Re: [PATCH] target/riscv: throw debug exception before page fault

[Richard Henderson]

On 1/20/25 05:39, Daniel Henrique Barboza wrote:

@@ -1708,10 +1709,25 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, 
int size,
      } else if (probe) {
          return false;
      } else {
-        raise_mmu_exception(env, address, access_type, pmp_violation,
-                            first_stage_error, two_stage_lookup,
-                            two_stage_indirect_error);
-        cpu_loop_exit_restore(cs, retaddr);
+        CPUWatchpoint *wp = riscv_cpu_addr_has_watchpoint(env, address);
+        int wp_access = 0;
+
+        if (wp) {
+            if (access_type == MMU_DATA_LOAD) {
+                wp_access |= BP_MEM_READ;
+            } else if (access_type == MMU_DATA_STORE) {
+                wp_access |= BP_MEM_WRITE;
+            }
+
+            cpu_check_watchpoint(cs, address, wp->len,
+                                 MEMTXATTRS_UNSPECIFIED,
+                                 wp_access, retaddr);
+        } else {

No point in walking the watchpoint list twice:

    cpu_check_watchpoint(cs, address, size, MEMTXATTRS_UNSPECIFIED,
                         wp_access, retaddr);

will return if and only if there is no wp match.
Then just fall through to ...

+            raise_mmu_exception(env, address, access_type, pmp_violation,
+                                first_stage_error, two_stage_lookup,
+                                two_stage_indirect_error);
+            cpu_loop_exit_restore(cs, retaddr);

... this.


r~