From patchwork Wed Nov 23 09:25:07 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Beulich X-Patchwork-Id: 698117 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 3tNxqq296Sz9t17 for ; Wed, 23 Nov 2016 20:29:27 +1100 (AEDT) Received: from localhost ([::1]:60416 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1c9Tro-0006XN-JZ for incoming@patchwork.ozlabs.org; Wed, 23 Nov 2016 04:29:24 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37180) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1c9Tnm-0003Qi-M0 for qemu-devel@nongnu.org; Wed, 23 Nov 2016 04:25:18 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1c9Tnj-00066W-HE for qemu-devel@nongnu.org; Wed, 23 Nov 2016 04:25:14 -0500 Received: from prv-mh.provo.novell.com ([137.65.248.74]:44902) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1c9Tnj-000660-7t for qemu-devel@nongnu.org; Wed, 23 Nov 2016 04:25:11 -0500 Received: from INET-PRV-MTA by prv-mh.provo.novell.com with Novell_GroupWise; Wed, 23 Nov 2016 02:25:09 -0700 Message-Id: <58356E83020000780012129C@prv-mh.provo.novell.com> X-Mailer: Novell GroupWise Internet Agent 14.2.1 Date: Wed, 23 Nov 2016 02:25:07 -0700 From: "Jan Beulich" To: References: <58356D610200007800121289@prv-mh.provo.novell.com> In-Reply-To: <58356D610200007800121289@prv-mh.provo.novell.com> Mime-Version: 1.0 Content-Disposition: inline X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 137.65.248.74 Subject: [Qemu-devel] [PATCH 3/3] xen: ignore direction in bufioreq handling 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@citrix.com, xen-devel , Paul Durrant , Stefano Stabellini Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" There's no way to communicate back read data, so only writes can ever be usefully specified. Ignore the field, paving the road for eventually re-using the bit for something else in a few (many?) years time. Signed-off-by: Jan Beulich Reviewed-by: Paul Durrant Acked-by: Stefano Stabellini --- a/xen-hvm.c +++ b/xen-hvm.c @@ -997,6 +997,7 @@ static int handle_buffered_iopage(XenIOS memset(&req, 0x00, sizeof(req)); req.state = STATE_IOREQ_READY; req.count = 1; + req.dir = IOREQ_WRITE; for (;;) { uint32_t rdptr = buf_page->read_pointer, wrptr; @@ -1014,7 +1015,6 @@ static int handle_buffered_iopage(XenIOS req.size = 1U << buf_req->size; req.addr = buf_req->addr; req.data = buf_req->data; - req.dir = buf_req->dir; req.type = buf_req->type; xen_rmb(); qw = (req.size == 8); @@ -1031,10 +1031,12 @@ static int handle_buffered_iopage(XenIOS handle_ioreq(state, &req); /* Only req.data may get updated by handle_ioreq(), albeit even that - * should not happen as such data would never make it to the guest. + * should not happen as such data would never make it to the guest (we + * can only usefully see writes here after all). */ assert(req.state == STATE_IOREQ_READY); assert(req.count == 1); + assert(req.dir == IOREQ_WRITE); assert(!req.data_is_ptr); atomic_add(&buf_page->read_pointer, qw + 1);