From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [RFC][PATCH] KVM: Introduce direct MSI message injection for in-kernel irqchips Date: Mon, 24 Oct 2011 13:09:13 +0200 Message-ID: <4EA54759.902@redhat.com> References: <4EA13917.7070401@siemens.com> <4EA533B8.4040407@redhat.com> <4EA53BBF.2010704@siemens.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , kvm , "Michael S. Tsirkin" To: Jan Kiszka Return-path: Received: from mx1.redhat.com ([209.132.183.28]:53849 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754779Ab1JXLJS (ORCPT ); Mon, 24 Oct 2011 07:09:18 -0400 In-Reply-To: <4EA53BBF.2010704@siemens.com> Sender: kvm-owner@vger.kernel.org List-ID: On 10/24/2011 12:19 PM, Jan Kiszka wrote: > > > > With the new feature it may be worthwhile, but I'd like to see the whole > > thing, with numbers attached. > > It's not a performance issue, it's a resource limitation issue: With the > new API we can stop worrying about user space device models consuming > limited IRQ routes of the KVM subsystem. > Only if those devices are in the same process (or have access to the vmfd). Interrupt routing together with irqfd allows you to disaggregate the device model. Instead of providing a competing implementation with new limitations, we need to remove the limitations of the old implementation. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.