From 0a4f0b3da67f4ac47d260a38bb956686d035b3d9 Mon Sep 17 00:00:00 2001
From: Binno <binno.shen@sifive.com>
Date: Thu, 11 Jul 2024 20:57:04 -0700
Subject: [PATCH] zkr: enable write for useed/sseed fileds of mseccfg csr

---
 riscv/csrs.cc | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/riscv/csrs.cc b/riscv/csrs.cc
index a45770dd..635faae7 100644
--- a/riscv/csrs.cc
+++ b/riscv/csrs.cc
@@ -322,6 +322,11 @@ bool mseccfg_csr_t::unlogged_write(const reg_t val) noexcept {
   new_val |= (val & MSECCFG_MMWP);  //MMWP is sticky
   new_val |= (val & MSECCFG_MML);   //MML is sticky
 
+  if (proc->extension_enabled(EXT_ZKR)) {
+    uint64_t mask = MSECCFG_USEED | MSECCFG_SSEED;
+    new_val = (new_val & ~mask) | (val & mask);
+  }
+
   proc->get_mmu()->flush_tlb();
 
   if (proc->extension_enabled(EXT_ZICFILP)) {