[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]
Subject: Re: [virtio-comment] [PATCH v10 02/10] admin: introduce device group and related concepts
On Thursday, 2023-02-09 at 10:13:46 -05, Michael S. Tsirkin wrote:On Thu, Feb 09, 2023 at 03:00:58PM +0000, David Edmondson wrote:On Thursday, 2023-02-09 at 07:13:36 -05, Michael S. Tsirkin wrote:Each device group has a type. For now, define one initial group: SR-IOV type - PCI SR-IOV virtual functions (VFs) of a given PCI SR-IOV physical function (PF). This group may contain one or more virtio devices.The specification says zero or more generally and nothing to refine that for SR-IOV groups.Well it says: (SR-IOV) physical function (PF) device as the owner and includes all its SR-IOV virtual functions (VFs) as members (see \hyperref[intro:PCIe]{[PCIe]}). how can that be zero?If I remove all of the VFs of a PF, does the group implicitly disappear?
Enable/Disable SR-IOV are dynamic operations controlled by NumVFs register.
We can mention that a group include all virtual functions
indicated by TotalVFs RO register.
This group exist as
long as the owner PF supports SR-IOV and has admin capabilities.
How about the converse?Each device within a group has a unique identifier. This identifier is the group member identifier. Note: one can argue both ways whether the new device group handling functionality (this and following patches) is closer to a new device type or a new transport type. However, I expect that we will add more features in the near future. To facilitate this as much as possible of the text is located in the new admin chapter. I did my best to minimize transport-specific text. Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> --- admin.tex | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ content.tex | 2 ++ 2 files changed, 51 insertions(+) create mode 100644 admin.tex diff --git a/admin.tex b/admin.tex new file mode 100644 index 0000000..2bc7322 --- /dev/null +++ b/admin.tex @@ -0,0 +1,49 @@ +\section{Device groups}\label{sec:Basic Facilities of a Virtio Device / Device groups} + +It is occasionally useful to have a device control a group of +other devices. Terminology used in such cases: + +\begin{description} +\item[Device group] + or just group, includes zero or more devices. +\item[Owner device] + or owner, the device controlling the group. +\item[Member device] + a device within a group. The owner device itself is not + a member of the group. +\item[Member identifier] + each member has this identifier, unique within the group + and used to address it through the owner device. +\item[Group type identifier] + specifies what kind of member devices there are in a + group, how is the member identifier is interpreted + and what kind of control the owner has. + A given owner can control a single group of a given type, + thus the type and the owner together identify the group. + \footnote{Even though some group types only support + specific transports, group type identifiers + are global rather than transport-specific - + we don't expect a flood of new group types.} +\end{description} + +The following group types, and their identifiers, are currently specified): +\begin{description} +\item[SR-IOV group type (0x1)] +This device group has a PCI Single Root I/O Virtualization +(SR-IOV) physical function (PF) device as the owner and includes +all its SR-IOV virtual functions (VFs) as members (see +\hyperref[intro:PCIe]{[PCIe]}). + +The PF device itself is not a member of the group. + +The group type identifier for this group is 0x1. + +A member identifier for this group can have a value 0x1 to 0xFFFF +and equals the SR-IOV VF number of the member device (see +\hyperref[intro:PCIe]{[PCIe]}). + +Both owner and member devices for this group type use the Virtio +PCI transport (see \ref{sec:Virtio Transport Options / Virtio Over PCI Bus}). +\end{description} + + diff --git a/content.tex b/content.tex index 0c2d917..ffe45c4 100644 --- a/content.tex +++ b/content.tex @@ -491,6 +491,8 @@ \section{Exporting Objects}\label{sec:Basic Facilities of a Virtio Device / Expo types. It is RECOMMENDED that devices generate version 4 UUIDs as specified by \hyperref[intro:rfc4122]{[RFC4122]}. +\input{admin.tex} + \chapter{General Initialization And Device Operation}\label{sec:General Initialization And Device Operation} We start with an overview of device initialization, then expand on the-- Tell her I'll be waiting, in the usual place.
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]