From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51162) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YxH8m-0000fy-VC for qemu-devel@nongnu.org; Tue, 26 May 2015 11:51:41 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YxH8m-00039q-4j for qemu-devel@nongnu.org; Tue, 26 May 2015 11:51:40 -0400 Message-ID: <55649677.2090502@redhat.com> Date: Tue, 26 May 2015 17:51:19 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1429964684-23872-1-git-send-email-aik@ozlabs.ru> <55646C18.4000303@redhat.com> <5564750C.8000100@ozlabs.ru> <556475BD.50401@redhat.com> <55647843.4040609@ozlabs.ru> <556479B6.1010501@redhat.com> <55647C75.5000704@ozlabs.ru> <55647D4C.6060008@redhat.com> <55648086.3010804@ozlabs.ru> <55648239.7070905@redhat.com> <20150526145557.4646.3678@loki> <55648A21.50401@redhat.com> <55649612.8070004@ozlabs.ru> In-Reply-To: <55649612.8070004@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 , Michael Roth , David Gibson Cc: Alex Williamson , qemu-ppc@nongnu.org, qemu-devel@nongnu.org, Alexander Graf On 26/05/2015 17:49, Alexey Kardashevskiy wrote: >> >> It's very little used, but that's just because it's not too common. >> There's nothing wrong with it. :) >> >> If you do del/set_size/add, you may want to put a >> memory_region_transaction_{begin,commit} around the whole dance. > > > Here I lost you again :) > Why? These are IOMMU MRs -> they are dynamic, what will begin()/commit() > change here? If you don't add them, the memory core may create two or three different flatviews. With begin/commit, it will only do one change. It's just an optimization. Paolo