diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 3106f96212..d93d481bd6 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -1141,16 +1141,16 @@ static const target_ulong hip_writable_mask = MIP_VSSIP;
 static const target_ulong hvip_writable_mask = MIP_VSSIP | MIP_VSTIP | MIP_VSEIP;
 static const target_ulong vsip_writable_mask = MIP_VSSIP;
 
-static const char valid_vm_1_10_32[16] = {
-    [VM_1_10_MBARE] = 1,
-    [VM_1_10_SV32] = 1
+static const bool valid_vm_1_10_32[16] = {
+    [VM_1_10_MBARE] = true,
+    [VM_1_10_SV32] = true
 };
 
-static const char valid_vm_1_10_64[16] = {
-    [VM_1_10_MBARE] = 1,
-    [VM_1_10_SV39] = 1,
-    [VM_1_10_SV48] = 1,
-    [VM_1_10_SV57] = 1
+static const bool valid_vm_1_10_64[16] = {
+    [VM_1_10_MBARE] = true,
+    [VM_1_10_SV39] = true,
+    [VM_1_10_SV48] = true,
+    [VM_1_10_SV57] = true
 };
 
 /* Machine Information Registers */
@@ -1230,7 +1230,7 @@ static RISCVException read_mstatus(CPURISCVState *env, int csrno,
     return RISCV_EXCP_NONE;
 }
 
-static int validate_vm(CPURISCVState *env, target_ulong vm)
+static bool validate_vm(CPURISCVState *env, target_ulong vm)
 {
     if (riscv_cpu_mxl(env) == MXL_RV32) {
         return valid_vm_1_10_32[vm & 0xf];
@@ -2669,7 +2669,8 @@ static RISCVException read_satp(CPURISCVState *env, int csrno,
 static RISCVException write_satp(CPURISCVState *env, int csrno,
                                  target_ulong val)
 {
-    target_ulong vm, mask;
+    target_ulong mask;
+    bool vm;
 
     if (!riscv_cpu_cfg(env)->mmu) {
         return RISCV_EXCP_NONE;