← Prev in month ← Prev in thread

[PATCH] ccw: clarify device reset

From
Cornelia Huck
Date
2021-10-11T11:39:00+00:00
ID
Thread
[PATCH] 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 <> ---  We have discussed this before while talking about reset behaviour, but I don't remember sending an actual patch.  If this looks good, I'll open an issue.  ---  conformance.tex
2 ++  content.tex
22 +++++++++++++++++++++-  2 files changed, 23 insertions(+), 1 deletion(-)  diff --git a/conformance.tex b/conformance.tex index c52f1a40be2d..24e862ad217a 100644 --- a/conformance.tex +++ b/conformance.tex @@ -122,6 +122,7 @@ 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} @@ -372,6 +373,7 @@ 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 5e716721edb3..0410f46f6a78 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 reset operation by making the subchannel +status pending to indicate successful completion of the channel command. +Notably, 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} + +Before making the subchannel status pending to indicate successful completion +of the reset command, the device MUST reinitialize field{device status} to +zero. + +The device MUST NOT send notifications or interact with the queues after +it signaled successful completion of the reset command. + +drivernormative{paragraph}{Resetting Devices}{Virtio Transport Options / Virtio over channel I/O / Device Operation / Resetting Devices} + +The driver MAY consider the reset operation to be complete already after +successful completion of the channel command, although it MAY also verify +reset completion by reading field{device status} via CCW_CMD_READ_STATUS +afterwards.
chapter{Device Types}label{sec:Device Types}
--  2.31.1
← Prev in month ← Prev in thread