tcg: Check for watchpoints in probe_write()

Let size > 0 indicate a promise to write to those bytes.
Check for write watchpoints in the probed range.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20190823100741.9621-10-david@redhat.com>
[rth: Recompute index after tlb_fill; check TLB_WATCHPOINT.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

accel/tcg/cputlb.c

@@ -1086,13 +1086,24 @@ void probe_write(CPUArchState *env, target_ulong addr, int size, int mmu_idx,
 {
     uintptr_t index = tlb_index(env, mmu_idx, addr);
     CPUTLBEntry *entry = tlb_entry(env, mmu_idx, addr);
+    target_ulong tlb_addr = tlb_addr_write(entry);
 
-    if (!tlb_hit(tlb_addr_write(entry), addr)) {
-        /* TLB entry is for a different page */
+    if (unlikely(!tlb_hit(tlb_addr, addr))) {
         if (!VICTIM_TLB_HIT(addr_write, addr)) {
             tlb_fill(env_cpu(env), addr, size, MMU_DATA_STORE,
                      mmu_idx, retaddr);
+            /* TLB resize via tlb_fill may have moved the entry. */
+            index = tlb_index(env, mmu_idx, addr);
+            entry = tlb_entry(env, mmu_idx, addr);
         }
+        tlb_addr = tlb_addr_write(entry);
+    }
+
+    /* Handle watchpoints.  */
+    if ((tlb_addr & TLB_WATCHPOINT) && size > 0) {
+        cpu_check_watchpoint(env_cpu(env), addr, size,
+                             env_tlb(env)->d[mmu_idx].iotlb[index].attrs,
+                             BP_MEM_WRITE, retaddr);
     }
 }