target/riscv: Deny access if access is partially inside the PMP entry

Access will fail if access is partially inside the PMP entry.
However,only setting ret = false doesn't really mean pmp violation
since pmp_hart_has_privs_default() may return true at the end of
pmp_hart_has_privs().

Signed-off-by: Weiwei Li <liweiwei@iscas.ac.cn>
Signed-off-by: Junqiang Wang <wangjunqiang@iscas.ac.cn>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230517091519.34439-13-liweiwei@iscas.ac.cn>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

target/riscv/pmp.c

@@ -327,8 +327,8 @@ bool pmp_hart_has_privs(CPURISCVState *env, target_ulong addr,
         if ((s + e) == 1) {
             qemu_log_mask(LOG_GUEST_ERROR,
                           "pmp violation - access is partially inside\n");
-            ret = false;
-            break;
+            *allowed_privs = 0;
+            return false;
         }
 
         /* fully inside */