Merge pull request #1732 from chihminchao/fix-zkr

Fix zkr

Author: aswaterman

riscv/csrs.cc

@@ -286,7 +286,8 @@ mseccfg_csr_t::mseccfg_csr_t(processor_t* const proc, const reg_t addr):
 void mseccfg_csr_t::verify_permissions(insn_t insn, bool write) const {
   basic_csr_t::verify_permissions(insn, write);
   if (!proc->extension_enabled(EXT_SMEPMP) &&
-      !proc->extension_enabled(EXT_ZICFILP))
+      !proc->extension_enabled(EXT_ZICFILP) &&
+      !proc->extension_enabled(EXT_ZKR))
     throw trap_illegal_instruction(insn.bits());
 }
 
@@ -302,6 +303,14 @@ bool mseccfg_csr_t::get_rlb() const noexcept {
   return (read() & MSECCFG_RLB);
 }
 
+bool mseccfg_csr_t::get_useed() const noexcept {
+  return (read() & MSECCFG_USEED);
+}
+
+bool mseccfg_csr_t::get_sseed() const noexcept {
+  return (read() & MSECCFG_SSEED);
+}
+
 bool mseccfg_csr_t::unlogged_write(const reg_t val) noexcept {
   if (proc->n_pmp == 0)
     return false;
@@ -321,6 +330,11 @@ 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)) {
@@ -1434,6 +1448,16 @@ void seed_csr_t::verify_permissions(insn_t insn, bool write) const {
   if (!proc->extension_enabled(EXT_ZKR) || !write)
     throw trap_illegal_instruction(insn.bits());
   csr_t::verify_permissions(insn, write);
+
+  if (state->v) {
+    if (state->mseccfg->get_sseed() && write)
+      throw trap_virtual_instruction(insn.bits());
+    else
+      throw trap_illegal_instruction(insn.bits());
+  } else if ((state->prv == PRV_U && !state->mseccfg->get_useed()) ||
+             (state->prv == PRV_S && !state->mseccfg->get_sseed())) {
+      throw trap_illegal_instruction(insn.bits());
+  }
 }
 
 reg_t seed_csr_t::read() const noexcept {

riscv/csrs.h

@@ -150,6 +150,8 @@ class mseccfg_csr_t: public basic_csr_t {
   bool get_mml() const noexcept;
   bool get_mmwp() const noexcept;
   bool get_rlb() const noexcept;
+  bool get_useed() const noexcept;
+  bool get_sseed() const noexcept;
  protected:
   virtual bool unlogged_write(const reg_t val) noexcept override;
 };