From 6d5a351a9833cf7555e6b91019c481b9e55b47bf Mon Sep 17 00:00:00 2001
From: Scott Johnson <scott.johnson@arilinc.com>
Date: Sun, 7 Mar 2021 17:16:20 -0800
Subject: [PATCH] Forbid `csrw vsstatus` from modifying the UXL field (#671)

Since this is not modifiable in the real sstatus, so it should not be
in the virtualized version either.
---
 riscv/processor.cc | 1 +
 1 file changed, 1 insertion(+)

diff --git a/riscv/processor.cc b/riscv/processor.cc
index 8abe552e..5b39d6fa 100644
--- a/riscv/processor.cc
+++ b/riscv/processor.cc
@@ -1189,6 +1189,7 @@ void processor_t::set_csr(int which, reg_t val)
           ((state.vsstatus & SSTATUS_XS) == SSTATUS_XS)) {
          state.vsstatus |= (xlen == 64 ? SSTATUS64_SD : SSTATUS32_SD);
       }
+      state.vsstatus = set_field(state.vsstatus, SSTATUS_UXL, xlen_to_uxl(max_xlen));
       break;
     }
     case CSR_VSIE: {