summaryrefslogtreecommitdiff
path: root/content.tex
diff options
context:
space:
mode:
Diffstat (limited to 'content.tex')
-rw-r--r--content.tex50
1 files changed, 8 insertions, 42 deletions
diff --git a/content.tex b/content.tex
index be9f176..cb090dd 100644
--- a/content.tex
+++ b/content.tex
@@ -88,45 +88,15 @@ space.
\subsection{Legacy Interface: A Note on transitions from earlier drafts}\label{sec:Basic Facilities of a Virtio Device / Feature Bits / Legacy Interface: A Note on transitions from earlier drafts}
-Earlier drafts of this specification (up to 0.9.X) defined a similar, but
-different interface between the hypervisor and the guest.
-Since these are widely deployed, this specification
-accommodates optional features to simplify transition
-from these earlier draft interfaces. Specifically:
+Careful consideration has been given on the transition from the older
+\hyperref[intro:Virtio PCI Draft]{[Virtio PCI Draft]} specification to
+this one. Advice pertaining to transitional devices and drivers
+is contained in sections named 'Legacy Interface' like this one.
-\begin{description}
-\item[Legacy Interface]
- is an interface specified by an earlier draft of this specification
- (up to 0.9.X)
-\item[Legacy Device]
- is a device implemented before this specification was released,
- and implementing a legacy interface on the host side
-\item[Legacy Driver]
- is a driver implemented before this specification was released,
- and implementing a legacy interface on the guest side
-\end{description}
-
-Legacy devices and legacy drivers are not compliant with this
-specification.
-
-To simplify transition from these earlier draft interfaces,
-it is possible to implement:
-
-\begin{description}
-\item[Transitional Device]
- a device supporting both drivers conforming to this
- specification, and allowing legacy drivers.
-
-\item[Transitional Driver]
- a driver supporting both devices conforming to this
- specification, and legacy devices.
-\end{description}
-
-Transitional devices and transitional drivers can be compliant with
-this specification (ie. when not operating in legacy mode).
-
-Devices or drivers with no legacy compatibility are referred to as
-non-transitional devices and drivers, respectively.
+\begin{note}
+ No legacy interfaces are required; ie. don't implement them unless you
+ have a need for backwards compatibility!
+\end{note}
Transitional Drivers can detect Legacy Devices by detecting that
the feature bit VIRTIO_F_VERSION_1 is not offered.
@@ -134,10 +104,6 @@ Transitional devices can detect Legacy drivers by detecting that
VIRTIO_F_VERSION_1 has not been acknowledged by the driver.
In this case device is used through the legacy interface.
-To make them easier to locate, specification sections documenting
-these transitional features are explicitly marked with 'Legacy
-Interface' in the section title.
-
\section{Device Configuration Space}\label{sec:Basic Facilities of a Virtio Device / Device Configuration Space}
Device configuration space is generally used for rarely-changing or