From 43ced114aa3de653ff650593a5d78e17629df0ac Mon Sep 17 00:00:00 2001 From: Anatol Belski Date: Fri, 15 May 2026 01:30:35 +0200 Subject: [PATCH] vm-virtio: checked_descriptor: Add unit test for exhausted chain After the iterator yields the only descriptor in a chain, the subsequent None must reflect exhaustion rather than a validation failure, so failed and failed_addr stay unset. Signed-off-by: Anatol Belski --- vm-virtio/src/checked_descriptor.rs | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/vm-virtio/src/checked_descriptor.rs b/vm-virtio/src/checked_descriptor.rs index e5e419bd2..34f266e06 100644 --- a/vm-virtio/src/checked_descriptor.rs +++ b/vm-virtio/src/checked_descriptor.rs @@ -458,4 +458,16 @@ mod unit_tests { // translated one. assert_eq!(result.unwrap_err(), GuestAddress(gva)); } + + #[test] + fn exhausted_chain_returns_none() { + // After the iterator yields the only descriptor in the chain, the + // subsequent None must reflect exhaustion, not a validation failure. + let (_mem, mem_atomic, mut queue) = setup_vq(128 * 1024, 0x4000, 256, 0); + let mem_guard = mem_atomic.memory(); + let mut chain = queue.pop_descriptor_chain(mem_guard).unwrap(); + let mut it = chain.checked_iter(None); + it.next().unwrap().unwrap(); + assert!(it.next().is_none()); + } }