virtio — archive

[Michael S. Tsirkin]

--- content.tex 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/content.tex b/content.tex index 2f467d5..cbbad09 100644 --- a/content.tex +++ b/content.tex @@ -1227,13 +1227,16 @@ at BAR selected by field{cap.bar} and store the first field{cap.length} bytes subsubsection{Legacy Interfaces: A Note on PCI Device Layout}label{sec:Virtio Transport Options / Virtio Over PCI Bus / PCI Device Layout / Legacy Interfaces: A Note on PCI Device Layout} -Transitional devices should present part of configuration +Transitional devices MUST present part of configuration registers in a legacy configuration structure in BAR0 in the first I/O region of the PCI device, as documented below. +When using the legacy interface, transitional drivers +MUST use the legacy configuration structure in BAR0 in the first +I/O region of the PCI device, as documented below. -When accessed through the legacy interface the driver MAY access +When using the legacy interface the driver MAY access the device-specific region using any width accesses, and -a transitional device MUST present it with the same results as +a transitional device MUST present driver with the same results as when accessed using the “natural” access method (i.e. 32-bit accesses for 32-bit fields, etc). @@ -1290,7 +1293,7 @@ Purpose & Device Specific & \ Note that only Feature Bits 0 to 31 are accessible through the Legacy Interface. When used through the Legacy Interface, -Transitional Devices must assume that Feature Bits 32 to 63 +Transitional Devices MUST assume that Feature Bits 32 to 63 are not acknowledged by Driver. As legacy devices had no field{config_generation} field, -- MST