From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: Re: [PATCH 1/2] kvm tools: Fix IRQ assignments Date: Fri, 06 May 2011 11:01:16 +0300 Message-ID: <1304668876.10534.9.camel@lappy> References: <1304666795-15251-1-git-send-email-levinsasha928@gmail.com> <1304667363.10534.5.camel@lappy> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: mingo@elte.hu, asias.hejun@gmail.com, gorcunov@gmail.com, prasadjoshi124@gmail.com, kvm@vger.kernel.org To: Pekka Enberg Return-path: Received: from mail-ww0-f44.google.com ([74.125.82.44]:33184 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754327Ab1EFIB2 (ORCPT ); Fri, 6 May 2011 04:01:28 -0400 Received: by wwa36 with SMTP id 36so3237135wwa.1 for ; Fri, 06 May 2011 01:01:27 -0700 (PDT) In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On Fri, 2011-05-06 at 10:43 +0300, Pekka Enberg wrote: > On Fri, May 6, 2011 at 10:36 AM, Sasha Levin wrote: > > afaik, we need to have same IRQ pins for devices which may have > > different IRQ lines (All virtio-blk share same IRQ pin but different > > line, I assume it'll be same with different virtio devices). > > > > So mptable has to manage association between device type and the > > corresponding IRQ pin/line assignment, So dynamic assignment will be > > more of a call with device type and return IRQ pin + line - which makes > > it more complex than just allocating next free IRQ line. > > Well then make kvm__request_irq() return a pointer to struct irq and > have a hard-coded array of IRQ pin + line pairs in irq.c, for example. > That'll reduce complexity in the virtio drivers and it'll serve as a > starting point for proper IRQ allocator. The big problem with dynamic allocations is having mptable register IRQ sources properly, So I went ahead and deleted IRQ source definitions from mptable.c and noticed that everything still works. I've spoke with Cyrill and neither him or myself were too sure if it's ok to do that now and if so, would it still be correct once SMP gets added. So here is my question: Would it be ok to drop IRQ source definitions from mptable? -- Sasha.