Merge pull request #1590 from YenHaoChen/pr-hvip

Fix hvip.VSEIP and hvip.VSTIP so they don't observe platform-specific interrupts

Author: aswaterman

riscv/csrs.cc

@@ -728,6 +728,10 @@ mip_csr_t::mip_csr_t(processor_t* const proc, const reg_t addr):
   mip_or_mie_csr_t(proc, addr) {
 }
 
+reg_t mip_csr_t::read() const noexcept {
+  return val | state->hvip->basic_csr_t::read();
+}
+
 void mip_csr_t::backdoor_write_with_mask(const reg_t mask, const reg_t val) noexcept {
   this->val = (this->val & ~mask) | (val & mask);
 }
@@ -1717,3 +1721,16 @@ void srmcfg_csr_t::verify_permissions(insn_t insn, bool write) const {
   if (state->v)
       throw trap_virtual_instruction(insn.bits());
 }
+
+hvip_csr_t::hvip_csr_t(processor_t* const proc, const reg_t addr, const reg_t init):
+  basic_csr_t(proc, addr, init) {
+}
+
+reg_t hvip_csr_t::read() const noexcept {
+  return basic_csr_t::read() | (state->mip->read() & MIP_VSSIP); // hvip.VSSIP is an alias of mip.VSSIP
+}
+
+bool hvip_csr_t::unlogged_write(const reg_t val) noexcept {
+  state->mip->write_with_mask(MIP_VSSIP, val); // hvip.VSSIP is an alias of mip.VSSIP
+  return basic_csr_t::unlogged_write(val & (MIP_VSEIP | MIP_VSTIP));
+}

riscv/csrs.h

@@ -349,7 +349,7 @@ typedef std::shared_ptr<misa_csr_t> misa_csr_t_p;
 class mip_or_mie_csr_t: public csr_t {
  public:
   mip_or_mie_csr_t(processor_t* const proc, const reg_t addr);
-  virtual reg_t read() const noexcept override final;
+  virtual reg_t read() const noexcept override;
 
   void write_with_mask(const reg_t mask, const reg_t val) noexcept;
 
@@ -364,6 +364,7 @@ class mip_or_mie_csr_t: public csr_t {
 class mip_csr_t: public mip_or_mie_csr_t {
  public:
   mip_csr_t(processor_t* const proc, const reg_t addr);
+  virtual reg_t read() const noexcept override final;
 
   // Does not log. Used by external things (clint) that wiggle bits in mip.
   void backdoor_write_with_mask(const reg_t mask, const reg_t val) noexcept;
@@ -850,4 +851,14 @@ class srmcfg_csr_t: public masked_csr_t {
   srmcfg_csr_t(processor_t* const proc, const reg_t addr, const reg_t mask, const reg_t init);
   virtual void verify_permissions(insn_t insn, bool write) const override;
 };
+
+class hvip_csr_t : public basic_csr_t {
+ public:
+  hvip_csr_t(processor_t* const proc, const reg_t addr, const reg_t init);
+  reg_t read() const noexcept override;
+ protected:
+  virtual bool unlogged_write(const reg_t val) noexcept override;
+};
+
+typedef std::shared_ptr<hvip_csr_t> hvip_csr_t_p;
 #endif

riscv/processor.cc

@@ -304,15 +304,6 @@ void state_t::reset(processor_t* const proc, reg_t max_isa)
     0              // shiftamt
   );
 
-  auto hvip_accr = std::make_shared<generic_int_accessor_t>(
-    this,
-    MIP_VS_MASK,   // read_mask
-    MIP_VS_MASK,   // ip_write_mask
-    MIP_VS_MASK,   // ie_write_mask
-    generic_int_accessor_t::mask_mode_t::NONE,
-    0              // shiftamt
-  );
-
   auto vsip_vsie_accr = std::make_shared<generic_int_accessor_t>(
     this,
     MIP_VS_MASK,   // read_mask
@@ -327,7 +318,7 @@ void state_t::reset(processor_t* const proc, reg_t max_isa)
   csrmap[CSR_VSIP] = vsip;
   csrmap[CSR_SIP] = std::make_shared<virtualized_csr_t>(proc, nonvirtual_sip, vsip);
   csrmap[CSR_HIP] = std::make_shared<mip_proxy_csr_t>(proc, CSR_HIP, hip_hie_accr);
-  csrmap[CSR_HVIP] = std::make_shared<mip_proxy_csr_t>(proc, CSR_HVIP, hvip_accr);
+  csrmap[CSR_HVIP] = hvip = std::make_shared<hvip_csr_t>(proc, CSR_HVIP, 0);
 
   auto nonvirtual_sie = std::make_shared<mie_proxy_csr_t>(proc, CSR_SIE, sip_sie_accr);
   auto vsie = std::make_shared<mie_proxy_csr_t>(proc, CSR_VSIE, vsip_vsie_accr);

riscv/processor.h

@@ -128,6 +128,7 @@ struct state_t
   csr_t_p htval;
   csr_t_p htinst;
   csr_t_p hgatp;
+  hvip_csr_t_p hvip;
   sstatus_csr_t_p sstatus;
   vsstatus_csr_t_p vsstatus;
   csr_t_p vstvec;