From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: [PATCH v2] report IRQ injection status to userspace. Date: Tue, 27 Jan 2009 13:41:07 -0200 Message-ID: <20090127154107.GC5806@amt.cnet> References: <20090121113227.GH27675@redhat.com> <20090121123428.GI27675@redhat.com> <20090126161038.GB3894@amt.cnet> <20090127132739.GG15778@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Avi Kivity , kvm@vger.kernel.org To: Gleb Natapov Return-path: Received: from mx2.redhat.com ([66.187.237.31]:58211 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752311AbZA0Plh (ORCPT ); Tue, 27 Jan 2009 10:41:37 -0500 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 n0RFfa70024004 for ; Tue, 27 Jan 2009 10:41:36 -0500 Content-Disposition: inline In-Reply-To: <20090127132739.GG15778@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Tue, Jan 27, 2009 at 03:27:39PM +0200, Gleb Natapov wrote: > > -1 here ? > > > I think 1 is better here. For level=0 we always want to report that interrupt > was injected and for the case of edge triggered interrupt and level=1 > ioapic_service() will always be called. BTW it seems that expression > old_irr != ioapic->irr in: > if ((!entry.fields.trig_mode && old_irr != ioapic->irr) > || !entry.fields.remote_irr) > ret = ioapic_service(ioapic, irq); > Will always be true since for edge triggered interrupt irr is always > cleared by ioapic_service(). Am I right? Right, I was thinking about if (irq >= 0 && irq < IOAPIC_NUM_PINS) { Should return MASKED if irq is outside the acceptable range? > > + } > > + } > > #endif > > > > Is that what you intended ? > > > Yes! If interrupt was lost due to making it should not be reinjected. That assumes guests won't mask the interrupt temporarily in the irqchip, hope that is OK (as Avi noted earlier guests use CPU to mask irqs temporarily, most of the time).