From 68d5ae3d3a64d23b5f3d7aa3edd6747f68ff90a2 Mon Sep 17 00:00:00 2001
From: Mike Zeller <mike@oxidecomputer.com>
Date: Tue, 11 Aug 2026 15:34:56 +0000
Subject: [PATCH] review feedback

---
 lib/propolis/src/hw/virtio/queue.rs | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/lib/propolis/src/hw/virtio/queue.rs b/lib/propolis/src/hw/virtio/queue.rs
index 5ca974459..4616e70ed 100644
--- a/lib/propolis/src/hw/virtio/queue.rs
+++ b/lib/propolis/src/hw/virtio/queue.rs
@@ -525,8 +525,13 @@ impl VirtQueue {
                 chain.push_buf(buf);
 
                 if flags.contains(DescFlag::NEXT) {
-                    if count == self.size() {
-                        // XXX: signal error condition?
+                    // The virto spec states:
+                    //
+                    // A driver MUST NOT create a descriptor chain longer than
+                    // the Queue Size of the device
+                    if count >= self.size() {
+                        // TODO (#1190): This needs to properly signal the error
+                        // condition
                         chain.idx = None;
                         return None;
                     }