From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vincent Whitchurch Subject: Re: [PATCH v3 5/5] vhost: add an RPMsg API Date: Tue, 14 Jul 2020 10:33:59 +0200 Message-ID: <20200714083359.wn4uoq3d7zzsddkc@axis.com> References: <20200527180541.5570-1-guennadi.liakhovetski@linux.intel.com> <20200527180541.5570-6-guennadi.liakhovetski@linux.intel.com> <20200617191741.whnp7iteb36cjnia@axis.com> <20200618090341.GA4189@ubuntu> <20200618093324.tu7oldr332ndfgev@axis.com> <20200618103940.GB4189@ubuntu> <20200618135241.362iuggde3jslx3p@axis.com> <20200618141412.GD4189@ubuntu> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Content-Disposition: inline In-Reply-To: <20200618141412.GD4189@ubuntu> Sender: kvm-owner@vger.kernel.org To: Guennadi Liakhovetski Cc: "kvm@vger.kernel.org" , "linux-remoteproc@vger.kernel.org" , "virtualization@lists.linux-foundation.org" , "sound-open-firmware@alsa-project.org" , Pierre-Louis Bossart , Liam Girdwood , "Michael S. Tsirkin" , Jason Wang , Ohad Ben-Cohen , Bjorn Andersson , Mathieu Poirier List-Id: virtualization@lists.linuxfoundation.org On Thu, Jun 18, 2020 at 04:14:12PM +0200, Guennadi Liakhovetski wrote: > On Thu, Jun 18, 2020 at 03:52:42PM +0200, Vincent Whitchurch wrote: > > Note that "the Linux side" is ambiguous for AMP since both sides can be > > Linux, as they happen to be in my case. I'm running virtio/rpmsg > > between two physical processors (of different architectures), both > > running Linux. > > Ok, interesting, I didn't know such configurations were used too. I understood > the Linux rpmsg implementation in the way, that it's assumed, that the "host" > has to boot the "device" by sending an ELF formatted executable image to it, is > that optional? You aren't sending a complete Linux image to the device side, > are you? I do pack the zImage, the dtb, and the initramfs into an ELF (along with a tiny "bootloader" with just a handful of instructions), but the remoteproc framework is not tied to the ELF format since ->parse_fw() and friends are overridable by the remoteproc driver. > > virtio has distinct driver and device roles so the completely different > > APIs on each side are understandable. But I don't see that distinction > > in the rpmsg API which is why it seems like a good idea to me to make it > > work from both sides of the link and allow the reuse of drivers like > > rpmsg-char, instead of imposing virtio's distinction on rpmsg. > > Understand. In principle I'm open to this idea, but before I implement it it > would be good to know what maintainers think? Certainly.