Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756192Ab0AMRPb (ORCPT ); Wed, 13 Jan 2010 12:15:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756058Ab0AMRP3 (ORCPT ); Wed, 13 Jan 2010 12:15:29 -0500 Received: from mx1.redhat.com ([209.132.183.28]:2869 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756049Ab0AMRP0 (ORCPT ); Wed, 13 Jan 2010 12:15:26 -0500 Date: Wed, 13 Jan 2010 19:12:30 +0200 From: "Michael S. Tsirkin" To: Davide Libenzi , "Michael S. Tsirkin" , Avi Kivity , kvm@vger.kernel.org, Linux Kernel Mailing List Subject: [PATCH 1/2] kvm: fix spurious interrupt with irqfd Message-ID: <20100113171230.GB19798@redhat.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1170 Lines: 36 kvm didn't clear irqfd counter on deassign, as a result we could get a spurious interrupt when irqfd is assigned back. this leads to poor performance and, in theory, guest crash. Signed-off-by: Michael S. Tsirkin --- virt/kvm/eventfd.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c index 62e4cd9..a9d3fc6 100644 --- a/virt/kvm/eventfd.c +++ b/virt/kvm/eventfd.c @@ -72,12 +72,13 @@ static void irqfd_shutdown(struct work_struct *work) { struct _irqfd *irqfd = container_of(work, struct _irqfd, shutdown); + u64 cnt; /* * Synchronize with the wait-queue and unhook ourselves to prevent * further events. */ - remove_wait_queue(irqfd->wqh, &irqfd->wait); + eventfd_ctx_remove_wait_queue(irqfd->eventfd, &irqfd->wait, &cnt); /* * We know no new events will be scheduled at this point, so block -- 1.6.6.144.g5c3af -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/