Re: [PATCH 2/3] KVM: x86: add system attribute to retrieve full set of supported xsave states

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

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Hi Paolo,

I love your patch! Perhaps something to improve:

[auto build test WARNING on kvm/queue]
[also build test WARNING on tip/master linus/master v5.17-rc1 next-20220125]
[cannot apply to linux/master]
[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/Paolo-Bonzini/KVM-x86-export-supported_xcr0-via-UAPI/20220126-232404
base:   https://git.kernel.org/pub/scm/virt/kvm/kvm.git queue
config: i386-allyesconfig (https://download.01.org/0day-ci/archive/20220127/202201270505.Zw7qAhV1-lkp(a)intel.com/config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
        # https://github.com/0day-ci/linux/commit/b2fde1186382c3f79ca5fd335b692b80de2f94af
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Paolo-Bonzini/KVM-x86-export-supported_xcr0-via-UAPI/20220126-232404
        git checkout b2fde1186382c3f79ca5fd335b692b80de2f94af
        # save the config file to linux build tree
        mkdir build_dir
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash arch/x86/kvm/

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

All warnings (new ones prefixed by >>):

   In file included from include/linux/uaccess.h:11,
                    from include/linux/sched/task.h:11,
                    from include/linux/sched/signal.h:9,
                    from include/linux/rcuwait.h:6,
                    from include/linux/percpu-rwsem.h:7,
                    from include/linux/fs.h:33,
                    from include/linux/huge_mm.h:8,
                    from include/linux/mm.h:717,
                    from include/linux/kvm_host.h:16,
                    from arch/x86/kvm/x86.c:19:
   arch/x86/kvm/x86.c: In function 'kvm_x86_dev_get_attr':
>> arch/x86/kvm/x86.c:4344:32: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
    4344 |   if (put_user(supported_xcr0, (u64 __user *)attr->addr))
         |                                ^
   arch/x86/include/asm/uaccess.h:221:24: note: in definition of macro 'do_put_user_call'
     221 |  register __typeof__(*(ptr)) __val_pu asm("%"_ASM_AX);  \
         |                        ^~~
   arch/x86/kvm/x86.c:4344:7: note: in expansion of macro 'put_user'
    4344 |   if (put_user(supported_xcr0, (u64 __user *)attr->addr))
         |       ^~~~~~~~
>> arch/x86/kvm/x86.c:4344:32: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
    4344 |   if (put_user(supported_xcr0, (u64 __user *)attr->addr))
         |                                ^
   arch/x86/include/asm/uaccess.h:223:14: note: in definition of macro 'do_put_user_call'
     223 |  __ptr_pu = (ptr);      \
         |              ^~~
   arch/x86/kvm/x86.c:4344:7: note: in expansion of macro 'put_user'
    4344 |   if (put_user(supported_xcr0, (u64 __user *)attr->addr))
         |       ^~~~~~~~
>> arch/x86/kvm/x86.c:4344:32: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
    4344 |   if (put_user(supported_xcr0, (u64 __user *)attr->addr))
         |                                ^
   arch/x86/include/asm/uaccess.h:230:31: note: in definition of macro 'do_put_user_call'
     230 |          [size] "i" (sizeof(*(ptr)))   \
         |                               ^~~
   arch/x86/kvm/x86.c:4344:7: note: in expansion of macro 'put_user'
    4344 |   if (put_user(supported_xcr0, (u64 __user *)attr->addr))
         |       ^~~~~~~~


vim +4344 arch/x86/kvm/x86.c

  4336	
  4337	static int kvm_x86_dev_get_attr(struct kvm_device_attr *attr)
  4338	{
  4339		if (attr->group)
  4340			return -ENXIO;
  4341	
  4342		switch (attr->attr) {
  4343		case KVM_X86_XCOMP_GUEST_SUPP:
> 4344			if (put_user(supported_xcr0, (u64 __user *)attr->addr))
  4345				return -EFAULT;
  4346			return 0;
  4347		default:
  4348			return -ENXIO;
  4349			break;
  4350		}
  4351	}
  4352	

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