From: "Michael S. Tsirkin" Subject: Re: [PATCH 0/2] kvm: fix spurious interrupt with irqfd Date: Wed, 20 Jan 2010 17:09:50 +0200 Message-ID: <20100120150950.GD3434@redhat.com> References: <20100113171222.GA19798@redhat.com> <4B5305CA.5070001@redhat.com> <20100119145202.GC28465@redhat.com> <4B570EDD.6000808@redhat.com> <20100120145822.GB3434@redhat.com> <4B571CAC.9000902@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: mtosatti@redhat.com, Davide Libenzi , kvm@vger.kernel.org, Linux Kernel Mailing List To: Avi Kivity Return-path: Content-Disposition: inline In-Reply-To: <4B571CAC.9000902@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On Wed, Jan 20, 2010 at 05:09:32PM +0200, Avi Kivity wrote: > On 01/20/2010 04:58 PM, Michael S. Tsirkin wrote: >> >>> I'm uncomfortable with pushing Davide's patch into stable and possibly >>> causing regressions with unrelated applications. Can't a guest live >>> with a spurious interrupt? >>> >> Well guests mask/unmask vector on each interrupt, so this will trigger >> an irq storm I think. >> >> >>> It's not like they're unknown. >>> >> Depends on the device really. >> In theory, if they trigger at an unfortunate time this could cause >> crashes. >> >> > > I'd like confirmation on both of these before I push things to stable. I have observed the interrupt storm. We end up with interrupt being disabled. Crash is a theoretical issue. -- MST