From patchwork Mon May 9 16:29:23 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Durrant X-Patchwork-Id: 619980 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3r3T9S309jz9t3c for ; Tue, 10 May 2016 02:58:36 +1000 (AEST) Received: from localhost ([::1]:42312 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1azoVt-0007iy-VE for incoming@patchwork.ozlabs.org; Mon, 09 May 2016 12:58:33 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52925) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1azoVZ-0007Gy-UK for qemu-devel@nongnu.org; Mon, 09 May 2016 12:58:18 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1azoVV-0001AC-0M for qemu-devel@nongnu.org; Mon, 09 May 2016 12:58:13 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:23484) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1azoVU-00018f-Ik for qemu-devel@nongnu.org; Mon, 09 May 2016 12:58:08 -0400 X-IronPort-AV: E=Sophos;i="5.24,601,1454976000"; d="scan'208";a="359271878" From: Paul Durrant To: , Date: Mon, 9 May 2016 17:29:23 +0100 Message-ID: <1462811363-16219-1-git-send-email-paul.durrant@citrix.com> X-Mailer: git-send-email 2.1.4 MIME-Version: 1.0 X-DLP: MIA1 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 66.165.176.63 Subject: [Qemu-devel] [PATCH v2] xen-hvm: ignore background I/O sections X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Anthony Perard , Paolo Bonzini , Paul Durrant , Stefano Stabellini Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Since Xen will correctly handle accesses to unimplemented I/O ports (by returning all 1's for reads and ignoring writes) there is no need for QEMU to register backgroud I/O sections. This patch therefore adds checks to xen_io_add/del so that sections with memory-region ops pointing at 'unassigned_io_ops' are ignored. Signed-off-by: Paul Durrant Cc: Stefano Stabellini Cc: Anthony Perard Cc: Paolo Bonzini --- v2: - Add missing braces --- xen-hvm.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/xen-hvm.c b/xen-hvm.c index 039680a..8ab44f0 100644 --- a/xen-hvm.c +++ b/xen-hvm.c @@ -510,8 +510,12 @@ static void xen_io_add(MemoryListener *listener, MemoryRegionSection *section) { XenIOState *state = container_of(listener, XenIOState, io_listener); + MemoryRegion *mr = section->mr; - memory_region_ref(section->mr); + if (mr->ops == &unassigned_io_ops) + return; + + memory_region_ref(mr); xen_map_io_section(xen_xc, xen_domid, state->ioservid, section); } @@ -520,10 +524,14 @@ static void xen_io_del(MemoryListener *listener, MemoryRegionSection *section) { XenIOState *state = container_of(listener, XenIOState, io_listener); + MemoryRegion *mr = section->mr; + + if (mr->ops == &unassigned_io_ops) + return; xen_unmap_io_section(xen_xc, xen_domid, state->ioservid, section); - memory_region_unref(section->mr); + memory_region_unref(mr); } static void xen_device_realize(DeviceListener *listener,