From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45196) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cTgpX-0004sQ-LF for qemu-devel@nongnu.org; Tue, 17 Jan 2017 22:22:36 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cTgpU-0006mg-Gl for qemu-devel@nongnu.org; Tue, 17 Jan 2017 22:22:35 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:38694 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cTgpU-0006lb-BI for qemu-devel@nongnu.org; Tue, 17 Jan 2017 22:22:32 -0500 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v0I3IfEV015573 for ; Tue, 17 Jan 2017 22:22:31 -0500 Received: from e37.co.us.ibm.com (e37.co.us.ibm.com [32.97.110.158]) by mx0b-001b2d01.pphosted.com with ESMTP id 281yknhd29-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 17 Jan 2017 22:22:31 -0500 Received: from localhost by e37.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 17 Jan 2017 20:22:30 -0700 Date: Wed, 18 Jan 2017 11:22:23 +0800 From: Dong Jia Shi References: <20170112072513.98411-1-bjsdjshi@linux.vnet.ibm.com> <20170112072513.98411-8-bjsdjshi@linux.vnet.ibm.com> <20170117154928.6b7886fb@t450s.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170117154928.6b7886fb@t450s.home> Message-Id: <20170118032223.GO30301@bjsdjshi@linux.vnet.ibm.com> Subject: Re: [Qemu-devel] [PATCH RFC v2 07/12] vfio/ccw: vfio based subchannel passthrough driver List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alex Williamson Cc: Dong Jia Shi , kvm@vger.kernel.org, linux-s390@vger.kernel.org, qemu-devel@nongnu.org, renxiaof@linux.vnet.ibm.com, cornelia.huck@de.ibm.com, borntraeger@de.ibm.com, agraf@suse.com, pmorel@linux.vnet.ibm.com, pasic@linux.vnet.ibm.com, wkywang@linux.vnet.ibm.com * Alex Williamson [2017-01-17 15:49:28 -0700]: > On Thu, 12 Jan 2017 08:25:08 +0100 > Dong Jia Shi wrote: > > > From: Xiao Feng Ren > > > > We use the IOMMU_TYPE1 of VFIO to realize the subchannels > > passthrough, implement a vfio based subchannels passthrough > > driver called "vfio-ccw". > > > > Support qemu parameters in the style of: > > "-device vfio-ccw,id=xx,hostid=xx(,guestid=xx),mdevid=xx" > > Why not adopt the same syntax as vfio-pci with mdev devices, > sysfsdev=%s where %s is a path to the mdev device in sysfs, which can > be /sys/bus/mdev/devices/$UUID or as you create from the hostid > below /sys/bus/css/devices/%x.%x.%04x/$UUID. Ok. This is a good point. I will change the cmdline interface to: -device vfio-ccw,id=xx,sysfsdev=xx(,devno=xx) Since "hostid" is removed, I will also rename "guestid" to "devno" to make it looking consistent with the virtio-ccw devices. > It seems if we know where > to find the mdev device then we can determine the parent information on > our own through sysfs. > This is true. > > Signed-off-by: Xiao Feng Ren [...] -- Dong Jia