From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-5394-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 0F5E2985B32 for ; Tue, 12 Feb 2019 11:26:04 +0000 (UTC) Date: Tue, 12 Feb 2019 11:25:47 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20190212112547.GC2715@work-vm> References: <20190204054053.GE29758@stefanha-x1.localdomain> <20190204101316.4e3e6rj32suwdmur@sirius.home.kraxel.org> <20190211092943-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [virtio-dev] Memory sharing device To: Roman Kiryanov Cc: "Michael S. Tsirkin" , Gerd Hoffmann , Stefan Hajnoczi , virtio-dev@lists.oasis-open.org, Lingfeng Yang List-ID: * Roman Kiryanov (rkir@google.com) wrote: > > > Our long term goal is to have as few kernel drivers as possible and to move > > > "drivers" into userspace. If we go with the virtqueues, is there > > > general a purpose > > > device/driver to talk between our host and guest to support custom hardware > > > (with own blobs)? > > > > The challenge is to answer the following question: > > how to do this without losing the benefits of standartization? > > We looked into UIO and it still requires some kernel driver to tell > where the device is, it also has limitations on sharing a device > between processes. The benefit of standardization could be in avoiding > everybody writing their own UIO drivers for virtual devices. > > Our emulator uses a battery, sound, accelerometer and more. We need to > support all of this. I looked into the spec, "5 Device types", and > seems "battery" is not there. We can invent our own drivers but we see > having one flexible driver is a better idea. Can you group these devices together at all in their requirements? For example, battery and accelerometers (to me) sound like low-bandwidth 'sensors' with a set of key,value pairs that update occasionally and a limited (no?) amount of control from the VM->host. A 'virtio-values' device that carried a string list of keys that it supported might make sense and be enough for at least two of your device types. Dave > Yes, I realize that a guest could think it is using the same device as > the host advertised (because strings matched) while it is not. We > control both the host and the guest and we can live with this. > > Regards, > Roman. -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org