From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:33096) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SlcxX-0005rq-UU for qemu-devel@nongnu.org; Mon, 02 Jul 2012 05:30:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SlcxR-0003ix-Jd for qemu-devel@nongnu.org; Mon, 02 Jul 2012 05:30:19 -0400 Received: from david.siemens.de ([192.35.17.14]:22313) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SlcxR-0003ig-9s for qemu-devel@nongnu.org; Mon, 02 Jul 2012 05:30:13 -0400 Message-ID: <4FF16A21.7050309@siemens.com> Date: Mon, 02 Jul 2012 11:30:09 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <20120702091813.GF8268@redhat.com> In-Reply-To: <20120702091813.GF8268@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] plan for device assignment upstream List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Marcelo Tosatti , Michael Tokarev , Avi Kivity , kvm , "qemu-devel@nongnu.org" On 2012-07-02 11:18, Michael S. Tsirkin wrote: > I've been thinking hard about Jan's patches for device > assignment. Basically while I thought it makes sense > to make all devices: assignment and not - behave the > same and use same APIs for injecting irqs, Anthony thinks there is huge > value in making irq propagation hierarchical and device assignment > should be special cased. On the long term, we will need direct injection, ie. caching, to allow making it lock-less. Stepping through all intermediate layers will cause troubles, at least performance-wise, when having to take and drop a lock at each stop. > > We seem to be at impasse for now and I think merging > assignment ASAP has higher value than this specific > issue. So I fold - let's do it as Anthony and Jan's > original patches proposed. > > Jan, can you please rebase and repost your original patchset (against > master, not against pci) that added query for host irqs callbacks for > device assignment? I'll re-review ignoring the idea of using the cache, > with intent apply after I'll drop cache code from the pci branch in a > couple of days (busy otherwise now). OK, will do ASAP. > > I still intend to rework this later on, but that can wait. > > Thanks, > Thanks as well, Jan -- Siemens AG, Corporate Technology, CT RTC ITP SDP-DE Corporate Competence Center Embedded Linux