed by >>)

   drivers/vfio/vfio_iommu_type1.c:981:48: sparse: sparse: cast removes address space '<asn:1>' of expression
>> drivers/vfio/vfio_iommu_type1.c:981:61: sparse: sparse: incorrect type in argument 2 (different address spaces) @@     expected void const [noderef] <asn:1> *from @@     got unsigned long long [usertype] * @@
   drivers/vfio/vfio_iommu_type1.c:981:61: sparse:     expected void const [noderef] <asn:1> *from
   drivers/vfio/vfio_iommu_type1.c:981:61: sparse:     got unsigned long long [usertype] *
   drivers/vfio/vfio_iommu_type1.c:988:27: sparse: sparse: cast removes address space '<asn:1>' of expression
>> drivers/vfio/vfio_iommu_type1.c:988:40: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void [noderef] <asn:1> *to @@     got unsigned long long [usertype] * @@
   drivers/vfio/vfio_iommu_type1.c:988:40: sparse:     expected void [noderef] <asn:1> *to
   drivers/vfio/vfio_iommu_type1.c:988:40: sparse:     got unsigned long long [usertype] *

vim +981 drivers/vfio/vfio_iommu_type1.c

   962	
   963	static int update_user_bitmap(u64 __user *bitmap, struct vfio_dma *dma,
   964				      dma_addr_t base_iova, size_t pgsize)
   965	{
   966		unsigned long pgshift = __ffs(pgsize);
   967		unsigned long nbits = dma->size >> pgshift;
   968		unsigned long bit_offset = (dma->iova - base_iova) >> pgshift;
   969		unsigned long copy_offset = bit_offset / BITS_PER_LONG;
   970		unsigned long shift = bit_offset % BITS_PER_LONG;
   971		unsigned long leftover;
   972	
   973		/* mark all pages dirty if all pages are pinned and mapped. */
   974		if (dma->iommu_mapped)
   975			bitmap_set(dma->bitmap, 0, nbits);
   976	
   977		if (shift) {
   978			bitmap_shift_left(dma->bitmap, dma->bitmap, shift,
   979					  nbits + shift);
   980	
 > 981			if (copy_from_user(&leftover, (u64 *)bitmap + copy_offset,
   982					   sizeof(leftover)))
   983				return -EFAULT;
   984	
   985			bitmap_or(dma->bitmap, dma->bitmap, &leftover, shift);
   986		}
   987	
 > 988		if (copy_to_user((u64 *)bitmap + copy_offset, dma->bitmap,
   989				 DIRTY_BITMAP_BYTES(nbits + shift)))
   990			return -EFAULT;
   991	
   992		return 0;
   993	}
   994	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org