From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38664) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ezNrq-0002sG-Dk for qemu-devel@nongnu.org; Fri, 23 Mar 2018 10:40:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ezNrm-0006Zn-Ga for qemu-devel@nongnu.org; Fri, 23 Mar 2018 10:40:30 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:37196 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ezNrm-0006ZA-8f for qemu-devel@nongnu.org; Fri, 23 Mar 2018 10:40:26 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6ECEF722D3 for ; Fri, 23 Mar 2018 14:40:22 +0000 (UTC) Date: Fri, 23 Mar 2018 17:40:15 +0300 From: "Michael S. Tsirkin" Message-ID: <20180323171752-mutt-send-email-mst@kernel.org> References: <20180323124637.11220-1-dgilbert@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180323124637.11220-1-dgilbert@redhat.com> Subject: Re: [Qemu-devel] [PATCH] vhost: Allow abutting regions List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert (git)" Cc: qemu-devel@nongnu.org, alex.williamson@redhat.com On Fri, Mar 23, 2018 at 12:46:37PM +0000, Dr. David Alan Gilbert (git) wrote: > From: "Dr. David Alan Gilbert" > > My rework of section adding combines overlapping or abutting regions, > but checks they're actually the same underlying RAM block. > Fix the case where two blocks abut but don't overlap; that new region > should get added (but not combined), but my previous patch was disallowing it. > > Fixes: c1ece84e7c9 > > Reported-by: Alex Williamson > Signed-off-by: Dr. David Alan Gilbert I prefer adjacent and not abutting. > --- > hw/virtio/vhost.c | 13 +++++++++---- > 1 file changed, 9 insertions(+), 4 deletions(-) > > diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c > index 250f886acb..fc9062a89f 100644 > --- a/hw/virtio/vhost.c > +++ b/hw/virtio/vhost.c > @@ -595,10 +595,15 @@ static void vhost_region_add_section(struct vhost_dev *dev, > prev_sec->offset_within_address_space, > prev_sec->offset_within_region); > } else { > - error_report("%s: Overlapping but not coherent sections " > - "at %"PRIx64, > - __func__, mrs_gpa); > - return; > + /* abutting regions are fine, but overlapping ones with > + * different blocks/offsets shouldn't happen > + */ > + if (mrs_gpa != prev_gpa_end + 1) { > + error_report("%s: Overlapping but not coherent sections " > + "at %"PRIx64, > + __func__, mrs_gpa); > + return; > + } > } > } > } > -- > 2.14.3