From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52215) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YxEJq-0000Vl-VI for qemu-devel@nongnu.org; Tue, 26 May 2015 08:50:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YxEJp-0003jP-JP for qemu-devel@nongnu.org; Tue, 26 May 2015 08:50:54 -0400 Message-ID: <55646C18.4000303@redhat.com> Date: Tue, 26 May 2015 14:50:32 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1429964684-23872-1-git-send-email-aik@ozlabs.ru> <1429964684-23872-7-git-send-email-aik@ozlabs.ru> <55633A54.8080807@ozlabs.ru> <20150526024628.GA30620@voom.redhat.com> <5564359A.2070009@redhat.com> <556447BB.9000802@ozlabs.ru> <55644819.3000003@redhat.com> <55646803.8040007@ozlabs.ru> In-Reply-To: <55646803.8040007@ozlabs.ru> Content-Type: text/plain; charset=koi8-r Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH qemu v7 06/14] spapr_iommu: Introduce "enabled" state for TCE table List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Kardashevskiy , David Gibson Cc: Michael Roth , Alex Williamson , qemu-ppc@nongnu.org, qemu-devel@nongnu.org, Alexander Graf On 26/05/2015 14:33, Alexey Kardashevskiy wrote: > >>>> If it's not true now that they can be unparented at any time like >>>> alias regions, we should probably try to make it true. >>> >>> Unfortunately it's not so easy... > > > Uff. Tricky :) > > memory_region_del_subregion() is not unparenting but just a wrapped > object_unref(), right? Right. The problematic thing to do is explicit object_unparent followed by one of the following: 1) memory_region_init for the same memory region that has been unparented 2) g_free of some dynamically-allocated data structure that contained the memory region. > But since iommu MR are resolved dynamically, the > whole conversation we are having here now has nothing to do with my&Mike > concern what we can and cannot do with DMA windows here. Is this correct? I don't understand what you're asking here, sorry. Paolo