[PATCH v2] ccw: clarify device reset

Unlike other transports, a reset triggered by the driver is actually complete once the command has been completed. Make this behaviour and the requirements more explicit.  Signed-off-by: Cornelia Huck <> ---  v1->v2: drop channel I/O internals, talk more specificly about virtio reset  ---  conformance.tex
2 ++  content.tex
22 +++++++++++++++++++++-  2 files changed, 23 insertions(+), 1 deletion(-)  diff --git a/conformance.tex b/conformance.tex index 80547db4939b..f7975d974c63 100644 --- a/conformance.tex +++ b/conformance.tex @@ -123,6 +123,7 @@ section{Conformance Targets}label{sec:Conformance / Conformance Targets}  item
ef{drivernormative:Virtio Transport Options / Virtio over channel I/O / Device Initialization / Communicating Status Information}  item
ef{drivernormative:Virtio Transport Options / Virtio over channel I/O / Device Operation / Host->Guest Notification / Notification via Adapter I/O Interrupts}  item
ef{drivernormative:Virtio Transport Options / Virtio over channel I/O / Device Operation / Guest->Host Notification} +item
ef{drivernormative:Virtio Transport Options / Virtio over channel I/O / Device Operation / Resetting Devices}  end{itemize}
conformance{subsection}{Network Driver Conformance}label{sec:Conformance / Driver Conformance / Network Driver Conformance} @@ -374,6 +375,7 @@ section{Conformance Targets}label{sec:Conformance / Conformance Targets}  item
ef{devicenormative:Virtio Transport Options / Virtio over channel I/O / Device Initialization / Setting Up Indicators / Setting Up Two-Stage Queue Indicators}  item
ef{devicenormative:Virtio Transport Options / Virtio over channel I/O / Device Operation / Host->Guest Notification / Notification via Adapter I/O Interrupts}  item
ef{devicenormative:Virtio Transport Options / Virtio over channel I/O / Device Operation / Guest->Host Notification} +item
ef{devicenormative:Virtio Transport Options / Virtio over channel I/O / Device Operation / Resetting Devices}  end{itemize}
conformance{subsection}{Network Device Conformance}label{sec:Conformance / Device Conformance / Network Device Conformance} diff --git a/content.tex b/content.tex index 5d112af206d2..899df5ffde6d 100644 --- a/content.tex +++ b/content.tex @@ -2775,8 +2775,28 @@ subsubsection{Guest->Host Notification}label{sec:Virtio Transport Options / Vi  subsubsection{Resetting Devices}label{sec:Virtio Transport Options / Virtio over channel I/O / Device Operation / Resetting Devices}
In order to reset a device, a driver sends the -CCW_CMD_VDEV_RESET command. +CCW_CMD_VDEV_RESET command. This command does not carry any payload.
+The device signals completion of the virtio reset operation through successful +conclusion of the CCW_CMD_VDEV_RESET channel command. In particular, the +command not only triggers the reset operation, but the reset operation is +already completed when the operation concludes successfully. + +devicenormative{paragraph}{Resetting Devices}{Virtio Transport Options / Virtio over channel I/O / Device Operation / Resetting Devices} + +The device MUST finish the virtio reset operation and reinitialize +field{device status} to zero before it concludes the CCW_CMD_VDEV_RESET +command successfully. + +The device MUST NOT send notifications or interact with the queues after +it signaled successful conclusion of the CCW_CMD_VDEV_RESET command. + +drivernormative{paragraph}{Resetting Devices}{Virtio Transport Options / Virtio over channel I/O / Device Operation / Resetting Devices} + +The driver MAY consider the virtio reset operation to be complete already after +successful conclusion of the CCW_CMD_VDEV_RESET channel command, although it +MAY also choose to verify reset completion by reading field{device status} via +CCW_CMD_READ_STATUS and checking whether it is 0 afterwards.
chapter{Device Types}label{sec:Device Types}
--  2.31.1