From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47888) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d5kEI-0003xm-0C for qemu-devel@nongnu.org; Tue, 02 May 2017 22:41:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d5kED-0003we-SD for qemu-devel@nongnu.org; Tue, 02 May 2017 22:41:26 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:45684) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1d5kED-0003wB-Jr for qemu-devel@nongnu.org; Tue, 02 May 2017 22:41:21 -0400 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v432cg8t016553 for ; Tue, 2 May 2017 22:41:19 -0400 Received: from e24smtp01.br.ibm.com (e24smtp01.br.ibm.com [32.104.18.85]) by mx0a-001b2d01.pphosted.com with ESMTP id 2a76c70fs8-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 02 May 2017 22:41:19 -0400 Received: from localhost by e24smtp01.br.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 2 May 2017 23:41:16 -0300 Received: from d24av01.br.ibm.com (d24av01.br.ibm.com [9.8.31.91]) by d24relay03.br.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v432fD9n34078918 for ; Tue, 2 May 2017 23:41:14 -0300 Received: from d24av01.br.ibm.com (localhost [127.0.0.1]) by d24av01.br.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id v432fDFI024522 for ; Tue, 2 May 2017 23:41:13 -0300 Date: Tue, 2 May 2017 23:41:01 -0300 From: joserz@linux.vnet.ibm.com References: <1492631083-23965-1-git-send-email-joserz@linux.vnet.ibm.com> <20170420100301.51a7f10c@t450s.home> <07d71898-c392-c14a-9901-87ad4287bd5d@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <07d71898-c392-c14a-9901-87ad4287bd5d@redhat.com> Message-Id: <20170503024101.GA31494@pacoca> Subject: Re: [Qemu-devel] [PATCH 0/2] VFIO: Make 8-byte accesses atomic List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: Alex Williamson , Richard Henderson , qemu-devel@nongnu.org, aik@ozlabs.ru, mdroth@linux.vnet.ibm.com On Fri, Apr 21, 2017 at 12:06:15PM +0200, Paolo Bonzini wrote: > > > On 20/04/2017 18:03, Alex Williamson wrote: > > On Thu, 20 Apr 2017 00:19:23 -0700 > > Richard Henderson wrote: > > > >> On 04/19/2017 12:44 PM, Jose Ricardo Ziviani wrote: > >>> This patchset has two patches: > >>> [1] 8-byte writes to non-mapped MMIO are broken into pairs of 4-byte writes, this patch makes such pairs atomic. > >>> > >>> [2] Enable 8-byte accesses in vfio_region_write and vfio_region_read. > >>> > >>> Patches based on master. > >>> > >>> Jose Ricardo Ziviani (2): > >>> vfio: Set MemoryRegionOps:max_access_size and min_access_size > >>> vfio: enable 8-byte reads/writes to vfio > >>> > >>> hw/vfio/common.c | 14 ++++++++++++++ > >>> 1 file changed, 14 insertions(+) > >>> > >> > >> I think these patches need to be squashed to be bisectable. > > > > No, I think it's fine. The point of patch 1/2 is to indicate that the > > hardware supports 8-byte accesses, which will still be broken into 2 > > 4-byte accesses because we don't yet set the implemented width beyond > > the default. The important part is that the mutex will now group the 4 > > byte access pair together rather than letting them get re-ordered. > > Patch 2/2 then implements native 8-byte access. I appreciate them > > being separate for this subtle nuance, but maybe I'm not seeing the > > same issue as you. Thanks, > ' > I agree, the patches looks fine as is. > > Paolo > Hello! Thank you all for your review but I have a quick question: is it ok for merge? :) Thanks