From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: [PATCH 08/10] Move IO APIC to its own lock. Date: Sun, 9 Aug 2009 17:57:39 +0300 Message-ID: <20090809145739.GS4764@redhat.com> References: <1249821671-32356-1-git-send-email-gleb@redhat.com> <1249821671-32356-9-git-send-email-gleb@redhat.com> <4A7EE326.9050300@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org To: Avi Kivity Return-path: Received: from mx2.redhat.com ([66.187.237.31]:48046 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750827AbZHIO5k (ORCPT ); Sun, 9 Aug 2009 10:57:40 -0400 Received: from int-mx2.corp.redhat.com (int-mx2.corp.redhat.com [172.16.27.26]) by mx2.redhat.com (8.13.8/8.13.8) with ESMTP id n79Evgxn031031 for ; Sun, 9 Aug 2009 10:57:42 -0400 Content-Disposition: inline In-Reply-To: <4A7EE326.9050300@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Sun, Aug 09, 2009 at 05:54:30PM +0300, Avi Kivity wrote: > On 08/09/2009 03:41 PM, Gleb Natapov wrote: >> Introduce new function kvm_notifier_set_irq() that should be used >> to change irq line level from irq notifiers. When irq notifier >> change irq line level it calls into irq chip code recursively. The >> function avoids taking a lock recursively. >> > > This looks really horrible. I don't have an alternative yet, but I'll > think of one. I agree this is not nice. This is needed only for device assignment case. That explains why I don't like device assignment :) The problem is that the only communication channel from guest to assigned device that goes through the host is interrupt injection/acknowledgement, so we try to do things (lowering IRQ) on this path that usually are done somewhere else. -- Gleb.