From 87785eb25c4ef92be94894be2a190cb79877cb16 Mon Sep 17 00:00:00 2001
From: Jonathan Woodruff <jdw57@cam.ac.uk>
Date: Thu, 14 Oct 2021 17:13:18 +0000
Subject: [PATCH] Don't translate invalid vaddrs in the DTLB.

---
 src_Core/RISCY_OOO/procs/lib/DTlb.bsv | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src_Core/RISCY_OOO/procs/lib/DTlb.bsv b/src_Core/RISCY_OOO/procs/lib/DTlb.bsv
index 33d63dc..aaa9df1 100644
--- a/src_Core/RISCY_OOO/procs/lib/DTlb.bsv
+++ b/src_Core/RISCY_OOO/procs/lib/DTlb.bsv
@@ -473,7 +473,13 @@ module mkDTlb#(
         else if (vm_info.sv39) begin
             let vpn = getVpn(r.addr);
             let trans_result = tlb.translate(vpn, vm_info.asid);
-            if (trans_result.hit) begin
+            if (!validVirtualAddress(r.addr)) begin
+                // page fault
+                Exception fault = r.write ? excStorePageFault : excLoadPageFault;
+                pendWait[idx] <= None;
+                pendResp[idx] <= tuple3(?, Valid (fault), False);
+                if(verbose) $display("[DTLB] req invalid virtual address: idx %d; ", idx, fshow(r));
+            end else if (trans_result.hit) begin
                 // TLB hit
                 let entry = trans_result.entry;
                 // check permission