From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jan Beulich" Subject: Re: [XEN][RFC PATCH V2 05/17] hvm: Modify hvm_op Date: Mon, 10 Sep 2012 14:38:16 +0100 Message-ID: <504E0968020000780009A397@nat28.tlf.novell.com> References: <5035E986020000780008A617@nat28.tlf.novell.com> <50360B81.2070402@citrix.com> <5037AE20020000780008A7A8@nat28.tlf.novell.com> <504DE4EF.5070004@citrix.com> <504E0600020000780009A37F@nat28.tlf.novell.com> <504DECBF.2000306@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <504DECBF.2000306@citrix.com> Content-Disposition: inline List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Julien Grall Cc: "christian.limpach@gmail.com" , "xen-devel@lists.xen.org" , Stefano Stabellini List-Id: xen-devel@lists.xenproject.org >>> On 10.09.12 at 15:35, Julien Grall wrote: > On 09/10/2012 02:23 PM, Jan Beulich wrote: >>>>> On 10.09.12 at 15:02, Julien Grall wrote: >>>>> >>> On 08/24/2012 04:38 PM, Jan Beulich wrote: >>> >>>>>>> On 23.08.12 at 12:52, Julien Grall wrote: >>>>>>> >>>>>>> >>>>> On 08/23/2012 08:27 AM, Jan Beulich wrote: >>>>> >>>>> >>>>>>> switch ( a.index ) >>>>>>> { >>>>>>> - case HVM_PARAM_IOREQ_PFN: >>>>>>> >>>>>>> >>>>>>> >>>>>> Removing sub-ops which a domain can issue for itself (which for this and >>>>>> another one below appears to be the case) is not allowed. >>>>>> >>>>>> >>>>>> >>>>> I removed these 3 sub-ops because it will not work with >>>>> QEMU disaggregation. Shared pages and event channel >>>>> for IO request are private for each device model. >>>>> >>>>> >>>> Then they need to be made inaccessible for that specific setup, not >>>> removed altogether. >>>> >>>> >>>> >>> What do you mean by specific feature ? >>> With this patch series, you are able to handle one or more >>> QEMU. >>> Keep a compatibility with the old IO emulation is hard. >>> >> Did you read my original reply? Code backing operations that a >> guest can issue itself (i.e. without qemu or another host side >> component involved) just can't be removed, as you/we have >> no control over which guest(s) may be making use of that >> functionality. >> > > Ah ok misundertanding of my part. I don't really understand > in which case a domain needs to retrieve its ioreq page. > How can I made it inaccessible ? Just rc = -EINVAL ? Probably, but you'd better talk to whoever added that code (including to determine whether this by mistake was left guest invokable). Jan