On Sat, Oct 06, 2018 at 11:31:04AM +0800, peng.hao2@xxxxxxxxxx wrote: >>On Thu, Oct 04, 2018 at 01:47:18PM -0400, Peng Hao wrote: >>> >>>From: Peng Hao <peng.hao2@xxxxxxxxxx> >>> >>> modify AVIC_LOGICAL_ID_ENTRY_VALID_MASK to unsigned >>> >>>Signed-off-by: Peng Hao <peng.hao2@xxxxxxxxxx> >>>--- >>> arch/x86/kvm/svm.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>>diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c >>>index d96092b..bf1ded4 100644 >>>--- a/arch/x86/kvm/svm.c >>>+++ b/arch/x86/kvm/svm.c >>>@@ -262,7 +262,7 @@ struct amd_svm_iommu_ir { >>> }; >>> >>> #define AVIC_LOGICAL_ID_ENTRY_GUEST_PHYSICAL_ID_MASK (0xFF) >>>-#define AVIC_LOGICAL_ID_ENTRY_VALID_MASK (1 << 31) >>>+#define AVIC_LOGICAL_ID_ENTRY_VALID_MASK (1UL << 31) > >>It is reasonable to change to unsigned, while not necessary to unsigned >>long? >AVIC_LOGICAL_ID_ENTRY_VALID_MASK is used in function avic_ldr_write. >here I think it doesn't matter if you use unsigned or unsigned long. Do you have any suggestions? In current case, AVIC_LOGICAL_ID_ENTRY_VALID_MASK is used to calculate the value of new_entry with type of u32. So the definition here is not harmful. Also, I did a quick grep and found similar definition (1 << 31) is popular in the whole kernel tree. The reason to make this change is not that strong to me. Would you minding sharing more reason behind this change? >>-- >>Wei Yang >>Help you, Help me -- Wei Yang Help you, Help me