From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: Merging kvm-apic into qemu-kvm Date: Thu, 26 Jan 2012 16:32:26 +0100 Message-ID: <4F21720A.9040306@siemens.com> References: <4F216E19.3040905@redhat.com> <4F217056.1030609@siemens.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: KVM list , qemu-devel To: Avi Kivity Return-path: Received: from goliath.siemens.de ([192.35.17.28]:20281 "EHLO goliath.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752004Ab2AZPcc (ORCPT ); Thu, 26 Jan 2012 10:32:32 -0500 In-Reply-To: <4F217056.1030609@siemens.com> Sender: kvm-owner@vger.kernel.org List-ID: On 2012-01-26 16:25, Jan Kiszka wrote: > On 2012-01-26 16:15, Avi Kivity wrote: >> The changes to kvm-apic are so drastic, that merging them into qemu-kvm >> in the normal way won't work. I can consider just dropping the existing >> implementation and switching to the new one, but the comment at the end >> >> Make the basic in-kernel irqchip support selectable via >> -machine ...,kernel_irqchip=on. Leave it off by default until it can >> fully replace user space models. >> >> suggests that things are still missing. >> >> Jan, what's still missing? > > - in-kernel PIT (patches done, waiting for some upstream bits to be > merged first) > - TPR acceleration via VAPIC (WIP) > - MSI support > > The latter is the big chunk. It requires quite some > refactoring/enhancement of the MSI layer. I posted the first version > last year. We need to agree on the design, then probably switch qemu-kvm > over while pushing generic bits upstream. And then we can extend the > upstream in-kernel *PIC using that new interfaces. Once upstream works > with MSI, we can switch qemu-kvm over, leaving basically only > device-assignment as the last missing bit. > >> Any idea on how to proceed? > > I had a qemu-kvm branch here that disables the upstream in-kernel *PIC > in favor of its current version. I still need to refresh that work (was > based on an earlier revision), but it was not that horrible. Let me check... It's online, see http://git.kiszka.org/?p=qemu-kvm.git;a=shortlog;h=refs/heads/kvm-irqchip-merge I merged the upstream patches one by one, resolving the mechanical and logical conflicts in each step. Was done for that backend/frontend concept, but the adjustments should basically be the same now. Want me to prepare a branch or will you do this? Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux