diff options
| author | rusty <rusty@0c8fb4dd-22a2-4bb5-bc14-6c75a5f43652> | 2014-05-12 01:57:36 +0000 |
|---|---|---|
| committer | rusty <rusty@0c8fb4dd-22a2-4bb5-bc14-6c75a5f43652> | 2014-05-12 01:57:36 +0000 |
| commit | aa9778215ce3bf31de1c8e8903f303c31eee9c31 (patch) | |
| tree | aa8710a6c06bdbe702f999a7fd50d9b697c63b5c | |
| parent | c6cdebe2743c70da09a47ab8b4fa7fbf94e95913 (diff) | |
VIRTIO-87: limit descriptor chain length even with INDIRECT.
As passed at meeting 2014-05-06:
https://lists.oasis-open.org/archives/virtio/201405/msg00016.html
Signed-off-by: Rusty Russell <rusty@au1.ibm.com>
git-svn-id: https://tools.oasis-open.org/version-control/svn/virtio@366 0c8fb4dd-22a2-4bb5-bc14-6c75a5f43652
| -rw-r--r-- | content.tex | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/content.tex b/content.tex index 4525975..83d1afd 100644 --- a/content.tex +++ b/content.tex @@ -404,7 +404,7 @@ struct virtq_desc { \end{lstlisting} The number of descriptors in the table is defined by the queue size -for this virtqueue. +for this virtqueue: this is the maximum possible descriptor chain length. \begin{note} The legacy \hyperref[intro:Virtio PCI Draft]{[Virtio PCI Draft]} @@ -456,6 +456,9 @@ VIRTIO_F_INDIRECT_DESC feature was negotiated. The driver MUST NOT set the VIRTQ_DESC_F_INDIRECT flag within an indirect descriptor (ie. only one table per descriptor). +A driver MUST NOT create a descriptor chain longer than the Queue Size of +the device. + \devicenormative{\paragraph}{Indirect Descriptors}{Basic Facilities of a Virtio Device / Virtqueues / The Virtqueue Descriptor Table / Indirect Descriptors} The device MUST ignore the write-only flag (\field{flags}\&VIRTQ_DESC_F_WRITE) in the descriptor that refers to an indirect table. |