From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oleksandr Dmytryshyn Subject: Re: Question about mapping between domains Date: Fri, 17 Jul 2015 10:43:32 +0300 Message-ID: References: <1436448706-2687-1-git-send-email-oleksandr.dmytryshyn@globallogic.com> <1436778275.7019.32.camel@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1436778275.7019.32.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: Keir Fraser , Ian Jackson , Tim Deegan , xen-devel , Stefano Stabellini , Jan Beulich List-Id: xen-devel@lists.xenproject.org Hi, Ian. Thank You for tips. On Mon, Jul 13, 2015 at 12:04 PM, Ian Campbell wrote: > There is an additional quirk for a 1:1 mapped dom0 which is that we > don't actually decrease reservation when ballooning, but keep the 1:1 > mfn in anticipation of ballooning it back in later. Currently we have this quirk enabled in DomD (driver domain) > If you can't arrange to use already ballooned buffers for your DMA > buffer then you will need to manually balloon it out before and balloon > it back in later. I've tried this and all is working (I can map and then unmap memory in both directions DomU -> DomD, DomD -> DomU) > You may also want to extend the dom0 1:1 quirk described above to your > 1:1 mapped domD. Currently this quirk is enabled in DomD. In this case I can map memory from DomU to DomD (as it done in all PV drivers). But is this quirk is enabled in DomU, I can also map memory from DomD to DomU.