From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-comment-return-582-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 6F808985DC7 for ; Fri, 11 Jan 2019 11:42:11 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" Date: Fri, 11 Jan 2019 11:42:00 +0000 Message-Id: <20190111114200.10026-4-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 3/3] shared memory: Define mmio registers To: virtio-comment@lists.oasis-open.org Cc: stefanha@redhat.com List-ID: From: "Dr. David Alan Gilbert" Define an MMIO interface to enumerate and map shared memory regions. Note: This hasn't been implemented, I also worrying it's using too much of the register address space. Signed-off-by: Dr. David Alan Gilbert --- content.tex | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/content.tex b/content.tex index 776162a..e2435ff 100644 --- a/content.tex +++ b/content.tex @@ -1641,6 +1641,33 @@ All register values are organized as Little Endian. selected by writing to \field{QueueSel}. } \hline + \mmioreg{SHMSel}{Shared memory region select}{0x0b0}{W}{% + Writing to this register selects the shared memory region \ref{sec:Basic Facilities of a Virtio Device / Shared Memory Regions} + following operations on \field{SHMId}, \field{SHMLenLow}, \field{SHMLenHigh}, + \field{SHMBaseLow} and \field{SHMBaseHigh} apply to. The index + number of the first region is zero (0x0); note that it is a + simple index that does not correspond to the \field{id}. + } + \hline + \mmioreg{SHMId}{Shared memory id}{0x0b4}{R}{% + This register returns the id value of the selected shared + memory region. + } + \hline + \mmiodreg{SHMLenLow}{SHMLenHigh}{Shared memory region 64 bit long length}{0x0b8}{0x0xbc}{R}{% + These registers return the length of the shared memory + region, as defined by the device for the region selected by + the \field{SHMSel} register. Reading from a non-existent + region (i.e. a too large \field{SHMSel} value) results in a + length of -1. This should be used to enumerate the list of + regions. + } + \hline + \mmiodreg{SHMBaseLow}{SHMBaseHigh}{Shared memory region 64 bit long physical address}{0x0c0}{0x0xc4}{W}{% + The driver writes these registers to indicate where it wishes + the device to map the shared memory region currently selected. + } + \hline \mmioreg{ConfigGeneration}{Configuration atomicity value}{0x0fc}{R}{ Reading from this register returns a value describing a version of the device-specific configuration space (see \field{Config}). The driver can then access the configuration space and, when finished, read \field{ConfigGeneration} again. @@ -1676,6 +1703,9 @@ driver seeing an inconsistent configuration state. The device MUST NOT access virtual queue contents when \field{QueueReady} is zero (0x0). +The device MUST NOT respond to SHM Base writes for none-existent +shared memory regions. + \drivernormative{\subsubsection}{MMIO Device Register Layout}{Virtio Transport Options / Virtio Over MMIO / MMIO Device Register Layout} The driver MUST NOT access memory locations not described in the table \ref{tab:Virtio Trasport Options / Virtio Over MMIO / MMIO Device Register Layout} @@ -1730,6 +1760,13 @@ If both values are valid, it MUST read \field{DeviceID} and if its value is zero (0x0) MUST abort initialization and MUST NOT access any other register. +Devices expecting shared memory regions MUST enumerate the +regions by selecting each region in tern and checking that the +length is not -1. + +Devices not expecting shared memory MUST NOT use the shared +memory registers. + Further initialization MUST follow the procedure described in \ref{sec:General Initialization And Device Operation / Device Initialization}~\nameref{sec:General Initialization And Device Operation / Device Initialization}. -- 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/