From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-comment-return-667-cohuck=redhat.com@lists.oasis-open.org Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Date: Wed, 27 Feb 2019 14:50:50 +0100 From: Cornelia Huck Message-ID: <20190227145050.0038e037.cohuck@redhat.com> In-Reply-To: <20190222115433.7160-4-dgilbert@redhat.com> References: <20190222115433.7160-1-dgilbert@redhat.com> <20190222115433.7160-4-dgilbert@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: [virtio-comment] Re: [PATCH v2 3/3] shared memory: Define mmio registers To: "Dr. David Alan Gilbert (git)" Cc: virtio-comment@lists.oasis-open.org, virtio-dev@lists.oasis-open.org, stefanha@redhat.com List-ID: On Fri, 22 Feb 2019 11:54:33 +0000 "Dr. David Alan Gilbert (git)" wrote: > From: "Dr. David Alan Gilbert" > > Define an MMIO interface to enumerate and map shared > memory regions. > > Note: This hasn't been implemented. > > Signed-off-by: Dr. David Alan Gilbert > --- > content.tex | 32 ++++++++++++++++++++++++++++++++ > 1 file changed, 32 insertions(+) (...) > @@ -1815,6 +1840,13 @@ 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 s/tern/turn/ > +length is not -1. > + > +Devices not expecting shared memory MUST NOT use the shared > +memory registers. Isn't that the _driver_ requirements section? These sentences also make more sense if they talk about a driver expecting something. What I also find a bit confusing is the requirement that they enumerate all regions (at least, that's how I read it.) Say we have a device type with shared regions foo, bar, and the optional baz. It should be fine if a driver finds foo, bar, and baz; as well as if a driver only finds foo and bar. Conversely, a driver only looking for foo and bar should work with a device exposing foo, bar, and baz. > + > 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}. > 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/