Difftest: add microarchitectural_pf_check API

include/isa.h

@@ -40,5 +40,6 @@ void isa_difftest_getregs(void *r);
 void isa_difftest_setregs(const void *r);
 void isa_difftest_raise_intr(word_t NO);
 void isa_difftest_sync(uint64_t *sync);
+bool isa_difftest_microarchitectural_pf_check(vaddr_t addr);
 
 #endif

src/isa/riscv64/difftest/ref.c

@@ -68,6 +68,13 @@ void isa_difftest_sync(uint64_t *sync) {
   // }
 }
 
+// Legal pagefault might be caused by microarchitural implements.
+// For instance, write pte and not sfence it will lead to pagefault.
+// (it may be still in sbuffer)
+bool isa_difftest_microarchitectural_pf_check(vaddr_t addr) {
+  return !ptw_is_safe(addr);
+}
+
 void isa_difftest_raise_intr(word_t NO) {
   DecodeExecState s;
   s.is_jmp = 0;

src/isa/riscv64/local-include/csr.h

@@ -205,5 +205,6 @@ void csr_write(uint32_t addr, rtlreg_t *src);
 
 enum { MODE_U = 0, MODE_S, MODE_H, MODE_M };
 void change_mode(uint8_t m);
+bool ptw_is_safe(vaddr_t vaddr);
 
 #endif

src/monitor/difftest/ref.c

@@ -25,6 +25,10 @@ void difftest_sync(uint64_t *sync) {
   isa_difftest_sync(sync);
 }
 
+void difftest_microarchitectural_pf_check(vaddr_t addr){
+  isa_difftest_microarchitectural_pf_check(addr);
+}
+
 void difftest_exec(uint64_t n) {
   cpu_exec(n);
 }