From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-return-2821-cohuck=redhat.com@lists.oasis-open.org Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Date: Wed, 10 Jan 2018 12:14:03 +0100 From: Cornelia Huck Message-ID: <20180110121403.0d17fa38.cohuck@redhat.com> In-Reply-To: <20180110130703-mutt-send-email-mst@kernel.org> References: <1515577653-9336-1-git-send-email-mst@redhat.com> <20180110113315.6d04a931.cohuck@redhat.com> <20180110130703-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [virtio] [PATCH v6 0/5] packed ring layout spec To: "Michael S. Tsirkin" Cc: virtio@lists.oasis-open.org, virtio-dev@lists.oasis-open.org List-ID: On Wed, 10 Jan 2018 13:10:49 +0200 "Michael S. Tsirkin" wrote: > On Wed, Jan 10, 2018 at 11:33:15AM +0100, Cornelia Huck wrote: > > On Wed, 10 Jan 2018 11:47:53 +0200 > > "Michael S. Tsirkin" wrote: > > > > > OK, this is in a shape where we could include it in the spec. > > > Changes from v5: > > > - scope reductions (see below). We can add more > > > features down the road, hopefully reduced scope will be enough > > > to finalize spec soon. > > > - cleanup and integrate in the spec > > > - pseudo-code > > > > > > Deferred features: > > > - dropped _F_DESC_LIST, 1.0 includes this unconditionally, we > > > can do same > > > - dropped event structure change notifications - needed for > > > efficient hardware implementations but let's add this on top > > > > > > 3 1st patches just move text around so all virtio 1.0 > > > things are in the same place. 2 last ones add the new layout > > > > > > Option to mark descriptors as not generating events isn't > > > yet implemented. Again, let's add this on top. > > > > > > I also note that for hardware implementations, a different > > > set of memory barriers is needed. Again, let's add this on top > > > > > > not linking into conformance sections, will add after spec > > > itself is approved. > > > > > > Michael S. Tsirkin (5): > > > content: move 1.0 queue format out to a separate section > > > content: move ring text out to a separate file > > > content: move virtqueue operation description > > > packed virtqueues: more efficient virtqueue layout > > > packed-ring: add in order request support > > > > > > conformance.tex | 4 +- > > > content.tex | 718 +++++--------------------------------------------------- > > > packed-ring.tex | 692 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > > split-ring.tex | 666 ++++++++++++++++++++++++++++++++++++++++++++++++++++ > > > 4 files changed, 1423 insertions(+), 657 deletions(-) > > > create mode 100644 packed-ring.tex > > > create mode 100644 split-ring.tex > > > > > > > One thing I just noticed: This does not seem to contain any changes for > > transports. For ccw, we use different payloads in the SET_VQ command > > for legacy (pre-virtio-1) and virtio-1 split layout. I think we would > > need a new SET_VQ payload for the packed ring guarded by a new > > revision, but I have not investigated it yet. I have not yet thought > > through how this interacts with feature negotiation, either. > > Good point. > There's exactly same number of chunks (descriptor, device and driver > event suppression). > > So the idea is to substitute descriptor for descriptor, device event > suppression for available ring and driver event suppression for > used ring. > > That's why we don't need to change transports. > > I will add text to clarify that. I think we also need to update the text for the transports, as they explicitly refer to avail/used. > > > Otherwise, I don't see any reason why the packed ring would not work > > fine for ccw as well. --------------------------------------------------------------------- To unsubscribe from this mail list, you must leave the OASIS TC that generates this mail. Follow this link to all your TCs in OASIS at: https://www.oasis-open.org/apps/org/workgroup/portal/my_workgroups.php