target/riscv: Make VSTIP and VSEIP read-only in hip

Signed-off-by: Georg Kotheimer <georg.kotheimer@kernkonzept.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20210311094902.1377593-1-georg.kotheimer@kernkonzept.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

target/riscv/csr.c

@@ -420,7 +420,8 @@ static const target_ulong sstatus_v1_10_mask = SSTATUS_SIE | SSTATUS_SPIE |
     SSTATUS_UIE | SSTATUS_UPIE | SSTATUS_SPP | SSTATUS_FS | SSTATUS_XS |
     SSTATUS_SUM | SSTATUS_MXR | SSTATUS_SD;
 static const target_ulong sip_writable_mask = SIP_SSIP | MIP_USIP | MIP_UEIP;
-static const target_ulong hip_writable_mask = MIP_VSSIP | MIP_VSTIP | MIP_VSEIP;
+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] = {
@@ -962,9 +963,9 @@ static int rmw_hvip(CPURISCVState *env, int csrno, target_ulong *ret_value,
                    target_ulong new_value, target_ulong write_mask)
 {
     int ret = rmw_mip(env, 0, ret_value, new_value,
-                      write_mask & hip_writable_mask);
+                      write_mask & hvip_writable_mask);
 
-    *ret_value &= hip_writable_mask;
+    *ret_value &= hvip_writable_mask;
 
     return ret;
 }