Hi Ashish, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on v5.11-rc6] [also build test WARNING on next-20210125] [cannot apply to kvm/linux-next tip/x86/mm tip/x86/core] [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/Ashish-Kalra/KVM-SVM-Add-KVM_SEV... base: 1048ba83fb1c00cd24172e23e8263972f6b5d9ac config: i386-randconfig-r015-20210209 (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 reproduce (this is a W=1 build): # https://github.com/0day-ci/linux/commit/c086cd5491c6b84adcffedc1bf798df75... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Ashish-Kalra/KVM-SVM-Add-KVM_SEV-SEND_START-command/20210204-093647 git checkout c086cd5491c6b84adcffedc1bf798df758b18080 # save the attached .config to linux build tree make W=1 ARCH=i386 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): arch/x86/kvm/svm/sev.c: In function 'handle_unencrypted_region': 945 | int len, s_off, d_off; | ^~~~~ vim +/d_off +945 arch/x86/kvm/svm/sev.c 934 935 static int handle_unencrypted_region(struct kvm *kvm, 936 unsigned long vaddr, 937 unsigned long vaddr_end, 938 unsigned long dst_vaddr, 939 unsigned int size, 940 bool *is_decrypted) 941 { 942 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; 943 struct page *page = NULL; 944 gfn_t gfn_start, gfn_end; 946 int srcu_idx; 947 int ret = 0; 948 949 /* ensure hva_to_gfn translations remain valid */ 950 srcu_idx = srcu_read_lock(&kvm->srcu); 951 952 if (!hva_to_gfn(kvm, vaddr, &gfn_start)) { 953 srcu_read_unlock(&kvm->srcu, srcu_idx); 954 return -EINVAL; 955 } 956 957 if (!hva_to_gfn(kvm, vaddr_end, &gfn_end)) { 958 srcu_read_unlock(&kvm->srcu, srcu_idx); 959 return -EINVAL; 960 } 961 962 if (sev->shared_pages_list_count) { 963 if (is_unencrypted_region(gfn_start, gfn_end, 964 &sev->shared_pages_list)) { 965 page = alloc_page(GFP_KERNEL); 966 if (!page) { 967 srcu_read_unlock(&kvm->srcu, srcu_idx); 968 return -ENOMEM; 969 } 970 971 /* 972 * Since user buffer may not be page aligned, calculate the 973 * offset within the page. 974 */ 975 s_off = vaddr & ~PAGE_MASK; 976 d_off = dst_vaddr & ~PAGE_MASK; 977 len = min_t(size_t, (PAGE_SIZE - s_off), size); 978 979 if (copy_from_user(page_address(page), 980 (void __user *)(uintptr_t)vaddr, len)) { 981 __free_page(page); 982 srcu_read_unlock(&kvm->srcu, srcu_idx); 983 return -EFAULT; 984 } 985 986 if (copy_to_user((void __user *)(uintptr_t)dst_vaddr, 987 page_address(page), len)) { 988 ret = -EFAULT; 989 } 990 991 __free_page(page); 992 srcu_read_unlock(&kvm->srcu, srcu_idx); 993 *is_decrypted = true; 994 return ret; 995 } 996 } 997 srcu_read_unlock(&kvm->srcu, srcu_idx); 998 *is_decrypted = false; 999 return ret; 1000 } 1001 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org