virtio — archive

[PATCH] document idx field in virtqueue used ring

From: Michael S. Tsirkin
To: [email protected]
Date: Sun, 15 Mar 2015 14:41:00 -0000

Section 2.4.8 The Virtqueue Used Ring lists the idx field, but never documents it. VIRTIO-136. Reported-by: Jason Wang <[email protected]> Signed-off-by: Michael S. Tsirkin <[email protected]> --- content.tex 3 +++ 1 file changed, 3 insertions(+) diff --git a/content.tex b/content.tex index d34685d..c9440a4 100644 --- a/content.tex +++ b/content.tex @@ -595,6 +595,9 @@ for drivers using untrusted buffers: if you do not know exactly how much has been written by the device, you usually have to zero the buffer to ensure no data leakage occurs. +field{idx} field indicates where the driver would put the next descriptor +entry in the ring (modulo the queue size). This starts at 0, and increases. + egin{note} The legacy hyperref[intro:Virtio PCI Draft]{[Virtio PCI Draft]} referred to these structures as vring_used and vring_used_elem, and -- MST