From mboxrd@z Thu Jan 1 00:00:00 1970 From: Olaf Hering Subject: Re: [PATCH v3 4/4] libxl: add support for vscsi Date: Thu, 26 Mar 2015 13:55:48 +0100 Message-ID: <20150326125548.GA21507@aepfle.de> References: <1425635156-2357-1-git-send-email-olaf@aepfle.de> <1425635156-2357-5-git-send-email-olaf@aepfle.de> <1426088006.21353.282.camel@citrix.com> <20150312162031.GB19536@aepfle.de> <1426178782.32572.55.camel@citrix.com> <20150313134420.GC25259@aepfle.de> <1426256282.32572.154.camel@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1426256282.32572.154.camel@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell Cc: Ian Jackson , xen-devel@lists.xen.org, Wei Liu , Stefano Stabellini List-Id: xen-devel@lists.xenproject.org On Fri, Mar 13, Ian Campbell wrote: > > > > > On Fri, 2015-03-06 at 10:45 +0100, Olaf Hering wrote: > > > > > > + ("feature_host", bool), > > > > > What is this feature thing? What does !host imply? > > > > This enables raw SCSI command passthrough in xenlinux. If the flag is > > > > off then each command is checked. The check allows many commands to > > > > passthrough, one command needs emulation and unhandled commands are > > > > rejected. The flag is a noop in pvops because it doesnt look at such > > > > flag. I was told its not required, dont know the details. > > > Sounds like it at the very least needs a better name. > > Ok, will rename it to feature_noemul or feature_xenlinux_raw_scsicmd or > > whatever. > Neither of those appear to be a good description of what you say quoted > above. Ian, after some thought its not clear to me why the name "feature_host" should be changed. The config option is "feature-host", the backend expects a property named "feature-host". So it seems natural to also name the variable that way. In the end it just passes a boolean from the config to xenstore, nothing else is done with it. > Also, should this be a defbool or not? This is a good idea. I remmeber xend had code to make sure that all devices within a vhost had the same value for "feature-host". I think the intention was that whole physical hosts are passed to a domU. A defbool makes it easier to preserve the initial value based on the first config item. Olaf