From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Date: Mon, 4 Apr 2022 08:03:07 -0400 From: "Michael S. Tsirkin" Message-ID: <20220404072833-mutt-send-email-mst@kernel.org> References: <20220302155608.24189-1-mgurtovoy@nvidia.com> <20220302155608.24189-2-mgurtovoy@nvidia.com> MIME-Version: 1.0 In-Reply-To: <20220302155608.24189-2-mgurtovoy@nvidia.com> Subject: [virtio-dev] Re: [PATCH v1 1/5] virtio: Introduce virtio subsystem Content-Type: text/plain; charset=us-ascii Content-Disposition: inline To: Max Gurtovoy Cc: virtio-comment@lists.oasis-open.org, cohuck@redhat.com, virtio-dev@lists.oasis-open.org, jasowang@redhat.com, parav@nvidia.com, shahafs@nvidia.com, oren@nvidia.com, stefanha@redhat.com List-ID: On Wed, Mar 02, 2022 at 05:56:04PM +0200, Max Gurtovoy wrote: > A virtio subsystem may contain one or more virtio devices. All of the > devices that make up a virtio subsystem share the same virtio subsystem > unique identifier. This identifier is the virtio qualified name (VQN). > Each device within a virtio subsystem has a unique identifier. This > identifier is the virtio device id (vdev_id). The combination of these > identifiers forms a globally unique value identifies a virtio device. > > Reviewed-by: Parav Pandit > Signed-off-by: Max Gurtovoy OK linux and qemu releases finally settling down so I have the time to review this, sorry about the delay. > --- > introduction.tex | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) > > diff --git a/introduction.tex b/introduction.tex > index 6d52717..8e6611e 100644 > --- a/introduction.tex > +++ b/introduction.tex > @@ -240,5 +240,23 @@ \section{Constant Specifications} > refer to values 1 and 2 of Fld respectively. Further, VIRTIO_FLD_XXX refers to > either VIRTIO_FLD_A or VIRTIO_FLD_B. > > +\section{Definitions}\label{sec:Introduction / Definitions} I think this belongs in Terminology section. > + > +\subsection{virtio device}\label{sec:Introduction / Definitions / virtio device} > + > +An entity that implements virtio specification. Applies to a driver equally ... if we are trying to explain it further, then I would say something along the lines of: virtio specifies an interface for a two-way communication between two parties called a device and a driver. driver is the party that initiates the communication setup and initialization. in common usage device is part of a hypervisor and driver part of a guest running within a VM on this hypervisor, but other uses are not precluded. > +\subsection{virtio subsystem}\label{sec:Introduction / Definitions / virtio subsystem} > + > +A virtio subsystem includes one or more virtio devices. > +Each virtio subsystem has a unique virtio qualified name (VQN) that is permanent for the lifetime of the virtio subsystem. the naming here is unfortunate. "subsystem" generally refers to something like a group of drivers within linux, and to a type of device in pci. VQN refers to a VQ number in the spec. I would suggest simply "device group". And please preface this with a bit of informal text explaining that sometimes it is useful to refer to a group of devices as a whole. > +The VQN is a 128-bit UUID. It is RECOMMENDED to use UUIDs as specified by \hyperref[intro:rfc4122]{[RFC4122]}. Do we really need the UUID at all? It is unique within which context? Can we split the UUID from this proposal? > +Virtio devices within one virtio subsystem share the same VQN. share in which sense? I don't see any way to retrieve the VQN from the device itself. > Each virtio device has a unique virtio > +device id (vdev_id) within a virtio subsystem. A valid vdev_id is a 64-bit field in the range of > +0x0 - 0xFFFFFFFFFFFFFFF0. are other values reserved? > Vdev_id 0xFFFFFFFFFFFFFFFF is a broadcast value that is used to specify all the > +virtio devices in a virtio subsystem and isn't a valid vdev_id. broadcast is a bit confusing. Just say "Vdev_id value 0xFFFFFFFFFFFFFFFF refers to all devices in a group". I think we should also add a special value meaning "this device itself". > + > +The vdev_id value when combined with the VQN forms a globally unique value that identifies the virtio device. > + > \newpage > -- > 2.21.0 --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org