Merge pull request #2163 from chihminchao/fix-double-trap

Fix double trap

Author: aswaterman

riscv/csr_init.cc

@@ -224,6 +224,25 @@ void state_t::csr_init(processor_t* const proc, reg_t max_isa)
   } else {
     add_hypervisor_csr(CSR_HIDELEG, hideleg);
   }
+
+  const reg_t menvcfg_mask = (proc->extension_enabled(EXT_ZICBOM) ? MENVCFG_CBCFE | MENVCFG_CBIE : 0) |
+                            (proc->extension_enabled(EXT_ZICBOZ) ? MENVCFG_CBZE : 0) |
+                            (proc->extension_enabled(EXT_SMNPM) ? MENVCFG_PMM : 0) |
+                            (proc->extension_enabled(EXT_SVADU) ? MENVCFG_ADUE: 0) |
+                            (proc->extension_enabled(EXT_SVPBMT) ? MENVCFG_PBMTE : 0) |
+                            (proc->extension_enabled(EXT_SSTC) ? MENVCFG_STCE : 0) |
+                            (proc->extension_enabled(EXT_ZICFILP) ? MENVCFG_LPE : 0) |
+                            (proc->extension_enabled(EXT_ZICFISS) ? MENVCFG_SSE : 0) |
+                            (proc->extension_enabled(EXT_SSDBLTRP) ? MENVCFG_DTE : 0)|
+                            (proc->extension_enabled(EXT_SMCDELEG) ? MENVCFG_CDE : 0);
+  menvcfg = std::make_shared<envcfg_csr_t>(proc, CSR_MENVCFG, menvcfg_mask, 0);
+  if (xlen == 32) {
+    add_user_csr(CSR_MENVCFG, std::make_shared<rv32_low_csr_t>(proc, CSR_MENVCFG, menvcfg));
+    add_user_csr(CSR_MENVCFGH, std::make_shared<rv32_high_csr_t>(proc, CSR_MENVCFGH, menvcfg));
+  } else {
+    add_user_csr(CSR_MENVCFG, menvcfg);
+  }
+
   const reg_t hedeleg_mask =
     (1 << CAUSE_MISALIGNED_FETCH) |
     (1 << CAUSE_FETCH_ACCESS) |
@@ -310,23 +329,6 @@ void state_t::csr_init(processor_t* const proc, reg_t max_isa)
   add_csr(CSR_MVENDORID, std::make_shared<const_csr_t>(proc, CSR_MVENDORID, 0));
   add_csr(CSR_MHARTID, std::make_shared<const_csr_t>(proc, CSR_MHARTID, proc->get_id()));
   add_csr(CSR_MCONFIGPTR, std::make_shared<const_csr_t>(proc, CSR_MCONFIGPTR, 0));
-  const reg_t menvcfg_mask = (proc->extension_enabled(EXT_ZICBOM) ? MENVCFG_CBCFE | MENVCFG_CBIE : 0) |
-                            (proc->extension_enabled(EXT_ZICBOZ) ? MENVCFG_CBZE : 0) |
-                            (proc->extension_enabled(EXT_SMNPM) ? MENVCFG_PMM : 0) |
-                            (proc->extension_enabled(EXT_SVADU) ? MENVCFG_ADUE: 0) |
-                            (proc->extension_enabled(EXT_SVPBMT) ? MENVCFG_PBMTE : 0) |
-                            (proc->extension_enabled(EXT_SSTC) ? MENVCFG_STCE : 0) |
-                            (proc->extension_enabled(EXT_ZICFILP) ? MENVCFG_LPE : 0) |
-                            (proc->extension_enabled(EXT_ZICFISS) ? MENVCFG_SSE : 0) |
-                            (proc->extension_enabled(EXT_SSDBLTRP) ? MENVCFG_DTE : 0)|
-                            (proc->extension_enabled(EXT_SMCDELEG) ? MENVCFG_CDE : 0);
-  menvcfg = std::make_shared<envcfg_csr_t>(proc, CSR_MENVCFG, menvcfg_mask, 0);
-  if (xlen == 32) {
-    add_user_csr(CSR_MENVCFG, std::make_shared<rv32_low_csr_t>(proc, CSR_MENVCFG, menvcfg));
-    add_user_csr(CSR_MENVCFGH, std::make_shared<rv32_high_csr_t>(proc, CSR_MENVCFGH, menvcfg));
-  } else {
-    add_user_csr(CSR_MENVCFG, menvcfg);
-  }
   const reg_t senvcfg_mask = (proc->extension_enabled(EXT_ZICBOM) ? SENVCFG_CBCFE | SENVCFG_CBIE : 0) |
                             (proc->extension_enabled(EXT_ZICBOZ) ? SENVCFG_CBZE : 0) |
                             (proc->extension_enabled(EXT_SVUKTE) ? SENVCFG_UKTE : 0) |

riscv/csrs.cc

@@ -544,11 +544,16 @@ mstatus_csr_t::mstatus_csr_t(processor_t* const proc, const reg_t addr):
   val(compute_mstatus_initial_value()) {
 }
 
+reg_t mstatus_csr_t::read() const noexcept {
+  return val & ~reg_t(state->menvcfg->read() & MENVCFG_DTE ? 0 : MSTATUS_SDT);
+}
+
 bool mstatus_csr_t::unlogged_write(const reg_t val) noexcept {
   const bool has_mpv = proc->extension_enabled('H');
   const bool has_gva = has_mpv;
+  const reg_t adj_write_mask = sstatus_write_mask & ~reg_t(state->menvcfg->read() & MENVCFG_DTE ? 0 : SSTATUS_SDT);
 
-  const reg_t mask = sstatus_write_mask
+  const reg_t mask = adj_write_mask
                    | MSTATUS_MIE | MSTATUS_MPIE
                    | (proc->extension_enabled('U') ? MSTATUS_MPRV : 0)
                    | MSTATUS_MPP | MSTATUS_TW
@@ -558,12 +563,11 @@ bool mstatus_csr_t::unlogged_write(const reg_t val) noexcept {
                    | (has_mpv ? MSTATUS_MPV : 0)
                    | (proc->extension_enabled(EXT_SMDBLTRP) ? MSTATUS_MDT : 0)
                    | (proc->extension_enabled(EXT_ZICFILP) ? (MSTATUS_SPELP | MSTATUS_MPELP) : 0)
-                   | (proc->extension_enabled(EXT_SSDBLTRP) ? SSTATUS_SDT : 0)
                    ;
 
   const reg_t requested_mpp = proc->legalize_privilege(get_field(val, MSTATUS_MPP));
   const reg_t adjusted_val = set_field(val, MSTATUS_MPP, requested_mpp);
-  reg_t new_mstatus = (read() & ~mask) | (adjusted_val & mask);
+  reg_t new_mstatus = (this->val & ~mask) | (adjusted_val & mask);
   new_mstatus = (new_mstatus & MSTATUS_MDT) ? (new_mstatus & ~MSTATUS_MIE) : new_mstatus;
   new_mstatus = (new_mstatus & MSTATUS_SDT) ? (new_mstatus & ~MSTATUS_SIE) : new_mstatus;
   maybe_flush_tlb(new_mstatus);

riscv/csrs.h

@@ -255,9 +255,7 @@ class mstatus_csr_t final: public base_status_csr_t {
  public:
   mstatus_csr_t(processor_t* const proc, const reg_t addr);
 
-  reg_t read() const noexcept override {
-    return val;
-  }
+  reg_t read() const noexcept override;
 
  protected:
   virtual bool unlogged_write(const reg_t val) noexcept override;