From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-comment-return-581-cohuck=redhat.com@lists.oasis-open.org Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 652A6985DBD for ; Fri, 11 Jan 2019 11:42:09 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" Date: Fri, 11 Jan 2019 11:41:58 +0000 Message-Id: <20190111114200.10026-2-dgilbert@redhat.com> In-Reply-To: <20190111114200.10026-1-dgilbert@redhat.com> References: <20190111114200.10026-1-dgilbert@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: [virtio-comment] [PATCH 1/3] shared memory: Define shared memory regions To: virtio-comment@lists.oasis-open.org Cc: stefanha@redhat.com List-ID: From: "Dr. David Alan Gilbert" Define the requirements and idea behind shared memory regions. Signed-off-by: Dr. David Alan Gilbert --- content.tex | 3 +++ shared-mem.tex | 25 +++++++++++++++++++++++++ 2 files changed, 28 insertions(+) create mode 100644 shared-mem.tex diff --git a/content.tex b/content.tex index b101d1b..321a2f4 100644 --- a/content.tex +++ b/content.tex @@ -331,6 +331,9 @@ Virtqueue format, or both. \input{split-ring.tex} \input{packed-ring.tex} + +\input{shared-mem.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 diff --git a/shared-mem.tex b/shared-mem.tex new file mode 100644 index 0000000..6da249c --- /dev/null +++ b/shared-mem.tex @@ -0,0 +1,25 @@ +\section{Shared Memory Regions}\label{sec:Basic Facilities of a Virtio Device / Shared Memory Regions} + +Shared memory regions are an additional facility +available to devices that need a region of memory that's +continuously shared between the host and the guest, rather +than passed between them in the way virtqueue elements are. + +Example uses include shared caches and version pools for versioned +data structures. + +Shared memory regions MUST NOT be used to control the operation +of the device, nor to stream data; those should still be performed +using virtqueues. + +A device may have multiple shared memory regions associated with +it. Each region has a \field{shmid} to identify it, the meaning +of which is device specific. + +Enumeration and location of shared memory regions is performed +using a transport-specific data structure. + +The guest physical address and the host virtual address MUST NOT +be used to identify structures within the memory regions; all +addressing MUST be relative to the start of a particular region. + -- 2.20.1 This publicly archived list offers a means to provide input to the OASIS Virtual I/O Device (VIRTIO) TC. In order to verify user consent to the Feedback License terms and to minimize spam in the list archive, subscription is required before posting. Subscribe: virtio-comment-subscribe@lists.oasis-open.org Unsubscribe: virtio-comment-unsubscribe@lists.oasis-open.org List help: virtio-comment-help@lists.oasis-open.org List archive: https://lists.oasis-open.org/archives/virtio-comment/ Feedback License: https://www.oasis-open.org/who/ipr/feedback_license.pdf List Guidelines: https://www.oasis-open.org/policies-guidelines/mailing-lists Committee: https://www.oasis-open.org/committees/virtio/ Join OASIS: https://www.oasis-open.org/join/